WO2011041889A1 - Digital video poster - Google Patents
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- WO2011041889A1 WO2011041889A1 PCT/CA2010/001574 CA2010001574W WO2011041889A1 WO 2011041889 A1 WO2011041889 A1 WO 2011041889A1 CA 2010001574 W CA2010001574 W CA 2010001574W WO 2011041889 A1 WO2011041889 A1 WO 2011041889A1
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- composite according
- emissive
- layer
- conductors
- emissive composite
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/12—Light sources with substantially two-dimensional radiating surfaces
- H05B33/14—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source
- H05B33/145—Arrangements of the electroluminescent material
Definitions
- the present disclosure relates to the field of addressable and programmable alternating current electroluminescent (EL) materials and in particular to methods of creating emissive pixels to provide static and moving images on plastic film.
- EL alternating current electroluminescent
- Digital out of home advertising is a market that uses flat panel liquid crystal, light emitting diode, electroluminescent and plasma screens to display information and images in ways that allow information content to be updated at will or to use graphic images including moving images (video) to illustrate products or to attract buyers to products.
- DOOH Digital out of home advertising
- Printed posters are also broadly used to advertise commodities and to provide information of a specific or general nature based on signage, including maps, instructions and directions.
- Printed posters in general are not made up of pixels and are not programmable or addressable. Compared with flat panel displays, printed posters are generally lighter in weight and less costly to produce.
- Advertising and other posters are generally produced on paper or plastic laminated paper or plastic substrates. They are also produced on other
- the technique permits only very limited variable data printing, such as letterpress numbering; 2) the methods require pre-press setup and preparation; 3) the methods are generally not cost effective for very short runs or proofing; 4) the technique can be wasteful of ink and can be associated with chemical exposure and undesirable environmental impact; costly films for print of plate exposure are needed, and this leads to a need to archive bulky print items; 5) sizes are limited to the dimensions of the plate or screen image area so that larger images require repeated printing and seamless connection between print areas.
- Digital printing is an image transfer technology that is used to translate an image from a digital source (digital storage medium) to drive some kind of printing device to deposit the image.
- Digital printing is distinguished from analog printing technologies through its advantages: 1) requires minimal press set up and has multicolour registration built into it; 2) the technology allows for variations like “print-on-the-fly", combining production printing with variable data handling and customization; 3) the technology is "non-contact", allowing substrates to be printed without disturbing them, without hold-down, to reduce effects like image distortion as can occur with screen printing; 4) the method allows for simplified "proofing", sampling and short runs more cost effectively than analog methods; 5) a broad range of color processing is available to digital printing, including classic 3-color (CYM), 4 color (CY K) and extended color gamut options; 6) there is less need for color overlap or trapping; 7) digital printing requires no film masters, stencils, screens or plates which translates into reduced space requirements for archiving; 8) less hazardous materials (chemicals) are generally involved, there is less waste in Digital printing which also leaves a smaller carbon/environmental footprint; 9) the technology allows for very large scale image generation through the use of digital web printers; 10) digital files permit more facile editing
- Digital printing has certain disadvantages. These are: 1) the technology has generally slower throughput than does analog printing; 2) digital prints generally cost more per run than do analog prints; 3) specially coated surfaces or substrates are required for digital print technology; 4) for thicker deposits, overprinting is required, and this translates into slower feeds; 5) digital inks and toners are provided in limited reservoir capacities and are expensive; 6) transparent chemistries are used in digital inks, meaning that their use is limited for white or light substrates; 7) the technology is relatively new and requires investment in training to accompany the equipment.
- Digital posters can be made by analog or digital or hybrid analog and digital printing technologies as described above and that are less complex than semiconductor microfabrication processes in order to create electronic circuitry and color. While digital flat panel displays can be said to be mass produced, the technology is presently too complex, too sensitive to error, and the substrates too rigid, to take advantage of printing to reduce cost.
- a digital poster is distinguished from a digital display in that the former is generally created on a flexible plastic film or a laminate of paper and plastic.
- Digital displays (collectively known as flat pane! displays) are generally fabricated on rigid glass or metal substrates using expensive and complex semiconductor microfabrication processes, though there is development effort to create digital displays on flexible substrates like plastic.
- Use of rigid substrates prevents flat panel displays from being used to bend around curved surfaces or to be molded or adapted to non-planar surfaces. Bending, flexing or shaping a display is desirable for example if the display must be placed on a curved surface like the interior surface of a transit vehicle a like bus, taxi, train or airplane which have curved interior surfaces against which poster advertising must be mounted.
- the poster is required to conform in shape to the surface to which it is attached.
- the support surface is flat, but in many cases the support surface is curved either to enhance the viewing effect, or to conform to some geometric constraint imposed by the environment in which the poster is deployed.
- a kiosk support surface may be cylindrical, requiring that the poster be shaped to conform to the kiosk surface.
- Digital flat panel displays are characterized by rigid form factors, meaning that they have well defined dimensions and layouts. While plasma and liquid crystal displays are available in sizes larger than 70 inches on the diagonal, their cost rises exponentially with size. Yet there are many cases where larger displays are required, billboards are one such example.
- An LED display can be made on the scale of a billboard. LED displays made from individual LED lamps require manual assembly in the case of billboard size units and must generally be viewed from afar because they have low resolution when viewed close up. LED displays do not use glass as a substrate, but instead are assembled in a metal frame. In general, LED displays are shapeable (conformal) within the limits of the metal support frame and the individual LED module sizes. LED displays must be housed in a protective framework to protect them from environmental damage. By contrast, a digital video poster may be scaled simply to larger or smaller sizes, and is more easily manufactured, lighter in weight and less expensive then a conventional flat panel display, including an LED display.
- Posters are widely distributed in outdoor and indoor locations.
- the poster can be protected behind, or encased in, a suitable transparent barrier like glass or plastic, or the poster can be fabricated from materials that resist environmental damage due to variations in light intensity, temperature or humidity.
- Fiat panel displays like LCDs and plasma displays must be protected against the environment by means of cumbersome and expensive housing.
- the housing also increases the size, thickness and weight of the flat panel display.
- a liquid crystal display has the disadvantage that it does not function as well at low temperature because the liquid crystal freezes or becomes viscous so that the frame speed is diminished.
- Plastic films, layers of plastic films, and plastic coatings are widely used to protect underlying surfaces because plastic can be formulated to be weather resistant, provide moisture and dust barrier properties, can be heated and cooled or exposed to oils, solvents, greases and acids and bases with little or no damage to itself or the underlying surface. It would be an advantage to be able to create a display that directly uses these protective properties of plastic by incorporating the plastic film as part of the flexible digital display itself. This would confer on the display the properties of weather resistance and other barrier properties that would enhance its use as a medium for outdoor advertising.
- Posters can be inked (printed) with pigments that fluoresce (emit light) or reflect light such that they appear bright, but only when exposed directly to visible light, or in some cases, to ultraviolet light.
- the purpose of incorporating fluorescent or reflective pigments is to enhance the visibility of the poster or to highlight some portion of the poster. Neither the fluorescent pigment nor the reflective pigment is self-emitting, meaning that the pigment requires an external light source to be activated, and neither the fluorescence nor reflectance states exhibit an intrinsic self-emitting property.
- posters in general are passive media that require an external light source in order to be observed.
- External illumination front illumination
- Illumination can also be achieved by printing the poster on a transparent or translucent plastic film. In this case, the light source can be placed behind the poster (back illumination).
- the static analog image of the poster is yielding to dynamic image making or image changing.
- a poster can be scrolled on a roller or rollers so that its message changes as a function of time.
- an analog poster can be mounted in segments on segmented surfaces that are moved to display a new image with each concerted movement of the mounting segments.
- a plurality of conductors can be created on an electroluminescent poster to cause printed regions of the unit to become emissive. An example of such a device is described in U.S. pat. No.
- Video capability is achieved by applying a voltage to turn the matrix of pixels or sub-pixels off and on at a frequency (called the frame rate) that is too fast for the human eye to perceive. This frequency is on the order of 30 Hz or greater in order to avoid image flicker.
- a digital video poster as described in this application is a flexible printed composite structure comprising electronically addressable elements (pixels) by means of which an image such as a fetter, number or picture or combination of them can be displayed and updated or changed in real time and remotely.
- Electroluminescence is the non-thermal conversion of electrical energy into light.
- One type of electroluminescent device is the light emitting diode (LED) in which light is generated by electron-hole recombination near a pn junction.
- LED displays are expensive and complex to produce.
- Organic LED (OLED) displays are manufactured using techniques similar to those described above for LCD panels. Addressing is achieved by means of an active matrix of thin film transistors associated with gate and data conducting lines which are conventionally arranged in the pattern of a grid. OLEDs are emissive structures that require no backlight as do LCD panels. This makes them more attractive for human perception. OLEDs can be made to be conformal and light weight.
- OLEDs can be manufactured on thin foils like metalized plastic or metal foils. This makes OLED displays flexible. Because they require semiconductor manufacturing, OLEDS are complex and expensive to produce. OLEDs are also very susceptible to the damage by the ambient environment, particularly moisture which severely degrades performance.
- LCD and LED liquid crystal display
- LCD and LED units are being used to in areas where static posters have been the dominant and conventional medium for advertising.
- One of the major appeals of the LCD and LED formats is their capacity to be programmed dynamically and addressed remotely, and the fact that LCDs and LED systems can display moving images.
- the cost advantage of a printed poster is not available to the LCD or LED panel because both the LCD panel and the LED panel are expensive to manufacture.
- the LED panel can be made to conform to shaped surfaces by custom manufacture of a rigid frame that is caused to adopt the desired shape. This frame is then populated with LEDs that are inserted into the frame manually.
- the advantage of being able to conform conveniently to a non-planar surface without the use of a rigid frame is not available to the LED technology.
- the LCD panel is generally not conformal. More specifically, LCD technologies cannot easily be scaled to larger sizes, especially the sizes of billboards, without great expense. Moreover, LCD technologies require expensive packaging to protect the display from water, heat and other environmental factors. LCDs consume significant power, where passive posters intrinsically require none to display an image.
- current industry practice in making flat panel displays based on liquid crystal media is to use two glass substrates as the structural material and the material on which many processing steps are conducted. The glass substrate is widely used because it is a general-purpose material, offering many of the characteristics required for display manufacturing. These characteristics include: resistance to high temperatures, dimensional stability, barrier to moisture, solvent resistance, structural strength, rigidity, and transparency.
- electroluminescent device is created from powdered phosphors. These are semiconductor materials like zinc sulphide (ZnS) doped with a phosphor like manganese ion (Mn2+). Compared with standard LEOs and OLEDs, it is substantially easier to fabricate a display based on semiconductor doped phosphors.
- ZnS zinc sulphide
- Mn2+ manganese ion
- thin film technology has been used to make electroluminescent displays
- thick film technology has been used to make electroluminescent lamps, in particular backlights for liquid crystal displays (LCDs).
- LCDs liquid crystal displays
- An example of a thin film device is described in US Patent 5,463,279.
- AMEL Active Matrix Electroluminescent
- TFEL Thin Film Electroluminescent
- Thick Dielectric Electroluminescence that uses powdered phosphors and that can be made into a 'paper thin', flexible, durable, energy efficient lighting sources.
- TDEL Thick Dielectric Electroluminescence
- a bipolar pulse voltage is applied to a capacitively driven device containing the phosphor.
- the high capacitance dielectric layer(s) causes current-limited electrical breakdown of a 0.5 to 30 micron thick phosphor layer.
- Electrical breakdown of the phosphor layer results in light emission via hot-electron impact excitation of luminescent atoms such as rare earth or transition metals.
- a typical thick film phosphor electroluminescent device comprises a layer of electroluminescent material in a dielectric matrix, sandwiched between two planar conducting electrodes.
- the electroluminescent material comprises phosphor particles, typically a zinc sulphide (ZnS) powder doped with manganese ( n), microencapsulated in a dielectric material.
- ZnS zinc sulphide
- n manganese
- silver- or graphite-loaded screen-printable inks, and indium tin oxide (ITO), a transparent conductive material, respectively are used to form the electrodes on a substrate such as a polyester film.
- TDEL devices allow for low cost and high-yield screen printing of a thick film dielectric layer.
- TDEL on plastic film has been used for Point of Sale shelf talkers, exhibition panels and small Bill Boards, none of which are addressable or programmable. It is claimed that some TDEL structures can be made to be addressable.
- J. Heikenfeld and A.J. Steckl teach in an article published in Proc. SID Vehicle Displays 2001, Detroit Ml, October 2001 , that an addressable TDEL device can be made on glass.
- TDEL has been deployed on plastic film such as polyvinyl chloride), though only at temperatures that do not damage the plastic.
- plastic film such as polyvinyl chloride
- This approach has the disadvantage that phosphors with more attractive properties like greater brightness, more selection of color or longer lifetime, cannot be used in conjunction with the plastic.
- the TDEL architecture has been deposited over given areas of a film and subsequently energized to make the entire area emissive.
- TDEL in this format has been used to create distinct large footprint images so that different areas of artwork can be made emissive at different times, thus giving the appearance of addressability on a poster.
- Such posters cannot be updated in real time, nor can moving images be displayed except as pre-formed segments like those used to define alphanumeric displays.
- Electrophoretic displays are also called electronic paper, or E-paper. This display technology is designed to mimic the appearance of black ink on paper. E-paper reflects like just like conventional printed paper in order that the image can be seen.
- An electrophoretic display is an information display that forms visible images derived from charged pigment particles dispersed in a fluid by rearranging the particles using an applied electric field (electrophoresis). Examples of commercial electrophoretic displays include the high-resolution active matrix displays used in the Amazon Kindle, Sony Librie, Sony Reader, and iRex iLiad e-readers.
- electrophoretic display are constructed from an electrophoretic imaging film manufactured by E Ink Corporation.
- E Ink Corporation One of the advantages of the electrophoretic display is that it can be manufactured on plastic, offering the possibility of conformability for use in billboards.
- e-paper is generally, but not necessarily, restricted to black and white images and requires ambient light to be made visible because it is required to operate in a reflective mode.
- an e-paper image is similar to an image printed on conventional paper. This is because the light reflected from the electronic ink emerges from a very thin layer adjacent to the viewing surface.
- US patent 6,252,624 issued on June 26, 2001 describes an electrophoretic display that can be created using multicolor printing operations similar to those used in screen printing.
- Electrochromic display such as one made by NanoChromics Displays or Acreo. Electrochromism results from a colour change in a material (usually a molecule) that is caused to undergo reversible oxidation and reduction. In this manner, one can produce an image that looks like ink on paper. Such displays, which can be manufactured on paper, require substantially less power than do LCD panels or LED or OLED displays.
- plastic may undergo temperature cycling.
- control of dimensional reproducibility as the film is cycled in temperature is required.
- a film should not shrink when it is heated and cooled so that accurate alignment of features of the substrates after each thermal cycling event is not compromised.
- expansion of the film during temperature cycling may lead to dimensional changes large enough to fracture, crack or deform circuitry or other features deposited on the plastic film surface. For this reason techniques should be developed to create dimensional stability in order to reproducibility deposit complex electronic circuits on plastics.
- PCT/CA2005/001397 entitled “Smart Composite Materials for Plastic Substrate”, which is attached by way of Appendix 1.
- laminating or otherwise attaching two or more films together in such a way that their combined coefficients of expansion compensate one another may achieve the same effect.
- a film of zero, or near-zero, expansion coefficient may be obtained.
- the desired reproducibility in dimensional stability may be achieved. It is the ability, therefore, to limit and to predict dimensional changes and confer dimensional reproducibility with temperature that can be exploited in a manufacturing process of a digital video poster.
- the present disclosure relates to a substantially plastic digital video poster having a plurality of superposed layers of different compositions and characteristics that combine to form a pixilated addressable flexible display with an embedded functionality.
- the present disclosure also relates to the method of manufacture of this device.
- the digital video poster which is the object of this disclosure allows addressable and programmable information and images to be displayed on flat surfaces and on any kind of shaped surface.
- the digital video poster can also be molded in order to be shaped. Therefore, it is an object of this disclosure to provide a shapeable, flexible, moldable digital video poster that can be adapted to any kind of planar or shaped surface.
- An object of the disclosure is the creation of a thick film electroluminescent poster in which a plurality of independent electrodes are provided on at least one side of a layer of shaped or unshaped electroluminescent material. A voltage may be applied selectively to each of these independent electrodes to illuminate a respective region, also called a pixel, of the poster.
- a thick film electroluminescent display is created by selecting the configuration of the independent electrodes to represent information, for example in the form of an image.
- the present disclosure seeks to create an addressable electroluminescent poster, i.e. an electroluminescent poster comprising a plurality of pixels wherein each pixel area may be separately and selectively illuminated.
- plastic substrates for the purpose of making a digital video poster.
- lower temperature deposition techniques to deposit or process conducting layers, dielectric layers or electroluminescent and alignment layers should be used.
- Thermal and dimensional stability of the plastic film are therefore controlled in order for a film to withstand processing temperatures above 100 °C that may be encountered in EL pixel manufacturing, including the manufacture of indium tin oxide, barrier coatings and electronic circuit elements such as conductors and transistors.
- plastic substrates are an alternative to glass, but standard processing techniques for both amorphous silicon (a-Si) and poly-silicon (poly-Si) TFTs on glass require temperatures higher than those compatible with commonly available plastics (-350°C for conventional a-Si TFTs and ⁇ 450°C for poly-Si TFTs).
- Organic TFT would be a suitable technology for plastic substrates.
- electrodes and emissive material comprising a plurality of layers are printed or coated on the glass substrate. In this manner, a plurality of electrode conductors can be configured in space to define a pixel.
- an emissive composite comprising: a first panel assembly comprising: a first plurality of conductors; a second panel assembly superposed to the first panel assembly and comprising: a second optically transmissive plurality of conductors; and an emissive layer interposed between the first and second plurality of conductors
- the first and second plurality of conductors are positioned generally perpendicular to one another. In an embodiment, the first and second plurality of conductors are provided in respective sets of stripes. In an embodiment, the first plurality of conductors are spaced apart from one another and disposed substantially parallel to one another. In an embodiment, the second plurality of conductors are spaced apart from one another and disposed substantially parallel to one another. In an embodiment, a region substantially between a first selected conductor of the first plurality of conductors and a second selected conductor of the second plurality of conductors defines a picture element. In an embodiment, the picture element is selected from the group consisting of a pixel and subpixel. In an embodiment, the picture element is selectively addressable by selecting the first selected conductor and the second selected conductor of the first and second plurality of conductors respectively. In an embodiment, the selection comprises the application of a voltage thereby providing for the addressed picture element to emit light.
- a voltage is applied across the first and second plurality of conductors thereby creating an electrical field therebetween providing energy to the emissive layer.
- the first panel assembly comprises a first substrate, the first plurality of conductors being coupled to the first substrate.
- the second panel assembly comprises a second substrate, the second plurality of conductors being coupled to the second substrate.
- the first substrate is a bottom substrate. In an embodiment, the first substrate is a top substrate. In an embodiment, the second substrate is a top substrate. In an embodiment, the second substrate is a bottom substrate.
- the composite further comprising a dielectric layer coupled to the first plurality of conductors.
- the emissive layer is coupled to the dielectric layer.
- the composite further comprising a dielectric planarizing adhesive layer coupled to both the first plurality of conductors and the dielectric layer.
- the composite further comprising a sealing optically transmissive dielectric layer coupled to the emissive layer.
- the second plurality of conductors is coupled to the transmissive dielectric layer.
- the transmissive dielectric layer is a vinyl compound.
- the transmissive dielectric layer is comprised of a lacquer based compound.
- a color layer is coupled to the second substrate.
- the color layer is in contact with a mask layer.
- the mask layer comprises a black-laquer based compound.
- a second sealing layer is in contact with the second plurality of conductors.
- a color layer is coupled to the second sealing layer.
- the color layer comprises a material selected from the group consisting of a colorant and color conversion material.
- the color layer comprises a plurality of picture elements.
- the picture elements are selected from the group consisting of pixels and subpixels.
- the pixels are selected from the group consisting of red pixels, green pixels and blue pixels.
- the subpixels are selected from the group consisting of red subpixels, green subpixels and blue subpixels.
- a first supplementary conductive layer is coupled to the dielectric layer.
- the second plurality of conductors is coupled to a second supplementary plurality of conductors, the second supplementary plurality having an impedance lower than the impedance of the second plurality of conductors.
- the composite further comprises an adhesive layer between the first and second panel assemblies.
- At least one layer of the composite is formed by coating. In an embodiment, each layer of the composite is formed by coating. In an embodiment, at least one layer of the composite is formed by printing. In an embodiment, each layer of the composite is formed by printing.
- the first substrate has a thickness between 25 and 500 micrometers. In an embodiment, the second substrate has a thickness between 25 and 500 micrometers.
- first plurality of conductors is formed from metal deposited on a substrate.
- the metal is selected from the group consisting of aluminum and copper.
- the first plurality of conductors comprises metal electrodes.
- the metal electrodes are formed by printing a conductive ink on a substrate.
- the metal electrodes are formed by printing a conductive polymer on a substrate.
- the emissive layer comprises a phosphor
- the second plurality of conductors are selected from the group consisting of: indium tin oxide, graphene, and polyethylene- dioxithiophene.
- an electromagnetic shield layer is coupled to the first substrate.
- a protective layer is coupled to the electromagnetic shield layer.
- an electromagnetic shield layer is coupled to the second substrate.
- a protective layer is coupled to the electromagnetic shield layer.
- the composite is substantially plastic.
- an emissive composite comprising: a first substrate; a first plurality of conductors coupled to the substrate; a dielectric layer coupled to the first plurality of conductors; an emissive layer coupled to the dielectric layer; a sealing optically transmissive dielectric layer coupled to the emissive layer; a second optically transmissive plurality of conductors coupled to the dielectric transmissive layer; a second substrate coupled to the second plurality of conductors; and a protective layer coupled to the second plurality of conductors.
- an emissive composite comprising: at least one color layer; an optically transmissive substrate coupled to the color layer; a first, plurality of transmissive conductors coupled to the optically transmissive substrate; an optically transmissive dielectric layer; an emissive layer coupled to the optically transmissive dielectric layer; a dielectric coupled to the emissive layer; a second plurality of conductors coupled to the dielectric layer; a second bottom substrate layer.
- an emissive composite comprising: an optically transmissive layer; a first, plurality of transmissive conductors coupled to the optically transmissive layer; an optically transmissive dielectric layer; at least one emissive color layer; a dielectric coupled to the emissive layer; a second plurality of conductors coupled to the dielectric layer; a second bottom substrate layer.
- an emissive composite comprising: an optically transmissive layer; a first, plurality of transmissive conductors coupled to the optically transmissive layer; an optically transmissive dielectric layer; at least one emissive color layer; a dielectric coupled to the emissive layer; a plurality of transistors coupled to the dielectric layer; and a second bottom substrate layer.
- a method of making the emissive composite comprising: printing an organic solvent soluble mask of the pattern of conducting electrodes on top of a layer of metal in contact with the first substrate; etching the unmasked metal film with acid and removing the printed mask with organic solvent.
- the emissive composite comprises a first substrate with a first plurality of conductors coupled thereto.
- a dielectric layer is coupled to the first plurality of conductors and to an emissive layer.
- a second optically transmissive plurality of conductors also coupled to a second substrate and an emissive layer is interposed between the first and second plurality of conductors.
- FIG. 1 is a schematic cross-sectional view of generalized build sequence of an exemplary embodiment of a thick dielectric EL (TDEL) laminate of the present disclosure showing a configuration of layers.
- TDEL thick dielectric EL
- FIG. 2 is a schematic cross-sectional view of an exemplary embodiment
- FIG. 3 is a schematic top view of an exemplary embodiment 100 of a thick dielectric EL laminate showing how the bottom row select conductor and top column select transparent conductors intersect and overlap to form pixels.
- FIG. 4 is a schematic top view of an exemplary embodiment 100 of a thick dielectric EL laminate showing how the bottom row select conductor and top column select transparent conductors intersect and overlap to form sub-pixels and grouping sub-pixels to form pixels.
- FIG. 5 is a schematic cross-sectional view of an exemplary embodiment 00 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue filters.
- FIG. 6 is a schematic cross-sectional view of an exemplary embodiment 100 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue emissive phosphors.
- FIG. 7 is a schematic cross-sectional view of an exemplary embodiment 00 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue filters controlled with thin film transistors.
- FIG. 8 is a schematic cross-sectional view of an exemplary embodiment 100 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue emissive phosphors controlled with thin film transistors.
- FIG. 1 shows one generalized build sequence for the digital video poster.
- the bottom substrate 120 is provided with a plurality of electrodes called the first conductive layer 130 on one surface.
- the bottom substrate 120 is provided with a bottom electromagnetic shield layer 115.
- a bottom protective layer 110 is placed over the bottom EM shield layer 115. This forms the bottom panel assembly 101.
- the top substrate 165 is provided with a plurality of electrodes called the second conductive layer 160 that are transparent to visible light (transmissive electrodes).
- the top substrate 165 is also transparent to visible light.
- the second dielectric layer 110 also transparent to visible light, serves to isolate the electroluminescent layer 150 from the conductor electrodes 160.
- the first dielectric layer 140 is placed in physical contact with the electroluminescent layer 150.
- the supplementary first conductive layer 135 is placed in physical contact with the first dielectric layer 140. This supplementary first conductive layer 135 is formed in a matching pattern to the first conductive layer 130. This forms the top panel assembly 102.
- top panel assembly 102 and bottom panel assembly 101 are joined by aligning the conductor patterns of the supplementary first conductive layer 135 to that of the first conductive layer 130 and bonding the assemblies with adhesive layer 132.
- the adhesive and bonding process allows or creates a conductive path between matched and aligned electrodes of the supplementary first conductive layer 135 and the first conductive layer 130.
- Color layer 170 and mask layer 180 can be attached.
- a top protective layer 190 and top electromagnetic shield layer are also attached.
- a voltage is applied across a first conductive electrode (conductor) 130, including electrodes 130a, 130b, 130c and so on, and a second conductive transmissive electrode 160 to create an electrical field between the second conductive transmissive electrode 160 and first conductive electrodes 130a, 130b, 130c and so on.
- the first conductive electrodes 130a, 130b, 130c and so on may have additional supplementary first conductive layer electrodes 135a, 135b, 135c and so on, matched in pattern and aligned to first conductive layer electrodes 130a, 130b, 130c and so on, incorporated by printing, coating or otherwise provided in order to improve the overall conductivity of the first conductive electrodes.
- the second conductive transmissive electrode 160 may also incorporate a supplementary second conductive electrode by printing, coating or otherwise provided in order to improve the overall conductivity of the second conductive transmissive electrode 160.
- the electric field between the conductive layer 130 (which may include layer 135) and the conductive layer 160 provides energy to the emissive or electroluminescent layer 150 by creating a capacitance, for example.
- the electric field is provided in the form of alternating current in the exemplary embodiments.
- the current is supplied in a frequency range of about 200 Hz to 2.5 kHz, and more preferably in the range of 400 Hz.
- the emissive material usually exhibits a voltage threshold (V thr ) for emission, so the typically the applied voltage is greater than 20 Volts, though it may be as high as 100 Volts or as high as 120 Volts or more.
- the current is in the range of pico-Ampere, though it may be higher, resulting overall in lower power consumption than an LCD, LED or plasma display.
- the applied voltage required to reach threshold for emission depends on the type of EL material and the conditions of manufacture of the EL layer.
- the EL Digital Video Poster has pixels. These are defined in FIGS 2 and 3 by intersecting sets of stripes of conductors 130 and 160 (and possibly including 135). These are created at right angles to one another and at opposite sides of the EL layer 150 and the dielectric layers 110 and 140. In FIG. 3, the intersection of the stripes of electrodes defines the pixel at positions 200.
- the sets of conductive stripes are conventionally called “rows” 160 and “columns” 130.
- Pixels independently illuminate by means of an addressing scheme called passive matrix addressing. In this scheme, rows are sequentially addressed or scanned electronically. At the same time a row is selected electronically, voltage pulses, each with a defined and independent peak voltage and pulse width, (the "modulation voltage”) can be applied simultaneously to each of the columns intersecting the addressed row. In consequence, voltages are applied with independent control across the pixels along a given row. This permits one to adjust the instantaneous luminosity needed for each pixel. Pixels not on the addressed row do not illuminate.
- a color pixel 310 may be formed by grouping three pixels in a row in an exemplary embodiment.
- the color layer 170 is a matrix of cells matched in pattern and aligned with the pixels 200.
- the purpose of the mask layer 180 may be to block out undesired pixels or sub-pixels. It is also used to isolate emission from different sub-pixels to prevent cross-contamination of the light emitted from adjacent or nearby pixels or sub-pixels that might otherwise enter the wrong area of the color layer 170 and diminish color image quality and contrast.
- the mask is applied in a pattern which provides a sharp definition around each sub-pixel and can therefore provide for higher resolution, typically higher than that provided by red-green-blue (RGB) or cyan-magenta-yellow (CMY) color display.
- the frame is a single complete scan of all the rows of the passive matrix.
- the frame repetition rate, or frame rate determines the visual quality of the moving image.
- the frame For video frame rates, the frame must be updated about 30 to 60 times per second or more for the eye not to detect a flickering image.
- the first TDEL laminate 00 is built from two major assemblies, the bottom panel assembly 101 and top panel assembly 102, and a number of other layers to suit a particular function of the digital poster.
- Other architectures may be conceived in which the order of the layers is changed to adapt the device to different performance requirements, such as enhanced luminosity or improved environmental performance, or improved dielectric or capacitance properties.
- the bottom substrate 120 can be selected from any of the following according to the intended use of the poster or according to the method of manufacture of the EL pixels.
- the bottom substrate 120 can be made from polymers which are derived from the categories of polymer films that are semicrystalline, semicrystalline amorphous, amorphous thermoplastic, but solvent cast.
- the group of thermoplastic semicrystalline polymers includes polyethylene terephthalate (PET) e.g. DuPont Melinex, and polyethylene naphthalate (PEN).
- PET polyethylene terephthalate
- PEN polyethylene naphthalate
- the next category are polymers that are thermoplastic, but non-crystalline, and these range from polycarbonate (PC) e.g. DuPont PURE-ACE and GE Lexan with a glass transition (Tg) of -150 °C, to polyethersulfone (PES) e.g.
- thermoplastic these polymers may also be solvent cast to give high optical clarity.
- the third category includes high Tg materials that cannot be melt processed. These include aromatic fluorine containing polyarylates (PAR) e.g. Ferrania's Arylite polycyclic olefin (PCO) e.g. Promerus's Appear and polyimkJe (PI) e.g. DuPont's Kapton.
- PAR polyarylates
- PCO polycyclic olefin
- PI polyimkJe
- the surface of the polymer film can be treated by methods well known to those skilled in the art to make the surface of the substrate printable.
- the substrate may also consist of plastic coated paper, natural and synthetic fabrics, wood and wood-based products, polymer composites including polymer nanocomposites, or a rigid substrate such as alumina ceramic, glass sheet or shaped glass, metals and metal alloys that have been suitably dielectrically insulated, or printed circuit board materials that are well known to those skilled in the art.
- the first conductive layer 130 (the column or pixel select layer) is applied by coating or printing or laminating.
- an aluminum film can be deposited on bottom substrate 120 and then subsequently patterned into stripes using standard and well-known photo-lithography involving photo-resist, photo-masks and ultraviolet and thermal curing.
- copper or other metallic conducting lines can be deposited on the rear substrate by means of electroless plating.
- the rear electrode can be a metal film like aluminum or copper on plastic that can be patterned by digital or analog printing of an ink that resists an etching process (such as acid etching).
- the bottom electromagnetic (EM) shield layer 115 is applied by coating or printing or laminating to the bottom substrate 120 on the surface opposite to that with the first conductive layer 130.
- the layer can be a metal film of aluminium, copper, silver, or gold.
- a conductive ink may be used such as a silver ink like CRSN 2442 available for example from Sun Chemical, or carbon conducting ink like 7105 or 7102 or 8144 Carbon Conductor from DuPont, or a conductive polymer such as polyethyelenedioxythiophene (PEDOT) available as Orgacon from Agfa.
- PEDOT polyethyelenedioxythiophene
- a bottom protective layer 110 is provided which may be attached to provide barriers to UV light, water, solvents and other materials that might damage the TDEL laminate 100.
- the bottom protective layer may also provide physical or mechanical protection from damage that may result from scratches or impacts.
- the top substrate 165 can be selected from any of the following according to the intended use of the poster or according to the method of manufacture of the EL pixels.
- the top substrate 165 can be made from polymers which are derived from the categories of polymer films that are semicrystalline, semicrystalline amorphous, amorphous thermoplastic, but solvent cast.
- the group of thermoplastic semicrystalline polymers includes polyethylene terephthalate (PET) e.g.
- the next category are polymers that are thermoplastic, but non-crystalline, and these range from polycarbonate (PC) e.g. DuPont PURE- ACE and GE Lexan with a glass transition (Tg) of -150 °C, to polyethersu!fone (PES) e.g. Sumitomo Bakelr e's Sumilite with a Tg of -220 °C. Although thermoplastic, these polymers may also be solvent cast to give high optical clarity.
- the third category includes high Tg materials that cannot be melt processed. These include aromatic fluorine containing polyarylates (PAR) e.g.
- PCO polycyclic olefin
- PI polyimide
- the surface of the polymer film can be treated by methods well known to those skilled in the art to make the surface of the substrate printable.
- the substrate may also consist of polymer composites including polymer nanocomposites, or a rigid substrate such as glass sheet or shaped glass.
- a transmissive second conductive layer 1$0 (the row select layer) is applied by coating or printing or laminating on top of the top substrate 165.
- This second conductive layer is sufficiently transmissive for the selected wavelengths of application, such as for the visible portions of the electromagnetic spectrum.
- This second conductive layer is patterned as rows, but these rows are oriented in careful registration so that they are perpendicular to (at right angles to) the patterns of electrodes 130 deposited on substrate 120. In this manner, electrically transmissive wires (electrodes) are created.
- FIG. 3 shows a top view of the configuration of electrodes where only the electrodes are shown and the intervening dielectric or other layers have been removed for clarity of viewing. The overlap of conductive layers 130 and 160 yields the areas 200 which indicate the locations of the pixels.
- the second electrode may be indium tin oxide (ITO) deposited over the surface of the top substrate 165.
- ITO indium tin oxide
- This ITO transmissive conductor is patterned into stripes using standard photolithographic methods. It can also be patterned by depositing a resist using a digital printer, followed by acid etching with 10% sulfuric acid.
- the ITO can be deposited as an ink in the form of a gel by screen or jet printing or deposited as a film from the vapour phase.
- a conductive polymer such as PEDOT available as Orgacon from Agfa for example, may be used instead of ITO.
- antimony tin oxide ATO is used to form the second transmissive conductive layer 160. It is known that ATO has a comparatively high impedance, ie, that its resistance can be on the order of 20 kQ. It is also known that ITO has a comparatively high resistivity, greater than 10 ⁇ / ⁇ , similarly for PEDOT. If pixels are to be switched on or off by activating particular row and column select electrodes to make moving images, the time constant for electrical transmission across the layers between electrodes 130 and 160 fabricated from high resistivity materials can be comparatively high.
- One method is to deposit by printing a line of heat curable silver ink (for example, Gwent Group silver ink C2050712D58) to make lines on each line of the more resistive conductor.
- the silver ink lines can be deposited first and then coated with lines 160. In this way, the impedance of the more resistive transparent material is lowered, and hence the time constant for switching a pixel is reduced. If the silver ink line is made to be very fine, it cannot be seen by the naked eye and very little light is lost due to the opacity of the silver ink.
- other transmissive conductors may be used to form the layer 160.
- the second transparent conducting layer of ITO 160 is patterned by acid etching with 10 percent H 2 S0 through a printed acid-proof resist.
- the second optically transmissive dielectric layer 110 is printed or coated over the plurality of first electrodes 160.
- the dielectric layer 110 may be derived without limitation from materials like SU8 (available from icrochem), DuPont Quick Prime, 3M Krylon acrylic spray, or vinyl compounds or epoxy compounds that are transparent to visible light.
- One or more coats of the 3M Krylon acrylic spray dielectric layer 110 are applied over the electrodes 160 to a thickness between 0.2 and 4.0 microns, more preferably between 1 and 2 microns, and most preferably to a thickness of 1.5 microns.
- the electroluminescent layer 150 is applied by means of printing or coating processes like those described above.
- the phosphor is applied as a single layer.
- An exemplary phosphor is micro-encapsulated zinc sulfide (ZnS-doped) Luxprint material 8152 from DuPont, obtainable in the form of a paste for thick film polymer electroluminescent coating.
- high brightness white phosphor 8152 is printed by screen coating to a thickness preferably between 20-45 microns. Other thicknesses are determined empirically when different phosphors are used. Empirical determination requires, for example, that the phosphor is coated to sufficient thickness to prevent dielectric breakdown, but with sufficient thinness to provide comparatively high capacitance.
- the phosphor is thermally cured at a temperature between 100 and 150 °C, and most preferably, between 120 and 140 °C.
- the emissive layer is printed over the second dielectric layer 110 in a single pass of the screen printer using a white polyester screen of 156 threads per inch.
- the emissive layer 150 together with the dielectric layer 110 and the bottom electrodes and plastic substrate 120 are heated to 130 °C for 15 minutes in an oven.
- the first dielectric layer 140 is printed or coated over the electroluminescent layer 150.
- the dielectric layer may be derived without limitation from materials like DuPont 7153 or 8153 High K dielectric insulator.
- Insulators may be derived from barium titanate (BaTi0 3 ) or high K polymers that are UV or thermally curable.
- One or more coats of the barium titanate dielectric layer 140 are applied over the electroluminescent layer 150 to a thickness between 5 and 30 microns, more preferably between 6 and 12 microns, and most preferably to a thickness of 12 microns.
- the dielectric layer 140 is printed over the electroluminescent layer 150 in two passes of the screen printer using a white polyester screen of 156 threads per inch. The dielectric layer 140 is heated after each pass of screen printing to 130 °C for 10 minutes in an oven.
- a plurality of bottom electrodes (supplementary first conductive layer)
- the bottom electrode is printed digitally by means of Ink jet printing, or is printed using an analog printing technique such as screen or flexographic printing.
- the bottom electrodes are patterned as parallel stripes by means of screen printing.
- An image (stencil) of the row electrodes created by computer aided design (CAD) drawing on acetate film is transferred to a CDF Direct-Films film resist from Ulano Corporation on 195 or 156 thread per inch polyester screen.
- CAD computer aided design
- the rear electrodes can be made from a conductive metal ink such as a silver ink like C SN 2442 available for example from Sun Chemical, or carbon conducting ink like 7105 or 7102 or 8144 Carbon Conductor (DuPont).
- a conductive metal ink such as a silver ink like C SN 2442 available for example from Sun Chemical, or carbon conducting ink like 7105 or 7102 or 8144 Carbon Conductor (DuPont).
- silver ink 5064 from DuPont is screen printed through the stencil onto the first dielectric layer 140 using a manual screen printer such as is available from Aremco Products, Inc.
- the transferred pattern together with the plastic film is heated to 130 °C for 10 minutes to cure the bottom row electrode pattern.
- Other conductive inks may be utilized to form the first conductive layer 135.
- Exemplary conductive compounds include copper, aluminum, and gold.
- the top panel assembly 102 and bottom panel assembly 101 are joined by aligning the conductor patterns of the supplementary first conductive layer 135 to that of the first conductive layer 130 and bonding the assemblies with adhesive layer 132.
- the adhesive and bonding process allows or creates a conductive path between matched and aligned electrodes of the supplementary first conductive layer 135 and the first conductive layer 130.
- Krylon spray adhesive adhesive is applied to the first conductive layer 130 or the supplementary first conductive layer 135.
- the top panel assembly 102 and bottom panel assembly 101 are aligned and laminated together via compression rollers, which are heated to 100 °C to thermally cure the adhesive.
- the compression rollers force a displacement of adhesive between the aligned electrodes of layers 130 and 135 to ensure electrical contact between the electrodes.
- a fiat bed lamination device with adjustable compression and heating may be used.
- Other alternatives may include adhesives with metal particles which may be aligned by a magnetic field during curing in the direction of conductivity, such as ZTACH anisotropic conductive adhesives available from SunRay Scientific.
- anisotropic conductive film adhesives may be used such as the ACF series of film adhesives from the 3M Company.
- the color layer 170 is applied to the top substrate 165. Red, blue and green sub-pixels are obtained by building a patterned filter 170 in alignment with the sub-pixels 310 formed by the intersections of the columns 130 and rows 160 of FIG 4.
- the emissive layer 150 comprises phosphors like ZnS:Mn and SrS.Ce which when combined superimpose their respective emissions to produce white light over the entire range of the visible electromagnetic spectrum.
- the red, blue and green filters transmit a narrow range of wavelengths corresponding to the colors of each sub-pixel.
- fluorescent dyes can be used to make the color filter.
- a black mask layer 180 overlays the color layer 170.
- the purpose of this layer may be to block out undesired pixels or sub-pixels, it is also used to isolate emission from different sub-pixels to prevent cross-contamination of the light emitted from adjacent or nearby pixels that might otherwise enter the wrong area of the RGB color layer and diminish color image quality and contrast.
- the mask is applied in a pattern which provides a sharp definition around each pixel and can therefore provide for higher resolution, typically higher than that provided by RGB or CMY color display.
- the top electromagnetic (EM) shield layer 195 is applied by coating or printing or laminating to the mask layer 180.
- the layer can be a transparent conductive metal such as ITO, or a conductive polymer such as PEDOT available as Orgacon from Agfa.
- the top EM shield layer 195 may be applied by coating or printing or laminating to the top protective layer 190 and bonded to the mask layer 180 by laminating with an adhesive.
- a top protective layer 190 is provided which may be attached to provide barriers to UV light, water, solvents and other materials that might damage the TDEL laminate 100.
- the top protective layer may also provide physical or mechanical protection from damage that may result from scratches or impacts.
- FIG. 5 shows another exemplary embodiment of the TDEL laminate 100.
- the emissive layer 150 is printed on top of the second dielectric layer 110 on top of the transmissive second conductive layer 160 and substrate layer 165 (and optionally, layers 190, 195, 180 and 170) as a matrix of emissive phosphor pixels.
- Electroluminescent layer 150 is applied by means of printing or coating processes like those described above.
- the phosphor is applied as a pixel matrix layer. Accordingly, white polyester screen of 156 threads per inch is first patterned into a matrix array of 100 x 100 pixels measuring 2 mm x 2 mm each with a spacing of 1 mm between pixels. The pixels are registered so that they coincide precisely with the position of the plurality of electrodes 130 and 135.
- Micro-encapsulated zinc sulfide (ZnS- doped) DuPont Luxprint high brightness white phosphor 8152 is screen printed by one pass of screen coating to a thickness preferably between 20-45 microns.
- the layer 150 is then baked for 15 minutes at 130 °C for 15 minutes in an oven.
- the dielectric layer 140 is printed or coated over the matrix of electroluminescent pixels 150.
- the dielectric layer isolates each pixel of electroluminescent material from its neighbor.
- the dielectric layer may be derived without limitation from materials like DuPont 7153 or 8153 High K dielectric insulator. Insulators may be derived from barium titanate (BaTi0 3 ) or high K polymers that are UV or thermally curable.
- One or more coats of the barium titanate dielectric layer 140 can be applied over the electroluminescent phosphor layer 150 to a thickness between 5 and 30 microns, more preferably between 6 and 12 microns, and most preferably to a thickness of 12 microns.
- the dielectric layer 140 is printed over the electroluminescent layer in one pass of the screen printer using a white polyester screen of 156 threads per inch.
- the dielectric layer 140 is heated after screen printing to 130 °C for 10 minutes in an oven.
- the first conductor plurality of electrodes is deposited in stripes of row electrodes 135 on the first dielectric layer 140. These electrodes are screen printed using a conductive silver ink such as Gwent C2050712D58 silver ink as previously discussed.
- FIG. 6 shows another exemplary embodiment of the TDEL laminate 100.
- the top or transmissive second conductor electrodes 161, 162, and 163 are arranged so that they will touch particular regions of the electroluminescent material sub-pixels 151, 152, and 153.
- Red, blue and green (RGB) emissive compounds 151, 152, and 153 are printed or coated onto the second electrode layer 161 , 162, 163 etc. using, without restriction, one or a combination of the printing or coating techniques described above, and in such a way as to preserve registration between each red or green or blue emissive pixel and its column or data select electrode.
- the RGB emissive layers are subsequently thermally cured.
- the column electrodes are separated by a dielectric layer that consists of rows and plane 140 that isolate the electrodes and the electroluminescent sub-pixels.
- the dielectric layer 140 can be derived from photo-curable inks like (1) SU8 from Microchem, Inc.; (2) from SunPoly, Inc., 305D UV curable dielectric ink; from DuPont, high K dielectric insulator 7153 and 8153. These inks can be screen printed as separate rows between the rows of sub-pixels. Typically, the dielectric rows are printed to a thickness of 20 microns.
- the sub-pixel threshold voltages are made equal and the relative luminosities of the sub-pixels are established so that they bear set or fixed ratios to one another at selected operating modulation voltages required to generate the desired luminosities for the red, green, and blue.
- the established ratios remain substantially constant over the full range of the modulation voltage in order to achieve correct color balance.
- the correct color balance is achieved for established luminosity ratios for the red, green and blue sub-pixels of about 3:6:1 , or sufficiently close to this ratio.
- CIE color coordinates and luminosity for the blue can be achieved with cerium doped strontium sulfide (SrS:Ce).
- Manganese doped zinc sulfide (ZnS:Mn) in combination with cerium doped strontium sulfide (SrS:Ce) or magnesium doped zinc sulfide (Zn 1-x Mg x S:Mn) with an appropriate ratio of Zn to Mg can be used to create a green emission.
- magnesium doped zinc sulfide (Zn -x g x S:Mn) can be used to generate red emission.
- a color filter 170 with a mask layer 180 can be inserted and aligned with the RGB phosphors to enhance luminosity and energy efficiency over the color-by-white design. In this way, self-consistent optimization of color coordinates and luminosity can be obtained for each pixel.
- FIG. 7 shows another embodiment of the TDEL laminate 100.
- thin film transistors 138a, 138b, 138c, and so on are used to activate the emissive layer 150.
- a color Filter 170 with a mask layer 80 can be inserted and aligned with the sub-pixels to generate the color pixels.
- a TFT is fabricated at each intersection of the row select electrodes 130 and column or data electrodes 137, the intersection which determines the location of the sub- pixel.
- a dielectric layer 133 isolates the row select electrodes 130 from the data electrodes 137.
- the thin film transistors can be fabricated from amorphous silicon, polycrystalline silicon or 11- VI semiconductor materials like CdS or CdSe using photolithography and/or combinations of laser annealing methods. These transistors are deposited on the bottom substrate 120.
- FIG. 8 shows another embodiment of the TDEL laminate 100.
- thin film transistors 138a, 138b, 138c, and so on are used to activate the emissive layers that are deposited as red, green and blue emissive compounds 151, 152, 153.
- a color filter 170 with a mask layer 180 can be inserted and aligned with the RGB phosphors to enhance luminosity and energy efficiency over the color-by-white design. In this way, self-consistent optimization of color coordinates and luminosity can be obtained for each pixel.
- a TFT is fabricated at each intersection of the row select electrodes 130 and column or data electrodes 137, the intersection which determines the location of the sub- pixel.
- One electrode of the TFT is in perfect register with the RGB sub-pixel.
- a dielectric layer 133 isolates the row select electrodes 130 from the data electrodes 137.
- the thin film transistors can be fabricated from amorphous silicon, polycrystalline silicon or ll-VI semiconductor materials like CdS or CdSe using photolithography and/or combinations of laser annealing methods. These transistors are deposited on the bottom substrate 120.
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- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
A substantially plastic digital video poster having a plurality of superposed layers of different compositions and characteristics that combine to form a pixilated addressable flexible display with an embedded functionality. The plastic digital video poster comprises an emissive composite. The emissive composite comprises superposed first and second panel assemblies. The first panel assembly comprises a first plurality of conductors. The second panel assembly comprise a second optically transmissive plurality of conductors and an emissive layer interposed between the first and second plurality of conductors. The emissive composite comprises a first substrate with a first plurality of conductors coupled thereto. A dielectric layer is coupled to the first plurality of conductors and to an emissive layer. A second optically transmissive plurality of conductors also coupled to a second substrate and an emissive layer is interposed between the first and second plurality of conductors.
Description
DIGITAL VIDEO POSTER
CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority on United States Provisional
Application Serial Number 61/278,116 filed October 5th, 2009 and incorporated herein by reference in its entirety.
TECHNICAL FIELD
The present disclosure relates to the field of addressable and programmable alternating current electroluminescent (EL) materials and in particular to methods of creating emissive pixels to provide static and moving images on plastic film.
BACKGROUND
Digital out of home advertising (DOOH) is a market that uses flat panel liquid crystal, light emitting diode, electroluminescent and plasma screens to display information and images in ways that allow information content to be updated at will or to use graphic images including moving images (video) to illustrate products or to attract buyers to products. In common with all of these display technologies is the use of an addressable matrix array of pixels of selected regions of illumination that can be selectively addressed by applying voltages to rows and columns of electrodes that govern the optical properties of each pixel. Printed posters are also broadly used to advertise commodities and to provide information of a specific or general nature based on signage, including maps, instructions and directions. Printed posters in general are not made up of pixels and are not programmable or addressable. Compared with flat panel displays, printed posters are generally lighter in weight and less costly to produce. Advertising and other posters are generally produced on paper or plastic laminated paper or plastic substrates. They are also produced on other
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substrates including wood and metal and composites of these. Most often, posters are printed on paper, plastic laminated paper or plastic film. An important lesson learned from the print industry is that printed document images can be created in high volume using relatively simple and well known printing techniques including flexography, gravure, photogravure, offset, linotype, screen and rotogravure, to mention some. Collectively, these printing technologies are called analog printing. Analog printing has certain advantages. These are: 1) many multiple copies can be produced quickly and inexpensively; high resolution and high image quality can be obtained by offset lithography and gravure; 3) expensive coated substrates are unnecessary to print satisfactory images; 4) inks can be less refined than those required for digital printing, making such inks less expensive; 5) screen printing offers single pass control of thickness of inks; 6) opaque inks can be screen printed on opaque dark substrate surfaces; 7) spot or process colors can be printed allowing color "kitchens" to be maintained from which virtually an color can be matched; and analog methods are existing technologies with existing installed base presses, trained operators and established markets and customers. Analog printing has certain disadvantages. These are: 1) the technique permits only very limited variable data printing, such as letterpress numbering; 2) the methods require pre-press setup and preparation; 3) the methods are generally not cost effective for very short runs or proofing; 4) the technique can be wasteful of ink and can be associated with chemical exposure and undesirable environmental impact; costly films for print of plate exposure are needed, and this leads to a need to archive bulky print items; 5) sizes are limited to the dimensions of the plate or screen image area so that larger images require repeated printing and seamless connection between print areas.
While analog printing methods address the needs of mass production, digital printing is desirable for variable information printing, customization, quick response, just-in-time delivery, and short print runs. Digital printing is an image transfer technology that is used to translate an image from a digital source (digital storage medium) to drive some kind of printing device to deposit the image. Digital printing is distinguished from analog printing technologies through
its advantages: 1) requires minimal press set up and has multicolour registration built into it; 2) the technology allows for variations like "print-on-the-fly", combining production printing with variable data handling and customization; 3) the technology is "non-contact", allowing substrates to be printed without disturbing them, without hold-down, to reduce effects like image distortion as can occur with screen printing; 4) the method allows for simplified "proofing", sampling and short runs more cost effectively than analog methods; 5) a broad range of color processing is available to digital printing, including classic 3-color (CYM), 4 color (CY K) and extended color gamut options; 6) there is less need for color overlap or trapping; 7) digital printing requires no film masters, stencils, screens or plates which translates into reduced space requirements for archiving; 8) less hazardous materials (chemicals) are generally involved, there is less waste in Digital printing which also leaves a smaller carbon/environmental footprint; 9) the technology allows for very large scale image generation through the use of digital web printers; 10) digital files permit more facile editing and storage than analog photographic images; 11) digital files are more or less agnostic with respect to electronic medium (internet, CD ROM, Video, etc); 12) analog information can be converted to digital information; and 12) the technology permits rapid and widespread dissemination of files for quick industry response. Digital printing has certain disadvantages. These are: 1) the technology has generally slower throughput than does analog printing; 2) digital prints generally cost more per run than do analog prints; 3) specially coated surfaces or substrates are required for digital print technology; 4) for thicker deposits, overprinting is required, and this translates into slower feeds; 5) digital inks and toners are provided in limited reservoir capacities and are expensive; 6) transparent chemistries are used in digital inks, meaning that their use is limited for white or light substrates; 7) the technology is relatively new and requires investment in training to accompany the equipment.
Having noted strengths and weakness of analog and digital printing technologies there is merit in combing the strengths of both to offset their weaknesses. Accordingly, new hybrid print technologies have emerged in the industry that combine, for example, rapid image creation and digital plate making
with fast production speed and high print quality characteristic of analog offset lithography. There also exist screen exposure masking systems that unite the strengths of digital processing with analog printing.
In order to reduce costs, there is a need to make display media that are less complex to fabricate or that use simplified methods in their manufacture. Digital posters can be made by analog or digital or hybrid analog and digital printing technologies as described above and that are less complex than semiconductor microfabrication processes in order to create electronic circuitry and color. While digital flat panel displays can be said to be mass produced, the technology is presently too complex, too sensitive to error, and the substrates too rigid, to take advantage of printing to reduce cost.
A digital poster is distinguished from a digital display in that the former is generally created on a flexible plastic film or a laminate of paper and plastic. Digital displays (collectively known as flat pane! displays) are generally fabricated on rigid glass or metal substrates using expensive and complex semiconductor microfabrication processes, though there is development effort to create digital displays on flexible substrates like plastic. Use of rigid substrates prevents flat panel displays from being used to bend around curved surfaces or to be molded or adapted to non-planar surfaces. Bending, flexing or shaping a display is desirable for example if the display must be placed on a curved surface like the interior surface of a transit vehicle a like bus, taxi, train or airplane which have curved interior surfaces against which poster advertising must be mounted. In many cases, the poster is required to conform in shape to the surface to which it is attached. Usually, the support surface is flat, but in many cases the support surface is curved either to enhance the viewing effect, or to conform to some geometric constraint imposed by the environment in which the poster is deployed. For example, a kiosk support surface may be cylindrical, requiring that the poster be shaped to conform to the kiosk surface.
Digital flat panel displays are characterized by rigid form factors, meaning that they have well defined dimensions and layouts. While plasma and liquid crystal displays are available in sizes larger than 70 inches on the diagonal, their cost rises exponentially with size. Yet there are many cases where larger
displays are required, billboards are one such example. An LED display can be made on the scale of a billboard. LED displays made from individual LED lamps require manual assembly in the case of billboard size units and must generally be viewed from afar because they have low resolution when viewed close up. LED displays do not use glass as a substrate, but instead are assembled in a metal frame. In general, LED displays are shapeable (conformal) within the limits of the metal support frame and the individual LED module sizes. LED displays must be housed in a protective framework to protect them from environmental damage. By contrast, a digital video poster may be scaled simply to larger or smaller sizes, and is more easily manufactured, lighter in weight and less expensive then a conventional flat panel display, including an LED display.
Posters are widely distributed in outdoor and indoor locations. For outdoor applications, the poster can be protected behind, or encased in, a suitable transparent barrier like glass or plastic, or the poster can be fabricated from materials that resist environmental damage due to variations in light intensity, temperature or humidity. These requirements can be relaxed to a greater or lesser degree for indoor applications. Fiat panel displays like LCDs and plasma displays must be protected against the environment by means of cumbersome and expensive housing. The housing also increases the size, thickness and weight of the flat panel display. Moreover, a liquid crystal display has the disadvantage that it does not function as well at low temperature because the liquid crystal freezes or becomes viscous so that the frame speed is diminished. There is a need to provide a display that does not require a housing to protect it, or that requires only inexpensive modifications that do not alter the flexibility of the display, or substantially increase its thickness or weight, and that operates independently of the ambient temperature. Plastic films, layers of plastic films, and plastic coatings are widely used to protect underlying surfaces because plastic can be formulated to be weather resistant, provide moisture and dust barrier properties, can be heated and cooled or exposed to oils, solvents, greases and acids and bases with little or no damage to itself or the underlying surface. It would be an advantage to be able to create a display that directly uses these protective properties of plastic by incorporating the plastic film as part of
the flexible digital display itself. This would confer on the display the properties of weather resistance and other barrier properties that would enhance its use as a medium for outdoor advertising.
Posters can be inked (printed) with pigments that fluoresce (emit light) or reflect light such that they appear bright, but only when exposed directly to visible light, or in some cases, to ultraviolet light. The purpose of incorporating fluorescent or reflective pigments is to enhance the visibility of the poster or to highlight some portion of the poster. Neither the fluorescent pigment nor the reflective pigment is self-emitting, meaning that the pigment requires an external light source to be activated, and neither the fluorescence nor reflectance states exhibit an intrinsic self-emitting property. Thus, posters in general are passive media that require an external light source in order to be observed. External illumination (front illumination) is accomplished usually by exposing the poster to a light source such as sunlight or artificial light, and is especially required under low ambient light conditions. Illumination can also be achieved by printing the poster on a transparent or translucent plastic film. In this case, the light source can be placed behind the poster (back illumination).
The advertising industry is dynamic and there is evidence that updating the information content or changing the information content of a poster frequently can improve the efficacy and utility of an advertising message. Accordingly, and increasingly, the static analog image of the poster is yielding to dynamic image making or image changing. For example, a poster can be scrolled on a roller or rollers so that its message changes as a function of time. Alternatively, an analog poster can be mounted in segments on segmented surfaces that are moved to display a new image with each concerted movement of the mounting segments. Alternatively a plurality of conductors can be created on an electroluminescent poster to cause printed regions of the unit to become emissive. An example of such a device is described in U.S. pat. No. 6,777,884 entitled "Electroluminescent Devices" by C.J.A. Baranardo et al. While such a method can be used to cause the poster image to appear to move and can therefore be used to change the information content of the poster, the method has the disadvantage in that the poster is not dynamically programmable. This is
because the artwork or image is pre-determined in the poster and is not composed of individual pixels in the manner of an LCD panel. Therefore the image cannot be erased or altered without first physically changing the artwork. A digital video poster, as described in this application, consists of pixels that can be addressed and programmed in much the same way as are flat panel displays. Video capability is achieved by applying a voltage to turn the matrix of pixels or sub-pixels off and on at a frequency (called the frame rate) that is too fast for the human eye to perceive. This frequency is on the order of 30 Hz or greater in order to avoid image flicker. A digital video poster as described in this application is a flexible printed composite structure comprising electronically addressable elements (pixels) by means of which an image such as a fetter, number or picture or combination of them can be displayed and updated or changed in real time and remotely.
The following are several examples of dynamically addressable displays from which some basic constructs can be derived in order to build a digital poster. Despite evidence that these are addressable displays, each has shortcomings that make them unsuitable as digital posters.
Electroluminescence is the non-thermal conversion of electrical energy into light. One type of electroluminescent device is the light emitting diode (LED) in which light is generated by electron-hole recombination near a pn junction. Compared with printed posters for advertising or signage, LED displays are expensive and complex to produce. Organic LED (OLED) displays are manufactured using techniques similar to those described above for LCD panels. Addressing is achieved by means of an active matrix of thin film transistors associated with gate and data conducting lines which are conventionally arranged in the pattern of a grid. OLEDs are emissive structures that require no backlight as do LCD panels. This makes them more attractive for human perception. OLEDs can be made to be conformal and light weight. Thus OLEDs can be manufactured on thin foils like metalized plastic or metal foils. This makes OLED displays flexible. Because they require semiconductor manufacturing, OLEDS are complex and expensive to produce. OLEDs are also very susceptible
to the damage by the ambient environment, particularly moisture which severely degrades performance.
The liquid crystal display (LCD) and light emitting diode (LED) industries make displays that are dynamically and remotely addressable and programmable. Increasingly, LCD and LED units are being used to in areas where static posters have been the dominant and conventional medium for advertising. One of the major appeals of the LCD and LED formats is their capacity to be programmed dynamically and addressed remotely, and the fact that LCDs and LED systems can display moving images. Nevertheless, the cost advantage of a printed poster is not available to the LCD or LED panel because both the LCD panel and the LED panel are expensive to manufacture. The LED panel can be made to conform to shaped surfaces by custom manufacture of a rigid frame that is caused to adopt the desired shape. This frame is then populated with LEDs that are inserted into the frame manually. The advantage of being able to conform conveniently to a non-planar surface without the use of a rigid frame is not available to the LED technology. The LCD panel is generally not conformal. More specifically, LCD technologies cannot easily be scaled to larger sizes, especially the sizes of billboards, without great expense. Moreover, LCD technologies require expensive packaging to protect the display from water, heat and other environmental factors. LCDs consume significant power, where passive posters intrinsically require none to display an image. Moreover, current industry practice in making flat panel displays based on liquid crystal media is to use two glass substrates as the structural material and the material on which many processing steps are conducted. The glass substrate is widely used because it is a general-purpose material, offering many of the characteristics required for display manufacturing. These characteristics include: resistance to high temperatures, dimensional stability, barrier to moisture, solvent resistance, structural strength, rigidity, and transparency.
There are several disadvantages in regards to this approach to substitute flat panel displays for digital posters. Glass is a brittle, thin and fragile material, making it unsuitable for environments where shock and vibrations are hazards, and unsuited for roll-to-roll volume manufacturing. Glass is dense and heavy,
adding to the weight of larger displays. Liquid crystal material must be handled as a liquid, requiring spacers and seals, and vacuum injection techniques. All of these add to the cost and complexity of the manufacturing process.
There is, therefore, a need to develop a replacement for the glass substrates in the manufacture of displays, and more generally, in the manufacture of displays in planar and non-planar formats. There is also a need to have a method and material that would allow electronics to be built into the material. There is a further need that a process be developed to make a suitable replacement for the glass substrate. The development of flexible and robust plastic digital video posters would lead to enhancements in both the variety and usage of poster products. In particular, flexibility opens up to an entirely new market where conformability and wearability are leader concepts. Plastic substrates exhibit, as main advantages in comparison with glass, a reduction in weight and thickness of the display, and virtually eliminate the problem of display breakage during both fabrication and use. Furthermore, plastic substrates offer the possibility of significant reductions in cost due to their compatibility with roll- to-roll (R2R) processing and printing technology.
Another type of electroluminescent device is created from powdered phosphors. These are semiconductor materials like zinc sulphide (ZnS) doped with a phosphor like manganese ion (Mn2+). Compared with standard LEOs and OLEDs, it is substantially easier to fabricate a display based on semiconductor doped phosphors. Traditionally, thin film technology has been used to make electroluminescent displays, and thick film technology has been used to make electroluminescent lamps, in particular backlights for liquid crystal displays (LCDs). An example of a thin film device is described in US Patent 5,463,279. Early computer screens manufactured by Sharp and by Planar Systems, used semiconductor materials doped with a phosphor to make images. These kinds of displays are manufactured in ways similar to OLEDs and LCD panels, particularly in their use and application of thin film transistor technology in the addressing architecture. In the industry, they are known as AMEL (Active Matrix Electroluminescent) and TFEL (Thin Film Electroluminescent) displays because they require complicated transistor matrices for their operation. Moreover, such
displays are manufactured on glass substrates. Accordingly, these kinds of displays are not conformal and are complex and expensive to manufacture.
There exists another category of Thick Dielectric Electroluminescence (TDEL) that uses powdered phosphors and that can be made into a 'paper thin', flexible, durable, energy efficient lighting sources. In the TDEL configuration, a bipolar pulse voltage is applied to a capacitively driven device containing the phosphor. Under continual 60-240 Hz AC operation, the high capacitance dielectric layer(s) causes current-limited electrical breakdown of a 0.5 to 30 micron thick phosphor layer. Electrical breakdown of the phosphor layer results in light emission via hot-electron impact excitation of luminescent atoms such as rare earth or transition metals. Sufficient hot carrier generation requires the use of a wide-band-gap semiconductor (ZnS, GaN) host material for the luminescent atoms. A typical thick film phosphor electroluminescent device comprises a layer of electroluminescent material in a dielectric matrix, sandwiched between two planar conducting electrodes. The electroluminescent material comprises phosphor particles, typically a zinc sulphide (ZnS) powder doped with manganese ( n), microencapsulated in a dielectric material. Typically, silver- or graphite-loaded screen-printable inks, and indium tin oxide (ITO), a transparent conductive material, respectively are used to form the electrodes on a substrate such as a polyester film. When an AC voltage is applied between the electrodes, the electroluminescent material emits light. An example of a thick film device is described in US Patent 5,686,792. Furthermore, in contrast to TFEL dielectrics deposited by atomic layer epitaxy, such as AI203:Ti02, TDEL devices allow for low cost and high-yield screen printing of a thick film dielectric layer.
To date, TDEL on plastic film has been used for Point of Sale shelf talkers, exhibition panels and small Bill Boards, none of which are addressable or programmable. It is claimed that some TDEL structures can be made to be addressable. For example, J. Heikenfeld and A.J. Steckl teach in an article published in Proc. SID Vehicle Displays 2001, Detroit Ml, October 2001 , that an addressable TDEL device can be made on glass.
Although the TDEL process described by Heikenfeld and Steckl to make an addressable display is attractive, it suffers from the shortcoming that the
fabrication process requires high temperature processing on glass, meaning that plastic substrates cannot be used and that therefore the product of this TDEL technology described by Heikenfeld and Steckl is not conformal and not scalable to large area formats.
In other applications, TDEL has been deployed on plastic film such as polyvinyl chloride), though only at temperatures that do not damage the plastic. This approach has the disadvantage that phosphors with more attractive properties like greater brightness, more selection of color or longer lifetime, cannot be used in conjunction with the plastic. Despite these restrictions, the TDEL architecture has been deposited over given areas of a film and subsequently energized to make the entire area emissive. TDEL in this format has been used to create distinct large footprint images so that different areas of artwork can be made emissive at different times, thus giving the appearance of addressability on a poster. Such posters cannot be updated in real time, nor can moving images be displayed except as pre-formed segments like those used to define alphanumeric displays. Examples of such displays are discussed in Murasko US Patent 6,203,391, issued March 20, 2001 , entitled "Electroluminescent Sign"; Murasko U.S. Pat. No. 6,811 ,895, issued Nov. 2, 2004, entitled "Illuminated Display System and Process"; and Barnardo et al U.S. Pat. No. 6,777,884, issued Aug. 17, 2004, entitled "Electroluminescent Devices". US Patent Application 2007/0040489, issued February 22, 2007, entitled "Static and Addressable Emissive Displays", claims methods for making addressable electroluminescent displays on a treated paper substrate using known printing technologies. This approach requires special treatment of the paper in order to smooth it and to make it withstand subsequent processing steps including the deposition of conducting inks, phosphor slurries, re-moisturizing events, heating, cooling and solvents.
Yet another class of display that can be made in a flexible format that is addressable and that may be suitable for some type of poster is one that uses the electrophoretic response. Electrophoretic displays are also called electronic paper, or E-paper. This display technology is designed to mimic the appearance of black ink on paper. E-paper reflects like just like conventional printed paper in
order that the image can be seen. An electrophoretic display is an information display that forms visible images derived from charged pigment particles dispersed in a fluid by rearranging the particles using an applied electric field (electrophoresis). Examples of commercial electrophoretic displays include the high-resolution active matrix displays used in the Amazon Kindle, Sony Librie, Sony Reader, and iRex iLiad e-readers. These displays are constructed from an electrophoretic imaging film manufactured by E Ink Corporation. One of the advantages of the electrophoretic display is that it can be manufactured on plastic, offering the possibility of conformability for use in billboards. Nevertheless, e-paper is generally, but not necessarily, restricted to black and white images and requires ambient light to be made visible because it is required to operate in a reflective mode. In some respects, an e-paper image is similar to an image printed on conventional paper. This is because the light reflected from the electronic ink emerges from a very thin layer adjacent to the viewing surface. US patent 6,252,624 issued on June 26, 2001, describes an electrophoretic display that can be created using multicolor printing operations similar to those used in screen printing.
Yet another kind of display is the electrochromic display, such as one made by NanoChromics Displays or Acreo. Electrochromism results from a colour change in a material (usually a molecule) that is caused to undergo reversible oxidation and reduction. In this manner, one can produce an image that looks like ink on paper. Such displays, which can be manufactured on paper, require substantially less power than do LCD panels or LED or OLED displays. US patent 7,336,410, February 26, 2008, describes a method of making a tiled (pixel) array for addressing a high resolution electrochromic display. Electrochromic displays, like electrophoretic displays, have the disadvantage that they require a liquid medium to effect image formation and operate only in a reflective mode.
Temperature variations affect dimensional stability, which is required to achieve precision registration of different layers used to make a display device. Moreover, during the manufacturing process, plastic may undergo temperature cycling. For digital video poster manufacturing, control of dimensional
reproducibility as the film is cycled in temperature is required. A film should not shrink when it is heated and cooled so that accurate alignment of features of the substrates after each thermal cycling event is not compromised. In addition, expansion of the film during temperature cycling may lead to dimensional changes large enough to fracture, crack or deform circuitry or other features deposited on the plastic film surface. For this reason techniques should be developed to create dimensional stability in order to reproducibility deposit complex electronic circuits on plastics. Some procedures for providing dimensional stability are discussed in international application No. PCT/CA2005/001397, entitled "Smart Composite Materials for Plastic Substrate", which is attached by way of Appendix 1. Instead of heat stabilization of a single film, laminating or otherwise attaching two or more films together in such a way that their combined coefficients of expansion compensate one another may achieve the same effect. In this manner, a film of zero, or near-zero, expansion coefficient may be obtained. It is then possible to fabricate plastic composites comprising substrates selected from the broad class of polymers with zero or near zero coefficient of thermal expansion. In this manner, the desired reproducibility in dimensional stability may be achieved. It is the ability, therefore, to limit and to predict dimensional changes and confer dimensional reproducibility with temperature that can be exploited in a manufacturing process of a digital video poster.
SUMMARY
The present disclosure relates to a substantially plastic digital video poster having a plurality of superposed layers of different compositions and characteristics that combine to form a pixilated addressable flexible display with an embedded functionality. The present disclosure also relates to the method of manufacture of this device.
It is an object of this disclosure to create a digital poster that is shapeable and/or conformal. The digital video poster which is the object of this disclosure
allows addressable and programmable information and images to be displayed on flat surfaces and on any kind of shaped surface. The digital video poster can also be molded in order to be shaped. Therefore, it is an object of this disclosure to provide a shapeable, flexible, moldable digital video poster that can be adapted to any kind of planar or shaped surface.
It is an object of this disclosure to make a digital video poster that can be scaled to an arbitrary size.
It is an object of the present disclosure to make a digital video poster that is protected by one or more layers of plastic film that make the poster weather resistance. It is also an object of this disclosure to use weather resistant plastic film laminates in the manufacture of a digital video poster.
It is an object of this disclosure to use analog printing, digital printing and hybrid analog and digital printing to make a flexible digital poster.
It is an object of this disclosure to create a digital poster that is self emitting (self-illuminating) and that requires neither back illumination nor an external or other light source in order to be viewed in a reflective mode. Therefore it is also an object of this disclosure to use semiconductor electroluminescent phosphors to provide for self illumination in a digital poster.
It is an object of this disclosure to make a digital video poster wherein the ability to address, program and create video images is through the selective activation of electroluminescent phosphors that comprise pixels, or pixels and sub-pixels.
It is an object of this disclosure to use electroluminescent phosphors that are not organic and that do not require expensive or complex means to protect them from ambient environment in order to operate.
It is an object of this disclosure to create an addressable digital poster based on electroluminescent phosphors and smart composite materials, the latter as disclosed in international application No. PCT/CA2005/001397, entitled "Smart Composite Materials for Plastic Substrate", and incorporate herein by reference. The disclosure uses elements and components that are readily
available, but it incorporates these components into a unique architecture, that has never before existed for electroluminescent display.
An object of the disclosure is the creation of a thick film electroluminescent poster in which a plurality of independent electrodes are provided on at least one side of a layer of shaped or unshaped electroluminescent material. A voltage may be applied selectively to each of these independent electrodes to illuminate a respective region, also called a pixel, of the poster. A thick film electroluminescent display is created by selecting the configuration of the independent electrodes to represent information, for example in the form of an image. Thus the present disclosure seeks to create an addressable electroluminescent poster, i.e. an electroluminescent poster comprising a plurality of pixels wherein each pixel area may be separately and selectively illuminated.
It is an object of this disclosure to make a digital video on a plastic film or a composite multilayer plastic film. There are a number of issues to be dealt with in order to use plastic substrates for the purpose of making a digital video poster. Because plastics are much more temperature sensitive than glass, lower temperature deposition techniques to deposit or process conducting layers, dielectric layers or electroluminescent and alignment layers should be used. Thermal and dimensional stability of the plastic film are therefore controlled in order for a film to withstand processing temperatures above 100 °C that may be encountered in EL pixel manufacturing, including the manufacture of indium tin oxide, barrier coatings and electronic circuit elements such as conductors and transistors. Among the TFEL and TDEL technologies, high quality displays are achieved by creating Active Matrix TFT arrays and high temperature deposition and annealing of the EL phosphors on glass. In accordance with the present disclosure, plastic substrates are an alternative to glass, but standard processing techniques for both amorphous silicon (a-Si) and poly-silicon (poly-Si) TFTs on glass require temperatures higher than those compatible with commonly available plastics (-350°C for conventional a-Si TFTs and ~450°C for poly-Si TFTs). Organic TFT would be a suitable technology for plastic substrates. Similarly, the creation of arrays of certain kinds of phosphors for TDEL on glass
has been described in for example, Wu et al., U.S. pat. 6,771 ,019 B, Aug. 3, 2004. However, in an embodiment, the process disclosed herein uses temperatures between 800-1000 °C and isostatic pressures between 70,000- 350,000 kPa (10,000-50,000 psi). This method is therefore not suitable for making phosphor pixels on plastic film.
In this disclosure, electrodes and emissive material comprising a plurality of layers are printed or coated on the glass substrate. In this manner, a plurality of electrode conductors can be configured in space to define a pixel.
In accordance with an aspect of the disclosure, there is provided an emissive composite comprising: a first panel assembly comprising: a first plurality of conductors; a second panel assembly superposed to the first panel assembly and comprising: a second optically transmissive plurality of conductors; and an emissive layer interposed between the first and second plurality of conductors
In an embodiment, the first and second plurality of conductors are positioned generally perpendicular to one another. In an embodiment, the first and second plurality of conductors are provided in respective sets of stripes. In an embodiment, the first plurality of conductors are spaced apart from one another and disposed substantially parallel to one another. In an embodiment, the second plurality of conductors are spaced apart from one another and disposed substantially parallel to one another. In an embodiment, a region substantially between a first selected conductor of the first plurality of conductors and a second selected conductor of the second plurality of conductors defines a picture element. In an embodiment, the picture element is selected from the group consisting of a pixel and subpixel. In an embodiment, the picture element is selectively addressable by selecting the first selected conductor and the second selected conductor of the first and second plurality of conductors respectively. In an embodiment, the selection comprises the application of a voltage thereby providing for the addressed picture element to emit light.
In an embodiment, a voltage is applied across the first and second plurality of conductors thereby creating an electrical field therebetween providing energy to the emissive layer.
In an embodiment, the first panel assembly comprises a first substrate, the first plurality of conductors being coupled to the first substrate. In an embodiment, the second panel assembly comprises a second substrate, the second plurality of conductors being coupled to the second substrate.
In an embodiment, the first substrate is a bottom substrate. In an embodiment, the first substrate is a top substrate. In an embodiment, the second substrate is a top substrate. In an embodiment, the second substrate is a bottom substrate.
In an embodiment, the composite further comprising a dielectric layer coupled to the first plurality of conductors. In an embodiment, the emissive layer is coupled to the dielectric layer.
In an embodiment, the composite further comprising a dielectric planarizing adhesive layer coupled to both the first plurality of conductors and the dielectric layer.
In an embodiment, the composite further comprising a sealing optically transmissive dielectric layer coupled to the emissive layer. In an embodiment, the second plurality of conductors is coupled to the transmissive dielectric layer. In an embodiment, the transmissive dielectric layer is a vinyl compound. In an embodiment, the transmissive dielectric layer is comprised of a lacquer based compound.
In an embodiment, a color layer is coupled to the second substrate. In an embodiment, the color layer is in contact with a mask layer. In an embodiment, the mask layer comprises a black-laquer based compound.
In an embodiment, a second sealing layer is in contact with the second plurality of conductors. In an embodiment, a color layer is coupled to the second sealing layer. In an embodiment, the color layer comprises a material selected from the group consisting of a colorant and color conversion material. In an embodiment, the color layer comprises a plurality of picture elements. In an embodiment, the picture elements are selected from the group consisting of pixels and subpixels. In an embodiment, the pixels are selected from the group consisting of red pixels, green pixels and blue pixels. In an embodiment, the
subpixels are selected from the group consisting of red subpixels, green subpixels and blue subpixels.
In an embodiment, a first supplementary conductive layer is coupled to the dielectric layer.
In an embodiment, the second plurality of conductors is coupled to a second supplementary plurality of conductors, the second supplementary plurality having an impedance lower than the impedance of the second plurality of conductors.
In an embodiment, the composite further comprises an adhesive layer between the first and second panel assemblies.
In an embodiment, at least one layer of the composite is formed by coating. In an embodiment, each layer of the composite is formed by coating. In an embodiment, at least one layer of the composite is formed by printing. In an embodiment, each layer of the composite is formed by printing.
In an embodiment, the first substrate has a thickness between 25 and 500 micrometers. In an embodiment, the second substrate has a thickness between 25 and 500 micrometers.
In an embodiment, first plurality of conductors is formed from metal deposited on a substrate. In an embodiment, the metal is selected from the group consisting of aluminum and copper. In an embodiment, the first plurality of conductors comprises metal electrodes. In an embodiment, the metal electrodes are formed by printing a conductive ink on a substrate. In an embodiment, the metal electrodes are formed by printing a conductive polymer on a substrate.
In an embodiment, the emissive layer comprises a phosphor.
In an embodiment, the second plurality of conductors are selected from the group consisting of: indium tin oxide, graphene, and polyethylene- dioxithiophene.
In an embodiment, an electromagnetic shield layer is coupled to the first substrate. In an embodiment, a protective layer is coupled to the electromagnetic shield layer. In an embodiment, an electromagnetic shield layer is coupled to the second substrate. In an embodiment, a protective layer is coupled to the electromagnetic shield layer.
In an embodiment, the composite is substantially plastic.
In accordance with an aspect of the disclosure, there is provided an emissive composite comprising: a first substrate; a first plurality of conductors coupled to the substrate; a dielectric layer coupled to the first plurality of conductors; an emissive layer coupled to the dielectric layer; a sealing optically transmissive dielectric layer coupled to the emissive layer; a second optically transmissive plurality of conductors coupled to the dielectric transmissive layer; a second substrate coupled to the second plurality of conductors; and a protective layer coupled to the second plurality of conductors.
In accordance with an aspect of the disclosure, there is provided an emissive composite comprising: at least one color layer; an optically transmissive substrate coupled to the color layer; a first, plurality of transmissive conductors coupled to the optically transmissive substrate; an optically transmissive dielectric layer; an emissive layer coupled to the optically transmissive dielectric layer; a dielectric coupled to the emissive layer; a second plurality of conductors coupled to the dielectric layer; a second bottom substrate layer.
In accordance with an aspect of the disclosure, there is provided an emissive composite comprising: an optically transmissive layer; a first, plurality of transmissive conductors coupled to the optically transmissive layer; an optically transmissive dielectric layer; at least one emissive color layer; a dielectric coupled to the emissive layer; a second plurality of conductors coupled to the dielectric layer; a second bottom substrate layer.
In accordance with an aspect of the disclosure, there is provided an emissive composite comprising: an optically transmissive layer; a first, plurality of transmissive conductors coupled to the optically transmissive layer; an optically transmissive dielectric layer; at least one emissive color layer; a dielectric coupled to the emissive layer; a plurality of transistors coupled to the dielectric layer; and a second bottom substrate layer.
In accordance with an aspect of the disclosure, there is provided a method of making the emissive composite comprising: printing an organic solvent soluble mask of the pattern of conducting electrodes on top of a layer of metal in
contact with the first substrate; etching the unmasked metal film with acid and removing the printed mask with organic solvent.
In an embodiment, the emissive composite comprises a first substrate with a first plurality of conductors coupled thereto. A dielectric layer is coupled to the first plurality of conductors and to an emissive layer. A second optically transmissive plurality of conductors also coupled to a second substrate and an emissive layer is interposed between the first and second plurality of conductors.
The foregoing and other objects, advantages, and features of the present disclosure will become more apparent upon reading of the following non- restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of generalized build sequence of an exemplary embodiment of a thick dielectric EL (TDEL) laminate of the present disclosure showing a configuration of layers.
FIG. 2 is a schematic cross-sectional view of an exemplary embodiment
100 of a thick dielectric EL laminate of the present disclosure with color by white phosphors and red, green and blue filters.
FIG. 3 is a schematic top view of an exemplary embodiment 100 of a thick dielectric EL laminate showing how the bottom row select conductor and top column select transparent conductors intersect and overlap to form pixels.
FIG. 4 is a schematic top view of an exemplary embodiment 100 of a thick dielectric EL laminate showing how the bottom row select conductor and top column select transparent conductors intersect and overlap to form sub-pixels and grouping sub-pixels to form pixels.
FIG. 5 is a schematic cross-sectional view of an exemplary embodiment 00 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue filters.
FIG. 6 is a schematic cross-sectional view of an exemplary embodiment 100 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue emissive phosphors.
FIG. 7 is a schematic cross-sectional view of an exemplary embodiment 00 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue filters controlled with thin film transistors.
FIG. 8 is a schematic cross-sectional view of an exemplary embodiment 100 of a pixelated thick dielectric EL laminate of the present disclosure with color by white red, green and blue emissive phosphors controlled with thin film transistors.
DESCRIPTION OF EMBODIMENTS The thick dielectric EL digital poster will be described in reference to
FIGS. 1, 2, 3, 4, 5, 6, 7 and 8.
FIG. 1 shows one generalized build sequence for the digital video poster. The bottom substrate 120 is provided with a plurality of electrodes called the first conductive layer 130 on one surface. On the opposite surface, the bottom substrate 120 is provided with a bottom electromagnetic shield layer 115. A bottom protective layer 110 is placed over the bottom EM shield layer 115. This forms the bottom panel assembly 101.
The top substrate 165 is provided with a plurality of electrodes called the second conductive layer 160 that are transparent to visible light (transmissive electrodes). The top substrate 165 is also transparent to visible light. The second dielectric layer 110, also transparent to visible light, serves to isolate the electroluminescent layer 150 from the conductor electrodes 160. The first dielectric layer 140 is placed in physical contact with the electroluminescent layer 150. The supplementary first conductive layer 135 is placed in physical contact with the first dielectric layer 140. This supplementary first conductive layer 135 is formed in a matching pattern to the first conductive layer 130. This forms the top panel assembly 102.
The top panel assembly 102 and bottom panel assembly 101 are joined by aligning the conductor patterns of the supplementary first conductive layer 135 to that of the first conductive layer 130 and bonding the assemblies with adhesive layer 132. The adhesive and bonding process allows or creates a conductive path between matched and aligned electrodes of the supplementary first conductive layer 135 and the first conductive layer 130. Color layer 170 and mask layer 180 can be attached. A top protective layer 190 and top electromagnetic shield layer are also attached.
In an exemplary embodiment of the first TDEL laminate apparatus 100 of FIG. 2 a voltage is applied across a first conductive electrode (conductor) 130, including electrodes 130a, 130b, 130c and so on, and a second conductive transmissive electrode 160 to create an electrical field between the second conductive transmissive electrode 160 and first conductive electrodes 130a, 130b, 130c and so on. The first conductive electrodes 130a, 130b, 130c and so on may have additional supplementary first conductive layer electrodes 135a, 135b, 135c and so on, matched in pattern and aligned to first conductive layer electrodes 130a, 130b, 130c and so on, incorporated by printing, coating or otherwise provided in order to improve the overall conductivity of the first conductive electrodes. Optionally and similarly, the second conductive transmissive electrode 160 may also incorporate a supplementary second conductive electrode by printing, coating or otherwise provided in order to improve the overall conductivity of the second conductive transmissive electrode 160.
The electric field between the conductive layer 130 (which may include layer 135) and the conductive layer 160 provides energy to the emissive or electroluminescent layer 150 by creating a capacitance, for example. The electric field is provided in the form of alternating current in the exemplary embodiments. The current is supplied in a frequency range of about 200 Hz to 2.5 kHz, and more preferably in the range of 400 Hz. The emissive material usually exhibits a voltage threshold (Vthr) for emission, so the typically the applied voltage is greater than 20 Volts, though it may be as high as 100 Volts or as high as 120 Volts or more. The current is in the range of pico-Ampere, though it may be higher,
resulting overall in lower power consumption than an LCD, LED or plasma display. The applied voltage required to reach threshold for emission depends on the type of EL material and the conditions of manufacture of the EL layer.
The EL Digital Video Poster has pixels. These are defined in FIGS 2 and 3 by intersecting sets of stripes of conductors 130 and 160 (and possibly including 135). These are created at right angles to one another and at opposite sides of the EL layer 150 and the dielectric layers 110 and 140. In FIG. 3, the intersection of the stripes of electrodes defines the pixel at positions 200. The sets of conductive stripes are conventionally called "rows" 160 and "columns" 130. Pixels independently illuminate by means of an addressing scheme called passive matrix addressing. In this scheme, rows are sequentially addressed or scanned electronically. At the same time a row is selected electronically, voltage pulses, each with a defined and independent peak voltage and pulse width, (the "modulation voltage") can be applied simultaneously to each of the columns intersecting the addressed row. In consequence, voltages are applied with independent control across the pixels along a given row. This permits one to adjust the instantaneous luminosity needed for each pixel. Pixels not on the addressed row do not illuminate.
In FIG 4, it can be seen that the pixels 200 in FIG 3 in combination with the color layer 170 and mask layer 180 in FIG 2 can be arranged in such a fashion as to produce color when viewed at a distance. Without stating a clear preference at this point and without narrowing the scope of the disclosure, a color pixel 310 may be formed by grouping three pixels in a row in an exemplary embodiment. The color layer 170 is a matrix of cells matched in pattern and aligned with the pixels 200. Within each grouping of 3 pixels, now each called sub-pixels, there is a corresponding cell of red 310a, green 310b, and blue 310c in the color layer 170. By varying the instantaneous luminosity of each of the 3 pixels, varying intensities of red, green and blue are generated. When viewed from a distance, this color pixel's light is spatially mixed and is perceived by the viewer as a distinct color pixel 300.
The purpose of the mask layer 180 may be to block out undesired pixels or sub-pixels. It is also used to isolate emission from different sub-pixels to
prevent cross-contamination of the light emitted from adjacent or nearby pixels or sub-pixels that might otherwise enter the wrong area of the color layer 170 and diminish color image quality and contrast. The mask is applied in a pattern which provides a sharp definition around each sub-pixel and can therefore provide for higher resolution, typically higher than that provided by red-green-blue (RGB) or cyan-magenta-yellow (CMY) color display.
The frame is a single complete scan of all the rows of the passive matrix. For moving images, the frame repetition rate, or frame rate, determines the visual quality of the moving image. For video frame rates, the frame must be updated about 30 to 60 times per second or more for the eye not to detect a flickering image.
Without stating a clear preference at this point, we examine the fabrication process for the TDEL architecture shown in FIGS. 1 and 2. Important features of an addressable digital poster can be described as follows in reference to these figures.
In an exemplary embodiment, the first TDEL laminate 00 is built from two major assemblies, the bottom panel assembly 101 and top panel assembly 102, and a number of other layers to suit a particular function of the digital poster. Other architectures may be conceived in which the order of the layers is changed to adapt the device to different performance requirements, such as enhanced luminosity or improved environmental performance, or improved dielectric or capacitance properties. Preferably for the bottom panel assembly 101, the bottom substrate 120 can be selected from any of the following according to the intended use of the poster or according to the method of manufacture of the EL pixels. For example, without narrowing the focus of the present disclosure, the bottom substrate 120 can be made from polymers which are derived from the categories of polymer films that are semicrystalline, semicrystalline amorphous, amorphous thermoplastic, but solvent cast. The group of thermoplastic semicrystalline polymers includes polyethylene terephthalate (PET) e.g. DuPont Melinex, and
polyethylene naphthalate (PEN). The next category are polymers that are thermoplastic, but non-crystalline, and these range from polycarbonate (PC) e.g. DuPont PURE-ACE and GE Lexan with a glass transition (Tg) of -150 °C, to polyethersulfone (PES) e.g. Sumitomo Bakelite's Sumilite with a Tg of -220 °C. Although thermoplastic, these polymers may also be solvent cast to give high optical clarity. The third category includes high Tg materials that cannot be melt processed. These include aromatic fluorine containing polyarylates (PAR) e.g. Ferrania's Arylite polycyclic olefin (PCO) e.g. Promerus's Appear and polyimkJe (PI) e.g. DuPont's Kapton. In the case of a polymer (plastic) foil or a laminate of polymer films, these are heated treated so that they are dimensionally stable. Moreover, the surface of the polymer film can be treated by methods well known to those skilled in the art to make the surface of the substrate printable. The substrate may also consist of plastic coated paper, natural and synthetic fabrics, wood and wood-based products, polymer composites including polymer nanocomposites, or a rigid substrate such as alumina ceramic, glass sheet or shaped glass, metals and metal alloys that have been suitably dielectrically insulated, or printed circuit board materials that are well known to those skilled in the art.
The first conductive layer 130 (the column or pixel select layer) is applied by coating or printing or laminating. In the first exemplary embodiment 100, an aluminum film can be deposited on bottom substrate 120 and then subsequently patterned into stripes using standard and well-known photo-lithography involving photo-resist, photo-masks and ultraviolet and thermal curing. Alternatively, copper or other metallic conducting lines can be deposited on the rear substrate by means of electroless plating. Alternatively, the rear electrode can be a metal film like aluminum or copper on plastic that can be patterned by digital or analog printing of an ink that resists an etching process (such as acid etching).
The bottom electromagnetic (EM) shield layer 115 is applied by coating or printing or laminating to the bottom substrate 120 on the surface opposite to that with the first conductive layer 130. The layer can be a metal film of aluminium, copper, silver, or gold. Alternatively, a conductive ink may be used such as a silver ink like CRSN 2442 available for example from Sun Chemical, or carbon
conducting ink like 7105 or 7102 or 8144 Carbon Conductor from DuPont, or a conductive polymer such as polyethyelenedioxythiophene (PEDOT) available as Orgacon from Agfa.
A bottom protective layer 110 is provided which may be attached to provide barriers to UV light, water, solvents and other materials that might damage the TDEL laminate 100. The bottom protective layer may also provide physical or mechanical protection from damage that may result from scratches or impacts. Preferably, for the top panel assembly 102, the top substrate 165 can be selected from any of the following according to the intended use of the poster or according to the method of manufacture of the EL pixels. For example, without narrowing the focus of the present disclosure, the top substrate 165 can be made from polymers which are derived from the categories of polymer films that are semicrystalline, semicrystalline amorphous, amorphous thermoplastic, but solvent cast. The group of thermoplastic semicrystalline polymers includes polyethylene terephthalate (PET) e.g. DuPont Melinex, and polyethylene naphthalate (PEN). The next category are polymers that are thermoplastic, but non-crystalline, and these range from polycarbonate (PC) e.g. DuPont PURE- ACE and GE Lexan with a glass transition (Tg) of -150 °C, to polyethersu!fone (PES) e.g. Sumitomo Bakelr e's Sumilite with a Tg of -220 °C. Although thermoplastic, these polymers may also be solvent cast to give high optical clarity. The third category includes high Tg materials that cannot be melt processed. These include aromatic fluorine containing polyarylates (PAR) e.g. Ferrania's Arylite polycyclic olefin (PCO) e.g. Promerus's Appear and polyimide (PI) e.g. DuPont's Kapton. In the case of a polymer (plastic) foil or a laminate of polymer films, these are heated treated so that they are dimensionaily stable. Moreover, the surface of the polymer film can be treated by methods well known to those skilled in the art to make the surface of the substrate printable. The substrate may also consist of polymer composites including polymer nanocomposites, or a rigid substrate such as glass sheet or shaped glass.
A transmissive second conductive layer 1$0 (the row select layer) is applied by coating or printing or laminating on top of the top substrate 165. Printing or coating methods like those described above for the first conductive layer 130 can be used. This second conductive layer is sufficiently transmissive for the selected wavelengths of application, such as for the visible portions of the electromagnetic spectrum. This second conductive layer is patterned as rows, but these rows are oriented in careful registration so that they are perpendicular to (at right angles to) the patterns of electrodes 130 deposited on substrate 120. In this manner, electrically transmissive wires (electrodes) are created. FIG. 3 shows a top view of the configuration of electrodes where only the electrodes are shown and the intervening dielectric or other layers have been removed for clarity of viewing. The overlap of conductive layers 130 and 160 yields the areas 200 which indicate the locations of the pixels. It can be seen that row select electrodes 160 and column or data electrodes 130 may be interchanged by those skilled in the art. The choice of material for the second conductive layer 160 differs depending on the application. In an exemplary embodiment of the apparatus 100, the second electrode may be indium tin oxide (ITO) deposited over the surface of the top substrate 165. This ITO transmissive conductor is patterned into stripes using standard photolithographic methods. It can also be patterned by depositing a resist using a digital printer, followed by acid etching with 10% sulfuric acid. The ITO can be deposited as an ink in the form of a gel by screen or jet printing or deposited as a film from the vapour phase. Alternatively, a conductive polymer such as PEDOT available as Orgacon from Agfa for example, may be used instead of ITO. In another embodiment, antimony tin oxide (ATO) is used to form the second transmissive conductive layer 160. It is known that ATO has a comparatively high impedance, ie, that its resistance can be on the order of 20 kQ. It is also known that ITO has a comparatively high resistivity, greater than 10 Ω/α, similarly for PEDOT. If pixels are to be switched on or off by activating particular row and column select electrodes to make moving images, the time constant for electrical transmission across the layers between electrodes 130 and 160 fabricated from high resistivity materials can be comparatively high. There are several methods that can be used to overcome
this high impedance. One method is to deposit by printing a line of heat curable silver ink (for example, Gwent Group silver ink C2050712D58) to make lines on each line of the more resistive conductor. Alternatively, the silver ink lines can be deposited first and then coated with lines 160. In this way, the impedance of the more resistive transparent material is lowered, and hence the time constant for switching a pixel is reduced. If the silver ink line is made to be very fine, it cannot be seen by the naked eye and very little light is lost due to the opacity of the silver ink. As are currently known, or may become known, in the art, other transmissive conductors may be used to form the layer 160. In the first embodiment of the TDEL laminate 100, the second transparent conducting layer of ITO 160 is patterned by acid etching with 10 percent H2S0 through a printed acid-proof resist.
Next the second optically transmissive dielectric layer 110 is printed or coated over the plurality of first electrodes 160. In the first exemplary embodiment 100, the dielectric layer 110 may be derived without limitation from materials like SU8 (available from icrochem), DuPont Quick Prime, 3M Krylon acrylic spray, or vinyl compounds or epoxy compounds that are transparent to visible light. One or more coats of the 3M Krylon acrylic spray dielectric layer 110 are applied over the electrodes 160 to a thickness between 0.2 and 4.0 microns, more preferably between 1 and 2 microns, and most preferably to a thickness of 1.5 microns.
Next the electroluminescent layer 150 is applied by means of printing or coating processes like those described above. In the first exemplary apparatus embodiment, the phosphor is applied as a single layer. An exemplary phosphor is micro-encapsulated zinc sulfide (ZnS-doped) Luxprint material 8152 from DuPont, obtainable in the form of a paste for thick film polymer electroluminescent coating. In the first exemplary embodiment, high brightness white phosphor 8152 is printed by screen coating to a thickness preferably between 20-45 microns. Other thicknesses are determined empirically when different phosphors are used. Empirical determination requires, for example, that the phosphor is coated to sufficient thickness to prevent dielectric breakdown, but with sufficient thinness to provide comparatively high capacitance. Usually, the
phosphor is thermally cured at a temperature between 100 and 150 °C, and most preferably, between 120 and 140 °C. In the first embodiment of the TDEL laminate 100, the emissive layer is printed over the second dielectric layer 110 in a single pass of the screen printer using a white polyester screen of 156 threads per inch. The emissive layer 150 together with the dielectric layer 110 and the bottom electrodes and plastic substrate 120 are heated to 130 °C for 15 minutes in an oven. Next the first dielectric layer 140 is printed or coated over the electroluminescent layer 150. In the first exemplary embodiment 100, the dielectric layer may be derived without limitation from materials like DuPont 7153 or 8153 High K dielectric insulator. Insulators may be derived from barium titanate (BaTi03) or high K polymers that are UV or thermally curable. One or more coats of the barium titanate dielectric layer 140 are applied over the electroluminescent layer 150 to a thickness between 5 and 30 microns, more preferably between 6 and 12 microns, and most preferably to a thickness of 12 microns. In the first embodiment of the TDEL laminate 100, the dielectric layer 140 is printed over the electroluminescent layer 150 in two passes of the screen printer using a white polyester screen of 156 threads per inch. The dielectric layer 140 is heated after each pass of screen printing to 130 °C for 10 minutes in an oven.
A plurality of bottom electrodes (supplementary first conductive layer)
135, in a matching pattern and aligned with the first conductive layer electrodes 130, is formed on the first dielectric layer 140. Without narrowing the scope of the disclosure, the bottom electrode is printed digitally by means of Ink jet printing, or is printed using an analog printing technique such as screen or flexographic printing. In the present embodiment, the bottom electrodes are patterned as parallel stripes by means of screen printing. An image (stencil) of the row electrodes created by computer aided design (CAD) drawing on acetate film is transferred to a CDF Direct-Films film resist from Ulano Corporation on 195 or 156 thread per inch polyester screen. The method of transferring the image of the CAD drawing is well known to those practiced in the art of screen printing. The rear electrodes can be made from a conductive metal ink such as a silver ink like C SN 2442 available for example from Sun Chemical, or carbon conducting
ink like 7105 or 7102 or 8144 Carbon Conductor (DuPont). In the present first embodiment of the TDEL laminate 100, silver ink 5064 from DuPont is screen printed through the stencil onto the first dielectric layer 140 using a manual screen printer such as is available from Aremco Products, Inc. The transferred pattern together with the plastic film is heated to 130 °C for 10 minutes to cure the bottom row electrode pattern. Other conductive inks may be utilized to form the first conductive layer 135. Exemplary conductive compounds include copper, aluminum, and gold. The top panel assembly 102 and bottom panel assembly 101 are joined by aligning the conductor patterns of the supplementary first conductive layer 135 to that of the first conductive layer 130 and bonding the assemblies with adhesive layer 132. The adhesive and bonding process allows or creates a conductive path between matched and aligned electrodes of the supplementary first conductive layer 135 and the first conductive layer 130. In the present first embodiment of the TDEL laminate 100, Krylon spray adhesive adhesive is applied to the first conductive layer 130 or the supplementary first conductive layer 135. The top panel assembly 102 and bottom panel assembly 101 are aligned and laminated together via compression rollers, which are heated to 100 °C to thermally cure the adhesive. The compression rollers force a displacement of adhesive between the aligned electrodes of layers 130 and 135 to ensure electrical contact between the electrodes. Alternatively, a fiat bed lamination device with adjustable compression and heating may be used. Other alternatives may include adhesives with metal particles which may be aligned by a magnetic field during curing in the direction of conductivity, such as ZTACH anisotropic conductive adhesives available from SunRay Scientific. Alternatively, anisotropic conductive film adhesives may be used such as the ACF series of film adhesives from the 3M Company. The color layer 170 is applied to the top substrate 165. Red, blue and green sub-pixels are obtained by building a patterned filter 170 in alignment with the sub-pixels 310 formed by the intersections of the columns 130 and rows 160
of FIG 4. In this exemplary embodiment of the TDEL laminate 100, a color-by- white technique is used, as first described by Tanaka et al., (SID 88 Digest, p 293, 1988, also U.S. Pat. No. 4,727,003, issued Feb. 23, 1988 to Ohseto et al.). In this method, the emissive layer 150 comprises phosphors like ZnS:Mn and SrS.Ce which when combined superimpose their respective emissions to produce white light over the entire range of the visible electromagnetic spectrum. The red, blue and green filters transmit a narrow range of wavelengths corresponding to the colors of each sub-pixel. Alternatively, fluorescent dyes can be used to make the color filter.
Next, another embodiment of the device 100 is a variation to deposit a black mask layer 180. This layer overlays the color layer 170. The purpose of this layer may be to block out undesired pixels or sub-pixels, it is also used to isolate emission from different sub-pixels to prevent cross-contamination of the light emitted from adjacent or nearby pixels that might otherwise enter the wrong area of the RGB color layer and diminish color image quality and contrast. The mask is applied in a pattern which provides a sharp definition around each pixel and can therefore provide for higher resolution, typically higher than that provided by RGB or CMY color display.
The top electromagnetic (EM) shield layer 195 is applied by coating or printing or laminating to the mask layer 180. The layer can be a transparent conductive metal such as ITO, or a conductive polymer such as PEDOT available as Orgacon from Agfa. Alternatively, the top EM shield layer 195 may be applied by coating or printing or laminating to the top protective layer 190 and bonded to the mask layer 180 by laminating with an adhesive.
A top protective layer 190 is provided which may be attached to provide barriers to UV light, water, solvents and other materials that might damage the TDEL laminate 100. The top protective layer may also provide physical or mechanical protection from damage that may result from scratches or impacts. FIG. 5 shows another exemplary embodiment of the TDEL laminate 100.
In this embodiment, the emissive layer 150 is printed on top of the second dielectric layer 110 on top of the transmissive second conductive layer 160 and
substrate layer 165 (and optionally, layers 190, 195, 180 and 170) as a matrix of emissive phosphor pixels. Electroluminescent layer 150 is applied by means of printing or coating processes like those described above. In this exemplary embodiment, the phosphor is applied as a pixel matrix layer. Accordingly, white polyester screen of 156 threads per inch is first patterned into a matrix array of 100 x 100 pixels measuring 2 mm x 2 mm each with a spacing of 1 mm between pixels. The pixels are registered so that they coincide precisely with the position of the plurality of electrodes 130 and 135. Micro-encapsulated zinc sulfide (ZnS- doped) DuPont Luxprint high brightness white phosphor 8152 is screen printed by one pass of screen coating to a thickness preferably between 20-45 microns. The layer 150 is then baked for 15 minutes at 130 °C for 15 minutes in an oven. Next the dielectric layer 140 is printed or coated over the matrix of electroluminescent pixels 150. As shown in FIG. 5, the dielectric layer isolates each pixel of electroluminescent material from its neighbor. As before, the dielectric layer may be derived without limitation from materials like DuPont 7153 or 8153 High K dielectric insulator. Insulators may be derived from barium titanate (BaTi03) or high K polymers that are UV or thermally curable. One or more coats of the barium titanate dielectric layer 140 can be applied over the electroluminescent phosphor layer 150 to a thickness between 5 and 30 microns, more preferably between 6 and 12 microns, and most preferably to a thickness of 12 microns. In this embodiment of the TDEL laminate 100, the dielectric layer 140 is printed over the electroluminescent layer in one pass of the screen printer using a white polyester screen of 156 threads per inch. The dielectric layer 140 is heated after screen printing to 130 °C for 10 minutes in an oven. Next the first conductor plurality of electrodes is deposited in stripes of row electrodes 135 on the first dielectric layer 140. These electrodes are screen printed using a conductive silver ink such as Gwent C2050712D58 silver ink as previously discussed. FIG. 6 shows another exemplary embodiment of the TDEL laminate 100.
The top or transmissive second conductor electrodes 161, 162, and 163 are arranged so that they will touch particular regions of the electroluminescent
material sub-pixels 151, 152, and 153. Red, blue and green (RGB) emissive compounds 151, 152, and 153 are printed or coated onto the second electrode layer 161 , 162, 163 etc. using, without restriction, one or a combination of the printing or coating techniques described above, and in such a way as to preserve registration between each red or green or blue emissive pixel and its column or data select electrode. The RGB emissive layers are subsequently thermally cured.
In the next step, the column electrodes are separated by a dielectric layer that consists of rows and plane 140 that isolate the electrodes and the electroluminescent sub-pixels. The dielectric layer 140 can be derived from photo-curable inks like (1) SU8 from Microchem, Inc.; (2) from SunPoly, Inc., 305D UV curable dielectric ink; from DuPont, high K dielectric insulator 7153 and 8153. These inks can be screen printed as separate rows between the rows of sub-pixels. Typically, the dielectric rows are printed to a thickness of 20 microns.
The remaining steps in the construction of the second embodiment of the
TDEL laminate 100 follow the procedures described above for the embodiment of the TDEL device. Preferably, the sub-pixel threshold voltages are made equal and the relative luminosities of the sub-pixels are established so that they bear set or fixed ratios to one another at selected operating modulation voltages required to generate the desired luminosities for the red, green, and blue. Preferably, the established ratios remain substantially constant over the full range of the modulation voltage in order to achieve correct color balance. Most preferably, the correct color balance is achieved for established luminosity ratios for the red, green and blue sub-pixels of about 3:6:1 , or sufficiently close to this ratio. CIE color coordinates and luminosity for the blue can be achieved with cerium doped strontium sulfide (SrS:Ce). Manganese doped zinc sulfide (ZnS:Mn) in combination with cerium doped strontium sulfide (SrS:Ce) or magnesium doped zinc sulfide (Zn1-xMgxS:Mn) with an appropriate ratio of Zn to Mg can be used to create a green emission. When x lies between 0.1 and 0.3, magnesium doped zinc sulfide (Zn -x gxS:Mn) can be used to generate red emission. In a variation of an embodiment of the TDEL laminate 100 of FIG. 6, a color filter 170 with a mask layer 180 can be inserted and aligned with the RGB
phosphors to enhance luminosity and energy efficiency over the color-by-white design. In this way, self-consistent optimization of color coordinates and luminosity can be obtained for each pixel.
FIG. 7 shows another embodiment of the TDEL laminate 100. In this embodiment, thin film transistors 138a, 138b, 138c, and so on, are used to activate the emissive layer 150. A color Filter 170 with a mask layer 80 can be inserted and aligned with the sub-pixels to generate the color pixels. A TFT is fabricated at each intersection of the row select electrodes 130 and column or data electrodes 137, the intersection which determines the location of the sub- pixel. A dielectric layer 133 isolates the row select electrodes 130 from the data electrodes 137. The thin film transistors can be fabricated from amorphous silicon, polycrystalline silicon or 11- VI semiconductor materials like CdS or CdSe using photolithography and/or combinations of laser annealing methods. These transistors are deposited on the bottom substrate 120.
FIG. 8 shows another embodiment of the TDEL laminate 100. In this embodiment, thin film transistors 138a, 138b, 138c, and so on, are used to activate the emissive layers that are deposited as red, green and blue emissive compounds 151, 152, 153. A color filter 170 with a mask layer 180 can be inserted and aligned with the RGB phosphors to enhance luminosity and energy efficiency over the color-by-white design. In this way, self-consistent optimization of color coordinates and luminosity can be obtained for each pixel. A TFT is fabricated at each intersection of the row select electrodes 130 and column or data electrodes 137, the intersection which determines the location of the sub- pixel. One electrode of the TFT is in perfect register with the RGB sub-pixel. A dielectric layer 133 isolates the row select electrodes 130 from the data electrodes 137. The thin film transistors can be fabricated from amorphous silicon, polycrystalline silicon or ll-VI semiconductor materials like CdS or CdSe using photolithography and/or combinations of laser annealing methods. These transistors are deposited on the bottom substrate 120.
From the foregoing, it will be observed that numerous variations and modifications can be effected with departing from the scope of the disclosure. It is intended to cover by the appended claims all such variations and modifications as fall within the scope of the claims.
Claims
WHAT IS CLAIMED IS: 1. An emissive composite comprising:
a first panel assembly comprising:
a first plurality of conductors;
a second panel assembly superposed to the first panel assembly and comprising:
a second optically transmissive plurality of conductors; and an emissive layer interposed between the first and second plurality of conductors
2. An emissive composite according to claim 1, wherein the first and second plurality of conductors are positioned generally perpendicular to one another.
3. An emissive composite according to claim 2, wherein the first and second plurality of conductors are provided in respective sets of stripes.
4. An emissive composite according to any one of claims 1 to 3, wherein the first plurality of conductors are spaced apart from one another and disposed substantially parallel to one another.
5. An emissive composite according to claim 1 to 4, wherein the second plurality of conductors are spaced apart from one another and disposed substantially parallel to one another.
6. An emissive composite according to any one of claims 2 to 5, wherein a region substantially between a first selected conductor of the first plurality of conductors and a second selected conductor of the second plurality of conductors defines a picture element.
7. An emissive composite according to claim 6, wherein the picture element is selected from the group consisting of a pixel and subpixel.
8. An emissive composite according to any one of claims 6 or 7, wherein said picture element is selectively addressable by selecting the first selected conductor and the second selected conductor of the first and second plurality of conductors respectively.
9. An emissive composite according to claim 8, wherein selection comprises the application of a voltage thereby providing for the addressed picture element to emit light.
10. An emissive composite according to any one of claims 1 to 9, wherein a voltage is applied across the first and second plurality of conductors thereby creating an electrical field therebetween providing energy to the emissive layer.
11. An emissive composite according to any one of claims 1 to 10, wherein the first panel assembly comprises a first substrate, the first plurality of conductors being coupled to the first substrate.
12. An emissive composite according to any one of claims 1 to 11 , wherein the second panel assembly comprises a second substrate, the second plurality of conductors being coupled to the second substrate.
13. An emissive composite according to any one of claims 11 or 12, wherein the first substrate is a bottom substrate.
14. An emissive composite according to any one of claims 11 or 12, wherein the first substrate is a top substrate.
15. An emissive composite according to claim 12, wherein the second substrate is a top substrate.
16. An emissive composite according to claim 12, wherein the second substrate is a bottom substrate.
17. An emissive composite according to any one of claims 1 to 16, further comprising a dielectric layer coupled to the first plurality of conductors.
18. An emissive composite according to claim 17, wherein the emissive layer is coupled to the dielectric layer.
19. An emissive composite according to any one of claims 17 or 18, further comprising a dielectric planarizing adhesive layer coupled to both the first plurality of conductors and the dielectric layer.
20. An emissive composite according to any one of claims 1 to 19, further comprising a sealing optically transmissive dielectric layer coupled to the emissive layer.
21. An emissive composite according to claim 20, wherein the second plurality of conductors is coupled to the transmissive dielectric layer.
22. An emissive composite according to any one of claims 20 or 21 , wherein the transmissive dielectric layer is a vinyl compound.
23. An emissive composite according to any one of claims 20 or 21 , wherein the transmissive dielectric layer is comprised of a lacquer based compound.
24. An emissive composite according to any one of claims 12 to 23, further comprising a color layer coupled to the second substrate.
25. An emissive composite according to claim 24, wherein the color layer is in contact with a mask layer.
26. An emissive composite according to claim 25, wherein the mask layer comprises a black-laquer based compound.
27. An emissive composite according to any one of claims 20 to 26, further comprising a second sealing layer in contact with the second plurality of conductors.
28. An emissive composite according to claim 27, further comprising a color layer coupled to the second sealing layer.
29. An emissive composite according to claim 28, wherein the color layer comprises a material selected from the group consisting of a colorant and color conversion material.
30. An emissive composite according to any one of claims 28 or 29, wherein the color layer comprises a plurality of picture elements.
31. An emissive composite according to claim 30, wherein the picture elements are selected from the group consisting of pixels and subpixels.
32. An emissive composite according to claim 31 , wherein the pixels are selected from the group consisting of red pixels, green pixels and blue pixels.
33. An emissive composite according to any one of claims 31 or 32, wherein the subpixels are selected from the group consisting of red subpixels, green subpixels and blue subpixels.
34. An emissive composite according to any one of claims 17 to 34, further comprising a first supplementary conductive layer coupled to the dielectric layer.
35. An emissive composite according to any one of claims 1 to 34, wherein the second plurality of conductors is coupled to a second supplementary plurality of conductors, the second supplementary plurality having an impedance lower than the impedance of the second plurality of conductors.
36. An emissive composite according to any one of claims 1 to 35, further comprising an adhesive layer between the first and second panel assemblies.
37. An emissive composite according to any one of claims 1 to 36, wherein at least one layer thereof is formed by coating.
38. An emissive composite according to any one of claims 1 to 36, wherein each layer thereof is formed by coating.
39. An emissive composite according to any one of claims 1 to 36, wherein at least one layer thereof is formed by printing.
40. An emissive composite according to any one of claims 1 to 36, wherein each layer thereof is formed by printing.
41. An emissive composite according to any one of claims 11 to 40, wherein the first substrate has a thickness between 25 and 500 micrometers.
42. An emissive composite according to any one of claims 12 to 41 , wherein the second substrate has a thickness between 25 and 500 micrometers.
43. An emissive composite according to any on of claims 1 to 42, wherein the first plurality of conductors is formed from metal deposited on a substrate.
44. An emissive composite according to claim 43, wherein the metal is selected from the group consisting of aluminum and copper.
45. An emissive composite according to any one of claims 1 to 42, wherein the first plurality of conductors comprises metal electrodes.
46. An emissive composite according to claim 45, wherein the metal electrodes are formed by printing a conductive ink on a substrate.
47. An emissive composite according to claim 45, wherein the metal electrodes are formed by printing a conductive polymer on a substrate.
48. An emissive composite according to any one of claims 1 to 47, wherein the emissive layer comprises a phosphor.
49. An emissive composite according to any one of claims 1 to 48, wherein the second plurality of conductors are selected from the group consisting of: indium tin oxide, graphene, and polyethylene-dioxithiophene.
50. An emissive composite according to any one of claims 11 to 49, wherein an electromagnetic shield layer is coupled to the first substrate.
51. An emissive composite according to claim 50, wherein a protective layer is coupled to the electromagnetic shield layer.
52. An emissive composite according to any one of claims 12 to 51 , wherein an electromagnetic shield layer is coupled to the second substrate.
53. An emissive composite according to claim 53, wherein a protective layer is coupled to the electromagnetic shield layer.
54. An emissive composite according to any one of claims 1 to 53, further comprising plastic material.
55. An emissive composite comprising:
a first substrate;
a first plurality of conductors coupled to the substrate;
a dielectric layer coupled to the first plurality of conductors;
an emissive layer coupled to the dielectric layer;
a sealing optically transmissive dielectric layer coupled to the emissive layer;
a second optically transmissive plurality of conductors coupled to the dielectric transmissive layer;
a second substrate coupled to the second plurality of conductors; and a protective layer coupled to the second plurality of conductors.
56. An emissive composite according to claim 55, wherein the first and second plurality of conductors are positioned generally perpendicular to one another.
57. An emissive composite according to claim 56, wherein the first and second plurality of conductors are provided in respective sets of stripes.
58. An emissive composite according to any one of claims 55 to 57, wherein the first plurality of conductors are spaced apart from one another and disposed substantially parallel to one another.
59. An emissive composite according to claim 55 to 58, wherein the second plurality of conductors are spaced apart from one another and disposed substantially parallel to one another.
60. An emissive composite according to any one of claims 56 to 59, wherein a region substantially between a first selected conductor of the first plurality of conductors and a second selected conductor of the second plurality of conductors defines a picture element.
61. An emissive composite according to claim 60, wherein the picture element is selected from the group consisting of a pixel and subpixel.
62. An emissive composite according to any one of claims 60 or 61 , wherein said picture element is selectively addressable by selecting the first selected conductor and the second selected conductor of the first and second plurality of conductors respectively.
63. An emissive composite according to claim 62, wherein selection comprises the application of a voltage thereby providing for the addressed picture element to emit light.
64. An emissive composite according to any one of claims 55 to 63, wherein a voltage is applied across the first and second plurality of conductors thereby creating an electrical field therebetween providing energy to the emissive layer.
65. An emissive composite according to any one of claims 55 to 64, wherein the first substrate is a bottom substrate.
66. An emissive composite according to any one of claims 55 to 64, wherein the first substrate is a top substrate.
67. An emissive composite according to claim any one of claims 55 to 64, wherein the second substrate is a top substrate.
68. An emissive composite according to any one of claims 55 to 64, wherein the second substrate is a bottom substrate.
69. An emissive composite according to any one of claims 55 to 68, further comprising a dielectric planarizing adhesive layer coupled to both the first plurality of conductors and the dielectric layer.
70. An emissive composite according to any one of claims 55 to 69, wherein the transmissive dielectric layer is a vinyl compound.
71. An emissive composite according to any one of claims 55 to 69, wherein the transmissive dielectric layer is comprised of a lacquer based compound.
72. An emissive composite according to any one of claims 55 to 71, further comprising a color layer coupled to the second substrate.
73. An emissive composite according to claim 72, wherein the color layer is in contact with a mask layer.
74. An emissive composite according to claim 73, wherein the mask layer comprises a black-laquer based compound.
75. An emissive composite according to any one of claims 55 to 74, further comprising a second sealing layer in contact with the second plurality of conductors.
76. An emissive composite according to claim 75, further comprising a color layer coupled to the second sealing layer.
77. An emissive composite according to claim 76, wherein the color layer comprises a material selected from the group consisting of a colorant and color conversion material.
78. An emissive composite according to any one of claims 76 or 77, wherein the color layer comprises a plurality of picture elements.
79. An emissive composite according to claim 78, wherein the picture elements are selected from the group consisting of pixels and subpixels.
80. An emissive composite according to claim 79, wherein the pixels are selected from the group consisting of red pixels, green pixels and blue pixels.
81. An emissive composite according to any one of claims 79 or 80, wherein the subpixels are selected from the group consisting of red subpixels, green subpixels and blue subpixels.
82. An emissive composite according to any one of claims 55 to 81, further comprising a first supplementary conductive layer coupled to the dielectric layer.
83. An emissive composite according to any one of claims 55 to 82, wherein the second plurality of conductors is coupled to a second supplementary plurality of conductors, the second supplementary plurality having an impedance lower than the impedance of the second plurality of conductors.
84. An emissive composite according to any one of claims 55 to 83, further comprising an adhesive layer.
85. An emissive composite according to any one of claims 55 to 84, wherein at least one layer thereof is formed by coating.
86. An emissive composite according to any one of claims 55 to 84, wherein each layer thereof is formed by coating.
87. An emissive composite according to any one of claims 55 to 84, wherein at least one layer thereof is formed by printing.
88. An emissive composite according to any one of claims 55 to 84, wherein each layer thereof is formed by printing.
89. An emissive composite according to any one of claims 55 to 88, wherein the first substrate has a thickness between 25 and 500 micrometers.
90. An emissive composite according to any one of claims 55 to 88, wherein the second substrate has a thickness between 25 and 500 micrometers.
91. An emissive composite according to any on of claims 55 to 90, wherein the first plurality of conductors is formed from metal deposited on a substrate.
92. An emissive composite according to claim 91 , wherein the metal is selected from the group consisting of aluminum and copper.
93. An emissive composite according to any one of claims 55 to 92, wherein the first plurality of conductors comprises metal electrodes.
94. An emissive composite according to claim 93, wherein the metal electrodes are formed by printing a conductive ink on a substrate.
95. An emissive composite according to claim 93, wherein the metal electrodes are formed by printing a conductive polymer on a substrate.
96. An emissive composite according to any one of claims 1 to 95, wherein the emissive layer comprises a phosphor.
97. An emissive composite according to any one of claims 55 to 96, wherein the second plurality of conductors are selected from the group consisting of: indium tin oxide, graphene, and polyethylene-dioxithiophene.
98. An emissive composite according to any one of claims 55 to 97, wherein an electromagnetic shield layer is coupled to the first substrate.
99. An emissive composite according to claim 98, wherein a protective layer is coupled to the electromagnetic shield layer.
100. An emissive composite according to any one of claims 55 to 99, wherein an electromagnetic shield layer is coupled to the second substrate.
101. An emissive composite according to claim 100, wherein a protective layer is coupled to the electromagnetic shield layer.
102. An emissive composite according to any one of claims 55 to 101 , further comprising plastic material.
103. An emissive composite comprising:
at feast one color layer;
an optically transmissive substrate coupled to the color layer;
a first, plurality of transmissive conductors coupled to the optically transmissive substrate;
an optically transmissive dielectric layer;
an emissive layer coupled to the optically transmissive dielectric layer; a dielectric coupled to the emissive layer;
a second plurality of conductors coupled to the dielectric layer;
a second bottom substrate layer.
104. An emissive composite according to claim 103, wherein a first electromagnetic shield layer is coupled to the mask layer.
105. An emissive composite according to claim 103, wherein the color layer is coupled to the mask layer.
106. An emissive composite according to claim 103, wherein the color layer is coupled to the optically transmissive substrate.
107. An emissive composite according to claim 103, wherein the optically transmissive substrate is coupled to the plurality of the optically transmissive conductors.
108. An emissive composite according to claim 107, wherein a first conductor of the first plurality of transmissive conductors comprises a conductor composed on a grid pattern.
109. An emissive composite according to claim 107, wherein the first plurality of transmissive conductors are spaced apart and disposed substantially parallel, and further comprising second plurality of conductors, the second plurality of conductors spaced apart and disposed substantially parallel in a second different orientation.
110. An emissive composite according to claim 107, wherein the first plurality of transmissive conductors and the second plurality of conductors are disposed to each other in a substantially perpendicular orientation, and wherein a region substantially between a first selected conductor of the first plurality of conductors and a second selected conductor of the second plurality of conductors defines a picture element.
111. An emissive composite according to claim 103, wherein the first optically transmissive plurality of conductors is coupled to a first supplementary plurality of conductors, the first supplementary plurality having an impedance lower than the impedance of the second, optically transmissive conductors.
112. An emissive composite according to claim 103, wherein at least one later thereof is formed by a process selected from the group consisting of coating and printing.
113. An emissive composite according to claim 103, wherein a top electromagnetic shield layer is coupled to the mask layer.
114. An emissive composite according to claim 103, wherein a top protective layer is coupled to the top electromagnetic shield layer.
115. An emissive composite according to claim 103, wherein a bottom protective layer is coupled to a bottom electromagnetic shield layer.
116. An emissive composite according to any one of claims 103 to 115, further comprising plastic material.
117. An emissive composite comprising:
an optically transmissive layer;
a first, plurality of transmissive conductors coupled to the optically transmissive layer;
an optically transmissive dielectric layer;
at least one emissive color layer;
a dielectric coupled to the emissive layer;
a second plurality of conductors coupled to the dielectric layer;
a second bottom substrate layer.
118. An emissive composite according to claim 117, wherein the optically transmissive substrate is coupled to the plurality of the optically transmissive conductors.
119. An emissive composite according to claim 117, wherein a first conductor of the first plurality of transmissive conductors comprises a conductor composed on a grid pattern.
120. An emissive composite according to claim 117, wherein the first plurality of transmissive conductors are spaced apart and disposed substantially parallel, and further comprising: a second plurality of conductors, the second plurality of conductors spaced apart and disposed substantially parallel in a second different orientation.
121. An emissive composite according to claim 120, wherein the first plurality of transmissive conductors and the second plurality of conductors are disposed to each other in a substantially perpendicular orientation, and wherein a region substantially between a first selected conductor of the first plurality of conductors and a second selected conductor of the second plurality of conductors defines a picture element.
122. An emissive composite according to claim 121 , wherein the picture element is selected from group consisting of a plurality of pixels, a plurality of red emissive pixels, a plurality of green emissive pixels, a plurality of blue emissive pixels, a plurality of subpixels, plurality of red emissive subpixels, a plurality of green emissive subpixles, and a plurality of blue emissive subpixels.
123. An emissive composite according to claim 122, wherein the emissive pixels comprise a phosphor.
124. An emissive composite according to claim 122, wherein the emissive subpixels comprise a phosphor.
125. An emissive composite according to any one of claims 115 to 124, further comprising plastic material.
126. An emissive composite comprising:
an optically transmissive layer;
a first, plurality of transmissive conductors coupled to the optically transmissive layer;
an optically transmissive dielectric layer;
at least one emissive color layer;
a dielectric coupled to the emissive layer;
a plurality of trnasistors coupled to the dielectric layer; and
a second bottom substrate layer.
127. An emissive composite according to claim 126, wherein the first plurality of transmissive conductors are spaced apart and disposed substantially parallel, and further comprising: a second plurality of thin film transistors, the second plurality of transistors spaced apart and disposed substantially parallel in a second different orientation.
128. An emissive composite according to claim 126, wherein the first plurality of transmissive conductors and the second plurality of transistors are disposed to each other in a substantially perpendicular orientation, and wherein a region substantially between a first selected conductor of the first plurality of conductors and a second selected transistor of the second plurality of transistors defines a picture element.
129. An emissive composite according to any one of claims 126 to 128, further comprising plastic material.
130. A method of making the emissive composite of claim 45 comprising: printing an organic solvent soluble mask of the pattern of conducting electrodes on top of a layer of metal in contact with the first substrate
etching the unmasked metal film with acid and removing the printed mask with organic solvent.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US27811609P | 2009-10-05 | 2009-10-05 | |
| US61/278,116 | 2009-10-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2011041889A1 true WO2011041889A1 (en) | 2011-04-14 |
Family
ID=43856335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CA2010/001574 Ceased WO2011041889A1 (en) | 2009-10-05 | 2010-10-05 | Digital video poster |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2011041889A1 (en) |
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| CN103325318A (en) * | 2013-05-16 | 2013-09-25 | 京东方科技集团股份有限公司 | Display substrate and display device |
| EP3826444A1 (en) * | 2019-11-19 | 2021-05-26 | Google LLC | Electromagnetic interference ("emi") sheet attenuators |
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| CN103325318A (en) * | 2013-05-16 | 2013-09-25 | 京东方科技集团股份有限公司 | Display substrate and display device |
| EP3826444A1 (en) * | 2019-11-19 | 2021-05-26 | Google LLC | Electromagnetic interference ("emi") sheet attenuators |
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