JP2011145390A - Electrophoretic display device and electronic equipment - Google Patents

Abstract

Disclosed is an electrophoretic display device and an electronic apparatus that have good visibility by preventing a shift between a color boundary of a color filter and an outline of an image when an image is viewed from an element substrate side.
An electrophoretic display device of the present invention is electrophoresed between an element substrate having a plurality of pixel electrodes and a counter substrate having a common electrode facing the pixel electrodes. In the electrophoretic display device having the element 32 sandwiched therebetween, a color filter CF is disposed between the plurality of pixel electrodes 35 and the electrophoretic element 32.
[Selection] Figure 4

Description

  The present invention relates to an electrophoretic display device and an electronic apparatus.

  The electrophoretic display device is provided between a counter substrate in which a transparent electrode (counter electrode) is uniformly formed on a transparent substrate, and an element substrate in which a pixel electrode and a thin film element (transistor) for driving the pixel electrode are formed. The electrophoretic element is sandwiched. Then, an image is formed by applying a desired potential difference between the transparent electrode and the pixel electrode. In such an apparatus, it is common to observe an image from the counter electrode side formed with a transparent electrode (for example, Patent Document 1).

JP 2003-107535 A

  However, since the electric field diffuses from the pixel electrode toward the counter electrode, when viewed from the observation surface side, the gradation boundary is blurred, and the contour of the image tends to be enlarged or reduced. Further, when a color filter is provided on the counter electrode side, the color boundary of the color filter and the color boundary of the electrophoretic element or the contour of the image are shifted, which may cause moiré.

  A configuration in which an electrophoretic display device is visually recognized from the element substrate side using a transparent semiconductor such as an oxide semiconductor is also known. However, in amorphous silicon TFTs and polysilicon TFTs that are widely used as TFT elements, the wiring for forming the thin film elements and circuits is not transparent, so that all images are recognized when observed from the back side of the element substrate. There is a drawback that you can not. Even when a transparent element such as an oxide semiconductor is used, when a metal material is used for the wiring, the same problem as described above occurs, and even if it is a transparent semiconductor, its transmittance is not 100%. However, there is a problem that the contrast of the display image is lowered.

  Therefore, a configuration in which a color filter is provided on the element substrate side has been proposed. In this case, the color filter is formed on the inner surface side of the element substrate, and a circuit layer including a pixel electrode, a TFT element that drives the pixel electrode, wiring, and the like is formed on the color filter. By adopting such a configuration, even when observed from the element substrate side, the electrophoretic particles are not diffused, and the shift between the color boundary of the color filter and the color boundary of the electrophoretic particle or the contour of the image is reduced. Although it has become possible to improve the visibility, parallax occurs due to the thickness of the circuit layer existing between the color filter and the electrophoretic element, and some gradation blurring remains. Further, depending on the properties of the planarizing film formed on the color filter, there is a concern that the characteristics of the TFT element may be deteriorated.

  The present invention has been made in view of the above-described problems of the prior art, and in a display device that visually recognizes an image from the element substrate side, visual recognition is performed by preventing a shift between the color boundary of the color filter and the contour of the image. One of the objects is to provide an electrophoretic display device and an electronic device with good characteristics.

  In order to solve the above problems, an electrophoretic display device according to the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, and between the first substrate and the second substrate. An electrophoretic element disposed on the first substrate, a plurality of first electrodes formed on the electrophoretic element side of the first substrate, and a plurality of first electrodes facing the electro-optical element side of the second substrate An electrophoretic display device having a second electrode formed in such a manner that a color filter is disposed between the plurality of first electrodes and the electrophoretic element.

  According to the present invention, since the color filter is disposed between the plurality of pixel electrodes on the element substrate and the electrophoretic element bonded to the element substrate, the color filter is provided on the counter substrate side or the back side of the element substrate. Compared to the configuration in which the filter is formed, the distance between the electrophoretic element or the pixel electrode and the color filter can be reduced. As a result, the color filter and the pixel electrode are suitably aligned, so that the color boundary between the color filter and the image outline does not shift, and the occurrence of moire can be prevented. Therefore, an electrophoretic display device with good visibility can be obtained.

Moreover, it is preferable that the said color filter consists of an adhesive agent for affixing the said electrophoretic element on the said element substrate.
According to the present invention, since the color filter can be formed using the adhesive for bonding the electrophoretic element onto the element substrate, the adhesive layer for bonding onto the element substrate on the electrophoretic element side. Is not required to be formed in advance.

Further, it is preferable that the color filter is disposed between the pixel electrode and an adhesive layer for bonding the electrophoretic element onto the element substrate.
According to the present invention, since the color filter is disposed between the pixel electrode and the adhesive layer for attaching the electrophoretic element on the element substrate, the existing electrophoretic element having the adhesive layer is removed. It is possible to reduce the distance between the color filter, the electrophoretic element, and the pixel electrode. Thereby, the shift | offset | difference of the color boundary of a color filter and the outline of an image can be suppressed.

Moreover, it is preferable that the said color filter has electroconductivity.
According to the present invention, since the color filter disposed between the pixel electrode and the electrophoretic element has conductivity, voltage application to the electrophoretic element is favorably performed.

A plurality of scanning lines each connected to at least one of the plurality of first electrodes via a selection transistor; a storage capacitor having a pair of electrodes connected to each of the plurality of first electrodes; It is preferable that the scanning line is one electrode of the pair of electrodes.
According to the present invention, the Cs-on-gate structure in which a storage capacitor is formed by using a scanning line improves the aperture ratio of the pixel and allows light from the back side of the element substrate to be sufficiently transmitted. Can do.

In addition, a partition wall is provided between the first substrate and the second substrate, and the electrophoresis element is configured by the partition particles and the electrophoretic particles and the dispersion medium sealed in the space defined by the partition wall. It is preferable that
According to the present invention, since the partition wall that partitions the plurality of pixels is provided on the element substrate, it is possible to prevent the particles of the electrophoretic element from being unevenly distributed. Thereby, the quality of a display image can be improved.

An electronic apparatus according to the present invention includes the electrophoretic display device described above.
ADVANTAGE OF THE INVENTION According to this invention, the electronic device in which a high quality display is possible is obtained by providing the display apparatus with favorable visibility.

1 is a diagram illustrating an overall configuration of an electrophoretic display device according to a first embodiment. 1 is a circuit block diagram of an electrophoretic display device according to a first embodiment. FIG. 3 is a diagram illustrating a pixel circuit of the electrophoretic display device according to the first embodiment. The circuit block diagram of a pixel. (A) is a top view of an element substrate, (b) is sectional drawing in the position in alignment with the A-A 'line of (a). Operation | movement explanatory drawing of an electrophoretic element. Sectional drawing of the electrophoretic display device of 2nd Embodiment. Sectional drawing of the electrophoretic display device of 3rd Embodiment. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of an electrophoretic display device according to the present invention. FIG. 2 is a circuit block diagram of the display according to the present embodiment. FIG. 3 is a diagram illustrating a pixel circuit of the electrophoretic display device.

The electrophoretic display device 100 shown in FIG. 1 includes a display body 2, a controller 3, a VRAM (Video Random Access Memory) 4, and a common electrode drive circuit 6.
The display body 2 receives the control signal from the controller 3 and the voltage supply from the common electrode drive circuit 6 and displays an image. In the display body 2, a display unit 5, a scanning line driving circuit 61, and a data line driving circuit 62 are formed.

The controller 3 is a control unit of the electrophoretic display device 100, receives image data to be displayed from the VRAM 4, and controls the display body 2 to display an image. Specifically, the scanning line driving circuit 61, the data line driving circuit 62, and the common electrode driving circuit 6 provided in the display body 2 are controlled to display an image. The control signal output from the controller 3 is, for example, a timing signal such as a clock signal or a start pulse, image data, a power supply voltage, or the like.
The VRAM 4 is used to temporarily store one or more image data to be displayed next on the display unit 5 from image data stored in a storage unit (not shown) such as a flash memory.
The common electrode drive circuit 6 is connected to a common electrode 37 (counter electrode; see FIG. 3) provided on the display body 2 and supplies an arbitrary common electrode potential Vcom to the common electrode 37.

FIG. 2 is a circuit diagram showing a schematic configuration of the electrophoretic display device 100 according to the present embodiment.
The electrophoretic display device 100 includes a display unit 5 in which a plurality of pixels 40 are arranged. Around the display unit 5, a scanning line driving circuit 61 and a data line driving circuit 62 are arranged. The scanning line driving circuit 61 and the data line driving circuit 62 are each connected to the controller 3.

  A plurality of scanning lines 66 extending from the scanning line driving circuit 61 and a plurality of data lines 68 extending from the data line driving circuit 62 are formed in the display unit 5, and the pixels 40 are provided corresponding to the intersection positions thereof. It has been.

  The scanning line driving circuit 61 is connected to each pixel 40 via m scanning lines 66 (Y1, Y2, Y3,..., Ym) extending in the row direction. The scanning lines 66 from the row to the m-th row are sequentially selected, and a selection signal defining the on timing of the selection transistors (selection transistors TRa and TRb: see FIG. 3) provided in the pixel 40 is selected. Is supplied to the pixel 40. The pixels 40 are arranged in a matrix of m pieces along the Y-axis direction and n pieces along the X-axis direction.

  In the electrophoretic display device 100 of this embodiment, the number of scanning lines 66 and data lines 68 can be set to an arbitrary natural number.

The data line driving circuit 62 is connected to each pixel 40 via n data lines 68 (X1, X2, X3,..., Xn) extending in the column direction. An image signal defining 1-bit image data corresponding to each of 40 is supplied to the pixel 40.
In this embodiment, when image data (pixel data) “0” (white) is defined, a low-level (L) image signal is supplied to the pixel 40, and the image data (pixel data) “1” ( When black is defined, a high level (H) image signal is supplied to the pixel 40. In addition, when the intermediate gray scale pixel data is defined, an image signal having an intermediate level between L and H is supplied to the pixel 40.

FIG. 3 is a circuit configuration diagram of the pixels 40A and 40B.
Each pixel 40A, 40B of the display unit 5 includes selection transistors TRa, TRb as pixel switching elements, a pixel electrode 35 (first electrode), an electrophoretic element 32, a common electrode 37 (second electrode), and a storage capacitor C1a, C1b is provided.
The selection transistors TRa and TRb are each composed of an N-MOS (Negative Metal Oxide Semiconductor) TFT.
The electrophoretic element 32 is sandwiched between the pixel electrode 35 and the common electrode 37.
The storage capacitors C1a and C1b are formed on an element substrate 30 (first substrate) to be described later, and a storage capacitor C1a is configured by a pair of electrodes 10a and 10b arranged to face each other through a dielectric film. The storage capacitor C1b is configured by 20b. And it charges with the image signal voltage each written through selection transistor TRa, TRb. As will be described in detail later, the storage capacitors C1a and C1b of the present embodiment have a Cs-on-gate structure in which a storage capacitor is formed using another adjacent scanning line 66.

The selection transistor TRa of the pixel 40A has an i-row scanning line 66 connected to its gate electrode, a data line 68 connected to the source, and one electrode 10a of the storage capacitor C1a and the pixel electrode 35 connected to the drain. And are connected to each other. The other electrode 10b of the storage capacitor C1a is connected to the (i−1) th scanning line 66.
The storage capacitor C1a of the pixel 40A has a configuration in which a capacitor is formed by the pixel electrode 35 in the pixel 40A and the scanning line 66 of the preceding i-1 row. That is, one electrode 10b of the storage capacitor C1a is composed of i-1 rows of scanning lines 66.
The selection transistor TRb of the pixel 40B has an i + 1 row scanning line 66 connected to its gate electrode, a data line 68 connected to the source, and one electrode 20a of the storage capacitor C1b and the pixel electrode 35 connected to the drain. And are connected. The other electrode 20b of the storage capacitor C1b is connected to the i-th scanning line 66.
The storage capacitor C1b of the pixel 40B is configured to form a capacitor by the pixel electrode 35 in the pixel 40B and the i-row scanning line 66 in the previous stage. That is, one electrode 20b of the storage capacitor C1b includes i rows of scanning lines 66.

In this pixel circuit, for example, when the i-th scanning line 66 is selected, the selection transistor TRa is turned on, and an image signal is input from the data line 68 to the pixel electrode 35 via the selection transistor TRa and held. The capacitor C1a is charged. When the i-th scanning line 66 is not selected, the selection transistor TRa is turned off, but thereafter, the charged particles of the electrophoretic element 32 in the pixel 40A are moved by the energy stored in the storage capacitor C1a.
When the i + 1-th scanning line 66 is selected, the selection transistor TRb is turned on, an image signal is input from the data line 68 to the pixel electrode 35 via the selection transistor TRb, and the storage capacitor C1b is charged. . When the scanning line 66 in the (i + 1) th row is not selected, the selection transistor TRb is turned off. Thereafter, the charged particles of the electrophoretic element 32 in the pixel 40B are moved by the energy stored in the storage capacitor C1b.

FIG. 4A is a partial cross-sectional view of the electrophoretic display device 100 in the display unit 5.
The electrophoretic display device 100 has a configuration in which an electrophoretic element 32 in which a plurality of microcapsules 20 are arranged is sandwiched between an element substrate 30 and a counter substrate 31 (second substrate). The plurality of microcapsules 20 are fixed by a binder 23.
In the display unit 5, a plurality of pixel electrodes 35 are arranged on the electrophoretic element 32 side of the element substrate 30, and a color filter CF is disposed between the plurality of pixel electrodes 35 and the electrophoretic element 32. .

The element substrate 30 is a substrate made of glass, plastic, or the like, and is a transparent substrate because it is disposed on the image display side. On the surface of the element substrate 30, the circuit layer 34 in which the selection transistors TRa and TRb, the scanning lines 66, the data lines 68, etc. are formed is provided. Are arranged.
The pixel electrode 35 is a transparent electrode formed of MgAg, ITO, IZO (indium / zinc oxide), or the like. Although not shown, the scanning line 66, the data line 68, the selection transistors TRa, TRb, and the like shown in FIGS. 3 and 4 are formed between the pixel electrode 35 and the element substrate 30.

  On the circuit layer 34, a color filter CF including a plurality of colored layers 51r, 51g, 51b is formed. Each colored layer 51r, 51g, 51b is formed on the pixel electrode 35, respectively. Each colored layer 51r, 51g, 51b has adhesiveness, and also functions as an adhesive when the counter substrate 31 is bonded to the element substrate 30 on the electrophoretic element 32 side. The electrophoretic element 32 is bonded to the pixel electrode 35 through the color filter CF. Each colored layer 51r, 51g, 51b has not only adhesiveness but also conductivity, and voltage application to the electrophoretic element 32 is favorably performed by the color filter CF having such conductivity. The migration of charged particles can be performed smoothly.

  On the other hand, the counter substrate 31 is a substrate made of glass, plastic, or the like, and is not necessarily transparent because it is disposed on the side opposite to the image display surface. A common electrode 37 having a planar shape facing the plurality of pixel electrodes 35 is formed on the electrophoretic element 32 side of the counter substrate 31, and the electrophoretic element 32 is provided on the common electrode 37. The common electrode 37 in this embodiment is a so-called reflective electrode having light reflectivity. For the common electrode 37, a metal material such as Cr, Mo, Mo alloy, Al, Al alloy, Ta, Ti, Ag alloy, or Ni alloy can be used. The material of the reflective electrode is not limited to metal, but may be conductive plastic having metallic luster. By setting the common electrode 37 as a reflective electrode, light transmitted from the gap between the electrophoretic particles or between the microcapsules without being reflected by the electrophoretic particles among the light incident from the element substrate 30 side. It can be reflected by the common electrode 37. Thereby, the utilization efficiency of light can be improved and the luminance in the display unit 5 can be increased.

  In general, the electrophoretic element 32 is handled as an electrophoretic sheet in a state in which the electrophoretic element 32 is formed in advance on the counter substrate 31 side. Then, by attaching an electrophoretic sheet on the color filter CF having adhesiveness to the separately manufactured element substrate 30 (the color filter CF, the pixel electrode 35, various circuits and the like are formed), The display unit 5 is formed.

FIG. 4B is a schematic cross-sectional view of the microcapsule 20.
The microcapsule 20 has a particle size of about 50 μm, for example, and encloses therein a dispersion medium 21, a plurality of white particles 27 (electrophoretic particles), and a plurality of black particles 26 (electrophoretic particles). It is a spherical body. As shown in FIG. 4A, the microcapsule 20 is sandwiched between the common electrode 37 and the pixel electrode 35, and one or more microcapsules 20 are arranged in one pixel 40.

The outer shell (wall film) of the microcapsule 20 is formed using a transparent polymer resin such as acrylic resin such as polymethyl methacrylate and polyethyl methacrylate, urea resin, and gum arabic.
The dispersion medium 21 is a liquid that disperses the white particles 27 and the black particles 26 in the microcapsules 20. Examples of the dispersion medium 21 include water, alcohol solvents (methanol, ethanol, isopropanol, butanol, octanol, methyl cellosolve, etc.), esters (ethyl acetate, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). ), Aliphatic hydrocarbons (pentane, hexane, octane, etc.), alicyclic hydrocarbons (cyclohexane, methylcyclohexane, etc.), aromatic hydrocarbons (benzene, toluene, benzenes having a long-chain alkyl group ( Xylene, hexylbenzene, hebutylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, tetradecylbenzene)), halogenated hydrocarbons (methylene chloride, chloroform, tetrachloride) Element, and 1,2-dichloroethane), can be exemplified a carboxylate, it may be other oils. These substances can be used alone or as a mixture, and a surfactant or the like may be further blended.

The white particles 27 are particles (polymer or colloid) made of a white pigment such as titanium dioxide, zinc white, and antimony trioxide, and are used, for example, by being negatively charged. The black particles 26 are particles (polymer or colloid) made of a black pigment such as aniline black or carbon black, and are used by being charged positively, for example.
These pigments include electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, compound charge control agents, titanium-based coupling agents, aluminum-based coupling agents, silanes as necessary. A dispersant such as a system coupling agent, a lubricant, a stabilizer, and the like can be added.
Further, instead of the black particles 26 and the white particles 27, for example, pigments such as red, green, and blue may be used. According to such a configuration, red, green, blue, or the like can be displayed on the display unit 5.

Here, FIG. 5A is a plan view of the element substrate 30, and FIG. 5B is a cross-sectional view at a position along the line AA ′ in FIG. 5A.
As shown in FIG. 5A, the selection transistors TRa and TRb include a semiconductor layer 41a having a substantially rectangular shape in plan view, a source electrode 41c extending from the data line 68, a semiconductor layer 41a, and a pixel electrode 35. A drain electrode 41d to be connected and a gate electrode 41e extending from the scanning line 66 are provided. In each of the pixels 40A and 40B, storage capacitors C1a and C1b are formed in regions where the pixel electrode 35 and the scanning line 66 overlap.

  In recent years, small display panels have been improved in definition, and accordingly, crosstalk due to parasitic capacitance between electrodes and wiring tends to occur, so that a large storage capacitor has been required. However, since the ratio of the data lines 68 to the scanning lines 66 other than the pixel electrode 35 is increased with the increase in definition, the problem of a decrease in the aperture ratio of the pixel due to an increase in the storage capacity becomes prominent. If the formation area of the storage capacitor in one pixel is large, the aperture ratio of the pixel is lowered and a sufficient display contrast cannot be obtained, so that observation from the element substrate 30 side is difficult.

  Therefore, in the present embodiment, by reducing the formation area of the storage capacitor with respect to the formation area of the pixel electrode 35, the ratio of the storage capacitor to the pixel region is reduced, and a part of the scanning line 66 is formed to extend. Thus, the so-called Cs-on-gate structure arranged so as to overlap the pixel electrode 35 increases the area of the light transmitting portion 42. Thereby, the aperture ratio in the pixel 40 is increased and light from the back side of the element substrate 30 can be sufficiently transmitted.

  5B, the gate electrode 41e (scanning line 66) made of Al or an Al alloy is formed on the element substrate 30, and the gate electrode 41e is covered with silicon oxide or silicon. A gate insulating film 41b made of nitride is formed. The thickness of the gate insulating film 41b is about 300 nm. A semiconductor layer 41a made of amorphous silicon or polysilicon is formed in a region facing the gate electrode 41e via the gate insulating film 41b. A source electrode 41c and a drain electrode 41d made of Al or an Al alloy are formed so as to partially run over the semiconductor layer 41a. An interlayer insulating film 34a made of silicon oxide or silicon nitride is formed to cover the source electrode 41c (data line 68), the drain electrode 41d, the semiconductor layer 41a, and the gate insulating film 41b. A pixel electrode 35 is formed on the interlayer insulating film 34a. The pixel electrode 35 and the drain electrode 41d are connected through a contact hole 34b that passes through the interlayer insulating film 34a and reaches the drain electrode 41d. In this way, the selection transistors TRa and TRb are configured.

  Here, the thicknesses of the gate electrode 41e, the pixel electrode 35, and various wirings are about 100 nm to 300 nm. Further, in order to reduce the electrical influence of the gate electrode 41e and various wirings on the electrophoretic element 32, it is preferable to make them as narrow as possible. Specifically, a line width of about 4 μm or less is suitable.

On the outermost layer of the element substrate 30, a plurality of colored layers 51 r, 51 g, 51 b constituting the color filter CF are pattern-formed on the pixel electrode 35 corresponding to each pixel 40. As described above, the color filter CF has moderate conductivity. The resistivity is preferably 1 × 10 ⁶ to 1 × 10 ¹² Ω / cm ² .

Next, a method for manufacturing the color filter CF will be described.
As the color filter CF, a filter in which colored layers 51r, 51g, and 51b of each color are formed for each pixel on a glass substrate by a dyeing method, a printing method, an electrodeposition method, a pigment dispersion method, or the like can be used.

In the dyeing method, an image is formed using a photosensitive resin obtained by mixing dichromate as a photosensitizer in gelatin, polyvinyl alcohol, or the like, and then dyed and manufactured.
In the printing method, it is manufactured by transferring a thermosetting ink or a photocurable ink to a glass substrate by a method such as screen printing or flexographic printing.
In the electrodeposition method, a glass substrate provided with an electrode is immersed in a solution containing a pigment or dye, and the hue is adhered by electrophoresis.
The pigment dispersion method is produced by forming an image with a colored resist in which a pigment is dispersed in a photocurable resin. The pigment dispersion method can produce a color filter CF with high heat resistance. Further, since there is an advantage that a high-precision image can be formed while dyeing is unnecessary, it has become the mainstream of color filter manufacturing technology.

The colored resist (photopolymerizable composition for color filter) is prepared by mixing a binder resin, a photopolymerization initiator, a pigment, a solvent, and the like.
As the binder resin, a copolymer containing at least one monomer having an acidic group is preferably used. Specific examples of such copolymer binder resins include (meth) acrylic acid, maleic acid, maleic anhydride, crotonic acid, itaconic acid, fumaric acid, isoprene sulfonic acid, styrene sulfonic acid, (o, m or p) -monomers having an acidic group such as polyvinylphenol, styrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, ( (Meth) butyl acrylate, vinyl acetate, acrylonitrile, (meth) acrylamide, glycidyl (meth) acrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, glycidyl crotonic acid, (meth) acrylic acid chloride, benzyl ( Meta) Acry , Copolymers of hydroxyethyl (meth) acrylate, N-methylolacrylamide, N, N-dimethylacrylamide, N-methacryloylmorpholine, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethylacrylamide And a binder resin obtained by copolymerizing In the present specification, “(meth) acryl” means “acryl or methacryl”. The same applies to “(meth) acrylate”.

  Examples of pigments include inorganic pigments such as barium sulfate, lead sulfate, titanium oxide, yellow lead, bengara, chromium oxide, and carbon black, anthraquinone pigments, perylene pigments, disazo pigments, phthalocyanine pigments, isoindoline pigments, Examples thereof include organic pigments such as indolinone pigments, dioxazine pigments, quinacridone pigments, perinone pigments, triphenylmethane pigments, and thioindigo pigments. Of these, phthalocyanine pigments, dioxazine pigments, anthraquinone pigments, and disazo pigments are particularly preferable. These pigments are used alone or in combination of two or more.

  In order to form the color filter CF with the photopolymerizable composition for a color filter, first, a photopolymerizable composition for a color filter having the above composition is prepared, and this is used as a color resist sensitizing solution, as a spin coater, a roll coater, It is applied to the glass substrate by a known method such as curtain coater or screen printing. Note that a black matrix may be formed of a metal such as chromium or lead oxide, carbon black, or the like on the glass substrate. The coating film thickness is preferably 0.5 to 10 μm after drying.

  Further, the color filter CF may be formed by an ink jet method using the above material. At this time, bank processing or water repellency processing may be performed on the element substrate 30 side so that the color filter CF does not flow out to adjacent pixels or mix with adjacent colors.

  Here, as a method for imparting conductivity to the color filter CF, there is a method in which a pigment is dispersed using a conductive polymer such as ponianiline, vitron (PEDOT), polypyrrole, polythiophene, or polyisothianaphthene as a binder resin. .

  Further, even when carbon nanotubes (CNT) are used, the color filter CF having conductivity can be produced. It is known that the color of CNT changes depending on its diameter, and it is possible to manufacture a color filter CF having conductivity by mixing CNTs of different direct line with a binder resin.

  The color filter CF of this embodiment itself has adhesiveness. For example, a color filter CF having adhesiveness can be obtained by forming the colored layers 51r, 51g, and 51b using a color adhesive in which the above-described pigment or CNT is dispersed in a transparent adhesive. As the adhesive, general adhesives such as acrylic resin, urethane resin, polyether, α-olefin, and epoxy resin can be used.

FIG. 6 is an operation explanatory diagram of the electrophoretic element. FIG. 6A shows a case where the pixel 40 displays white, and FIG. 6B shows a case where the pixel 40 displays black.
In the case of white display shown in FIG. 6A, the common electrode 37 is held at a relatively high potential and the pixel electrode 35 is held at a relatively low potential. As a result, the negatively charged white particles 27 are attracted to the common electrode 37, while the positively charged black particles 26 are attracted to the pixel electrode 35. As a result, when this pixel is viewed from the common electrode 37 side which is the display surface side, white (W) is recognized.
In the case of black display shown in FIG. 6B, the common electrode 37 is held at a relatively low potential, and the pixel electrode 35 is held at a relatively high potential. As a result, the positively charged black particles 26 are attracted to the common electrode 37, while the negatively charged white particles 27 are attracted to the pixel electrode 35. As a result, when this pixel is viewed from the common electrode 37 side, black (B) is recognized.

  FIG. 6 is an operation explanatory diagram when black particles are positively charged and white particles are negatively charged. However, if necessary, black particles can be negatively charged and white particles can be positively charged. Good. In this case, when a potential is supplied in the same manner as described above, a display in which white display and black display are reversed can be obtained.

  In the electrophoretic display device 100 of this embodiment, the color filter CF is adjacent to the pixel electrode 35, and there is no conventional gap between the two. For this reason, each colored layer 51r, 51g, 51b of the color filter CF and each pixel electrode 35 are well aligned, and there is no deviation between the color boundary of the color filter CF and the contour of the image. It becomes possible to prevent. Further, since the color filter CF is provided in contact with the electrophoretic element 32, the problem of parallax caused by the distance between them is solved, and a high-quality display image can be obtained.

  Further, the color filter CF of the present embodiment has adhesiveness and functions as an adhesive layer for bonding the electrophoretic element 32 onto the element substrate 30. For this reason, it is not necessary to previously form an adhesive layer on the microcapsule 20 as an electrophoretic sheet. Therefore, a release sheet attached to the surface of the adhesive layer is not necessary, and the cost is reduced and the manufacture is facilitated.

  Furthermore, the color filter CF of the present embodiment is not disposed below the selection transistors TRa and TRb but is disposed on the pixel electrode 35 and has a function of bonding the electrophoretic element 32 and the element substrate 30 together. Therefore, it is not necessary to form a planarizing film on the color filter CF. For this reason, the characteristics of the selection transistors TRa and TRb are not deteriorated due to the properties of the planarizing film.

  In addition, since the storage capacitors C1a and C1b have a Cs on gate structure, a normal amorphous silicon TFT can be used. When a configuration other than the Cs on gate structure is adopted, a dedicated manufacturing process for aligning the color filter CF to manufacture amorphous silicon is required. However, such a limitation is eliminated by adopting a Cs on gate structure.

[Second Embodiment]
Next, an electrophoretic display device 200 according to a second embodiment of the present invention will be described. FIG. 7 shows a cross-sectional view of the electrophoretic display device 200 of the present embodiment. The electrophoretic display device 200 of this embodiment is different from the previous embodiment in that the position of the color filter is different.

  The electrophoretic display device 200 of the present embodiment is the same as the first embodiment in that the color filter CF is disposed between the circuit layer 34 and the electrophoretic element 32, but a normal color having no adhesiveness. A filter CF is employed, and the electrophoretic element 32 is bonded onto the color filter CF via an adhesive layer 33. The color filter CF is composed of a plurality of colored layers 51r, 51g, 51b existing on the plurality of pixel electrodes 35 formed on the outermost layer of the element substrate 30, and has conductivity as in the above embodiment. Is preferred.

  The element substrate 30 and the counter substrate 31 are bonded via a transparent adhesive layer 33 provided on the electrophoretic element 32. By imparting conductivity to the adhesive layer 33, a predetermined voltage can be efficiently applied to the electrophoretic element 32.

  When manufacturing the electrophoretic display device 200 of the present embodiment, a plurality of micro-chips are provided for the element substrate 30 including the circuit layer 34 (including the selection transistors TRa and TRb, the pixel electrode 35, and the like) and the color filter CF. The display unit 5 is formed by attaching an electrophoretic sheet having an adhesive layer 33 to the surface of the capsule.

  According to the electrophoretic display device 200 of the present embodiment, the same effects as those of the previous embodiment can be obtained, and after the color filter CF is formed on the element substrate 30 by using the normal transparent adhesive layer 33, electricity can be obtained. Since the electrophoretic element 32 is bonded, it can be formed by the same material and manufacturing process as those of the conventional color filter, so that the manufacturing is easy and the cost can be reduced.

[Third Embodiment]
Next, an electrophoretic display device 300 according to a third embodiment of the invention will be described. FIG. 8 shows a cross-sectional view of the electrophoretic display device 300 of the present embodiment. The electrophoretic display device 300 of this embodiment is different from the previous embodiment in that a partition is provided on the counter substrate 31 side. In FIG. 8, the illustration of the selection transistors TRa, TRb, etc. is omitted.

The electrophoretic display device 300 according to the present embodiment includes a counter substrate 31 in which a common electrode 37 and an insulating layer 74 are sequentially formed from the substrate surface, and an element substrate that is disposed to face the counter substrate 31 via the electrophoretic element. The electrophoretic element 32 is divided into a plurality of regions by a partition wall 72 disposed between the counter substrate 31 and the element substrate 30.
The partition wall 72 is a partition wall having a lattice shape in plan view, which is formed with a certain height in the thickness direction of the electrophoretic display device 300 and divides (divides) a plurality of sealing spaces. As the partition wall 72, for example, a plastic or a metal material can be used.
By covering the surface of the common electrode 37 with the insulating layer 74, the common electrode 37 can be protected from the dispersion medium 21, and deterioration of the electrode can be prevented.

  In the present embodiment, the inner space is divided into a plurality of matrix-shaped sealing spaces 71 by the frame-shaped partition wall 72, and each sealing space 71 is hermetically sealed between the counter substrate 31 and the element substrate 30. Is sealed. Since the protective layer 52 is formed on the outermost layer on the inner side of the element substrate 30 (the side facing the counter substrate 31) so as to cover the colored layers 51r, 51g, 51b of each color, the partition wall 72 and the color filter CF When the colored layers 51r, 51g, and 51b have conductivity, the insulation between the partition wall 72 and the colored layers 51r, 51g, and 51b is ensured. In each sealed space 71 formed by the partition walls 72, the dispersion medium 21, the plurality of white particles 27, and the plurality of black particles 26 constituting the electrophoretic element 32 are respectively enclosed. Each particle 26 and 27 moves in the sealed space 71.

  According to the configuration of the present embodiment, since there is no gap between the color filter CF and the pixel electrode 35 as in the above-described embodiment, the shift between the color boundary of the color filter CF and the contour of the image. It is possible to prevent the occurrence of moire and the like. Further, in the present embodiment, the electrophoretic element 32 is configured by the partition wall 72, the electrophoretic particles 26 and 27 and the dispersion medium 21 sealed in the sealed space 71 defined by the partition wall 72. As described above, since the dispersion medium 21 and the particles 26 and 27 are enclosed in the plurality of sealed spaces 71 defined by the partition walls 72, the particles 26 and 27 are unevenly distributed at predetermined positions of the display unit 5. This is prevented. That is, the partition wall 72 performs the same function as the outer shell portion of the microcapsule 20. Thereby, a good display image can be obtained.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the previous embodiment, the larger the area ratio of the light transmission portion 42 (FIG. 5) in the pixel 40 can be expected to improve the reflectivity of the electrophoretic display device. Therefore, the storage capacitors C1a and C1b have a Cs on gate structure. In this way, the area of the light transmission part 42 is increased, but a configuration other than the Cs on gate structure may be used.

  In the previous embodiment, an example in which amorphous silicon TFTs are used as the selection transistors TRa and TRb has been described. However, channel etch type amorphous silicon TFTs, HTPS (high temperature polysilicon) TFTs, LTPS (low temperature polysilicon) TFTs, An oxide TFT or an organic TFT may be used.

  Although the configuration of the electrophoretic display device has been described in the previous embodiment, the configuration of the first embodiment of the present invention is applied to a liquid crystal display device and an organic EL (electroluminescence) device in addition to the electrophoretic display device. Applicable as appropriate.

(Electronics)
Next, the case where the electrophoretic display devices 100, 200, and 300 of the above embodiments are applied to an electronic device will be described.

[clock]
FIG. 9 is a front view of the wrist watch 1000. The wrist watch 1000 includes a watch case 1002 and a pair of bands 1003 connected to the watch case 1002.
On the front surface of the watch case 1002, a display unit 1005 including the electrophoretic display device of each of the above embodiments, a second hand 1021, a minute hand 1022, and an hour hand 1023 are provided. On the side surface of the watch case 1002, a crown 1010 and an operation button 1011 are provided as operation elements. The crown 1010 is connected to a winding stem (not shown) provided inside the case, and is integrally provided with the winding stem so that it can be pushed and pulled in multiple stages (for example, two stages) and can be rotated. . The display unit 1005 can display a background image, a character string such as date and time, or a second hand, a minute hand, and an hour hand.

[Electronic paper]
FIG. 10 is a perspective view illustrating a configuration of the electronic paper 1100. An electronic paper 1100 includes the electrophoretic display device of the above embodiment in a display area 1101. The electronic paper 1100 is flexible and includes a main body 1102 made of a rewritable sheet having the same texture and flexibility as conventional paper.

[Electronic notebook]
FIG. 11 is a perspective view showing the configuration of the electronic notebook 1200. An electronic notebook 1200 is obtained by bundling a plurality of the electronic papers 1100 and sandwiching them between covers 1201. The cover 1201 includes display data input means (not shown) for inputting display data sent from an external device, for example. Thereby, according to the display data, the display content can be changed or updated while the electronic paper is bundled.

[Watches]
According to the wristwatch 1000, the electronic paper 1100, and the electronic notebook 1200, the electrophoretic display device according to the present invention is employed. Therefore, an electronic device having a display unit with excellent operation reliability and high display quality is provided. Become.

  In addition, said electronic device illustrates the electronic device which concerns on this invention, Comprising: The technical scope of this invention is not limited. For example, the present invention is also applied to a display unit of an electronic device such as an IC card, a rewritable paper, a mobile phone, a portable audio device, a PDA, an electronic dictionary, a fingerprint authentication device, a central processing unit, an electronic fan, an electronic price tag, and an electronic advertisement. The electrophoretic display device according to the above can be suitably used.

DESCRIPTION OF SYMBOLS 100,200,300 ... Electrophoretic display apparatus, 5 ... Display part, 20 ... Microcapsule, 26 ... Black particle (electrophoretic particle), 27 ... White particle (electrophoretic particle), 30 ... Element substrate (1st board | substrate) 31 ... Counter substrate (second substrate) 32 ... Electrophoretic particles 34 ... Circuit layer 35 ... Pixel electrode (first electrode) 37 ... Common electrode (second electrode) 40, 40A, 40B ... Pixel, 66 ... scanning line, 68 ... data line, 72 ... partition, C1a, C1b ... retention capacitor, TRa, TRb ... selection transistor, CF ... color filter, 1000 ... watch (electronic device), 1100 ... electronic paper (electronic device), 1200 ... electronic notebook (electronic equipment)

Claims (7)

A first substrate;
A second substrate disposed opposite the first substrate;
An electrophoretic element disposed between the first substrate and the second substrate;
A plurality of first electrodes formed on the electrophoretic element side of the first substrate;
An electrophoretic display device having, on the electro-optic element side of the second substrate, a second electrode formed to face the plurality of first electrodes,
An electrophoretic display device, wherein a color filter is disposed between the plurality of first electrodes and the electrophoretic element.   The electrophoretic display device according to claim 1, wherein the color filter is made of an adhesive for attaching the electrophoretic element to the first substrate.   The electrophoretic display device according to claim 1, wherein the color filter is disposed between the first electrode and an adhesive layer for attaching the electrophoretic element to the first substrate.   The electrophoretic display device according to claim 1, wherein the color filter has conductivity. A plurality of scanning lines each connected to at least one of the plurality of first electrodes via a select transistor;
A storage capacitor having a pair of electrodes connected to each of the plurality of first electrodes,
The electrophoretic display device according to claim 1, wherein the scanning line is one electrode of the pair of electrodes. A partition is provided between the first substrate and the second substrate;
The electrophoretic element is configured by the electrophoretic particles and a dispersion medium enclosed in the partition, a space defined by the partition, and the electrophoretic element. Electrophoretic display device.   An electronic apparatus comprising the electrophoretic display device according to claim 1.

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