JP3231836B2 - Lens array plate, liquid crystal display device and optical connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens array plate excellent in mass productivity and array precision of GI type lenses, a liquid crystal display device using the same and excellent in a wide viewing angle, and a lens array. The present invention relates to an optical connector made of a board.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
There has been known a lens array plate in which an I-shaped lens 2 is bundled and fixed with a resin 3 and an end surface thereof is optically polished. However, there are problems that the production requires many steps and is inferior in mass productivity, and that the arrangement of the rod-shaped lenses tends to be irregular, the array accuracy is poor, and the production of a large-area plate is difficult.

On the other hand, a GI-type lens unit whose refractive index changes based on a change in polymerization composition is formed by filling a lens-forming material into a through-hole provided in a plastic base material having an affinity for its component monomer and polymerizing the same. (Japanese Patent Application Laid-Open No. 62-222203) has been proposed. However, light is more likely to leak to the plastic substrate than the GI type lens unit, and transmission light interferes between the nearest GI type lens units. There is a problem that the unit arrangement density is poor and the aperture ratio is low.

On the other hand, as shown in FIG. 4, a light diffused behind a liquid crystal panel 4 in which a polarizing plate 41 and a phase difference plate 45 are bonded to a liquid crystal cell 44 in which a liquid crystal 43 is sealed with a glass plate 42 with a transparent electrode. There has been known a liquid crystal display device having a light source 5 that emits light. However, as in the case of viewing a large screen at a short distance or viewing a single screen from multiple directions by many people, the visibility varies greatly depending on the screen viewing angle, such as a decrease in contrast, inversion of the display, or a change in hue. And the viewing angle that can be seen in a good display state is narrow. Such variations in visibility are considered to be essential due to the liquid crystal itself which cannot be solved even by variously changing the composition of the liquid crystal, the polarizing plate, and the retardation plate.

[0005]

DISCLOSURE OF THE INVENTION The present invention can easily produce a large-area plate, is excellent in mass productivity, is excellent in array precision in which GI-type lenses are regularly arranged, and has an arrangement of GI-type lens units. It is an object of the present invention to develop a lens array plate which is excellent in density and hardly causes interference of transmission light between lenses, and a liquid crystal display device having a wide viewing angle which can be viewed in a good display state.

[0006]

Means for Solving the Problems The present invention has a different refractive index.
A monomer or oligomer forming a polymer, or
Polymers with different refractive indices are chemically
Mix in combinations where the polymerization composition changes based on the difference in properties
The lens-forming material obtained is insoluble in its component monomers and filled in a through-hole array provided in a light-transmissive or light-reflective substrate and polymerized to form a refractive index based on a change in the polymer composition. Provided are a lens array plate characterized by having GI type lens units whose lengths change in a vertical and horizontal direction and in a separated state, and a liquid crystal display device characterized by disposing such a lens array plate on the viewing side of a liquid crystal panel. Things.

[0007]

The lens array plate having the above structure can form a GI type lens by filling and polymerizing a lens forming material into a through-hole array provided on a base material, and is excellent in mass productivity and easy to manufacture a large area plate. is there. Further, since it is easy to form a uniform through-hole regularly in the base material, lenses can be arrayed with high accuracy. Moreover, by using a base material that is insoluble in the component monomers, the GI
The lens unit can be drawn in a separated state without fail, the lens forming material can be prevented from penetrating into the base portion between the through holes, and the GI type lens unit can be prevented from adjoining. It is also possible to prevent transmission light from leaking into the GI-type lens unit and to prevent interference between the GI-type lens units, to reduce the interval between the GI-type lens units, to arrange the lens units with high density, and to increase the aperture ratio. .

On the other hand, by using the above-mentioned lens array plate, only the light beam transmitted through the liquid crystal layer at an angle perpendicular to or close to that of the liquid crystal layer from the image forming light beam transmitted through the liquid crystal panel and passing through the liquid crystal panel in various directions. Can be taken out. Such extracted light is based on the fact that the optical characteristics of the liquid crystal depend on the light incident angle, that is, the variation in visibility due to the difference in the incident angle of light is prevented, and a good display state is exhibited and the visibility is excellent. Form an image. Then, the extracted light beam is imaged on the light diffusion plate and diffused through the light diffusion plate, whereby an image light beam having good display quality can be provided in a wide area. As a result, a decrease in contrast, inversion of display, or a change in hue due to a viewing angle is suppressed, a viewing angle or visibility of good display is improved, and a transmission range of an image can be expanded, and a good viewing range is expanded. be able to.

[0009]

FIG. 1 illustrates a lens array plate 1 according to the present invention. 11 is a base material, and 12 is a GI lens unit. Reference numeral 13 denotes a portion in which the polymer layer soluble in the component monomer of the lens forming material formed on the inner wall of the through hole provided in the base material 11 has become the outer peripheral portion of the GI lens unit due to the penetration of the component of the lens forming material. is there.

The lens array plate of the present invention is formed by, for example, using an interfacial gel copolymerization method utilizing a gel effect from the inner wall interface, by using a lens forming material whose refractive index changes based on a change in polymerization composition. It can be formed by a method of filling and filling a through-hole array provided in a base material insoluble in the component monomer of the lens forming material and polymerizing.

The above-mentioned lens-forming material whose refractive index changes based on a change in the polymerization composition is, for example, a monomer or oligomer forming a polymer having a different refractive index, or a polymer having a different refractive index, and a polymerization rate or a gelation rate. Polymerization treatment
It can be obtained as a mixture or the like in a combination in which the polymerization composition changes based on the difference in chemical properties at the time (JP-A-62-222203).

As the above-mentioned monomer, oligomer or polymer, those which form a polymer having excellent transparency are preferably used. Examples thereof include methyl methacrylate, ethyl methacrylate, methacrylic aliphatic esters such as trifluoroethyl methacrylate, methacrylic anhydride, ethylene dimethacrylate, methyl acrylate, vinyl acetate, or mixtures thereof, and vinyl benzoate. ,
Vinyl aromatic carboxylate such as vinyl O-chlorobenzoate, vinyl P-chlorobenzoate, vinyl α-naphthoate, vinyl β-naphthoate, acrylonitrile, pentachlorostyrene, α-methylstyrene, benzyl methacrylate, methacrylic acid Examples include phenyl and mixtures thereof.

Specific examples of a combination for forming a GI type lens, that is, a lens whose refractive index decreases from the center in the radial direction to the outside, include methyl methacrylate and vinyl benzoate, acrylonitrile, pentachlorostyrene,
A combination of benzyl methacrylate or α-methylstyrene, a combination of trifluoroethyl methacrylate and O-chlorobenzoate, a combination of n-butyl methacrylate and vinyl benzoate, a combination of methyl acrylate and vinyl benzoate And combinations of methacrylonitrile and α-methylstyrene.

The substrate used is not particularly limited as long as it is insoluble in the component monomers of the lens-forming material and is light-transmissive or light-reflective . In addition to plastics such as polyimide or fluororesin, Ru can be used, such as a substrate made of an inorganic substance such as glass or metal. By using a base material that is insoluble in the component monomer of the lens forming material, it becomes possible to separate and arrange the GI type lens units via the space between the through holes.

The thickness of the substrate may be appropriately determined according to the lens effect of the GI lens unit formed in the through hole.
Generally, the thickness is 50 μm to 30 mm. The through-hole array can be formed by any method such as a physical method using a drill or a laser, a chemical method such as etching, and a forming method with holes using a stamper or a mold.

The through holes to be formed are appropriately determined according to the size and arrangement density of the desired GI type lens unit. In general, the diameter or one side is 10 μm to 10 mm, especially about 50 μm to 1 mm. The opening shape of the through-hole is generally a circle, a square, a hexagon, or the like, but is not limited thereto, and can be appropriately determined according to a pixel shape or the like.

In the through-hole array, it is preferable that the interval between the through-holes is as constant as possible. That is, in the present invention, since the base portion between the through holes serves as a separation area of the GI lens unit 12, as illustrated in FIG.
It is preferable that the distance between the through-holes is constant from the viewpoint of uniformity of the lens unit and high-density arrangement. The distance between the through holes is appropriately determined according to the size, arrangement density, and the like of the target GI lens unit.
5 mm.

The GI type lens is formed on the inner wall of the through-hole formed in the base material by smoothly polymerizing the filled lens forming material with a polymerization composition that changes the refractive index. It is preferable to provide a soluble polymer layer. The formation of the polymer layer may be performed by any method such as a method of dipping in a polymer solution or a method of spraying a polymer solution. Also, the thickness of the polymer layer to be formed can be appropriately determined,
The objective can be sufficiently achieved even with a thickness of 1 μm or less.

The plastic used for forming the polymer layer may be any plastic that is soluble in the component monomers of the lens-forming material. In general, at least one of component monomers of the lens-forming material, such as methyl methacrylate, ethyl methacrylate, and methacrylic acid aliphatic ester such as trifluoroethyl methacrylate, and the monomer having the highest content ratio is used as a component. Things are used. Such a polymer layer forms the outer peripheral portion 13 of the GI lens unit when the GI lens unit 12 is formed by polymerizing a lens forming material filled as illustrated in FIG.

As described above, the lens array plate of the present invention
The GI type lens units are arranged vertically and horizontally in a separated state, and can be preferably used for various uses such as formation of a liquid crystal display device having good visibility or display state, and optical connectors.

FIG. 3 illustrates a liquid crystal display device formed using the lens array plate of the present invention. 1 is a lens array plate,
4 is a liquid crystal panel, 5 is a light source, and 6 is a light diffusion plate. The liquid crystal panel 4 is formed by bonding a polarizing plate 41 to both sides of a liquid crystal cell 44, and the liquid crystal cell 44 is formed by sealing a liquid crystal 43 with a glass plate 42 with a transparent electrode.

In FIG. 3, the liquid crystal panel 4 has a size of 480 × 6.
It consists of a 10-inch version of 40 pixels, and the pixel size is about 0,0.
It is 3 mm square. The lens array plate 1 is arranged on the viewing side of the liquid crystal panel 4, and the light diffusing plate 6 is arranged on an erecting equal-magnification image plane of the liquid crystal image via the lens array plate 1. A light source 5 composed of a cold cathode tube is provided on the back side of the liquid crystal panel 4.
Is arranged.

The lens array plate 1 is formed on a substrate made of a polyimide film having a thickness of 1 mm by using a laser to a thickness of 50 μm.
A polymethyl methacrylate layer having a thickness of about 3 μm is formed by immersion on the inner wall of a through-hole having a diameter of 100 μm and formed in a vertical and horizontal array at intervals with a benzyl methacrylate / Methyl methacrylate: 1/3 (weight ratio) and benzoyl peroxide 0.1%.
The GI type lens unit formed in each through hole is formed by filling and enclosing a monomer mixture to which 5% by weight is added, and heating and curing the mixture at 60 ° C. for 10 hours. As described above, the polymethyl methacrylate layer is arranged in a vertically and horizontally separated state with the deteriorated cured portion (13) of the polymethyl methacrylate layer as an outer peripheral portion.

There is no particular limitation on the liquid crystal panel or liquid crystal cell used in the present invention, and any of known ones can be used. Examples of general liquid crystal panels include a twisted nematic type, a super twisted nematic type, a homogeneous type, a thin film transistor type, an active matrix driven type and a simple matrix driven type.

As a general polarizing plate attached to a liquid crystal cell, a polarizing plate which is obtained by treating a film made of a hydrophilic polymer such as polyvinyl alcohol with a dichroic dye such as iodine and stretching it, or polyvinyl chloride And a polarizing film formed by treating a plastic film and orienting the polyene, or a polarizing film covered with a protective film. Note that the polarizing plate is disposed on one side or both sides of the liquid crystal cell.

The retardation plate is used as necessary for the purpose of compensating for birefringent light by the liquid crystal cell. The retardation plate can be obtained, for example, as a birefringent film obtained by stretching a polymer film uniaxially or biaxially, or a laminate thereof. A retardation plate can also be arranged on one side or both sides of the liquid crystal cell.

The lens array plate in the liquid crystal display device is
This is for taking out a liquid crystal image formed by light transmitted through the liquid crystal layer at an angle close to or perpendicular to the liquid crystal layer. A preferred lens array plate is capable of converting a liquid crystal image into an erect equal-magnification image at least in pixel units of a liquid crystal panel. The conversion of the liquid crystal image into an erect equal-magnification image in pixel units is achieved by using a lens array plate in which GI lens units having substantially the same size as pixels are arrayed corresponding to each pixel of the liquid crystal panel. be able to. In addition, a lens array plate in which two or more GI type lens units smaller than the pixel are arrayed in correspondence with each pixel of the liquid crystal panel, and the fetched light rays are narrowed down to those transmitted through the liquid crystal layer at an angle closer to the vertical. This is advantageous for sharpening an image.

In the liquid crystal display device of the present invention, if necessary, a light-shielding portion may be provided in order to prevent the image forming light beams from the pixels transmitted through the GI type lens unit from being mixed with each other and causing the image to crosstalk. Can be provided. The light-shielding portion can be provided at an appropriate position on the viewing side of the liquid crystal panel integrally with or separately from the lens array plate.

The light diffusing plate 6 provided on the viewing side of the liquid crystal display device is arranged on an erecting equal-magnification image plane of the liquid crystal image via the lens array plate 1 to scatter image light and enlarge the viewing angle. It is for. In the embodiment of FIG. 3, according to the focal length of the GI type lens unit in the lens array plate 1, a position where the image receiving side and the image forming side have the same interval, that is, the light diffusing plate 6
Are arranged on the opposite side of the liquid crystal surface at the same interval as the distance from the center of the GI lens unit 12 to the liquid crystal surface (43).

The light diffusing plate to be used may be any as long as it can scatter such image light, and there is no particular limitation on the material, structure and the like. Examples thereof include those in which organic or inorganic fine particles or fillers are dispersed in a transparent resin sheet, those in which polymer or low-molecular domains are expressed in a sheet-like resin, those on a polymer film or a glass plate. Provided with a resin layer in which inorganic or organic fine particles or fibers are dispersed, and those obtained by physically or chemically roughening the surface of a polymer film or a glass plate.

An appropriate light source may be used as the light source disposed on the back surface of the liquid crystal panel. Examples thereof include point light emitters and surface light emitters such as cold cathode tubes, hot cathode tubes, tungsten lamps, metal halide lamps, xenon lamps, and electroluminescence lamps. A low-temperature light source such as a cold-cathode tube or an electroluminescence lamp is preferably used. In the present invention, for example,
A method in which light from a light source is incident on a liquid crystal panel via an optical fiber, a reflection plate, or the like may be employed.

In the present invention, a liquid crystal panel, a lens array plate, a light diffusing plate, a light source such as an EL lamp, and the like are fixed as necessary. It is generally preferable to fix the display rather than to suppress a decrease in display quality due to interface reflection. The fixation can be performed using, for example, a transparent adhesive or a pressure-sensitive adhesive, and the kind of the adhesive or the like is not particularly limited. In particular, it is preferable that the refractive index is the same as or close to that of the object to be fixed. Further, from the viewpoint of preventing a change in the optical properties of the adherend, those which do not require a high-temperature process for curing and drying are preferable, and those which do not require a long curing treatment or drying time are desirable.

On the other hand, FIGS. 5 and 6 show a state in which the lens array plate of the present invention is used as an optical connector. FIG. 5 shows an IIT through an optical connector 8 composed of a lens array plate.
This is a state in which the plate 7 and the CCD plate 9 are connected. FIG. 6 shows a state in which an optical fiber 10 is connected via an optical connector 8 formed of a lens array plate. 11 is an optical fiber 1
0 is a plug provided at the connection end. In the present invention,
The connection between the optical fiber and the light receiving element or the light emitting element can also be performed, and there is no particular limitation on the connection target. As the optical connector, a connector that can transmit an erect 1: 1 image is usually used, but the application form in the present invention is not limited to this.

[0034]

The lens array plate of the present invention is excellent in the array precision of GI type lenses, and even when the GI type lens units are arranged at high density, transmission light does not interfere between the lens units, and the aperture ratio is excellent. Things. In addition, it can be formed by a method of filling and polymerizing a lens-forming material into holes, which is excellent in mass productivity and easy to manufacture a large-area plate. On the other hand, the liquid crystal display device of the present invention hardly changes contrast, hue, and the like depending on the viewing angle, and has an excellent viewing angle or visibility that can be viewed in a good display state with excellent clarity. The addition of the light diffusing plate can further widen the viewing angle, so that the liquid crystal display can be viewed in a favorable display state from almost all directions on the front surface of the liquid crystal display device.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view of an embodiment of a lens array plate.

FIG. 2 is a partial cross-sectional perspective view of a conventional lens array plate.

FIG. 3 is a sectional view of an embodiment of the liquid crystal display device.

FIG. 4 is a cross-sectional view of a conventional liquid crystal display device.

FIG. 5 is a sectional view of an embodiment as an optical connector.

FIG. 6 is a cross-sectional view of another embodiment as an optical connector.

[Explanation of symbols]

1: Lens array plate 11: Base material 12: GI type lens unit 13: Peripheral portion of GI type lens unit (changed region of polymer layer) 4: Liquid crystal panel 41: Polarizing plate 44: Liquid crystal cell 42: Glass plate with transparent electrode 43: Liquid crystal 5: Light source 6: Light diffusing plate 7: IIT plate 8: Optical connector 9: CCD plate 10: Optical fiber

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Umemoto 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nippon Denko Corporation (72) Inventor Ei Yamamoto 1-1-2 Shimohozumi, Ibaraki-shi, Osaka No. Japan Todenko Co., Ltd. (72) Inventor Yasuhiro Koike 1-31-30 Ookayama, Meguro-ku, Tokyo No. 303, Ooyamayama Park 303 (56) References JP-A-4-240601 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 3/00

Claims (5)

(57) [Claims] A monomer forming a polymer having a different refractive index.
-Or oligomer, or a polymer having a different refractive index,
Polymerization group based on differences in chemical properties during polymerization
A polymerized composition formed by filling a lens-forming material mixed in a combination that changes its composition into a through-hole array provided in a light-transmissive or light-reflective substrate insoluble in its component monomers and polymerizing the same. A lens array plate having GI type lens units whose refractive index changes based on a change in the vertical and horizontal directions and in a separated state. 2. The substrate provided with a through-hole array according to claim 1, wherein a polymer layer soluble in a component monomer of the lens-forming material is provided on an inner wall of the through-hole. 3. A liquid crystal display device, wherein the lens array plate according to claim 1 is arranged on a viewing side of a liquid crystal panel. 4. The liquid crystal display device according to claim 3, wherein a light diffusing plate is arranged on an erecting equal-magnification image plane of the liquid crystal image via the lens array plate. 5. An optical connector comprising the lens array plate according to claim 1.