JP2008238669A - Pattern printing sheet - Google Patents

Abstract

A member for providing a coordinate detection means that can be applied to a data input system in which handwriting is directly performed on a screen of a display device, is lightweight, mass-produced, inexpensive, easy to increase in area, and A pattern printing sheet having a wide reading angle and excellent reading performance is provided.
A pattern printing sheet according to the present invention has a transparent pattern 3 having a non-visible light reflecting property printed on a surface of a liquid repellent layer 22 of a substrate 2 composed of a base material 21 and a liquid repellent layer 22. The ink constituting the pattern 3 includes a material that reflects invisible light, and the material that reflects invisible light has a fixed cholesteric structure having wavelength selective reflectivity with respect to wavelengths in the invisible light region. a liquid crystal material having liquid-repellent layer 22 contains a leveling agent, a surface free energy of the liquid repellent layer 22 is in the range of 40~45mJ / m ^2.
[Selection] Figure 1

Description

  The present invention relates to a pattern-printed transparent sheet that is installed on the front surface of a medium for displaying various image information and provides various information accompanying the image information. Especially, it is a member that provides coordinate detection means that can be suitably applied to a data input system for handwriting directly on the screen of a display device, and is particularly lightweight, mass-produced, inexpensive, and large in area. The present invention relates to a pattern printing sheet that is easy and has a wide reading angle and excellent reading performance.

In recent years, there has been an increasing need to convert handwritten characters, pictures, symbols, and the like into electronic data that can be handled by an information processing device. In particular, handwritten information can be processed in real time without passing through a reading device such as a scanner. There is an increasing demand for a method for inputting data to, etc.
As such, a sheet on which a pattern reflecting non-visible light is printed as position information for indicating the position of the input electronic pen and the input locus has been proposed. For example, in Patent Document 1, a mark that is a transparent sheet that is attached to the front or front of a display device and that can provide position information for indicating the position of an input trajectory by an input electronic pen or the like is light having a predetermined wavelength. Printed with ink that emits light that can be read by the input locus reading means. However, Patent Document 1 does not describe the type of ink that embodies such a transparent sheet, merely describes the idea or desire of the transparent sheet, and specific examples of the sheet are as follows. Absent. Further, Patent Document 2 discloses a coordinate input device using a transparent member printed with special ink that reflects an infrared region. However, Patent Document 2 also discloses a type of ink that embodies such a device. Are not described, only ideas or desires are described, and there are no specific examples of sheets.

It is conceivable to use cholesteric liquid crystal as a pattern material that reflects invisible light used in such a sheet. In general, the lower layer of the liquid crystal layer has an alignment layer for aligning the liquid crystal. By applying an alignment process such as rubbing to the alignment layer, the cholesteric liquid crystal draws a beautiful spiral and spirals with respect to the substrate plane. Align and orient so that the axis is vertical. However, if the spiral axis is perpendicular to the substrate plane, reading with the pen is only performed in the 0 ° (vertical) direction. When the position information is read with the electronic pen as described above, since various ways of holding the pen are assumed on the use side, the reading range with the pen should be wide, preferably 25 ° or more. .
Japanese Patent Laid-Open No. 2003-256137 JP-A-2001-243006

  The present invention has been made to solve the above-described problems, and can be suitably used for providing additional information to an image display medium, for example, directly inputting data by handwriting on a display device. An object of the present invention is to provide a pattern printing sheet that is lightweight, can be mass-produced, inexpensive, easy to increase in area, and has a wide reading angle and excellent reading performance.

As a result of intensive studies to achieve the above object, the present inventors have provided a liquid repellent layer under a pattern made of a liquid crystal material having a cholesteric structure (cholesteric liquid crystal material), and containing a leveling agent. It has been found that by setting the surface free energy in the range of 40 m to 45 mJ / m ² , the cholesteric liquid crystal material is repelled by the water repellent layer, the orientation is curved, disturbed, and the reading angle is widened. Is completed.
That is, in the present invention, a non-visible light-reflective transparent pattern is printed on the surface of the water-repellent layer in a substrate composed of a base material and a water-repellent layer, and the ink constituting the transparent pattern reflects invisible light. The material that reflects the invisible light is a liquid crystal material having a fixed cholesteric structure having wavelength selective reflectivity with respect to the wavelength in the invisible light region, and the water repellent layer is leveled. A pattern printing sheet containing an agent and having a surface free energy of the water repellent layer in the range of 40 to 45 mJ / m ² is provided.

  The pattern printing sheet of the present invention can be suitably used for providing additional information to an image display medium, for example, by handwriting directly on a display device and inputting the position coordinates of handwritten information. In addition to being able to reduce the working space without being disturbed, the light weight, mass production, low cost, easy area enlargement, and excellent reading performance with a wide reading angle.

As shown in FIG. 1, the pattern printing sheet 1 of the present invention has a non-visible light reflective transparent pattern 3 printed on the surface of a water repellent layer 22 in a substrate 2 composed of a base material 21 and a water repellent layer 22. And the ink constituting the transparent pattern 3 includes a material that reflects invisible light, and the material that reflects invisible light has a wavelength selective reflectivity with respect to the wavelength in the invisible light region. It is a liquid crystal material having a cholesteric structure, and provides a pattern printing sheet 1 in which the water repellent layer 22 contains a leveling agent and the surface free energy of the water repellent layer 22 is in the range of 40 to 45 mJ / m ² .

  The invisible light is preferably infrared or ultraviolet. As infrared rays, it is light in a near infrared region of 800 to 2500 nm, and infrared rays having a selective reflection peak wavelength at 800 to 950 nm are preferable. Moreover, as an ultraviolet-ray, it is preferable in it being an ultraviolet-ray which has a selective reflection peak wavelength in 200-400 nm.

The ink constituting the invisible light reflective transparent pattern (hereinafter also referred to simply as the transparent pattern) used in the present invention has a fixed cholesteric structure and has a function of reflecting invisible light. The component is not particularly limited. In addition, when a cross section of a transparent pattern cut by a surface perpendicular to the substrate is observed with a scanning electron microscope, a multilayer structure in which the transparent pattern has a constant repetition period (also referred to as a multilayer film structure, which is appropriately used hereinafter) Contains.
Hereinafter, a liquid crystal material exhibiting a cholesteric structure applicable to the sheet of the present invention will be described.
The liquid crystal molecules contained in the transparent ink used in the present invention are liquid crystal materials exhibiting a cholesteric liquid crystal phase, and are not particularly limited as long as they have cholesteric regularity, but are polymerizable to polymerizable nematic liquid crystals. A polymerizable chiral nematic liquid crystal material (polymerizable monomer or polymerizable oligomer) or a polymer cholesteric liquid crystal material mixed with the above chiral agent can be used.
In the present invention, among the polymerizable liquid crystal materials, it is preferable to use a polymerizable monomer or polymerizable oligomer having an acrylate structure as a polymerizable functional group.
The liquid crystal means, in a narrow sense, a fluid liquid substance having optical anisotropy. However, in the present invention, in addition to the liquid crystal, in addition to this, the liquid narrowly defined liquid crystal is polymerized, cooled, or the like. In addition, the term also includes a solidified product while maintaining optical anisotropy.
The liquid crystal material exhibiting (expressing) the cholesteric structure is essentially a visible light region as long as it exhibits a high reflectance (usually about 5 to 50%) at at least a part of wavelengths in the non-visible light region. High transmittance is not necessarily required at the wavelength of. Even if the liquid crystal material having the cholesteric structure is completely opaque, if the area of the non-formation part (margin part) of the liquid crystal material is appropriately large and the transmitted light from there is used, the transparent pattern It is because it is possible to obtain desired transparency as a whole. However, it is needless to say that the liquid crystal material itself has a higher visible light transmittance. In general, when the liquid crystal material having such a cholesteric structure brings the high reflection wavelength region to the invisible light region, the visible light region transmits a visible light of about 70% or more with a thickness of about several μm. Get rate. On the other hand, in the non-visible light region, it is common to obtain a high reflectance of about 5 to 50%. The temperature range in which the polymerizable liquid crystal material exhibits a cholesteric phase is not particularly limited as long as the polymerizable liquid crystal material can be fixed in a cholesteric phase state. This is preferable because the drying process during printing and the phase transition of the liquid crystal can be performed simultaneously.

If it is the above materials, a liquid crystal molecule can be optically fixed in the state of a cholesteric liquid crystal, and a pattern which is easy to handle as a sheet and which is stable at room temperature can be formed.
Alternatively, a liquid crystal polymer (polymer cholesteric liquid crystal) that has a high glass transition point and can be solidified into a glass state at room temperature by cooling after heating can be used. Similarly, these materials can form liquid crystal molecules that are optically fixed in the form of liquid crystals having cholesteric regularity, and form a stable pattern at room temperature that is easy to handle as an optical sheet. Because you can.
A method for forming a cholesteric liquid crystal is also described in JP-A Nos. 2001-5684 and 2001-110045.

  Examples of nematic liquid crystal molecules (liquid crystalline monomers) that can be used in the present invention include compounds represented by the following formulas (1) to (11). The compounds exemplified here have an acrylate structure and can be polymerized by ultraviolet irradiation or the like.

［化合物（１１）において、Ｘ¹は２〜５(整数）である。］

[In the compound (11), X ¹ is 2 to 5 (integer). ]

  Examples of the liquid crystal polymer include a polymer in which a mesogenic group exhibiting liquid crystal is introduced into the main chain, a side chain, or both positions of the main chain and the side chain, a polymer cholesteric liquid crystal in which a cholesteryl group is introduced into the side chain, A liquid crystalline polymer as disclosed in Kaihei 9-133810, a liquid crystalline polymer as disclosed in JP-A-11-293252, or the like can be used.

  The chiral agent contained in the transparent ink used in the present invention is a material that has an asymmetric carbon atom and forms a chiral nematic phase by mixing with a nematic liquid crystal, and is not particularly limited as long as it has polymerizability. However, a material having an acrylate structure as exemplified in Formula (12) is preferable because it can be polymerized by ultraviolet irradiation.

［Ｘは２〜５（整数）である。］

[X is 2 to 5 (integer). ]

  The property of reflecting the invisible light of the transparent pattern in the present invention utilizes the wavelength selective reflectivity (similar principle as Bragg reflection in X-ray diffraction) of a liquid crystal material having a cholesteric structure. The reflection peak wavelength (wavelength satisfying the Bragg reflection condition) is determined by the pitch length of the cholesteric structure contained in the pattern. When nematic liquid crystal and a chiral agent are used as the liquid crystal material, the addition amount of the chiral agent is adjusted. By doing so, the pitch length can be controlled. In order to obtain the target selective reflection peak wavelength in the non-visible light region, the amount of chiral agent added varies depending on the type of liquid crystal used and the type of chiral agent. For example, the liquid crystal of formula (11) and the chiral agent of formula (12) are used. When used, a cholesteric phase having a reflection peak in the infrared region is formed by adding about 3 parts by weight of the chiral agent to 100 parts by weight of the liquid crystal, and an ultraviolet light by adding about 5 parts by weight of the chiral agent to 100 parts by weight of the liquid crystal. A cholesteric liquid crystal having a reflection peak in the region is formed. When polymer cholesteric liquid crystal is used as the liquid crystal material, a polymer material having a target pitch length may be selected.

The polymer of nematic liquid crystal molecules and a chiral agent in the present invention can be obtained, for example, by adding a known photopolymerization initiator or the like to a polymerizable nematic liquid crystal and a polymerizable chiral agent and irradiating with ultraviolet rays to cause radical polymerization. .
In the present invention, when a transparent pattern is printed, it is preferable to use a coating solution in which a polymerizable monomer, a polymerizable oligomer, or a chiral agent is dissolved in a solvent.
The solvent is not particularly limited as long as it has sufficient solubility in the material, and a known one may be used. For example, anone (cyclohexanone), cyclopentanone, toluene, acetone, MEK (methyl ethyl ketone), MIBK (methyl) Common solvents such as isobutyl ketone), DMF (N, N-dimethylformamide), DMA (N, N-dimethylacetamide), methyl acetate, ethyl acetate, n-butyl acetate, 3-methoxybutyl acetate, A mixed solvent is mentioned.
In the sheet of the present invention, the transparent pattern printing method is not particularly limited, and a known method can be used. Examples thereof include a flexographic printing method, a gravure printing method, a stencil printing method, and an ink jet printing method.

The water repellent layer in the pattern printing sheet of the present invention repels each droplet of ink during dot printing that forms a transparent pattern. These droplets rise as a result of being repelled and are greatly curved. These curves are fixed by drying and cross-linking of the droplets, and the transparent pattern includes a multilayer structure having a curved portion. By forming the curved portion, a non-visible light reflective pattern printing sheet having a wide reading angle can be obtained.
Furthermore, in the present invention, a leveling agent is contained in the water-repellent layer, and the surface free energy of the water-repellent layer is in the range of 40 to 45 mJ / m ² , so that a wide reading angle of 25 ° or more can be obtained. .

The surface free energy can be calculated by measuring the contact angle of the surface to be measured using two different liquids. For example, from the contact angle measurement of pure water and diiodomethane, it is calculated | required by the relational expression of (1) using the Owens-Wendt-Kaelble method.
γ _S = γ _S ^d + γ _S ^p (1)
(Γ _S : solid surface free energy, γ _S ^d : solid dispersion force, γ _S ^p : solid polar interaction force)
The surface free energy of the film are known water and diiodomethane gamma _L ^d, sought gamma _L ^p, gamma respective contact angles from _L a (theta) is substituted into equation (2) below γ _S ^d, γ _S ^p , (1).
(1/2) × γ _L × (1 + cos θ) = (γ _S ^d × γ _L ^d ) ^1/2 + (γ _S ^p × γ _L ^p ) ^1/2
... (2)
(Γ _L : surface free energy of liquid, γ _L ^d : dispersion force of liquid, γ _L ^p : polar interaction force of liquid)

FIG. 2 is a photograph (a) of a dot-shaped cross section of a transparent pattern (a cross section cut by a plane orthogonal to the substrate of the transparent pattern), which is an embodiment of the sheet of the present invention, and repetition of cholesteric liquid crystal in the partial cross section. It is a scanning electron micrograph (b)-(d) which shows a layer structure.
(A) shows that the water repellent layer repels the ink constituting the transparent pattern, so that the dot shape of the transparent pattern 3 rises and becomes a disk shape or an elliptical hemisphere. (B) is a partial cross-sectional photograph of the top of the dot shape of (a), and (c) and (d) are partial cross-sectional photographs of the left inclined portion and the right inclined portion of the dot shape of (a), respectively. . As described above, since the dot shape has a long inclined portion, a curved portion is formed in a multilayer film having a cholesteric structure, that is, a parallel plane group, in the entire dot shape, and is microscopically seen in the photographs (b) to (d). A wide reading angle can be realized by the principle described later in combination with a simple curve.
As described above, the curved portion included in the multilayer structure in the present invention includes not only a curved portion caused by the contour shape of each transparent pattern but also a microscopic curved portion in each transparent pattern. is there.
On the other hand, as shown in FIG. 3, in a scanning electron micrograph showing a repeated layer structure of a conventional cholesteric liquid crystal, which is a comparative example for the present invention, the multilayer structure is flat (consisting of substantially parallel plane groups). The reflection angle when a light beam having a constant incident angle is incident is a constant value over the entire multilayer surface, and the reading angle range is narrow.

  In the present invention, the curved shape of the multilayer film structure over the entire dot shape is such that each film surface constituting the parallel surface group (or a line corresponding to the cut surface of the film surface) is curved as shown in FIG. In addition to a curved line at the corresponding cut surface, it may be a cross-connected refraction plane (a broken line at the corresponding cut surface) line, or a combination of a curved surface and a refraction plane. When each membrane surface is a curved surface, each membrane surface is not only a continuous curved surface (continuous curve for the corresponding cut surface) but also a discontinuous curved surface including a fault, cusp, etc. (discontinuous curve for the corresponding cut surface). May be. In addition, when each film surface is a curved surface, each film surface has a curved surface group that is always convex in one direction, such as a hemispherical surface (a curved group that is convex in one direction in the corresponding cut surface), or a concave surface and a convex surface. It may be any one of a curved surface that repeats alternately (in the corresponding cut surface, a sine wave-shaped wave curve group). Further, the degree of distribution of the tangential angle of the film surface due to the curvature of each film surface is appropriately set according to the application and the design request, but is usually about 10 to 30 °.

In the liquid crystal having the above-described cholesteric (chiral nematic) structure, the axis of each liquid crystal molecule is present in each layer surface of the multilayer structure and is uniformly aligned in a specific direction in the layer surface. In addition, the alignment direction of the liquid crystal molecular axes changes sequentially as a function of the layer thickness direction, and as the direction of rotation proceeds toward the thickness direction of the cholesteric structure, the rotation axis faces the thickness direction of the multilayer film. It has a spiral structure (cholesteric structure) with a constant period that rotates in a specific direction within the layer surface of the film. A characteristic of the cholesteric structure is that it is a circularly polarized light component in which the rotational direction of the helix coincides with the rotational direction of the electric field and reflects circularly polarized light having a wavelength corresponding to the helical pitch (selective reflectivity). The selective reflection wavelength λ (nm) is generally given by the following equation.
λ = p · n · cos θ
p: helical pitch of cholesteric liquid crystal (nm)
n: average refractive index of liquid crystal θ: incident angle of light (angle from surface normal)
One pitch of the cholesteric structure means that the axis direction of the elongated liquid crystal molecules is required to draw a helix and rotate 360 ° as the axis direction of the thin liquid crystal molecules advances in the layer thickness direction (spiral axis, separate from the liquid crystal molecule axis). Observing a cross section cut by a plane that is actually perpendicular to the substrate of the transparent pattern, however, the liquid crystal molecular axis rotates in the same direction in the layer plane every time the liquid crystal molecular axis rotates 180 °. A repeated layer structure can be seen in the layer thickness direction (see FIGS. 2 and 3). Therefore, the apparent interlayer pitch seen when observing the cross section is ½ of the helical pitch of the liquid crystal. Therefore, if the apparent interlayer pitch seen when the cross section is observed is 250 nm, the pitch of the liquid crystal is 500 nm.

  In the present invention, as the material used for the composition for forming the water repellent layer (water repellent layer composition), it is preferable to select a material having the property of repelling the ink droplets forming the transparent pattern. In particular, a transparent resin using an organic resin, an inorganic resin, or the like is preferable in that a layer can be formed by coating. This resin is not particularly limited, and examples thereof include a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin. Among these, from the viewpoint of obtaining durability, solvent resistance, and a wide reading angle, a resin of a type that is cured by crosslinking is preferable, and further, it can be crosslinked in a short time by ionizing radiation such as ultraviolet rays and electron beams. An ionizing radiation curable resin is more preferable.

Examples of the thermoplastic resin include acrylic resins, polyester resins, thermoplastic urethane resins, vinyl acetate resins, cellulose resins, and the like, and the base material is a cellulose resin such as TAC (triacetyl cellulose). In this case, as the thermoplastic resin, for example, a cellulose resin such as nitrocellulose, acetylcellulose, cellulose acetate propionate, and ethylhydroxyethylcellulose is preferable.
Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, urethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, silicon resin. , Polysiloxane resin, curable acrylic resin, and the like. When a thermosetting resin is used, a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier and the like can be further added as necessary.

As a material used for the water repellent layer composition, an ionizing radiation curable resin is preferable as described above, and various reactive monomers and / or reactive oligomers are preferably used. For example, examples of the reactive monomer include the above-mentioned polyfunctional (meth) acrylate monomer. Examples of the reactive oligomer include an oligomer having a radical polymerizable unsaturated group in the molecule, for example, the above-mentioned polyfunctional (meth) acrylate oligomer.
Moreover, as a polymerization initiator of a reactive monomer or a reactive oligomer, the above-mentioned bisacylphosphine oxide-based or α-aminoketone-based photopolymerization initiator may be mentioned.

The leveling agent used in the water-repellent layer composition according to the present invention is not particularly limited as long as it repels ink that forms a transparent pattern. As the type of leveling agent, various compounds such as silicones, fluorines, polyethers, acrylics, titanates, etc. can be used to repel the ink of liquid crystal material that forms a fixed cholesteric structure. Is preferably a silicone or acrylic compound.
The addition amount may be appropriately adjusted according to a desired reading angle, but is preferably 0.01 to 0.1% by mass with respect to the total amount of the water-repellent layer composition.

From the viewpoint of obtaining a wide reading angle, in addition to adding the leveling agent (liquid-repellent substance), the water-repellent layer is further added with fine particles to form a cholesteric liquid crystal formed thereon. Concavities and convexities may be formed on the Bragg reflecting surface of the structure.
As the fine particles, those usually used can be added in an appropriate amount without any particular restriction. For example, inorganic particles include transparent particles such as α-alumina, silica, kaolinite, glass, calcium carbonate, diamond, silicon carbide and the like. Examples of the particle shape include a sphere, a spheroid, a polyhedron, a truncated polyhedron, and a scaly shape, and are not particularly limited, but a spherical shape is preferable. Organic materials include synthetic resin beads such as cross-linked acrylic resin and polycarbonate resin. Among these, α-alumina and silica are preferable and spherical ones are particularly preferable because they are highly transparent and easily obtain spherical particles. The particle diameter of the fine particles is about 50 μm to 5 mm.

  Further, in the water-repellent layer, if necessary, the transparent pattern invisible light reflection function, the moire preventing effect, and the transparency in the present invention are within the range not hindering, for example, coating liquid or Various known additives in the ink may be added as appropriate. Examples of the additive include a light stabilizer such as an ultraviolet absorber, an antistatic agent, a heat stabilizer, a lubricant, a surfactant, and a dispersion stabilizer.

The water repellent layer can be formed of the water repellent layer composition ink obtained as described above by a known layer forming method such as a coating method or a printing method. Specifically, the ink of the (meth) acrylate resin composition is applied to the printing surface of the transparent pattern 3, or the ink of the water repellent layer composition is applied to the base material, using a coating method such as roll coating, comma coating, or die coating, or It may be formed by a printing method such as screen printing or gravure printing.
The thickness of the water repellent layer is usually about 0.1 to 10 μm, and is preferably 0.1 to 5 μm from the viewpoint of being able to form a thin film and being inexpensive.

The substrate 21 used in the pattern printing sheet of the present invention may be a transparent substrate or an opaque substrate.
The transparent substrate is a material that transmits visible light (average transmittance is 60% or more, preferably about 80% or more at a wavelength of 380 nm to 780 nm), and infrared reflectance used for reading compared to a dot pattern. Is not particularly limited as long as it is sufficiently low, but those formed of a material with few optical defects are preferable. A so-called film, sheet, or plate is appropriately used. Specifically, as the material for the transparent substrate, glass, TAC (triacetyl cellulose), PET (polyethylene terephthalate), polycarbonate, polyvinyl chloride, acrylic, polyolefin, or the like is preferably used. Moreover, thickness is suitably selected from the range of about 20-5000 micrometers according to material, required performance, and a usage form.
When using a material that easily dissolves or swells in a solvent such as a polymer film such as a TAC film as the transparent substrate, the substrate should be prevented from being attacked by the solvent in the coating solution used during transparent pattern printing. It is preferable to provide a barrier layer thereon. In this case, the barrier layer may also serve as the alignment film. For example, a water-soluble substance such as PVA (polyvinyl alcohol) or HEC (hydroxyethyl cellulose) may be used as the barrier layer.
Examples of the opaque substrate include paper, cloth, plastic to which a dye or pigment is added, a metal plate, and the like.

Further, in the pattern printed sheet of the present invention, when handwriting is input with an input terminal such as a pen type, the pattern is printed in order to give a strength that can withstand repeated input terminals or to make the appearance completely transparent. A transparent layer (or a hard coat layer (a surface protective layer made of a hard coating) may be provided so as to fill the gap between the patterns with a transparent material having a refractive index close to that of the material. As another function, The transparent layer may be added with functions such as abrasion resistance, antireflection, anti-slip, antistatic, antifouling, antiglare, etc. The material of the transparent layer is not particularly limited, Those used in the field of sheets and lenses can be used, for example, acrylic resins, silicon resins, and the like that are crosslinked and cured by ultraviolet rays, electron beams, heat, etc., and have a glass transition temperature of 100 ° C. or higher. A Lil resin is preferable.
Furthermore, when attaching the pattern printing sheet of this invention to a display apparatus, in order to ensure the visibility, you may provide an anti-reflective film etc. in the sheet | seat surface or inside. The material of the antireflection film is not particularly limited, and those used in the field of ordinary display sheets and lenses can be used. For example, a dielectric in which a thin film of a low refractive index material such as magnesium fluoride or fluorine resin and a thin film of a high refractive index material such as zirconium oxide or titanium oxide are laminated so that the low refractive index thin film is the outermost surface A multilayer film or the like is a typical one.

The pattern printing sheet 1 of the present invention is installed in combination with or integrated with various image display media, and is used for the purpose of providing various information (position coordinates, etc.) attached to the image. As this image display medium, media that display various types of image information are targeted. The image information to be displayed may be in the form of either a still image or a moving image. The types of information include encryption codes such as letters, numbers, figures, barcodes, and photographic images (landscapes, people, paintings, and other various types). And so on. Specific examples of the image display medium 5 include display devices such as CRT (cathode ray tube), LCD (liquid crystal display device), PDP (plasma display), EL (electroluminescence) display device, or paper or resin on which an image is printed. Examples include books, brochures, catalogs, forms, instruction manuals, etc. made of film. Examples of the usage or specification form include various types described later (such as a mobile phone). Among them, a representative one is a use that is installed opposite to the front surface of a display device such as a CRT and inputs position coordinate information of an image to be handwritten on a screen. Hereinafter, this application will be described in detail. As shown in FIG. 5, information on the position of the input terminal on the sheet 1 can be provided by reading the reflection pattern of the pattern printing sheet 1 using the input terminal 6 capable of irradiating and detecting invisible light. is there.
The pattern printing sheet 1 of the present invention is preferably mounted on a display device 5 capable of displaying an image, and is preferably mounted facing the front surface of the display device.
Note that mounting attached to the front face includes both a form in which the display apparatus is attached in close contact with the front face of the display apparatus and a form in which the display apparatus is mounted in an isolated state through the gap.

In the pattern printing sheet of the present invention, the transparent pattern is set so that position information of the input terminal on the sheet surface can be derived from a partial pattern read by an input terminal equipped with a sensor.
The transparent pattern in the present invention is also exemplified in Patent Document 1, for example, by setting a plurality of dot shapes, and patterning a combination of these multiple-shaped dots arranged within a predetermined range in a plane, The thickness of the ruled lines arranged vertically and horizontally is changed, and the combination of the sizes of the overlapping portions of the ruled lines within a predetermined range is patterned. The values of the x and y coordinates are directly linked to the vertical and horizontal sizes of the dots. However, as a particularly simple and preferred one, a reference point arranged at equal intervals in the vertical and horizontal directions is set, and dots displaced vertically and horizontally with respect to this reference point are arranged, and the reference of these dots There is a method using a relative positional relationship from a point. This method is advantageous in increasing the resolution of the input device because the dot size can be made small and constant.

In the pattern printing sheet of the present invention, in order to detect the reflection pattern by the invisible light sensor provided in the input terminal, it is preferable that the invisible light reflectance at the wavelength irradiated and detected by the sensor is large. Usually, the reflectance is about 5 to 50% at the wavelength irradiated and detected by the sensor, and preferably 20% or more.
When a liquid crystal material having a cholesteric structure is used as the invisible light reflecting material, the reflection by the cholesteric structure reflects only circularly polarized light in the same direction as the cholesteric helix, so that the maximum is only about 50%. Not reach.
In the case of reflection with a cholesteric structure, the reflection intensity generally increases as the printing thickness increases, but if it is too thick, the orientation of the liquid crystal is disturbed, the transparency is lowered, and the drying load is increased. The thickness is usually about 1 to 20 μm, preferably about 3 to 10 μm.
When a non-visible light reflecting pigment is used as the non-visible light reflecting material, the printed thickness of the non-visible light reflecting pattern may be 0.1 μm or more, but is usually about 1 to 20 μm. In general, the thicker the film thickness, the better the reflectivity. However, since the coloring becomes dark and the transparency is impaired, it is necessary to adjust appropriately.

  In the pattern printing sheet of the present invention, the dot shape of the dot pattern is not particularly limited as long as it can be easily distinguished from adjacent dots, and usually the shape in plan view is a circle, an ellipse, a polygon or the like. Also, there is no particular limitation on the three-dimensional shape of the dot. Usually, when the pen-type input terminal comes into contact with it, it slides smoothly without resistance, and the dot and the terminal are hardly damaged from each other. Although it is preferably a disc shape, it may be hemispherical, concave, or polygonal.

The display device on which the pattern printing sheet of the present invention is mounted may be connected to an information processing device that processes handwritten input data, or may be independent. Can be displayed on the screen and intuitive input is possible, which is preferable.
Examples of information processing apparatuses that handle handwritten input information include various portable terminals such as mobile phones and PDAs, personal computers, videophones, televisions having an intercommunication function, and Internet terminals.

The input terminal 6 that can be used in the present invention is not particularly limited as long as it can emit invisible light i and can detect the reflected light r of the pattern as shown in FIG. For example, as an example in which the pen-type input terminal 6 also includes the read data processing device 7, a pen tip that does not include ink, graphite, or the like, disclosed in JP 2003-256137 A, an invisible light irradiation unit And a camera incorporating a communication interface such as a wireless transceiver using a CMOS camera, processor, memory, Bluetooth technology, etc., and a battery.
As the operation of the pen type input terminal 6, when the pen tip is drawn so as to contact the front surface of the sheet 1 printed with the dot pattern as shown in FIG. The applied pen pressure is detected, the CMOS camera is activated, and a predetermined range in the vicinity of the pen tip is irradiated with a non-visible light beam having a predetermined wavelength emitted from the non-visible light irradiation unit, and a pattern is imaged. For example, it is performed several tens to 100 times per second). When the pen-type input terminal 6 includes the read data processing device 7, the input trace associated with the movement of the pen tip during handwriting is digitized and converted into data by analyzing the captured pattern with a processor. The input trajectory data is generated and transmitted to the information processing apparatus.
Note that a communication interface such as a processor, a memory, a wireless transceiver using Bluetooth technology, and a member such as a battery are provided outside the pen-type input terminal 6 as a read data processing device 7 as shown in FIG. May be. In this case, the pen-type input terminal 6 may be connected to the read data processing device 7 with the code 8 or may transmit the read data wirelessly using radio waves, invisible light, or the like.
In addition, the input terminal 6 may be a reader as described in JP-A-2001-243006.

The read data processing device 7 applicable in the present invention has a function of calculating position information from continuous imaging data read by the input terminal 6, combining it with time information, and providing it as input trajectory data that can be handled by the information processing device. If it has, it will not specifically limit, What is necessary is just to comprise members, such as a processor, memory, a communication interface, and a battery.
Further, the read data processing device 7 may be built in the input terminal 6 as disclosed in JP 2003-256137 A, or may be built in an information processing device including a display device. Further, the read data processing device 7 may transmit the position information wirelessly to an information processing device provided with a display device, or may transmit it by a wired connection connected by a code or the like.
The information processing apparatus connected to the display device 5 sequentially updates the images displayed on the display device 5 based on the locus information transmitted from the read data processing device 7, thereby obtaining the locus input by handwriting on the input terminal 6. It can be displayed on the display device as if it were written with a pen on paper.

As described above, the pattern printing sheet of the present invention can be mounted on an existing display device as it is, and the production thereof is easier than a position input device such as an electrostatic type or a pressure sensitive type incorporated in the display device. And cost can be reduced. In addition, even if the function for providing location information is reduced due to thin patterns or scratches that can provide printed location information, only the sheet needs to be replaced. It becomes easy to handle for the person.
The pattern printing sheet of the present invention can be used as a liquid crystal protective sheet when mounted on a liquid crystal display. In addition, the pattern printing sheet of the present invention may be used in addition to being placed on the front surface of the display device, such as when used on paper such as an inspection request table (see Japanese Patent Application Laid-Open No. 2004-341831).

The pattern printing sheet of the present invention can be detachably mounted facing the front surface of the display device. In this way, not only one display device but also another display device can be attached. Further, it is preferable that the sheet itself is provided with a mounting means for the display device so that the sheet can be mounted without performing processing for mounting on the display device side. The mounting means may be provided integrally with the seat or may be provided separately.
Examples of such mounting means include a device that hooks a buckle-shaped object on the corner of the display device, and a device that sandwiches an end of the display device. In the case of mounting on the front surface of the display device, there is a sticking tool that is provided on the contact surface side that comes into contact with the display device and has adhesiveness or adhesiveness for sticking to the display device. Examples of the sticking tool include those having adhesiveness or tackiness that are integrally attached to the sheet, and those that include an adhesive or pressure-sensitive adhesive directly applied to the contact surface.

The pattern printing sheet of the present invention is preferably made separable in order to improve the manufacturing convenience. Specific examples include those that can be separated with a cutting tool such as a scissors or a dedicated cutting tool, and those that can be separated by hand by inserting perforations. If this is the case, the user can cut according to the size of the display device owned by each user, so the manufacturer has set several predetermined sizes. This is because a sheet may be manufactured. Further, a perforation may be made in the standard size of a general-purpose display device.
Also, if such usage is possible, it is possible to divide one sheet on which a pattern providing position information is printed, and to indicate different coordinate ranges for each sheet. When such a sheet is used, for example, if a sheet indicating continuous coordinates is applied to an adjacent display device, continuity can be given to input data. Further, by using a plurality of sheets having different coordinate ranges for one input device, different meanings can be given to the respective sheets.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1
(1) Preparation of coating solution for invisible light (infrared) reflective transparent pattern Nematic-isotropic with acryloyl group polymerizable at both ends, mesogenic structure at the center and spacer between the acryloyl group 100 parts by weight of a liquid crystal monomer having a transition temperature of around 110 ° C. (having the molecular structure shown by the compound (11)) and a chiral agent having a polymerizable acryloyl group at both ends (shown by the above chemical formula (12)) A cyclohexanone solution having 3 parts by weight dissolved in cyclohexanone was prepared. In this methyl ethyl ketone solution, 4 parts by weight of a photopolymerization initiator (manufactured by BASF Japan Ltd., Lucillin TPO), 0.0054 parts by weight of a leveling agent (BYK-361N), 0.02 parts by weight of polymerization are prohibited. An agent (trade name BHT, manufactured by Kanto Chemical Co., Inc.) was added.
(2) Preparation of coating solution for water repellent layer Leveling agent having 100 parts by weight of pentaerythritol triacrylate (PETA, Nippon Kayaku Co., Ltd., trade name KAYARAD PET-30) and an acrylic skeleton (Bik Chemie Co., Ltd., product) Name BYK-361N) 0.06 parts by weight, polymerization initiator (Ciba Specialty Chemicals Co., Ltd., Irgacure 184) 4 parts by weight was added and mixed, and then a solvent in which methyl ethyl ketone and butyl acetate were mixed in a ratio of 1: 1 was resin. The coating solution for water repellent layer was prepared by adding and adapting so that the content was 50% by mass.
(3) Preparation of pattern printing sheet The water-repellent layer coating solution of (2) was applied to a polyethylene terephthalate (PET) substrate with a bar coater to a thickness of 1 μm and cured by ultraviolet irradiation. A water repellent layer was formed. Next, on this water-repellent layer, the non-visible light reflective transparent pattern coating solution (1) is coated with a dot pattern with a thickness of 6 to 8 μm by a gravure printing method, and cured by ultraviolet irradiation, A transparent sheet on which a dot pattern was printed was produced. The surface free energy of the water repellent layer was 42.3 mJ / m ² .
When infrared rays were irradiated and the reflected light was detected as an image, it could be read up to 30 ° and had a wide reading angle.

Example 2
In Example 1, the dot pattern was printed in the same manner except that the leveling agent (2) was changed to 0.03 part by weight of the leveling agent having an acrylic skeleton (product name BYK-354, manufactured by Big Chemie Co., Ltd.). A transparent sheet was prepared. The surface free energy of this liquid repellent layer is 40.6 mJ / m ^{2. When} the reflected light is detected as an image by irradiating infrared rays, it can be read up to 30 ° and has a wide reading angle. It was.

Example 3
In Example 1, the dot pattern was printed in the same manner except that the leveling agent (2) was changed to 0.03 parts by weight of the leveling agent having a silicone skeleton (product name BYK-300, manufactured by Big Chemie Co., Ltd.). A transparent sheet was prepared. The surface free energy of this liquid repellent layer is 44.3 mJ / m ^{2. When} the reflected light is detected as an image by irradiating infrared rays, it can be read up to 30 ° and has a wide reading angle. It was.

Example 4
In Example 1, the dot pattern was printed in the same manner except that the leveling agent (2) was changed to 0.03 part by weight of the leveling agent having a silicone skeleton (product name BYK-310, manufactured by Big Chemie Co., Ltd.). A transparent sheet was prepared. The surface free energy of this liquid repellent layer is 44.8 mJ / m ^{2. When} the reflected light is detected as an image by irradiating infrared rays, it can be read up to 25 ° and has a wide reading angle. It was.

Example 5
A transparent sheet on which a dot pattern was printed was prepared in the same manner as in Example 1 except that the polymerization initiator (2) was changed to 4 parts by weight of Lucillin TPO (manufactured by BASA Japan Co., Ltd.). The surface free energy of this liquid repellent layer is 42.3 mJ / m ^{2. When} the reflected light is detected as an image by irradiating infrared rays, it can be read up to 30 ° and has a wide reading angle. It was.

Example 6
A transparent sheet on which a dot pattern was printed was prepared in the same manner as in Example 1 except that (2) PETA was changed to 100 parts by weight of trimethylolpropane triacrylate. The surface free energy of this liquid repellent layer is 43.4 mJ / m ^{2. When} the reflected light is detected as an image by irradiating infrared rays, it can be read up to 30 ° and has a wide reading angle. It was.

Comparative Example 1
In Example 1, the dot pattern was printed in the same manner except that the leveling agent (2) was changed to 0.06 part by weight of the leveling agent having an acrylic skeleton (product name BYK-380, manufactured by Big Chemie Co., Ltd.). A transparent sheet was prepared. The surface free energy of this liquid repellent layer was 46.5 mJ / m ² , and when the infrared light was irradiated and the reflected light was detected as an image, the reading angle was up to 10 °.

Comparative Example 2
In Example 1, the dot pattern was printed in the same manner except that the leveling agent (2) was changed to 0.06 parts by weight of the leveling agent having a silicone skeleton (product name BYK-UV3500, manufactured by Big Chemie Co., Ltd.). A transparent sheet was prepared. The surface free energy of this liquid repellent layer was 32.6 mJ / m ² , and when the reflected light was detected as an image by irradiating infrared rays, the reading angle was up to 5 °.

Comparative Example 3
A transparent sheet on which a dot pattern was printed was prepared in the same manner as in Example 1 except that the solvent of the water repellent layer coating solution (2) was changed to butyl acetate. The surface free energy of this liquid repellent layer was 48.4 mJ / m ² , and when the infrared light was irradiated and the reflected light was detected as an image, the reading angle was up to 15 °.

Comparative Example 4
A transparent sheet on which a dot pattern was printed was prepared in the same manner as in Example 1 except that the solvent of the water repellent layer coating solution (2) was changed to methyl isobutyl ketone. The surface free energy of this liquid repellent layer was 49.4 mJ / m ² , and when the infrared ray was irradiated and the reflected light was detected as an image, the reading angle was up to 10 °.

  As described above in detail, the pattern printing sheet of the present invention is a member that provides coordinate detection means that can be applied to a data input system of a type that is directly handwritten on the screen of a display device, and can reduce the work space. In addition, it is lightweight, can be mass-produced, is inexpensive, can be easily increased in area, and has a wide reading angle and excellent reading performance. For this reason, it can be used easily and has high practical performance. Various information processing such as mobile terminals such as mobile phones and PDAs, personal computers, videophones, televisions equipped with an intercommunication function, Internet terminals, etc. Can be used in the device.

It is sectional drawing which shows one embodiment of the pattern printing sheet of this invention. The cross-sectional photograph (FIG. 2-a) of the dot shape of the transparent pattern which is one embodiment of the pattern printing sheet of this invention, and the scanning electron micrograph which shows the repeating layer structure of a cholesteric liquid crystal in the partial cross section (FIG. 2-) b to d). It is a scanning electron micrograph which shows the repeating layer structure of the conventional flat cholesteric liquid crystal. It is a principal part enlarged plan view which shows the example in which the dot pattern was irregularly arranged in the pattern printing sheet of this invention. It is the schematic of the whole system using the pattern printing sheet of this invention.

Explanation of symbols

1: Pattern printing sheet 2: Substrate 3: Transparent pattern 5: Display device 6: Input terminal (pen type)
7: Reading data processing device 8: Code 21: Base material 22: Water repellent layer i: Invisible light (incident light)
r: reflected light

Claims (16)

A transparent pattern having non-visible light reflectivity is printed on the surface of the water-repellent layer in the substrate comprising the base material and the water-repellent layer, and the ink constituting the transparent pattern includes a material that reflects invisible light, The material that reflects invisible light is a liquid crystal material having a fixed cholesteric structure having wavelength selective reflectivity with respect to wavelengths in the invisible light region,
The water-repellent layer contains a leveling agent, pattern-printed sheet surface free energy of the water-repellent layer is in the range of 40~45mJ / m ^2.   The pattern printing sheet according to claim 1, wherein the liquid crystal material having a cholesteric structure is a chiral nematic liquid crystal material obtained by mixing a nematic liquid crystal with a chiral agent.   The pattern printing sheet according to claim 1, wherein the liquid crystal material having a cholesteric structure is a polymer cholesteric liquid crystal material.   The pattern printing sheet according to claim 2, wherein the nematic liquid crystal and / or the chiral agent is a compound having an acrylate structure.   The pattern printing sheet according to claim 1, wherein the transparent pattern is a dot pattern.   The pattern printing sheet according to claim 1, wherein a printing thickness of the transparent pattern is 1 to 20 μm.   The pattern printing sheet according to claim 1, further comprising a transparent layer on the transparent pattern.   The pattern printing sheet according to claim 1, wherein the invisible light is infrared light or ultraviolet light.   The pattern printing sheet according to claim 1, wherein the transparent pattern has a selective reflection peak wavelength at 800 to 950 nm.   The pattern printing sheet according to claim 1, wherein the transparent pattern has a selective reflection peak wavelength at 200 to 400 nm.   The pattern printing sheet can provide information on the position of the input terminal on the sheet by reading the reflection pattern of the sheet using an input terminal capable of irradiating and detecting invisible light. The printed pattern sheet as described.   The pattern printing sheet according to claim 11, wherein the pattern printing sheet is a sheet attached to a display device capable of displaying an image.   The pattern printing sheet according to claim 12, which is mounted to face the front surface of the display device.   The pattern printing sheet according to claim 12, further comprising mounting means for mounting on the display device.   The pattern printing sheet according to claim 14, wherein the mounting means is an adhesive tool that is provided on a contact surface side that comes into contact with the display device and has an adhesive property or an adhesive property to be attached to the display device.   The pattern printing sheet according to claim 1, which is separable.

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