WO2011016456A1 - Complex light control plate, area light source device and transmission-type image display device - Google Patents

Complex light control plate, area light source device and transmission-type image display device Download PDF

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Publication number
WO2011016456A1
WO2011016456A1 PCT/JP2010/063113 JP2010063113W WO2011016456A1 WO 2011016456 A1 WO2011016456 A1 WO 2011016456A1 JP 2010063113 W JP2010063113 W JP 2010063113W WO 2011016456 A1 WO2011016456 A1 WO 2011016456A1
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WO
WIPO (PCT)
Prior art keywords
light
control plate
light control
plate
convex portion
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Application number
PCT/JP2010/063113
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French (fr)
Japanese (ja)
Inventor
寛史 太田
裕次郎 川口
武志 川上
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住友化学株式会社
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Publication of WO2011016456A1 publication Critical patent/WO2011016456A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0273—Diffusing elements; Afocal elements characterized by the use
    • G02B5/0278—Diffusing elements; Afocal elements characterized by the use used in transmission
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0215—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures the surface having a regular structure
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0231—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures the surface having microprismatic or micropyramidal shape
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • G02F1/133607—Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Definitions

  • the present invention relates to a composite light control plate, a surface light source device, and a transmissive image display device.
  • the direct type image display device (108) for example, as shown in FIG. 5, a device in which a light source (107) is arranged on the back side of a transmissive image display unit (109) is widely used.
  • the transmissive image display unit (109) include a liquid crystal display panel in which linear polarizing plates (192, 192) are arranged on both surfaces of a liquid crystal cell (191).
  • the light source (107) a plurality of linear light sources such as a straight tube type cold cathode ray tube are arranged in parallel with each other.
  • the light emitting diode is usually a point light source, and is used by arranging it in a discrete manner.
  • the conventional deflection structure plate is used in a direct type image display device in combination with a point light source such as a light emitting diode, the light from the point light source cannot be made sufficiently uniform, and the transmission type The image displayed by the image display unit has a problem that the brightness differs between the vicinity of the point light source and the position away from the point light source.
  • the present inventor has intensively studied to develop a deflection structure plate capable of uniformly illuminating the transmissive image display unit by sufficiently uniformly dispersing the light from the point light source, resulting in the present invention.
  • light incident from the first surface (11, 21, 31) can be emitted from the second surface (12, 22, 32) located on the opposite side of the first surface, and , Extending in the first direction (X11, X21, X31), and a plurality of convex portions (13, 13) arranged in parallel in a second direction (X12, X22, X32) orthogonal to the first direction. 23, 33) are formed on the second surface (12, 22, 32), the first light control plate (10), the second light control plate (20), and the third light control plate (30). ) Are combined light control plates (1) stacked on each other in this order, and the first light control plate (10) and the third light control plate (30) are defined as follows.
  • the second light control plate (20) has a first direction (X21) parallel to the first direction (X11) of the first light control plate (10). And the first surface (21) faces the second surface (12) of the first light control plate (10), and the third light control plate (30) The direction (X31) is orthogonal to the first direction (X11) of the first light control plate (10), and the first surface (31) is the second direction of the second light control plate (20).
  • a composite light control plate facing the second surface (22) is provided.
  • Light control plate In a cross section orthogonal to the first direction of the convex portion, an axis passing through both ends of the convex portion with respect to the second direction is defined as an x axis, and the center of the both ends is located on the x axis.
  • a composite light control plate capable of suppressing luminance unevenness more stably, and a surface light source device and a transmissive image display device including the composite light control plate.
  • the composite light control plate (1) of the present embodiment includes a first light diffusion plate (first light control plate) (10) and a second light diffusion plate (second light control plate).
  • a plate) (20) and a third light diffusing plate (third light control plate) (30) are superimposed on each other.
  • the overlapping order of the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) is the same as the first light diffusing plate (10) and the second light diffusing plate. This is the order of the light diffusion plate (20) and the third light diffusion plate (30).
  • the first light diffusion plate (10) has a first surface (11) and a second surface (12).
  • the second surface (12) is a surface located on the opposite side to the first surface (11). Light incident from the first surface (11) can be emitted from the second surface (12).
  • the first surface (11) of the first light diffusing plate (10) is usually a flat surface, may be a mirror surface, or may be a surface having light diffusibility over the entire surface.
  • a convex portion (13) is formed on the second surface (12).
  • the convex portion (13) extends in the first direction (X11).
  • a plurality of the convex portions (13) are formed on the second surface (12), and are arranged in parallel in the second direction (X12).
  • the second direction (X12) is a direction orthogonal to the first direction (X11).
  • Cross-sectional shape of the plurality of convex portions (13) formed on a second surface (12), the convex portion (13) may be substantially identical between, the x-axis direction length (w a ) May be used in combination with a plurality of types of convex portions.
  • the thickness (d1) of the first light diffusing plate (10) is the distance from the first surface (11) to the top of the convex portion (13).
  • the first light diffusing plate (10) has a thickness (d1) of, for example, 0.1 mm to 5 mm, and may be a film or a sheet. ) Is a sheet shape of 1 mm or more.
  • the convex portion (13) formed on the second surface (12) of the first light diffusion plate (10) has a contour shape represented by z (x) that satisfies the above formula (1).
  • An example of the cross-sectional shape of such a convex portion (13) is shown in FIG. In FIG. 2, one convex portion (13) is shown enlarged.
  • the shape of the convex portion will be described using a local xz coordinate system shown in FIG. In this xz coordinate system, the x-axis is a direction in which a plurality of convex portions (13) are arranged, and is an axis parallel to the second direction (X12).
  • the z-axis is an axis parallel to the thickness direction of the light diffusing plate (10), and is orthogonal to the first direction (X11) and the second direction (X12).
  • the cross-sectional shape of the convex portion (13) is such that both ends (13a, 13a) are located on the x-axis and the top portion (13b) is located on the z-axis.
  • the cross-sectional shape of the convex portion (13) has a contour line symmetrical with respect to the z-axis.
  • the contour when the convex portion in the x-axis direction length of (13) was w a, in the range of -0.475w a ⁇ x ⁇ 0.475w a, satisfying the following formula (1) z It is represented by (x).
  • z 0 (x) has the formula (2) (In the formula (2), h a is 0.25w a ⁇ 0.75w a, k a is 0 to less than -1.0.) Is defined by. ]
  • h a in the z 0 which defines a z (x) in equation (1) (x) is 0.525w a, it shows the case k a is -0.400.
  • w a is the length in the x-axis direction of the convex portion (13)
  • h a is the convex portion (13 when the convex portion (13) is shaped as z 0 (x). )
  • the contour of the convex portion (13) is the contour indicated by 0.95 ⁇ z 0 (x) when z 0 (x) is obtained for a certain width w a .
  • the width w a of the convex portion (13) is usually 40 ⁇ m or more, preferably 250 ⁇ m or more because the formation of the convex portion (13) is easy, and the pattern resulting from the convex portion (13) is visually Therefore, it is usually 800 ⁇ m or less, preferably 450 ⁇ m or less.
  • Convex portions (13) is preferably h a in the above formula (2) is 0.4w a ⁇ 0.7w a, k a is preferably -0.5 or more.
  • h a and k a are (A) h a is 0.4825 w a to 0.521 w a and k a is ⁇ 0.232 to ⁇ 0.227, or h a is 0.4852 w a to 0.521 w a , K a is -0.232 to -0.227, (B) h a is from 0.5966 w a to 0.6837 w a , and k a is from ⁇ 0.075 to ⁇ 0.069, (C) h a is 0.525 w a and k a is ⁇ 0.4, It is.
  • Convex portions of the first light diffusing plate (10) and the second light diffusing plate (20) (13) are both able h a and k a is in the range represented by the above (B), more preferably .
  • the second light diffusion plate (20) has a first surface (21) and a second surface (22).
  • the second surface (22) is a surface located on the opposite side to the first surface (21). Light incident from the first surface (21) can be emitted from the second surface (22).
  • the first surface (21) of the second light diffusing plate (20) is usually a flat surface, may be a mirror surface, or may be a surface having light diffusibility over the entire surface.
  • a convex portion (23) is formed on the second surface (22) of the second light diffusing plate (20).
  • the convex portion (23) extends in the first direction (X21).
  • a plurality of the convex portions (23) are formed on the second surface (22), and are arranged in parallel in the second direction (X22).
  • the second direction (X22) is a direction orthogonal to the first direction (X21).
  • Cross-sectional shape of the plurality of convex portions (23) formed on the second face (22), the convex portion (23) may be substantially identical between, the x-axis direction length (w a ) May be used in combination with a plurality of types of convex portions.
  • the thickness (d2) of the second light diffusing plate (20) is the distance from the first surface (21) to the top of the convex portion (23).
  • the second light diffusing plate (20) has a thickness (d2) of, for example, 0.1 mm to 5 mm, and may be a film or a sheet. ) Is a film of less than 1 mm.
  • the convex portion (23) formed on the second surface (22) of the second light diffusing plate (20) may have an isosceles triangular cross-section, for example, or the first light diffusion
  • the convex portion (13) in the plate (10) may have the same shape as described above.
  • the third light diffusion plate (30) has a first surface (31) and a second surface (32).
  • the second surface (32) is a surface located on the opposite side to the first surface (31). Light incident from the first surface (31) can be emitted from the second surface (32).
  • the first surface (31) of the third light diffusing plate (30) is usually a flat surface, may be a mirror surface, or may be a surface having light diffusibility over the entire surface.
  • a convex portion (33) is formed on the second surface (32) of the third light diffusion plate (30).
  • the convex portion (33) extends in the first direction (X31).
  • a plurality of the convex portions (33) are formed on the second surface (32), and are arranged in parallel in the second direction (X32).
  • the second direction (X32) is a direction orthogonal to the first direction (X31).
  • the cross-sectional shapes of the plurality of convex portions (33) formed on the second surface (32) may be substantially the same between the convex portions (33), or a plurality of different lengths in the x-axis direction.
  • a combination of types of convex portions may be used.
  • the thickness (d3) of the third light diffusion plate (30) is the distance from the first surface (31) to the top of the convex portion (33).
  • the third light diffusing plate (30) has a thickness (d3) of, for example, 0.1 mm to 5 mm, and may be a film or a sheet. ) Is a film of less than 1 mm.
  • the third light diffusing plate (30) is defined above, and the convex portion (33) formed on the second surface (32) has a cross-sectional shape of the first light diffusing plate.
  • the convex portion (13) in (10) has the same shape as described above.
  • the convex portion (13) of the first light diffusing plate (10) and the convex portion (33) of the third light diffusing plate (30) may have the same cross-sectional shape or different from each other. It may have a cross-sectional shape.
  • the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) are made of a transparent material.
  • the refractive index of the transparent material is, for example, 1.46 to 1.62, and the refractive index of the transparent material constituting the first light diffusing plate (10) is usually 1.56 to 1.62.
  • transparent materials include transparent resin materials and transparent glass materials.
  • transparent resin materials examples include polycarbonate resin (refractive index: 1.59), MS resin (methyl methacrylate-styrene copolymer resin) (refractive index: 1.56 to 1.59), polystyrene resin (refractive index: 1.59) and the like are exemplified, and polystyrene resin is preferred from the viewpoint of cost and low moisture absorption.
  • additives such as an ultraviolet absorber, an antistatic agent, an antioxidant, a processing stabilizer, a flame retardant, and a lubricant can be added to the transparent resin material. These additives can be used alone or in combination of two or more.
  • UV absorbers examples include benzotriazole UV absorbers, benzophenone meter UV absorbers, cyanoacrylate UV absorbers, malonic ester UV absorbers, oxalic anilide UV absorbers, and triazine UV absorbers. Preferred are benzotriazole ultraviolet absorbers and triazine ultraviolet absorbers.
  • the transparent resin material is usually used without adding a light diffusing agent as an additive, but may be added with a light diffusing agent as long as it is a slight amount that does not impair the object of the present invention.
  • the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) are used as the light diffusing agent when the light diffusing agent is added to the transparent material.
  • a powder having a refractive index different from that of the transparent material to be used is used, and is used by being dispersed in the transparent material.
  • organic particles such as styrene resin particles and methacrylic resin particles, and inorganic particles such as calcium carbonate particles and silica particles are used, and the particle diameter is usually 0.8 ⁇ m to 50 ⁇ m.
  • the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) may be a single layer plate made of a single transparent material, or may be mutually It may be a multilayer board having a structure in which layers made of different transparent materials are laminated.
  • a skin layer having a thickness of usually 10 ⁇ m to 200 ⁇ m, preferably 20 ⁇ m to 100 ⁇ m is formed on one or both sides of the light diffusion plate (10, 20, 30). It is preferable to use a transparent resin material to which an ultraviolet absorber is added as the transparent resin material constituting the skin layer.
  • the light diffusing plate (10, 20, 30) By adopting such a configuration, it is possible to prevent deterioration of the light diffusing plate (10, 20, 30) due to ultraviolet light that may be included in the light source or external light, particularly when a fluorescent tube or the like is used as the light source.
  • a skin layer is formed on the first surface (11, 21, 31), and at this time, the second surface (12, 22, 32) is formed. It is more preferable from the viewpoint of cost that no skin layer is formed on ().
  • the content of the ultraviolet absorber is usually 0.5% by mass to 5% by mass, preferably based on the transparent resin material. Is 1% by mass to 2.5% by mass.
  • the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) may be coated with an antistatic agent on one side or both sides.
  • an antistatic agent By applying an antistatic agent, dust adhesion due to static electricity can be prevented, and a decrease in light transmittance due to dust adhesion can be prevented.
  • the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) can be manufactured, for example, by a method of cutting out from a transparent material. Moreover, when using a transparent resin material as a transparent material, it can manufacture by normal methods, such as an injection molding method, an extrusion molding method, a press molding method, a photopolymer method, for example.
  • the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) are overlapped with each other in this order. It has been made.
  • the second light diffusing plate (20) has a first direction (X21) in the first light diffusing plate (10). Parallel to one direction (X11).
  • the first direction (X31) is orthogonal to the first direction (X11) of the first light diffusion plate (10).
  • the second light diffusing plate (20) has a first surface (21) which is the first light diffusing plate (10). Facing the second face (12).
  • the second light diffusing plate (20) is usually superimposed on the first light diffusing plate (10) via an air layer, and the distance between the second light diffusing plates (20) is the second surface (12
  • the distance (d12) from the top portion (13b) of the convex portion (13) formed on the first surface (21) of the second light diffusion plate (20) is usually 5 mm or less, and the composite light From the viewpoint of making the control plate (1) compact, the distance (d12) is 0 mm, and the top portion (13b) of the convex portion (13) formed on the first light diffusion plate (10) is
  • the first light diffusion plate (20) may be in contact with the first surface (21).
  • the first surface (31) faces the second surface (22) of the second light diffusion plate (20).
  • the third light diffusing plate (30) is usually superimposed on the second light diffusing plate (20) via an air layer, and the distance between the third light diffusing plates (30) and the second surface (22) of the second light diffusing plate (20).
  • the distance (d23) from the top part (23b) of the convex part (23) formed on the first surface (31) of the third light diffusion plate (30) is usually 5 mm or less, and the composite light From the viewpoint of making the control plate (1) compact, the distance (d23) is 0 mm, and the top portion (23b) of the convex portion (23) formed on the second light diffusion plate (20) is
  • the third light diffusing plate (30) may be in contact with the first surface (31).
  • the first surface (21) of the second light diffusing plate (20) is preferably a surface having light diffusibility over the entire surface from the viewpoint of preventing the occurrence of moiré.
  • the first surface (21) may be constituted by a skin layer containing fine particles called a matting agent.
  • One surface (21) may be embossed or blasted, or a matting layer may be formed by applying a coating solution containing a matting agent and a binder.
  • the convex portion (13) formed on the second surface (12) of the first light diffusion plate (10) or the second portion of the second light diffusion plate (20) can be prevented.
  • the convex portion (23) formed on the surface (22) is composed of a plurality of types of convex portions (13, 23) having different widths, and the plurality of types of convex portions (13, 23). It is also preferable that they are arranged in parallel in an irregular order.
  • the convex portion (13) of the first light diffusing plate (10) and the convex portion (33) of the third light diffusing plate (30) may have the same cross-sectional shape or different from each other. It may have a cross-sectional shape.
  • the first surface (11) of the first light diffusing plate (10) and the first surface (31) of the third light diffusing plate (30) may be surfaces having light diffusibility.
  • the first surfaces (11, 31) are constituted by a skin layer containing fine particles called a matting agent.
  • the first surface (11, 31) may be embossed or blasted, or a matting agent may be mixed with a binder to form a coating solution, which is then used as the first surface ( 11 and 31) to impart light diffusibility.
  • the composite light control plate (1) of the present embodiment is preferably used by being incorporated in the surface light source device (6).
  • the surface light source device (6) includes the composite light control plate (1) of the present embodiment and a light source (7).
  • the light source (7) supplies light to the first surface (11) of the first light diffusion plate (10) constituting the composite light control plate (1).
  • Examples of the light source (7) include a linear light source such as a cold cathode ray tube, and a point light source such as an LED (light emitting diode) is preferable.
  • the interval (L) between the plurality of light sources (7) is the distance between the light source centers, and is usually 10 mm to 150 mm.
  • the distance (D) from the center of the light source (7) to the first surface (11) of the first light diffusion plate (10) is usually 3 mm to 50 mm, and the ratio [L / D] is 2 or more. Furthermore, it is preferable that it is 2.5 or more from the point which can make a surface light source device thin.
  • the transmissive image display device (8) includes the surface light source device (6) and the transmissive image display unit (9).
  • the transmissive image display section (9) is exemplified by a transmissive liquid crystal display section composed of, for example, a liquid crystal cell (91) and linearly polarizing plates (92) arranged on both surfaces thereof.
  • the transmissive image display section (9) is illuminated with light transmitted through the composite light control plate (1) to display an image.
  • the light passing through the composite light control plate (1) is light output from a plurality of light sources (7) constituting the surface light source device (6).
  • the composite light control plate (1) may be arranged so that the first direction (X11) of the first light diffusion plate (10) is the horizontal direction of the screen. It may be arranged in the vertical direction.
  • the composite light control plate (1) of this embodiment is arranged so that the first direction (X11) of the first light diffusion plate (10) is in the horizontal direction of the screen, the first light diffusion plate (10) is arranged.
  • the second direction (X12) is the vertical direction, and the second direction (X32) of the third light diffusing plate (30) is the horizontal direction.
  • the composite light control plate (1) of the present embodiment is arranged so that the first direction (X11) of the first light diffusion plate (10) is the vertical direction of the screen, the first light diffusion plate (10) is arranged.
  • the second direction (X12) is the horizontal direction, and the second direction (X32) of the third light diffusing plate (30) is the vertical direction.
  • k a in equation (2) representing the contour shape of the convex portion of the first light diffusing plate (10, 13) is convex portion of the third light diffuser plate (30) of (33) is preferably smaller than k a in equation (2) representing the contour shape.
  • the light source interval (LV) in the vertical direction of the screen is equal to or larger than the light source interval (LH) in the horizontal direction.

Abstract

Disclosed is a complex light control plate (1) comprising first to fourth light diffusion plates (10 to 30) laminated on one another in this order, wherein each of the first light diffusion plate (10) and the third light diffusion plate (30) is as defined below, the first direction (X21) of the second light diffusion plate (20) is parallel with the first direction (X11) of the first light diffusion plate (10), and the first direction (X31) of the third light diffusion plate (30) is orthogonal to the first direction (X11) of the first light diffusion plate (10). Light diffusion plate: with respect to a cross-section surface of a projected part formed on the light diffusion plate (wherein the cross-section surface is taken in the direction orthogonal to the first direction), the shape of the outline form of the cross-section surface is represented by z(x) that fulfils formula (1): 0.95 × z0(x) ≤ z(x) ≤ 1.05 × z0(x) [wherein z0(x) is defined by formula (2)] in a range of -0.475wa ≤ x ≤ 0.475wa, wherein wa represents the length of the projected part in the second direction.

Description

複合光制御板、面光源装置および透過型画像表示装置Composite light control plate, surface light source device, and transmissive image display device
本発明は、複合光制御板、面光源装置および透過型画像表示装置に関する。 The present invention relates to a composite light control plate, a surface light source device, and a transmissive image display device.
　直下型画像表示装置(108)として、例えば図５に示すように、透過型画像表示部(109)の背面側に光源(107)が配置されたものが広く用いられている。透過型画像表示部(109)としては、例えば液晶セル(191)の両面に直線偏光板(192、192)が配置された液晶表示パネルが挙げられる。光源(107)としては、直管型の冷陰極線管などのような線状光源が複数本、互いに平行に配置されて用いられている。 As the direct type image display device (108), for example, as shown in FIG. 5, a device in which a light source (107) is arranged on the back side of a transmissive image display unit (109) is widely used. Examples of the transmissive image display unit (109) include a liquid crystal display panel in which linear polarizing plates (192, 192) are arranged on both surfaces of a liquid crystal cell (191). As the light source (107), a plurality of linear light sources such as a straight tube type cold cathode ray tube are arranged in parallel with each other.
　かかる直下型画像表示装置(108)としては、光源(107)からの光を均一に分散させて透過型画像表示部(109)を均一に照明できることが望ましく、このため光源(107)と透過型画像表示部(109)との間には、光源(107)側から入射した光を、その向きを変えて反対側の透過型像表示部(109)側から出射させる機能を有する一枚の光制御板(101)が配置されて用いられている〔特許文献１：特開平７－１９８９１３号公報〕。 As such a direct type image display device (108), it is desirable that the light from the light source (107) is uniformly dispersed to uniformly illuminate the transmissive image display unit (109). Between the image display unit (109) and the light source (107) side, a single piece of light having the function of changing the direction and emitting the light from the opposite transmissive image display unit (109) side A control plate (101) is disposed and used [Patent Document 1: Japanese Patent Laid-Open No. 7-198913].
　近年、直管型冷陰極線管に代えて、省エネルギーの観点から、発光ダイオードを光源として用いることが検討されている。発光ダイオードは通常、点状光源であり、これを離散的に配置して用いられる。 In recent years, it has been studied to use a light emitting diode as a light source from the viewpoint of energy saving instead of a straight tube type cold cathode ray tube. The light emitting diode is usually a point light source, and is used by arranging it in a discrete manner.
特開平７－１９８９１３号公報JP-A-7-198913
　しかし、従来の偏向構造板は、発光ダイオードのような点状光源と組み合わせて直下型画像表示装置に用いると、点状光源からの光を十分に均一なものとすることができず、透過型画像表示部により表示される画像は、点状光源の近傍と、これから離れた位置とで明るさが異なるものになるという問題があった。 However, when the conventional deflection structure plate is used in a direct type image display device in combination with a point light source such as a light emitting diode, the light from the point light source cannot be made sufficiently uniform, and the transmission type The image displayed by the image display unit has a problem that the brightness differs between the vicinity of the point light source and the position away from the point light source.
　そこで本発明者は、点状光源からの光を十分に均一に分散させて、透過型画像表示部を均一に照明できる偏向構造板を開発するべく鋭意検討した結果、本発明に至った。 Therefore, the present inventor has intensively studied to develop a deflection structure plate capable of uniformly illuminating the transmissive image display unit by sufficiently uniformly dispersing the light from the point light source, resulting in the present invention.
　すなわち本発明は、第１の面(11,21,31)から入射した光が該第１の面と反対側に位置する第２の面(12,22,32)から出射可能であり、かつ、第１の方向(X11,X21,X31)に延在すると共に、該第１の方向に直交する第２の方向(X12,X22,X32)に並列配置された複数の凸状部(13,23,33)が前記第２の面(12,22,32)に形成されている第１の光制御板(10)、第２の光制御板(20)および第３の光制御板(30)が、この順序で互いに重ね合わされてなる複合光制御板(1)であって、前記第１の光制御板(10)および前記第３の光制御板(30)は、それぞれ以下に定義される光制御板であり、前記第２の光制御板(20)は、第１の方向(X21)が前記第１の光制御板(10)の第１の方向(X11)に対して並行であり、かつ第１の面(21)が第１の光制御板(10)の第２の面(12)と向かい合い、前記第３の光制御板(30)は、第１の方向(X31)が前記第１の光制御板(10)の第１の方向(X11)に対して直交し、かつ第１の面(31)が前記第２の光制御板(20)の第２の面(22)と向かい合っている複合光制御板を提供するものである。 That is, according to the present invention, light incident from the first surface (11, 21, 31) can be emitted from the second surface (12, 22, 32) located on the opposite side of the first surface, and , Extending in the first direction (X11, X21, X31), and a plurality of convex portions (13, 13) arranged in parallel in a second direction (X12, X22, X32) orthogonal to the first direction. 23, 33) are formed on the second surface (12, 22, 32), the first light control plate (10), the second light control plate (20), and the third light control plate (30). ) Are combined light control plates (1) stacked on each other in this order, and the first light control plate (10) and the third light control plate (30) are defined as follows. The second light control plate (20) has a first direction (X21) parallel to the first direction (X11) of the first light control plate (10). And the first surface (21) faces the second surface (12) of the first light control plate (10), and the third light control plate (30) The direction (X31) is orthogonal to the first direction (X11) of the first light control plate (10), and the first surface (31) is the second direction of the second light control plate (20). A composite light control plate facing the second surface (22) is provided.
　光制御板：前記凸状部の前記第１の方向に直交する断面において、当該凸状部の前記第２の方向に対する両端をとおる軸線をｘ軸とし、前記ｘ軸上において前記両端の中心をとおり前記ｘ軸に直交する軸線をｚ軸とし、前記凸状部のｘ軸方向の長さをｗaとしたとき、
上記断面において前記凸状部の輪郭形状が、－０．４７５ｗa≦ｘ≦０．４７５ｗaの範囲において、式（１）
Figure JPOXMLDOC01-appb-M000003
 〔式（１）において、ｚ0 (ｘ)は、式（２）
Figure JPOXMLDOC01-appb-M000004
 （式（２）において、ｈaは０．２５ｗa～０．７５ｗaであり、ｋaは－１．０以上０未満である。）
で定義される。〕
を満たすｚ(ｘ)で表される光制御板。 Light control plate: In a cross section orthogonal to the first direction of the convex portion, an axis passing through both ends of the convex portion with respect to the second direction is defined as an x axis, and the center of the both ends is located on the x axis. When the axis perpendicular to the x axis is the z axis and the length of the convex portion in the x axis direction is w a ,
Contour shape of the convex portion in the cross section is in a range of -0.475w a ≦ x ≦ 0.475w a, formula (1)
Figure JPOXMLDOC01-appb-M000003
 [In the formula (1), z 0 (x) has the formula (2)
Figure JPOXMLDOC01-appb-M000004
 (In the formula (2), h a is 0.25w a ~ 0.75w a, k a is 0 to less than -1.0.)
Defined by ]
A light control plate represented by z (x) satisfying
　本発明によれば、より安定して輝度ムラを抑制可能な複合光制御板並びにその複合光制御板を含む面光源装置および透過型画像表示装置を提供することができる。 According to the present invention, it is possible to provide a composite light control plate capable of suppressing luminance unevenness more stably, and a surface light source device and a transmissive image display device including the composite light control plate.
本実施形態の複合光制御板を模式的に示す図面である。It is drawing which shows the composite light control board of this embodiment typically. 第１の光制御板に形成される凸状部の断面形状の一例を模式的に示す図面である。It is drawing which shows typically an example of the cross-sectional shape of the convex part formed in a 1st light control board. 凸状部の断面形状の輪郭線が満足する条件を示す図面である。It is drawing which shows the conditions which the outline of the cross-sectional shape of a convex part satisfies. 本実施形態の複合光制御板を組み込んだ面光源装置および透過型画像表示装置を模式的に示す図面である。It is drawing which shows typically the surface light source device and the transmissive image display apparatus incorporating the compound-light control board of this embodiment. 従来の面光源装置および透過型画像表示装置を模式的に示す図面である。1 is a diagram schematically showing a conventional surface light source device and a transmissive image display device.
〔複合光制御板〕
　図１に示すように、本実施形態の複合光制御板(1)は、第１の光拡散板（第１の光制御板）(10)、第２の光拡散板（第２の光制御板）(20)および第３の光拡散板（第３の光制御板）(30)が、互いに重ね合わされてなるものである。これら第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)の重ね合わせ順序は、上記の第１の光拡散板(10)、第２の光拡散板(20)、第３の光拡散板(30)の順序である。 [Composite light control board]
As shown in FIG. 1, the composite light control plate (1) of the present embodiment includes a first light diffusion plate (first light control plate) (10) and a second light diffusion plate (second light control plate). A plate) (20) and a third light diffusing plate (third light control plate) (30) are superimposed on each other. The overlapping order of the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) is the same as the first light diffusing plate (10) and the second light diffusing plate. This is the order of the light diffusion plate (20) and the third light diffusion plate (30).
〔第１の光拡散板〕
　第１の光拡散板(10)は、第１の面(11)と第２の面(12)とを有する。第２の面(12)は、第１の面(11)と反対側に位置する面である。第１の面(11)から入射した光は、第２の面(12)から出射可能である。 [First light diffusion plate]
The first light diffusion plate (10) has a first surface (11) and a second surface (12). The second surface (12) is a surface located on the opposite side to the first surface (11). Light incident from the first surface (11) can be emitted from the second surface (12).
　第１の光拡散板(10)の第１の面(11)は通常、平坦面であり、鏡面であってもよいし、全面に亙って光拡散性を有する面であってもよい。 The first surface (11) of the first light diffusing plate (10) is usually a flat surface, may be a mirror surface, or may be a surface having light diffusibility over the entire surface.
　第２の面(12)には、凸状部(13)が形成されている。この凸状部(13)は、第１の方向(X11)に延在するものである。この凸状部(13)は、第２の面(12)に複数、形成されており、第２の方向(X12)に並列配置されている。第２の方向(X12)は、第１の方向(X11)に直交する方向である。第２の面(12)に形成される複数の凸状部(13)の断面形状は、凸状部(13)間で概ね同一であってもよいし、ｘ軸方向の長さ(ｗa)が異なる複数種類の凸状部を組み合わされて用いられていてもよい。 A convex portion (13) is formed on the second surface (12). The convex portion (13) extends in the first direction (X11). A plurality of the convex portions (13) are formed on the second surface (12), and are arranged in parallel in the second direction (X12). The second direction (X12) is a direction orthogonal to the first direction (X11). Cross-sectional shape of the plurality of convex portions (13) formed on a second surface (12), the convex portion (13) may be substantially identical between, the x-axis direction length (w a ) May be used in combination with a plurality of types of convex portions.
　なお、第１の光拡散板(10)の厚さ(d1)は、第１の面(11)から凸状部(13)の頂部までの距離である。第１の光拡散板(10)は、厚さ(d1)が例えば０．１ｍｍ～５ｍｍであり、フィルム状であってもよいし、シート状であってもよいが、通常は厚さ(d1)が１ｍｍ以上のシート状である。 The thickness (d1) of the first light diffusing plate (10) is the distance from the first surface (11) to the top of the convex portion (13). The first light diffusing plate (10) has a thickness (d1) of, for example, 0.1 mm to 5 mm, and may be a film or a sheet. ) Is a sheet shape of 1 mm or more.
〔凸状部〕
　第１の光拡散板(10)の第２の面(12)に形成される凸状部(13)は、その輪郭形状が、上記式（１）を満たすｚ(ｘ)で表される。このような凸状部(13)の断面形状の一例を図２に示す。この図２では、一つの凸状部(13)を拡大して示している。この凸状部の形状を図２に示す局所的なｘｚ座標系を用いて説明する。このｘｚ座標系において、ｘ軸は複数の凸状部(13)が配列する方向であり、第２の方向(X12)に並行な軸である。ｚ軸は、光拡散板(10)の厚み方向に並行な軸であり、第１の方向(X11)および第２の方向(X12)に対して直交している。このｘｚ座標系のｘｚ面において、凸状部(13)の断面形状は、両端(13a,13a)がｘ軸上に位置し、頂部(13b)がｚ軸上に位置する。 (Convex part)
The convex portion (13) formed on the second surface (12) of the first light diffusion plate (10) has a contour shape represented by z (x) that satisfies the above formula (1). An example of the cross-sectional shape of such a convex portion (13) is shown in FIG. In FIG. 2, one convex portion (13) is shown enlarged. The shape of the convex portion will be described using a local xz coordinate system shown in FIG. In this xz coordinate system, the x-axis is a direction in which a plurality of convex portions (13) are arranged, and is an axis parallel to the second direction (X12). The z-axis is an axis parallel to the thickness direction of the light diffusing plate (10), and is orthogonal to the first direction (X11) and the second direction (X12). In the xz plane of the xz coordinate system, the cross-sectional shape of the convex portion (13) is such that both ends (13a, 13a) are located on the x-axis and the top portion (13b) is located on the z-axis.
　凸状部(13)の断面形状は、ｚ軸に対して対称な輪郭線を有する。この輪郭線は、凸状部(13)のｘ軸方向の長さをｗaとしたとき、－０．４７５ｗa≦ｘ≦０．４７５ｗaの範囲において、下記式（１）を満足するｚ(ｘ)で表される。
Figure JPOXMLDOC01-appb-M000005
 〔式（１）において、ｚ0 (ｘ)は、式（２）
Figure JPOXMLDOC01-appb-M000006
 （式（２）において、ｈaは０．２５ｗa～０．７５ｗaであり、ｋaは－１．０以上０未満である。）で定義される。〕 The cross-sectional shape of the convex portion (13) has a contour line symmetrical with respect to the z-axis. The contour, when the convex portion in the x-axis direction length of (13) was w a, in the range of -0.475w a ≦ x ≦ 0.475w a, satisfying the following formula (1) z It is represented by (x).
Figure JPOXMLDOC01-appb-M000005
 [In the formula (1), z 0 (x) has the formula (2)
Figure JPOXMLDOC01-appb-M000006
 (In the formula (2), h a is 0.25w a ~ 0.75w a, k a is 0 to less than -1.0.) Is defined by. ]
　図２では、式（１）においてｚ(ｘ)を規定するｚ0(ｘ)におけるｈaが０．５２５ｗaであり、ｋaが－０．４００である場合を示している。ｗaは上記のとおり凸状部(13)のｘ軸方向の長さであり、ｈaは凸状部(13)をｚ0(ｘ)で示される形状とした場合における凸状部(13)の両端(13a、13a)間における最大高さに対応する。 In Figure 2, h a in the z 0 which defines a z (x) in equation (1) (x) is 0.525w a, it shows the case k a is -0.400. As described above, w a is the length in the x-axis direction of the convex portion (13), and h a is the convex portion (13 when the convex portion (13) is shaped as z 0 (x). ) Corresponds to the maximum height between both ends (13a, 13a).
　凸状部(13)の輪郭線は、図３に示すように、ある幅ｗaに対してｚ0(ｘ)を求めた場合に、０．９５×ｚ0(ｘ)で示される輪郭線と、１．０５×ｚ0(ｘ)で示される輪郭線の間の領域を通る輪郭線であればよい。 As shown in FIG. 3, the contour of the convex portion (13) is the contour indicated by 0.95 × z 0 (x) when z 0 (x) is obtained for a certain width w a . And a contour line passing through a region between the contour lines indicated by 1.05 × z 0 (x).
　凸状部(13)の幅ｗaは、凸状部(13)の形成が容易であることから、通常４０μｍ以上、好ましくは２５０μｍ以上であり、凸状部(13)に起因する模様が肉眼で視認されにくいことから、通常８００μｍ以下、好ましくは４５０μｍ以下である。幅ｗaとして具体的には、ｗa＝４１０μｍ、ｗa＝４００μｍおよびｗa＝３２５μｍが例示できるが、ｗaの値はこれらに限定されるものではない。 The width w a of the convex portion (13) is usually 40 μm or more, preferably 250 μm or more because the formation of the convex portion (13) is easy, and the pattern resulting from the convex portion (13) is visually Therefore, it is usually 800 μm or less, preferably 450 μm or less. Specific examples of the width w a include w a = 410 μm, w a = 400 μm, and w a = 325 μm, but the value of w a is not limited thereto.
　凸状部(13)は、上記式（２）におけるｈaは０．４ｗa～０．７ｗaであることが好ましく、ｋaは－０．５以上であることが好ましい。 Convex portions (13) is preferably h a in the above formula (2) is 0.4w a ~ 0.7w a, k a is preferably -0.5 or more.
　ｈaおよびｋaとして好ましくは、
（Ａ）ｈaが０．４８２５ｗa～０．５２１ｗaであり、ｋaが－０．２３２～－０．２２７であること、または、ｈaが０．４８５２ｗa～０．５２１ｗaであり、ｋaが－０．２３２～－０．２２７であること、
（Ｂ）ｈaが０．５９６６ｗa～０．６８３７ｗaであり、ｋaが－０．０７５～－０．０６９であること、
（Ｃ）ｈaが０．５２５ｗaであり、ｋaが－０．４であること、
である。 Preferably, h a and k a are
(A) h a is 0.4825 w a to 0.521 w a and k a is −0.232 to −0.227, or h a is 0.4852 w a to 0.521 w a , K a is -0.232 to -0.227,
(B) h a is from 0.5966 w a to 0.6837 w a , and k a is from −0.075 to −0.069,
(C) h a is 0.525 w a and k a is −0.4,
It is.
　ｈaおよびｋaが上記（Ａ）で示される凸状部(13)の形状として具体的には、例えばｈa＝０．５２１ｗa、ｋa＝－０．２２９で示される形状、ｈa＝０．５２１ｗa、ｋa＝－０．２２７で示される形状、ｈa＝０．４８２５ｗa、ｋa＝－０．２３２で示される形状が挙げられる。 shape h a and k a are specifically as the shape of the convex portion (13) represented by the above (A), it is indicated, for example, h a = 0.521w a, with k a = -0.229, h a = 0.521 w a , a shape represented by k a = −0.227, a shape represented by h a = 0.4825 w a , k a = −0.232.
　上記（Ｂ）で示される凸状部(13)の形状として具体的には、例えばｈa＝０．５９６６ｗa、ｋa＝－０．０７５で示される形状、ｈa＝０．６８３７ｗa、ｋa＝－０．０６９で示される形状が挙げられる。 Specifically the shape of the convex portion represented by (B) (13), for example, h a = 0.5966w a, k a = shape represented by -0.075, h a = 0.6837w a, A shape represented by k a = −0.069 may be mentioned.
　第１の光拡散板(10)および第２の光拡散板(20)の凸状部(13)は共に、ｈaおよびｋaが上記（Ｂ）で示される範囲であることが、さらに好ましい。 Convex portions of the first light diffusing plate (10) and the second light diffusing plate (20) (13) are both able h a and k a is in the range represented by the above (B), more preferably .
〔第２の光拡散板〕
　第２の光拡散板(20)は、第１の面(21)と第２の面(22)とを有する。第２の面(22)は、第１の面(21)と反対側に位置する面である。第１の面(21)から入射した光は、第２の面(22)から出射可能である。 [Second light diffusion plate]
The second light diffusion plate (20) has a first surface (21) and a second surface (22). The second surface (22) is a surface located on the opposite side to the first surface (21). Light incident from the first surface (21) can be emitted from the second surface (22).
　第２の光拡散板(20)の第１の面(21)は通常、平坦面であり、鏡面であってもよいし、全面に亙って光拡散性を有する面であってもよい。 The first surface (21) of the second light diffusing plate (20) is usually a flat surface, may be a mirror surface, or may be a surface having light diffusibility over the entire surface.
　第２の光拡散板(20)の第２の面(22)には、凸状部(23)が形成されている。この凸状部(23)は、第１の方向(X21)に延在するものである。この凸状部(23)は、第２の面(22)に複数、形成されており、第２の方向(X22)に並列配置されている。第２の方向(X22)は、第１の方向(X21)に直交する方向である。第２の面(22)に形成される複数の凸状部(23)の断面形状は、凸状部(23)間で概ね同一であってもよいし、ｘ軸方向の長さ(ｗa)が異なる複数種類の凸状部を組み合わされて用いられていてもよい。 A convex portion (23) is formed on the second surface (22) of the second light diffusing plate (20). The convex portion (23) extends in the first direction (X21). A plurality of the convex portions (23) are formed on the second surface (22), and are arranged in parallel in the second direction (X22). The second direction (X22) is a direction orthogonal to the first direction (X21). Cross-sectional shape of the plurality of convex portions (23) formed on the second face (22), the convex portion (23) may be substantially identical between, the x-axis direction length (w a ) May be used in combination with a plurality of types of convex portions.
　なお、第２の光拡散板(20)の厚さ(d2)は、第１の面(21)から凸状部(23)の頂部までの距離である。第２の光拡散板(20)は、厚さ(d2)が例えば０．１ｍｍ～５ｍｍであり、フィルム状であってもよいし、シート状であってもよいが、通常は厚さ(d2)が１ｍｍ未満のフィルム状である。 The thickness (d2) of the second light diffusing plate (20) is the distance from the first surface (21) to the top of the convex portion (23). The second light diffusing plate (20) has a thickness (d2) of, for example, 0.1 mm to 5 mm, and may be a film or a sheet. ) Is a film of less than 1 mm.
　第２の光拡散板(20)の第２の面(22)に形成される凸状部(23)は、その断面形状が、例えば二等辺三角形であってもよいし、第１の光拡散板(10)における凸状部(13)として上記したものと同様の形状であってもよい。 The convex portion (23) formed on the second surface (22) of the second light diffusing plate (20) may have an isosceles triangular cross-section, for example, or the first light diffusion The convex portion (13) in the plate (10) may have the same shape as described above.
〔第３の光拡散板〕
　第３の光拡散板(30)は、第１の面(31)と第２の面(32)とを有する。第２の面(32)は、第１の面(31)と反対側に位置する面である。第１の面(31)から入射した光は、第２の面(32)から出射可能である。 [Third light diffusion plate]
The third light diffusion plate (30) has a first surface (31) and a second surface (32). The second surface (32) is a surface located on the opposite side to the first surface (31). Light incident from the first surface (31) can be emitted from the second surface (32).
　第３の光拡散板(30)の第１の面(31)は通常、平坦面であり、鏡面であってもよいし、全面に亙って光拡散性を有する面であってもよい。 The first surface (31) of the third light diffusing plate (30) is usually a flat surface, may be a mirror surface, or may be a surface having light diffusibility over the entire surface.
　第３の光拡散板(30)の第２の面(32)には、凸状部(33)が形成されている。この凸状部(33)は、第１の方向(X31)に延在するものである。この凸状部(33)は、第２の面(32)に複数、形成されており、第２の方向(X32)に並列配置されている。第２の方向(X32)は、第１の方向(X31)に直交する方向である。第２の面(32)に形成される複数の凸状部(33)の断面形状は、凸状部(33)間で概ね同一であってもよいし、ｘ軸方向の長さが異なる複数種類の凸状部を組み合わされて用いられていてもよい。 A convex portion (33) is formed on the second surface (32) of the third light diffusion plate (30). The convex portion (33) extends in the first direction (X31). A plurality of the convex portions (33) are formed on the second surface (32), and are arranged in parallel in the second direction (X32). The second direction (X32) is a direction orthogonal to the first direction (X31). The cross-sectional shapes of the plurality of convex portions (33) formed on the second surface (32) may be substantially the same between the convex portions (33), or a plurality of different lengths in the x-axis direction. A combination of types of convex portions may be used.
　なお、第３の光拡散板(30)の厚さ(d3)は、第１の面(31)から凸状部(33)の頂部までの距離である。第３の光拡散板(30)は、厚さ(d3)が例えば０．１ｍｍ～５ｍｍであり、フィルム状であってもよいし、シート状であってもよいが、通常は厚さ(d3)が１ｍｍ未満のフィルム状である。 The thickness (d3) of the third light diffusion plate (30) is the distance from the first surface (31) to the top of the convex portion (33). The third light diffusing plate (30) has a thickness (d3) of, for example, 0.1 mm to 5 mm, and may be a film or a sheet. ) Is a film of less than 1 mm.
　第３の光拡散板(30)は上記で定義されるものであり、その第２の面(32)に形成される凸状部(33)は、その断面形状が、第１の光拡散板(10)における凸状部(13)として上記したものと同様の形状である。 The third light diffusing plate (30) is defined above, and the convex portion (33) formed on the second surface (32) has a cross-sectional shape of the first light diffusing plate. The convex portion (13) in (10) has the same shape as described above.
　第１の光拡散板(10)の凸状部(13)と、第３の光拡散板(30)の凸状部(33)とは、互いに同一の断面形状であってもよいし、異なる断面形状であってもよい。 The convex portion (13) of the first light diffusing plate (10) and the convex portion (33) of the third light diffusing plate (30) may have the same cross-sectional shape or different from each other. It may have a cross-sectional shape.
〔光拡散板の構成材料〕
　第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)は透明材料からなる。透明材料の屈折率は、例えば１．４６～１．６２であり、第１の光拡散板(10)を構成する透明材料の屈折率は、通常１．５６～１．６２である。透明材料としては、透明樹脂材料、透明ガラス材料が例示でき、透明樹脂材料としては、ポリカーボネート樹脂（屈折率：１．５９）、ＭＳ樹脂（メタクリル酸メチル－スチレン共重合体樹脂）（屈折率：１．５６～１．５９）、ポリスチレン樹脂（屈折率：１．５９）などが例示され、コストの面および吸湿率が低い点で、好ましくはポリスチレン樹脂である。 [Constituent material of light diffusion plate]
The first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) are made of a transparent material. The refractive index of the transparent material is, for example, 1.46 to 1.62, and the refractive index of the transparent material constituting the first light diffusing plate (10) is usually 1.56 to 1.62. Examples of transparent materials include transparent resin materials and transparent glass materials. Examples of transparent resin materials include polycarbonate resin (refractive index: 1.59), MS resin (methyl methacrylate-styrene copolymer resin) (refractive index: 1.56 to 1.59), polystyrene resin (refractive index: 1.59) and the like are exemplified, and polystyrene resin is preferred from the viewpoint of cost and low moisture absorption.
　透明材料として透明樹脂材料を用いる場合、この透明樹脂材料に紫外線吸収剤、帯電防止剤、酸化防止剤、加工安定剤、難燃剤、滑剤などの添加剤を添加することもできる。これらの添加剤はそれぞれ単独で、または２種以上を組み合わせて用いることができる。 When a transparent resin material is used as the transparent material, additives such as an ultraviolet absorber, an antistatic agent, an antioxidant, a processing stabilizer, a flame retardant, and a lubricant can be added to the transparent resin material. These additives can be used alone or in combination of two or more.
　紫外線吸収剤としては、例えばベンゾトリアゾール系紫外線吸収剤、ベンゾフェノン計紫外線吸収剤、シアノアクリレート系紫外線吸収剤、マロン酸エステル系紫外線吸収剤、シュウ酸アニリド系紫外線吸収剤、トリアジン系紫外線吸収剤などが挙げられ、好ましくはベンゾトリアゾール系紫外線吸収剤、トリアジン系紫外線吸収剤である。 Examples of UV absorbers include benzotriazole UV absorbers, benzophenone meter UV absorbers, cyanoacrylate UV absorbers, malonic ester UV absorbers, oxalic anilide UV absorbers, and triazine UV absorbers. Preferred are benzotriazole ultraviolet absorbers and triazine ultraviolet absorbers.
　透明樹脂材料は通常、添加剤として光拡散剤を添加することなく用いられるが、本発明の目的を損なわない僅かな量であれば、光拡散剤を添加して用いてもよい。 The transparent resin material is usually used without adding a light diffusing agent as an additive, but may be added with a light diffusing agent as long as it is a slight amount that does not impair the object of the present invention.
　透明材料に光拡散剤を添加する場合に用いられる光拡散剤として通常は、第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)を構成する透明材料とは屈折率が異なる粉末が用いられ、透明材料中に分散させて用いられる。このような光拡散剤としては、例えばスチレン樹脂粒子、メタクリル樹脂粒子などの有機粒子、炭酸カルシウム粒子、シリカ粒子などの無機粒子が用いられ、その粒子径は通常０．８μｍ～５０μｍである。 Usually, the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) are used as the light diffusing agent when the light diffusing agent is added to the transparent material. A powder having a refractive index different from that of the transparent material to be used is used, and is used by being dispersed in the transparent material. As such a light diffusing agent, organic particles such as styrene resin particles and methacrylic resin particles, and inorganic particles such as calcium carbonate particles and silica particles are used, and the particle diameter is usually 0.8 μm to 50 μm.
〔光拡散板の層構成〕
　第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)は、単独の透明材料で構成された単層板であってもよいし、互いに異なる透明材料で構成された層が積層された構造の多層板であってもよい。光拡散板(10,20,30)が多層板である場合、光拡散板(10,20,30)の片面または両面は、通常１０μｍ～２００μｍ、好ましくは２０μｍ～１００μｍの厚みのスキン層が形成された構造とし、このスキン層を構成する透明樹脂材料として紫外線吸収剤が添加されたものを用いることが好ましい。かかる構成とすることにより、光源や外部からの光に含まれることのある紫外線による光拡散板(10,20,30)の劣化を防止することができ、特に光源として蛍光管などを用いた場合には、蛍光管からの紫外線による劣化を防止できることから、第１の面(11,21,31)にスキン層が形成されていることが好ましく、このとき第２の面(12,22,32)にはスキン層が形成されていないことが、コストの面でさらに好ましい。スキン層を構成する透明材料として透明樹脂材料に紫外線吸収剤が添加されたものを用いる場合、紫外線吸収剤の含有量は、透明樹脂材料を基準として通常０．５質量％～５質量％、好ましくは１質量％～２．５質量％である。 [Layer structure of light diffusion plate]
The first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) may be a single layer plate made of a single transparent material, or may be mutually It may be a multilayer board having a structure in which layers made of different transparent materials are laminated. When the light diffusion plate (10, 20, 30) is a multilayer plate, a skin layer having a thickness of usually 10 μm to 200 μm, preferably 20 μm to 100 μm is formed on one or both sides of the light diffusion plate (10, 20, 30). It is preferable to use a transparent resin material to which an ultraviolet absorber is added as the transparent resin material constituting the skin layer. By adopting such a configuration, it is possible to prevent deterioration of the light diffusing plate (10, 20, 30) due to ultraviolet light that may be included in the light source or external light, particularly when a fluorescent tube or the like is used as the light source. In order to prevent deterioration due to ultraviolet rays from the fluorescent tube, it is preferable that a skin layer is formed on the first surface (11, 21, 31), and at this time, the second surface (12, 22, 32) is formed. It is more preferable from the viewpoint of cost that no skin layer is formed on (). When a transparent resin material to which an ultraviolet absorber is added is used as the transparent material constituting the skin layer, the content of the ultraviolet absorber is usually 0.5% by mass to 5% by mass, preferably based on the transparent resin material. Is 1% by mass to 2.5% by mass.
　第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)は、片面または両面に帯電防止剤が塗布されていてもよい。帯電防止剤を塗布することにより、静電気によるホコリの付着などを防止して、ホコリの付着による光線透過率の低下を防止することができる。 The first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) may be coated with an antistatic agent on one side or both sides. By applying an antistatic agent, dust adhesion due to static electricity can be prevented, and a decrease in light transmittance due to dust adhesion can be prevented.
〔光拡散板の製造〕
　第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)は、例えば透明材料から削り出す方法により製造することができる。また、透明材料として透明樹脂材料を用いる場合は、例えば射出成形法、押出成形法、プレス成形法、フォトポリマー法などの通常の方法により製造することができる。 (Manufacture of light diffusion plate)
The first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) can be manufactured, for example, by a method of cutting out from a transparent material. Moreover, when using a transparent resin material as a transparent material, it can manufacture by normal methods, such as an injection molding method, an extrusion molding method, a press molding method, a photopolymer method, for example.
〔複合光制御板〕
　本実施形態の複合光制御板(1)は、かかる第１の光拡散板(10)、第２の光拡散板(20)および第３の光拡散板(30)が、この順序で互いに重ね合わされてなるものである。 [Composite light control board]
In the composite light control plate (1) of this embodiment, the first light diffusing plate (10), the second light diffusing plate (20), and the third light diffusing plate (30) are overlapped with each other in this order. It has been made.
　図１に示すように、本実施形態の複合光制御板(1)において、第２の光拡散板(20)は、第１の方向(X21)が第１の光拡散板(10)の第１の方向(X11)に対して並行である。第３の光拡散板(30)は、第１の方向(X31)が第１の光拡散板(10)の第１の方向(X11)に対して直交する。 As shown in FIG. 1, in the composite light control plate (1) of the present embodiment, the second light diffusing plate (20) has a first direction (X21) in the first light diffusing plate (10). Parallel to one direction (X11). In the third light diffusion plate (30), the first direction (X31) is orthogonal to the first direction (X11) of the first light diffusion plate (10).
　図１に示すように、本実施形態の複合光制御板(1)において、第２の光拡散板(20)は、第１の面(21)が第１の光拡散板(10)の第２の面(12)と向かい合う。第２の光拡散板(20)は通常、空気層を介して第１の光拡散板(10)に重ね合わされ、その間隔は、第１の光拡散板(10)の第２の面(12)に形成された凸状部(13)の頂部(13b)から、第２の光拡散板(20)の第１の面(21)までの距離(d12)で通常５ｍｍ以下であり、複合光制御板(1)をコンパクトなものとする観点から、この距離(d12)が０ｍｍであって、第１の光拡散板(10)に形成された凸状部(13)の頂部(13b)が、第２の光拡散板(20)の第１の面(21)に接していてもよい。 As shown in FIG. 1, in the composite light control plate (1) of the present embodiment, the second light diffusing plate (20) has a first surface (21) which is the first light diffusing plate (10). Facing the second face (12). The second light diffusing plate (20) is usually superimposed on the first light diffusing plate (10) via an air layer, and the distance between the second light diffusing plates (20) is the second surface (12 The distance (d12) from the top portion (13b) of the convex portion (13) formed on the first surface (21) of the second light diffusion plate (20) is usually 5 mm or less, and the composite light From the viewpoint of making the control plate (1) compact, the distance (d12) is 0 mm, and the top portion (13b) of the convex portion (13) formed on the first light diffusion plate (10) is The first light diffusion plate (20) may be in contact with the first surface (21).
　第３の光拡散板(30)は、第１の面(31)が第２の光拡散板(20)の第２の面(22)と向かい合う。第３の光拡散板(30)は通常、空気層を介して第２の光拡散板(20)に重ね合わされ、その間隔は、第２の光拡散板(20)の第２の面(22)に形成された凸状部(23)の頂部(23b)から、第３の光拡散板(30)の第１の面(31)までの距離(d23)で通常５ｍｍ以下であり、複合光制御板(1)をコンパクトなものとする観点から、この距離(d23)が０ｍｍであって、第２の光拡散板(20)に形成された凸状部(23)の頂部(23b)が、第３の光拡散板(30)の第１の面(31)に接していてもよい。 In the third light diffusion plate (30), the first surface (31) faces the second surface (22) of the second light diffusion plate (20). The third light diffusing plate (30) is usually superimposed on the second light diffusing plate (20) via an air layer, and the distance between the third light diffusing plates (30) and the second surface (22) of the second light diffusing plate (20). The distance (d23) from the top part (23b) of the convex part (23) formed on the first surface (31) of the third light diffusion plate (30) is usually 5 mm or less, and the composite light From the viewpoint of making the control plate (1) compact, the distance (d23) is 0 mm, and the top portion (23b) of the convex portion (23) formed on the second light diffusion plate (20) is The third light diffusing plate (30) may be in contact with the first surface (31).
　第１の光拡散板(10)の第２の面(12)および第２の光拡散板(20)の第２の面(22)に形成された凸状部(13,23)に起因するモアレの発生を防止しうる点で、第２の光拡散板(20)の第１の面(21)は、全面に亙って光拡散性を有する面であることが好ましい。第１の面(21)を光拡散性を有する面とするには、例えば、マット化剤と呼ばれる微細な粒子を含むスキン層で第１の面(21)を構成してもよいし、第１の面(21)にエンボス加工、ブラスト加工を施してもよいし、マット化剤およびバインダーを含む塗布液を塗布してマット層を形成してもよい。 It originates in the convex-shaped part (13,23) formed in the 2nd surface (12) of the 1st light diffusing plate (10), and the 2nd surface (22) of the 2nd light diffusing plate (20). The first surface (21) of the second light diffusing plate (20) is preferably a surface having light diffusibility over the entire surface from the viewpoint of preventing the occurrence of moiré. In order to make the first surface (21) a surface having light diffusibility, for example, the first surface (21) may be constituted by a skin layer containing fine particles called a matting agent. One surface (21) may be embossed or blasted, or a matting layer may be formed by applying a coating solution containing a matting agent and a binder.
　モアレを防止しうる点では、第１の光拡散板(10)の第２の面(12)に形成された凸状部(13)か、または第２の光拡散板(20)の第２の面(22)に形成された凸状部(23)を、相互に幅が異なる複数種類の凸状部(13,23)で構成し、これら複数種類の凸状部(13,23)が不規則な順序で並列配置されていることも好ましい。 In terms of preventing moire, the convex portion (13) formed on the second surface (12) of the first light diffusion plate (10) or the second portion of the second light diffusion plate (20) can be prevented. The convex portion (23) formed on the surface (22) is composed of a plurality of types of convex portions (13, 23) having different widths, and the plurality of types of convex portions (13, 23). It is also preferable that they are arranged in parallel in an irregular order.
　第１の光拡散板(10)の凸状部(13)と、第３の光拡散板(30)の凸状部(33)とは、互いに同一の断面形状であってもよいし、異なる断面形状であってもよい。 The convex portion (13) of the first light diffusing plate (10) and the convex portion (33) of the third light diffusing plate (30) may have the same cross-sectional shape or different from each other. It may have a cross-sectional shape.
　第１の光拡散板(10)の第１の面(11)および第３の光拡散板(30)の第１の面(31)は、光拡散性を有する面としてもよい。これら第１の面(11,31)を、光拡散性を有する面とするには、例えばマット化剤と呼ばれる微細な粒子を含むスキン層でこれら第１の面（11,31）を構成してもよいし、第１の面（11,31）にエンボス加工、ブラスト加工などを施してもよいし、マット化剤をバインダーと混合して塗布液とし、この塗布液を第１の面（11,31）に塗布して、光拡散性を与えてもよい。 The first surface (11) of the first light diffusing plate (10) and the first surface (31) of the third light diffusing plate (30) may be surfaces having light diffusibility. In order to make these first surfaces (11, 31) surfaces having light diffusibility, for example, the first surfaces (11, 31) are constituted by a skin layer containing fine particles called a matting agent. Alternatively, the first surface (11, 31) may be embossed or blasted, or a matting agent may be mixed with a binder to form a coating solution, which is then used as the first surface ( 11 and 31) to impart light diffusibility.
〔面光源装置〕
　本実施形態の複合光制御板(1)は、図４に示すように、面光源装置(6)に組み込まれて好適に用いられる。この面光源装置(6)は、本実施形態の複合光制御板(1)と、光源(7)とを備えるものである。 [Surface light source device]
As shown in FIG. 4, the composite light control plate (1) of the present embodiment is preferably used by being incorporated in the surface light source device (6). The surface light source device (6) includes the composite light control plate (1) of the present embodiment and a light source (7).
　光源(7)は複数であり、互いに離間して配置されている。この光源(7)は、複合光制御板(1)を構成する第１の光拡散板(10)の第１の面(11)に光を供給する。 There are a plurality of light sources (7), which are arranged apart from each other. The light source (7) supplies light to the first surface (11) of the first light diffusion plate (10) constituting the composite light control plate (1).
〔光源〕
　光源(7)としては、例えば冷陰極線管などの線状光源が挙げられるが、好ましくはＬＥＤ（発光ダイオード）などの点状光源である。 〔light source〕
Examples of the light source (7) include a linear light source such as a cold cathode ray tube, and a point light source such as an LED (light emitting diode) is preferable.
　複数の光源(7)の間の間隔(L)は、光源中心間の距離で、通常１０ｍｍ～１５０ｍｍである。光源(7)中心から第１の光拡散板(10)の第１の面(11)までの距離(D)は、通常３ｍｍ～５０ｍｍであり、これらの比〔Ｌ／Ｄ〕は２以上、さらには２．５以上であることが、面光源装置を薄くすることができる点で、好ましい。 The interval (L) between the plurality of light sources (7) is the distance between the light source centers, and is usually 10 mm to 150 mm. The distance (D) from the center of the light source (7) to the first surface (11) of the first light diffusion plate (10) is usually 3 mm to 50 mm, and the ratio [L / D] is 2 or more. Furthermore, it is preferable that it is 2.5 or more from the point which can make a surface light source device thin.
〔透過型画像表示装置〕
　この面光源装置(6)は、図４に示すように、透過型画像表示装置(8)に組み込まれて好適に用いられる。この透過型画像表示装置(8)は、上記の面光源装置(6)と透過型画像表示部(9)とを備えている。透過型画像表示部(9)は、例えば液晶セル(91)と、その両面に配置された直線偏光板(92)から構成された透過型液晶表示部が例示される。この透過型画像表示装置(8)において、透過型画像表示部(9)は、複合光制御板(1)を透過した光によって照明されて、画像を表示する。複合光制御板(1)を通過する光は、面光源装置(6)を構成する複数の光源(7)から出力される光である。 [Transparent image display device]
As shown in FIG. 4, the surface light source device (6) is suitably used by being incorporated in the transmissive image display device (8). The transmissive image display device (8) includes the surface light source device (6) and the transmissive image display unit (9). The transmissive image display section (9) is exemplified by a transmissive liquid crystal display section composed of, for example, a liquid crystal cell (91) and linearly polarizing plates (92) arranged on both surfaces thereof. In the transmissive image display device (8), the transmissive image display section (9) is illuminated with light transmitted through the composite light control plate (1) to display an image. The light passing through the composite light control plate (1) is light output from a plurality of light sources (7) constituting the surface light source device (6).
〔複合光制御板の配置〕
　透過型画像表示装置(9)において、複合光制御板(1)は、第１の光拡散板(10)の第１の方向(X11)が画面の横方向になるように配置されていてもよいし、縦方向になるように配置されていてもよい。 [Arrangement of composite light control board]
In the transmissive image display device (9), the composite light control plate (1) may be arranged so that the first direction (X11) of the first light diffusion plate (10) is the horizontal direction of the screen. It may be arranged in the vertical direction.
〔第１の光拡散板の第１の方向が横方向になる場合〕
　第１の光拡散板(10)の第１の方向(X11)が画面の横方向になるように本実施形態の複合光制御板(1)を配置すると、第１の光拡散板(10)の第２の方向(X12)は縦方向となり、第３の光拡散板(30)の第２の方向(X32)は横方向となるが、この場合、斜め横方向から見たときの輝度ムラをより抑制できることから、第３の光拡散板(30)の凸状部(33)の輪郭形状を示す式（２）におけるｈaとｗaとの比〔Ｒ3＝ｈa／ｗa〕は、第１の光拡散板(10)の凸状部(13)の輪郭形状を示す式（２）におけるｈaとｗaとの比〔Ｒ1＝ｈa／ｗa〕よりも小さいことが好ましく、また、第３の光拡散板(30)の凸状部(33)の輪郭形状を示す式（２）におけるｋaは、第１の光拡散板(10)の凸状部(13)の輪郭形状を示す式（２）におけるｋaよりも小さいことが好ましい。さらに好ましくは、透過型画像表示装置(9)における光源(7)の配置において画面の縦方向の光源間隔(LV)が、横方向の光源間隔(LH)と等しいか、これよりも大きいことである。 [When the first direction of the first light diffusion plate is the horizontal direction]
When the composite light control plate (1) of this embodiment is arranged so that the first direction (X11) of the first light diffusion plate (10) is in the horizontal direction of the screen, the first light diffusion plate (10) is arranged. The second direction (X12) is the vertical direction, and the second direction (X32) of the third light diffusing plate (30) is the horizontal direction. In this case, the luminance unevenness when viewed from the oblique horizontal direction because it can further suppress the third light diffusing plate h a and w ratio of a [R3 = h a / w a] in equation (2) representing the contour shape of the convex portion (33) of (30) it is preferable convex portion (13) smaller than the ratio [R1 = h a / w a] of h a and w a in equation (2) representing the contour shape of the first light diffusing plate (10) in addition, k a in equation (2) representing the contour shape of the convex portion of the third light diffuser plate (30) (33), the convex portion of the first light diffusing plate (10) (13) is preferably smaller than k a in equation (2) representing the contour shape. More preferably, in the arrangement of the light source (7) in the transmissive image display device (9), the light source interval (LV) in the vertical direction of the screen is equal to or larger than the light source interval (LH) in the horizontal direction. is there.
〔第１の光拡散板の第１の方向が縦方向になる場合〕
　第１の光拡散板(10)の第１の方向(X11)が画面の縦方向になるように本実施形態の複合光制御板(1)を配置すると、第１の光拡散板(10)の第２の方向(X12)は横方向となり、第３の光拡散板(30)の第２の方向(X32)は縦方向となるが、この場合、斜め横方向から見たときの輝度ムラをより抑制できることから、第１の光拡散板(10)の凸状部(13)の輪郭形状を示す式（２）におけるｈaとｗaとの比〔Ｒ1＝ｈa／ｗa〕は、第３の光拡散板(30)の凸状部(33)の輪郭形状を示す式（２）におけるｈaとｗaとの比〔Ｒ3＝ｈa／ｗa〕よりも小さいことが好ましく、また、第１の光拡散板(10)の凸状部(13)の輪郭形状を示す式（２）におけるｋaは、第３の光拡散板(30)の凸状部(33)の輪郭形状を示す式（２）におけるｋaよりも小さいことが好ましい。さらに好ましくは、透過型画像表示装置(9)における光源(7)の配置において、画面の縦方向の光源間隔(LV)が、横方向の光源間隔(LH)と等しいか、これよりも大きいことである。 [When the first direction of the first light diffusion plate is the vertical direction]
When the composite light control plate (1) of the present embodiment is arranged so that the first direction (X11) of the first light diffusion plate (10) is the vertical direction of the screen, the first light diffusion plate (10) is arranged. The second direction (X12) is the horizontal direction, and the second direction (X32) of the third light diffusing plate (30) is the vertical direction. In this case, the luminance unevenness when viewed from the oblique horizontal direction because it can further suppress the first light diffusing plate h a and w ratio of a [R1 = h a / w a] in equation (2) representing the contour shape of the convex portion (13) of (10) , preferably a third less than the ratio [R3 = h a / w a] of h a and w a in equation (2) representing the contour shape of the convex portion of the light diffuser plate (30) (33) in addition, k a in equation (2) representing the contour shape of the convex portion of the first light diffusing plate (10, 13) is convex portion of the third light diffuser plate (30) of (33) is preferably smaller than k a in equation (2) representing the contour shape. More preferably, in the arrangement of the light source (7) in the transmissive image display device (9), the light source interval (LV) in the vertical direction of the screen is equal to or larger than the light source interval (LH) in the horizontal direction. It is.
１：複合光制御板
10：第１の光拡散板
　11：第１の面　　　12：第２の面
　13：凸状部　　　　13a：凸状部の両端　　13b：凸状部の頂点
　X11:第１の方向　　X12:第２の方向
20：第２の光拡散板
　21：第１の面　　　22：第２の面
　23：凸状部　　　　23b：凸状部の頂点
　X21:第１の方向　　X22:第２の方向
30：第３の光拡散板
　31：第１の面　　　32：第２の面
　33：凸状部
　X31:第１の方向　　X32:第２の方向
6：面光源装置
7：光源
8：直下型画像表示装置
9：透過型画像表示部
　91：液晶セル　　　92：直線偏光板
101: 従来の光制御板
107：従来の光源
108：従来の直下型画像表示装置
109：従来の透過型画像表示部
　191：従来の液晶セル　　　192：従来の直線偏光板 1: Composite light control board
10: 1st light diffusing plate 11: 1st surface 12: 2nd surface 13: Convex part 13a: Both ends of convex part 13b: Vertex of convex part X11: 1st direction X12: 2nd direction
20: 2nd light diffusing plate 21: 1st surface 22: 2nd surface 23: Convex part 23b: Vertex of convex part X21: 1st direction X22: 2nd direction
30: 3rd light diffusing plate 31: 1st surface 32: 2nd surface 33: Convex part X31: 1st direction X32: 2nd direction
6: Surface light source device
7: Light source
8: Direct type image display device
9: Transmission type image display unit 91: Liquid crystal cell 92: Linear polarizing plate
101: Conventional light control board
107: Conventional light source
108: Conventional direct-type image display device
109: Conventional transmission type image display unit 191: Conventional liquid crystal cell 192: Conventional linear polarizing plate

Claims (6)

  1. 　第１の面から入射した光が該第１の面と反対側に位置する第２の面から出射可能であり、かつ、第１の方向に延在すると共に、該第１の方向に直交する第２の方向に並列配置された複数の凸状部が前記第２の面に形成されている第１の光制御板、第２の光制御板および第３の光制御板が、この順序で互いに重ね合わされてなる複合光制御板であって、前記第１の光制御板および前記第３の光制御板は、それぞれ以下に定義される光制御板であり、
    　前記第２の光制御板は、第１の方向が前記第１の光制御板の第１の方向に対して並行であり、かつ第１の面が第１の光制御板の第２の面と向かい合い、前記第３の光制御板は、第１の方向が前記第１の光制御板の第１の方向に対して直交し、かつ第１の面が前記第２の光制御板の第２の面と向かい合っている、
    複合光制御板。
    光制御板：前記凸状部の前記第１の方向に直交する断面において、当該凸状部の前記第２の方向に対する両端をとおる軸線をｘ軸とし、前記ｘ軸上において前記両端の中心をとおり前記ｘ軸に直交する軸線をｚ軸とし、前記凸状部のｘ軸方向の長さをｗaとしたとき、
    上記断面において前記凸状部の輪郭形状が、－０．４７５ｗa≦ｘ≦０．４７５ｗaの範囲において式（１）
    Figure JPOXMLDOC01-appb-M000001
     〔式（１）において、ｚ０(ｘ)は、式（２）
    Figure JPOXMLDOC01-appb-M000002
     （式（２）において、ｈaは０．２５ｗa～０．７５ｗaであり、ｋaは－１．０以上０未満である。）
    で定義される。〕
    を満たすｚ(ｘ)で表される光制御板。     Light incident from the first surface can be emitted from the second surface located on the opposite side of the first surface, extends in the first direction, and is orthogonal to the first direction. The first light control plate, the second light control plate, and the third light control plate in which a plurality of convex portions arranged in parallel in the second direction are formed on the second surface are in this order. A composite light control plate overlaid on each other, wherein the first light control plate and the third light control plate are each a light control plate defined below,
    The second light control plate has a first direction parallel to the first direction of the first light control plate, and the first surface is the second surface of the first light control plate. The third light control plate has a first direction perpendicular to the first direction of the first light control plate and a first surface of the third light control plate. Facing 2 side,
    Composite light control board.
    Light control plate: In a cross section orthogonal to the first direction of the convex portion, an axis passing through both ends of the convex portion with respect to the second direction is defined as an x axis, and the center of the both ends is located on the x axis. When the axis perpendicular to the x axis is the z axis and the length of the convex portion in the x axis direction is w a ,
    In the cross section, the contour shape of the convex portion is in the range of −0.475 w a ≦ x ≦ 0.475 w a in the formula (1).
    Figure JPOXMLDOC01-appb-M000001
     [In the formula (1), z 0 (x) has the formula (2)
    Figure JPOXMLDOC01-appb-M000002
     (In the formula (2), h a is 0.25w a ~ 0.75w a, k a is 0 to less than -1.0.)
    Defined by ]
    A light control plate represented by z (x) satisfying
  2. 　前記式（２）におけるｈａが０．４ｗａ～０．７ｗａである請求項１に記載の複合光制御板。 Complex optical control plate according to claim 1 h a is 0.4 w a ~ 0.7 w a in the formula (2).
  3. 　前記式（２）におけるｋａが－０．５以上である請求項１または請求項２に記載の複合光制御板。 3. The composite light control plate according to claim 1, wherein k a in the formula (2) is −0.5 or more.
  4. 　前記式（２）におけるｈａが０．４８２５ｗa～０．５２１ｗａであり、ｋａが－０．２３２～－０．２２７であるか、ｈａが０．５９６６ｗａ～０．６８３７ｗａであり、ｋａが－０．０７５～－０．０６９であるか、またはｈａが０．５２５ｗａであり、ｋａが－０．４である請求項１～請求項３のいずれかに記載の複合光制御板。 In the formula (2), h a is 0.4825 w a to 0.521 w a and k a is −0.232 to −0.227, or h a is 0.5966 w a to 0.6837 w a 4. The method according to claim 1, wherein k a is −0.075 to −0.069, or h a is 0.525w a and k a is −0.4. Composite light control board.
  5. 　請求項１～請求項４のいずれかに記載の複合光制御板と、
    　互いに間隔を空けて配置され、前記複合制御板を構成する第１の光制御板の第１の面に光を供給する複数の光源と、
    を備える面光源装置。     A composite light control plate according to any one of claims 1 to 4,
    A plurality of light sources arranged to be spaced apart from each other and supplying light to the first surface of the first light control plate constituting the composite control plate;
    A surface light source device comprising:
  6. 　請求項５に記載の面光源装置と、
    　前記複数の光源から出力され前記複合光制御板を通過した光によって照明されて画像を表示する透過型画像表示部と
    　を備える透過型画像表示装置。     A surface light source device according to claim 5;
    A transmissive image display device comprising: a transmissive image display unit that displays an image illuminated by light output from the plurality of light sources and passed through the composite light control plate.
PCT/JP2010/063113 2009-08-06 2010-08-03 Complex light control plate, area light source device and transmission-type image display device WO2011016456A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07218911A (en) * 1994-02-08 1995-08-18 Hitachi Ltd Liquid crystal display device and view angle setting method for same
JPH08146225A (en) * 1994-11-22 1996-06-07 Tosoh Corp Backlight
JP2590227Y2 (en) * 1993-06-04 1999-02-10 株式会社エンプラス Surface light source device
JP2007286261A (en) * 2006-04-14 2007-11-01 Sony Corp Optical sheet, backlight device and liquid crystal display
JP2009075366A (en) * 2007-09-20 2009-04-09 Toppan Printing Co Ltd Optical sheet, backlight unit, and display

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2590227Y2 (en) * 1993-06-04 1999-02-10 株式会社エンプラス Surface light source device
JPH07218911A (en) * 1994-02-08 1995-08-18 Hitachi Ltd Liquid crystal display device and view angle setting method for same
JPH08146225A (en) * 1994-11-22 1996-06-07 Tosoh Corp Backlight
JP2007286261A (en) * 2006-04-14 2007-11-01 Sony Corp Optical sheet, backlight device and liquid crystal display
JP2009075366A (en) * 2007-09-20 2009-04-09 Toppan Printing Co Ltd Optical sheet, backlight unit, and display

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