CN101943367B - Light control plate, surface light source device and transmission type image display device - Google Patents

Light control plate, surface light source device and transmission type image display device Download PDF

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Publication number
CN101943367B
CN101943367B CN201010224563.0A CN201010224563A CN101943367B CN 101943367 B CN101943367 B CN 101943367B CN 201010224563 A CN201010224563 A CN 201010224563A CN 101943367 B CN101943367 B CN 101943367B
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China
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convex shaped
shaped part
equal
mentioned
light
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Expired - Fee Related
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CN201010224563.0A
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Chinese (zh)
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CN101943367A (en
Inventor
太田宽史
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Sumitomo Chemical Co Ltd
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Sumitomo Chemical Co Ltd
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
    • G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
    • G02B6/003—Lens or lenticular sheet or layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/0006—Arrays
    • G02B3/0037—Arrays characterized by the distribution or form of lenses
    • G02B3/0056—Arrays characterized by the distribution or form of lenses arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G02B5/1833—Diffraction gratings comprising birefringent materials
    • 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
    • G02F1/133524—Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
    • 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
    • G02F1/133526—Lenses, e.g. microlenses or Fresnel lenses
    • 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

Abstract

The invention provides a light control plate which can stably restrain uneven brightness better, a surface light source device comprising the light control plate, and a transmission type image display device. The light control plate is the light control plate which causes the incident light from a first surface to exit from a second surface. The second surface is provided with a plurality of convex parts which extend along a first direction and are parallel to a second direction orthogonal to the first direction. When on an orthogonal cross section of the first direction of the convex part, an axis passing through two ends of the convex part in the second direction is considered to be axis X, an axis passing through the center of two ends on the axis X and orthogonal to the axis X is considered to be axis Z, and the length of the convex part in the direction of axis X is set as wa, the outline shape of the convex part on the cross section is in the range that x is more than or equal to -0.475wa and less than or equal to 0.475wa and expressed by z(x)=(z0(x)xr)+/-0.01 wa (r is the number between 0.95 and 1.05); z0(x) can be expressed by the formula, wherein ha is a constant number more than or equal to 0.27wa and less than or equal to 1.02wa, and ka is the constant number more than or equal to -0.38 and less than or equal to 0.00.

Description

Opital control board, planar light source device and transmission image display device
Technical field
The present invention relates to Opital control board, planar light source device and transmission image display device.
Background technology
In the transmission image display devices such as liquid crystal indicator, as the routine straight-down negative planar light source device that uses of one of light source backlight of exporting liquid crystal display part.As typical planar light source device, utilization is arranged with the device of a plurality of light sources in the rear side of the Opital control board of light diffusing board and so on.In this planar light source device, can make light-emitting area easily improve brightness by increasing the light source number configure, but there is but then the problem that luminance uniformity is lower and so on.Particularly, because near the brightness directly over light source uprises the periodicity brightness disproportionation occurring, be exactly problem, and because of the slimming of planar light source device or make above-mentioned periodicity brightness disproportionation become larger problem in order to reduce the reduction of the light source number of power consumption.
Thereby, in order to ensure luminance uniformity, for example, in the flat 6-273760 communique of TOHKEMY (patent documentation 1), on the light diffusing board as one of Opital control board example corresponding to be formed with light quantity correction pattern with the distance of light source.Equally, in TOHKEMY 2004-127680 communique (patent documentation 2), the prism of cross section indentation is set by near the part directly over the light source of the light source side at light diffusing board, near the light disperseing directly over the more light source of light quantity.
But, the prism of the cross section indentation of the light quantity correction pattern as patent documentation 1 and patent documentation 2, make it for holding in the formation backlight of dependence with the distance of light source position, because of dislocation and the caused distortion etc. of generating heat of the Opital control board of light diffusing board and so on, and cause luminance uniformity to worsen.
Summary of the invention
Thereby, the object of the invention is to, provide a kind of and can more stably suppress the Opital control board of brightness disproportionation, the planar light source device that comprises this Opital control board and transmission image display device.
The Opital control board the present invention relates to is that a kind of making can be from being positioned at the Opital control board with second outgoing of first surface opposition side from the light of first surface incident, wherein, on second, be formed with a plurality of convex shaped parts that extend and configure side by side along first direction in the second direction with first direction quadrature, on the cross section at convex shaped part and first direction quadrature, if the axis at the two ends by this convex shaped part in above-mentioned second direction is x axle, be located on x axle center by two ends and with the axis of x axle quadrature be z axle, and the axial length of the x that establishes convex shaped part is while being wa, on above-mentioned cross section, the contour shape of convex shaped part is in the scope of-0.475wa≤x≤0.475wa, can be represented by the z (x) that meets formula (1),
z B(x)-0.01w a≤z(x)≤z B(x)+0.01w a...(1)
Wherein, z in formula (1) b(x)=z 0(x) * r (r be more than or equal to 0.95 and be less than or equal to 1.05 constant), z 0(x) by formula (2), represent.
z 0 ( x ) = h a - 8 h a ( x w a ) 2 1 - k a + ( 1 - k a ) 2 + 16 k a ( x w a ) 2 · · · ( 2 )
(in formula (2), h ato be more than or equal to 0.27w aand be less than or equal to 1.02w aconstant, k ato be more than or equal to-0.38 and be less than or equal to 0.00 constant.)
In this formation, because convex shaped part has the represented cross sectional shape of above-mentioned z (x), so can more stably reduce from the brightness disproportionation of the light of Opital control board outgoing.
The planar light source device the present invention relates to possesses: the Opital control board the present invention relates to; Be spaced from each other and be configured, and the first surface of Opital control board is supplied with to a plurality of light sources of light.
This planar light source device is owing to possessing the Opital control board the present invention relates to, so can more stably reduce from the brightness disproportionation of the light of Opital control board outgoing.
The transmission image display device the present invention relates to possesses: the Opital control board the present invention relates to; Be spaced from each other and be configured, and the first surface of Opital control board is supplied with to a plurality of light sources of light; And by export and throw light on to show by the light of Opital control board the transmission type image display part of image from a plurality of light sources.
In this transmission image display device, owing to possessing the Opital control board the present invention relates to, the transmission type image display part so the enough light that has stably suppressed brightness disproportionation of energy throws light on.Thereby, can stably show the image that there is no brightness disproportionation.
Accompanying drawing explanation
Fig. 1 is the sectional view that schematically shows the formation of transmission image display device one embodiment the present invention relates to.
Fig. 2 is the enlarged drawing of light diffusing board used on the transmission image display device shown in Fig. 1.
Fig. 3 means the figure of one of cross sectional shape with the bearing of trend quadrature of convex shaped part example.
Fig. 4 is the figure that allows amplitude of fluctuation that the outline line of the convex shaped part cross sectional shape shown in presentation graphs 3 is shown.
Fig. 5 means the figure from the hope intensity distributions of the output light of convex shaped part.
Fig. 6 means the figure of one of assay method of intensity distributions example.
Fig. 7 means the figure for the analogy model of convex shaped part design.
Fig. 8 means the figure of one of convex shaped part design operation.
Fig. 9 means the figure of one of intensity distributions between two light sources of adjacency example.
Figure 10 means the figure of his example of the intensity distributions between two light sources of adjacency.
Figure 11 means the figure of other examples of the intensity distributions between two light sources of adjacency.
Figure 12 means the figure of one of cross sectional shape with the bearing of trend quadrature of convex shaped part example.
Figure 13 is the figure that the condition that represents that the outline line of the convex shaped part cross sectional shape shown in Figure 12 is satisfied is shown.
Figure 14 means the z of the shape example 1 of the convex shaped part shown in Figure 12 0(x) figure.
Figure 15 means the figure of the condition that the outline line of shape example 1 is satisfied.
Figure 16 means the z of the shape example 2 of the convex shaped part shown in Figure 12 0(x) figure.
Figure 17 means the figure of the condition that the outline line of shape example 2 is satisfied.
Figure 18 means the figure with his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 19 is the figure that the condition that represents that the outline line of the convex shaped part cross sectional shape shown in Figure 18 is satisfied is shown.
Figure 20 means the z of the shape example 3 of the convex shaped part shown in Figure 18 0(x) figure.
Figure 21 means the figure of the condition that the outline line of shape example 3 is satisfied.
Figure 22 means the z of the shape example 4 of the convex shaped part shown in Figure 18 0(x) figure.
Figure 23 means the figure of the condition that the outline line of shape example 4 is satisfied.
Figure 24 means the figure with his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 25 means the figure of the condition that the outline line of the convex shaped part shown in Figure 24 is satisfied.
Figure 26 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 27 means the figure of the condition that the outline line of the convex shaped part shown in Figure 26 is satisfied.
Figure 28 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 29 means the figure of the condition that the outline line of the convex shaped part shown in Figure 28 is satisfied.
Figure 30 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 31 means the figure of the condition that the outline line of the convex shaped part shown in Figure 30 is satisfied.
Figure 32 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 33 means the figure of the condition that the outline line of the convex shaped part shown in Figure 32 is satisfied.
Figure 34 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 35 means the figure of the condition that the outline line of the convex shaped part shown in Figure 34 is satisfied.
Figure 36 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 37 means the figure of the condition that the outline line of the convex shaped part shown in Figure 36 is satisfied.
Figure 38 means the figure with other examples of the cross sectional shape of the bearing of trend quadrature of convex shaped part.
Figure 39 means the figure of the condition that the outline line of the convex shaped part shown in Figure 38 is satisfied.
Figure 40 means the schematic diagram of the analogy model of embodiment and comparative example.
Figure 41 means that the convex shaped part that uses in the simulation of embodiment 1 is at the chart of the design data of design phase.
Figure 42 means that the convex shaped part that uses in the simulation of embodiment 2 is at the chart of the design data of design phase.
Figure 43 means that the convex shaped part that uses in the simulation of embodiment 3 is at the chart of the design data of design phase.
Figure 44 means that the convex shaped part that uses in the simulation of embodiment 4 is at the chart of the design data of design phase.
Figure 45 means that the convex shaped part that uses in the simulation of embodiment 5 is at the chart of the design data of design phase.
Figure 46 means that the convex shaped part that uses in the simulation of embodiment 6 is at the chart of the design data of design phase.
Figure 47 means that the convex shaped part that uses in the simulation of embodiment 7 is at the chart of the design data of design phase.
Figure 48 means that the convex shaped part that uses in the simulation of embodiment 8 is at the chart of the design data of design phase.
Figure 49 means that the convex shaped part that uses in the simulation of embodiment 9 is at the chart of the design data of design phase.
Figure 50 means that the convex shaped part that uses in the simulation of embodiment 10 is at the chart of the design data of design phase.
Figure 51 means that the convex shaped part that uses in the simulation of embodiment 11 is at the chart of the design data of design phase.
Figure 52 means that the convex shaped part that uses in the simulation of embodiment 12 is at the chart of the design data of design phase.
Figure 53 means the chart of the analog result of embodiment 1～12 and comparative example 1～3.
Figure 54 means that the convex shaped part that uses in the simulation of embodiment 13 is at the chart of the design data of design phase.
Figure 55 means the figure of cross sectional shape of the convex shaped part of embodiment 14～17 and comparative example 2.
Figure 56 means the figure of the result of simulating 1 in comparative example 2.
Figure 57 means the figure of the result of simulating 2 in comparative example 2.
Figure 58 means the figure of the intensity distributions of the result of simulating 3 in example 2 based on the comparison.
Figure 59 means the figure of the result of simulating 1 in embodiment 14.
Figure 60 means the figure of the result of simulating 2 in embodiment 14.
Figure 61 means the figure based on simulating the intensity distributions of 3 result in embodiment 14.
Figure 62 means the figure of the result of simulating 1 in embodiment 15.
Figure 63 means the figure of the result of simulating 2 in embodiment 15.
Figure 64 means the figure based on simulating the intensity distributions of 3 result in embodiment 15.
Figure 65 means the figure of the result of simulating 1 in embodiment 16.
Figure 66 means the figure of the result of simulating 2 in embodiment 16.
Figure 67 means the figure based on simulating the intensity distributions of 3 result in embodiment 16.
Figure 68 means the figure of the result of simulating 1 in embodiment 17.
Figure 69 means the figure of the result of simulating 2 in embodiment 17.
Figure 70 means the figure based on simulating the intensity distributions of 3 result in embodiment 17.
Embodiment
Below, with reference to accompanying drawing, the embodiment of Opital control board of the present invention, planar light source device and transmission image display device is described.In addition, in the description of the drawings to the additional same reference numerals of identical element, and omit repeat specification.In addition, the dimensional ratios of accompanying drawing not necessarily with explanation in consistent.
(the first embodiment)
Fig. 1 is the sectional view that schematically shows the formation of transmission image display device one embodiment the present invention relates to.In Fig. 1, transmission image display device is decomposed to represent.Fig. 2 is the enlarged drawing of the light diffusing board (Opital control board) that has of the planar light source device that comprises in the transmission image display device shown in Fig. 1, represents the section constitution of light diffusing board.In Fig. 2, for convenience of explanation, also schematically show two light sources of adjacency.
As transmission type image display part 10, the two sides that for example can be set forth in liquid crystal cells 11 disposes the display panels of linear polarization plate 12,13.In this case, transmission image display device 1 is liquid crystal indicator (or LCD TV).Liquid crystal cells 11 and Polarizer 12,13 can adopt parts used on the transmission image display devices such as liquid crystal indicator in the past.As liquid crystal cells 11, can illustration TFT type, the known liquid crystal cells such as STN type.
Planar light source device 20 is so-called straight-down negative planar light source devices 20, and has the light source portion 30 that comprises a plurality of light sources 31 that configured side by side.Each light source 31 refers to the upwardly extending linear light source in the side of the orientation quadrature with a plurality of light sources 31, can the straight tube-like light source of illustration as fluorescent light (cold cathode line lamp).The mode devices spaced apart that a plurality of light sources 31 are positioned at same plane P1 with the central axis of each light source 31 is configured, and when the distance between the central axis of two light sources 31,31 of establishing adjacency is L, distance L is for example 10mm～150mm.At this, although light source 31 is wire, can also adopt point source of light as LED etc.In addition, for convenience of explanation, the plane P 1 shown in Fig. 1 is imaginary plane.
A plurality of light sources 31 are preferably configured in lamp box 32 as illustrated in fig. 1, and the inner face 32a of lamp box 32 preferably forms light reflection surface.Thus, the light of exporting from each light source 31 outputs to transmission type image display part 10 1 sides reliably, therefore can effectively utilize the light from each light source 31.In the present embodiment, establishing light source portion 30 has the above-mentioned desirable lamp box 32 forming and describes.
Planar light source device 20 has in the front face side of light source portion 30 (in Fig. 1 for upside) that is transmission type image display part 10 1 sides with respect to the spaced apart light diffusing board 40 as Opital control board being configured of light source 31.As described later, when establishing spacing distance between above-mentioned light diffusing board 40 and a plurality of light source 31 and be D, spacing distance D is for example 3mm～50mm.In planar light source device 20, in order to seek slimming, make L/D be more than or equal to 1.5, preferably L/D is more than or equal to 2, and more preferably L/D is more than or equal to 2.5, selects like this distance L and the spacing distance D of 31,31 of two light sources of adjacency.
Light diffusing board 40 is for the picture of each light source 31 is not projected on transmission type image display part 10, and for carrying out diffusion irradiation by the light from light source portion 30 that is from the direct light of each light source 31 and the reflected light after the inner face 32a of lamp box 32 reflection towards transmission type image display part 10.The thickness d of light diffusing board 40 1normally be more than or equal to 0.1mm and be less than or equal to 5mm, being preferably more than or equal to 0.5mm and being less than or equal to 3mm, being more preferably more than or equal to 0.8mm and being less than or equal to 2mm.
Light diffusing board 40 consists of transparent material.The refractive index of transparent material is more than or equal to 1.48 and be less than or equal to 1.62 or be more than or equal to 1.56 and be less than or equal to 1.62 conventionally, as transparent material can illustration transparent resin, clear glass.In addition, as transparent resin, can illustration polycarbonate resin 1.59), MS resin (methacrylic acid methyl-styrene copolymer resin) (refractive index: 1.56～1.59), polystyrene resin (refractive index: 1.59) etc. (refractive index:.
When adopting transparent resin material as transparent material, can also in this transparent resin material, add the adjuvants such as ultraviolet light absorber, anti-live agent, antioxidant, processing stabilizers, fire retardant, lubricant.These adjuvants can be respectively separately or make two or more use that combines.
As ultraviolet light absorber, such as enumerating benzotriazole, be that ultraviolet light absorber, benzophenone series ultraviolet light absorber, cyanoacrylate are that ultraviolet light absorber, malonate are that ultraviolet light absorber, oxanilide are that ultraviolet light absorber, triazine are ultraviolet light absorber etc., preferably benzotriazole is that ultraviolet light absorber, triazine are ultraviolet light absorber.
Transparent resin material, is not used as adjuvant although conventionally can not add light diffusing agent, if the small quantity of harmless the object of the invention also can add light diffusing agent and uses.
As light diffusing agent, conventionally adopt the index of refraction powder different from the transparent material as above of main composition light diffusing board 40, and it is dispersed in transparent material and uses.As this light diffusing agent, such as adopting the inorganic particulates such as organic filler, sal tartari particle, silicon dioxide granule such as styrene resin particle, methacrylic resin particle, its particle footpath is generally 0.8 μ m～50 μ m.
In addition, can also the face of light source 31 1 sides be made as to the face with optical diffuse in order to reduce ripple.For example, both can form with the epidermal area that comprises the fine particle that is referred to as coarse agent the face of light source 31 1 sides, also can implement embossment processing, spray processing the face of light source 31 1 sides, can also apply the coating liquid that comprises coarse agent and bonding agent and form rough layer.
Light diffusing board 40 can be both the lamina that independent transparent material forms, and can be also that the layer that different transparent materials forms mutually passes through the multilayer board that laminates this structure.When light diffusing board 40 is multilayer board, the one or two sides of employing light diffusing board 40 is conventionally formed with 10 μ m～200 μ m, preferably forms this structure of epidermal area of 20 μ m～100 μ m thickness, as the transparent material that forms this epidermal area, preferably adopt the material that is added with ultraviolet light absorber.By adopting this formation, can prevent from being likely contained in the deteriorated of the light diffusing board 40 that causes from the ultraviolet ray in light source 31 or outside light.Particularly, when adopting fluorescent tube etc. as light source 31, can prevent that ultraviolet ray from fluorescent tube from causing deteriorated, so be preferably formed with epidermal area on the face of light source 31 1 sides, now for example, on the face of transmission type image display part 10 (liquid crystal panel) side, do not form epidermal area, this is even more ideal on aspect cost.The material that is added with ultraviolet light absorber in employing is when forming the transparent resin material of epidermal area, and its amount is usingd transparent resin material as benchmark, normally 0.5 quality %～5 quality %, preferably 1 quality %～2.5 quality %.
Can also be coated with anti-live agent in the one or two sides of light diffusing board 40.By applying anti-live agent, can prevent adhering to of dust that static causes etc., because adhering to the light transmittance being caused, reduces dust preventing.
As shown in Figure 1 and Figure 2, light diffusing board 40 has the first surface 40a of general planar in light source portion 30 1 sides, and has second 40b in transmission type image display part 10 1 sides.On second 40b, be formed with a plurality of convex shaped parts (optical element portion) 41.In being formed with the light diffusing board 40 of this convex shaped part 41, can be by thickness d 1be made as the top of convex shaped part 41 and the distance between first surface 40a.
As shown in Figure 2, each convex shaped part 41 is at the upper wire optical element extending of a direction (first direction).As optical element, can illustration lens or prism.A plurality of convex shaped parts 41 with the roughly configuration side by side in the direction of quadrature of its bearing of trend.Although it is desirable to two sides 40c, 40d (with reference to Fig. 1) that a plurality of convex shaped parts 41 spread all over light diffusing board 40 closely forms, the end 41a, the 41a that are the convex shaped part 41 of adjacency are positioned at same position on the Width of convex shaped part 41, but in order to make to make easily, can also be less than or equal in 41 settings of a plurality of convex shaped parts the width w of convex shaped part 41 athe position of general planar of 5% left and right.
And the cross sectional shape of the bearing of trend quadrature of each convex shaped part 41 is roughly the same 41 of a plurality of convex shaped parts.In addition, as mentioned above, spacing distance D and be that L/D meets and is more than or equal to 1.5 in abutting connection with the ratio of the distance L of 31,31 of two light sources, preferably L/D is more than or equal to 2, more preferably L/D is more than or equal to 2.5 and so on condition, selects like this spacing distance D and distance L.
Fig. 3 means the figure of one of cross sectional shape with the bearing of trend quadrature of convex shaped part example, and a convex shaped part is amplified and represented.Adopt the local xz coordinate system of setting as illustrated in fig. 3 that the cross sectional shape of convex shaped part 41 is described.The x axle that forms xz coordinate system is the axis of the orientation (second direction) that is parallel to a plurality of convex shaped parts 41, z axle be parallel to thickness of slab direction (with first and the direction of second direction quadrature) axis.
In the axial length of the x that establishes convex shaped part 41, be w atime, the outline line of the convex shaped part 41 in the xz face of this xz coordinate system can be represented by the z (x) that meets formula (3).
z B(x)-0.01w a≤z(x)≤z B(x)+0.01wa...(3)
In formula (3), z b(x)=z 0(x) * r (r be more than or equal to 0.95 and be less than or equal to 1.05 number).Z 0(x) can be represented by formula (4).
z 0 ( x ) = h a - 8 h a ( x w a ) 2 1 - k a + ( 1 - k a ) 2 + 16 k a ( x w a ) 2 · · · ( 4 )
In formula (4), h ato be more than or equal to 0.27w aand be less than or equal to 1.02w aconstant, k ato be more than or equal to-0.38 and be less than or equal to 0.00 constant.H acorresponding to being z at convex shaped part 41 0(x) the axial maximum height of z between two ends 41a, the 41a of the convex shaped part 41 during represented shape.In addition, k amean the parameter of the sharp-pointed degree of convex shaped part 41.
In Fig. 3, be illustrated in the scope that meets formula (3) z 0(x) (wherein, in formula (4), h a=0.4825w a, k a=-0.232) correspondingly stretched in the z-direction and stipulated doubly shape that is z (the x)=z of (for example 1 times) b(x) situation.In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41 has the axisymmetric outline line with respect to z.
If consider near the foozle both ends of convex shaped part 41 and the impact that brings intensity distributions, the cross sectional shape of convex shaped part 41 is at-0.5w a* 0.95≤x≤0.5w ain * 0.95, with the z (x) that meets formula (3), represent, preferably at-0.5w a≤ x≤0.5w athe z (x) that middle use meets formula (3) represents.
Contour shape to the represented convex shaped part 41 of formula (3) describes particularly.With optional position x arelative z (x a) corresponding to position x athe convex shaped part 41 at place is height.Thereby z (x) represents the contour shape of convex shaped part 41.In formula (3), 0.01w acorresponding to position x aoutline line in the short transverse at place allow amplitude of fluctuation.Thereby, establishing z b(x) while being the reference contour as benchmark, the outline line of convex shaped part 41 as shown in Figure 4, so long as z b(x)-0.01w arepresented outline line and z b(x)+0.01w abetween represented outline line, allow the outline line in amplitude of fluctuation.Thereby the outline line of the convex shaped part 41 that formula (3) is represented is with respect to z b(x) represented reference contour is at 0.01w achange allow in amplitude.In addition,, although represent the situation of r=1 in Fig. 4, r is so long as be more than or equal to 0.95 and be less than or equal to 1.05 number.
Width w as convex shaped part 41 a, can illustration w a=410 μ m, w a=400 μ m, w a=353 μ m or w a=325 μ m.Although w avalue be not limited thereto, but w abe preferably less than 800 μ m, be preferably more than or equal to 10 μ m and be less than or equal to 800 μ m, be more preferably more than or equal to 20 μ m and be less than or equal to 600 μ m.
In addition, although h aand k afor the value in above-mentioned scope, but h aand k aaccording to the refractive index of the refractive index of light diffusing board 40, particularly convex shaped part 41, be for example preferably the scope shown in table 1.
[table 1]
Figure BSA00000185539400101
More preferably in each ranges of indices of refraction of above-mentioned table 1, according to L/D, be the scope shown in table 2～table 8.
[table 2]
Figure BSA00000185539400111
[table 3]
Figure BSA00000185539400112
[table 4]
Figure BSA00000185539400121
[table 5]
Figure BSA00000185539400122
[table 6]
Figure BSA00000185539400131
[table 7]
Figure BSA00000185539400132
[table 8]
Figure BSA00000185539400141
Light diffusing board 40 for example can be manufactured by the method for cutting out from transparent material.In addition, in the situation that adopting transparent resin material as transparent material, such as manufacturing by methods such as injection molded method, extruding formation method, punching formation, photopolymerization (photopolymer) methods.
In the planar light source device 20 that comprises light diffusing board 40 and transmission image display device 1, the light of exporting from each light source 31 of light source portion 30 directly or in the inner face 32a of lamp box 32 reflection incides light diffusing board 40.The light that incides light diffusing board 40 irradiates to transmission type image display part 10 from second 40b.Now, because be formed with a plurality of convex shaped parts 41 on second 40b of light diffusing board 40, therefore light is via convex shaped part 41 outgoing.Because convex shaped part 41 has the represented cross sectional shape of above-mentioned z (x), thus according to light pass through position (outgoing position), light reflects to various directions.By means of this diffusion effect, from the light generation diffusion of light source 31 and generate planar light, and brightness disproportionation is inhibited.Therefore, the picture of light source 31 can not project on transmission type image display part 10.And, because the cross sectional shape of convex shaped part 41 can be represented by the z (x) that meets formula (3), so can also realize the luminance uniformity of higher frontal (normal direction of first surface 40a).
In addition, because the cross sectional shape of convex shaped part 41 can be represented by the z (x) that meets formula (3), so even if L/D for example, changes from setting (design load) such as the distortion causing with respect to the dislocation of light source 31 or heating etc. because of light diffusing board 40, also be difficult to occur brightness disproportionation, can more stably suppress brightness disproportionation.
Thereby, in possessing the planar light source device 20 of light diffusing board 40, the light that more stably output brightness inequality is inhibited.And, in the transmission image display device 1 that comprises light diffusing board 40, the light being inhibited due to the brightness disproportionation transmission type image display part 10 that can throw light on, so can simultaneously seek the improvement of display quality, one side suppresses the display quality change causing because of distortion that light diffusing board 40 causes with respect to the dislocation of light source 31 or heating etc.
(the second embodiment)
In the first embodiment, establishing the shape that convex shaped part 41 has an outline line z (x) that meets formula (3) is illustrated.But, also can establish convex shaped part 41 for by the shape that is formed with the detecting device configuring second 40b of a plurality of convex shaped parts 41 and realizes in measuring the intensity distributions 50 shown in Fig. 5 for the light from light source 31 outputs.Mode to convex shaped part 41 when having the cross sectional shape of the intensity distributions 50 realizing shown in Fig. 5 describes.Except convex shaped part 41 is identical with the first embodiment for having the characteristic this point shown in Fig. 3, so additional same reference numerals describes in the key element identical with the first embodiment, and the repetitive description thereof will be omitted.
As previously mentioned, convex shaped part 41 has following cross sectional shape, that is: by the cross sectional shape that is formed with the detecting device configuring second 40b of a plurality of convex shaped parts 41 and realizes in measuring the intensity distributions 50 shown in Fig. 5 for the light from light source 31 output, the cross sectional shape of a plurality of convex shaped parts 41 is identical shaped.Fig. 5 means the hope intensity distributions from the emergent light of convex shaped part.
With reference to Fig. 5, the condition satisfied to intensity distributions 50 describes.If the direction parallel with second direction is X-direction, the position of the light source 31 in X-direction is initial point (reference point) O.In Fig. 5, transverse axis represents in X-direction that, with respect to the position of light source, the longitudinal axis represents intensity.Intensity distributions 50 meets following condition.Below, take the region of X >=0 to describe as example, but like this too for the region of X≤0.
(a) have at maximum intensity I max90%～10% interval intensity be the linear change region 51 that linear function changes.
(b) linear change region 51 is with respect to the maximum intensity I in intensity distributions max50% intensity (0.5I max) some P be point symmetry.That is, if establish maximum intensity I maxthe X-axis of 50% intensity on position be X 0.5, with respect to P (X 0.5, 0.5I max) be point symmetry.
Although intensity distributions 50 meets above-mentioned (a) and condition (b), and then, more preferably meet following condition (c) and (d).Here be also to take the region of X >=0 to describe as example.
(c) establishing from maximum intensity I maxthe initial point O of X-direction of the 50% intensity distance of starting at be w 1(=X 0.5), from maximum intensity I maxthe initial point O of X-direction of the 90% intensity distance of starting at be w 2, from maximum intensity I maxthe initial point O of X-direction of the 10% intensity distance of starting at be w 3time, w 1with w 2absolute value or the w of difference 1with w 3the absolute value w of difference 4be more than or equal to the length l of regulation.Here, about the length l of regulation, illustration w 1/ 10, w preferably 1/ 8, more preferably w 1/ 6.
(d) in intensity distributions 50, from maximum intensity I maxto the region of terminal part, with respect to a P (X 0.5, 0.5I max) be point symmetry.
Because thering is condition (d) event condition (b), be met.As previously mentioned, although intensity distributions 50 meets above-mentioned (a) and condition (b), in the following description, unless otherwise indicated, convex shaped part 41 satisfies condition (a) for realizing～shape of intensity distributions (d).In Fig. 3 illustration intensity distributions 50 for trapezoidal, be in other words exactly the smooth mountain type shape of top one side, but be not limited thereto.For example, intensity distributions 50 can also be the triangle of one side tip attenuates towards top mountain type and so on.And then although in Fig. 5, intensity distributions 50 is symmetrical with respect to the position of initial point O, as long as be just and negative region with respect to initial point O at X, meet respectively above-mentioned condition (a)～(c) or condition (a)～(d).
With reference to Fig. 6, illustrate for verifying whether light diffusing board 40 realizes one of the assay method example of the intensity distributions of the intensity distributions 50 shown in Fig. 5.Fig. 6 means the figure of one of assay method of intensity distributions example.
As shown in Figure 6, the light source 31 of use will be measured examfrom first surface 40a, leave the distance D of regulation 0and configure.As light source 31 examcan the linear light source of illustration as CCFL or the point source of light as LED.Distance D 0can be made as 100mm.Then, from light source 31 examoutput light, detects in the interior transmission of light diffusing board 40 and from the light of second 40b outgoing with the photodetector (not shown) that is configured in second 40b mono-side.Now, the light that photodetector is configured to exporting along the normal direction of first surface 40a detects.In the following description, by the normal direction of first surface 40a also referred to as frontal.
For example, in transmission image display device 1 (liquid crystal indicator), light source 31 is generally 3mm～50mm with the distance D of light diffusing board 40.On the other hand, the width of convex shaped part 41 is less than or equal to 800 μ m conventionally, is preferably more than or equal to 10 μ m and is less than or equal to 800 μ m, it would be desirable and is more than or equal to 20 μ m and is less than or equal to 600 μ m.Like this, light diffusing board 40 is being applicable in transmission image display device 1 grade, distance D is fully large with respect to the size of convex shaped part 41.Thereby, by establishing the distance configuration light source 31 that distance D 0 is the so abundant length of 100mm as described above exammeasure the intensity distributions of checking use, just can think and also can realize same intensity distributions in the configuration of actual planar light source device 20 and transmission image display device 1.Therefore, light diffusing board 40 so long as detect obtained intensity distributions with above-mentioned assay method and satisfy condition (a)～(d).
The light diffusing board 40 with the convex shaped part 41 that meets above-mentioned condition (a)～(d) can be manufactured as follows.One of the manufacture method of light diffusing board 40 example is described.In the manufacture of light diffusing board 40, have: the decision operation of the cross sectional shape of convex shaped part 41; The manufacturing process of light diffusing board 40 with the convex shaped part 41 of the cross sectional shape determining in determining operation.
(the decision operation of cross sectional shape)
The cross sectional shape of convex shaped part 41 can utilize the simulation design based on Ray Tracing to obtain desirable intensity distributions.One of the determining method of the cross sectional shape of convex shaped part 41 example is more specifically described.In order to simulate, adopt following 3 to be similar to here.
In the face with light source 31 quadratures, implement simulation.
If the diameter that light source 31 is pointolite that is light source is 0.
Only consider direct transmitted light.
In simulation, adopt analogy model as shown in Figure 7.That is, the cross sectional shape model that forms the light diffusing board 40 before convex shaped part 41 is represented by rectangle 60, establish the position of light source 31 distance D of regulation in the first side 60a from rectangle 60.The distance D of regulation for example decides according to planar light source device 20 and the transmission image display device 1 of the applicable light diffusing board 40 of hypothesis.Distance D as previously mentioned, for example, can be selected from 3mm～50mm.
Under above-mentioned approximate and model, for example, determine as follows the cross sectional shape of convex shaped part 41.
(step 1) as shown in Figure 8, as the function of the distance from light source 31, makes the direct transmitted light of rectangle 60 towards the mode of frontal, obtains respectively the locational gradient of each outgoing of the Second Edge 60b that rectangle 60 has.This gradient determining method can be the same method of method adopting in the method for designing with Fresnel lens.Gradient decides for the unit line key element 61 of Second Edge 60b.In Fig. 8, schematically show a part of process of calculating gradient.
(step 2) obtains light to the locational transmissivity of incident light quantity, transmissivity, outgoing of each the unit line key element 61 on the incoming position of rectangle 60, and obtains the outgoing light quantity of each the unit line key element 61 relative with each gradient.
(step 3) adjusts the size of the unit line key element 61 relative with each gradient, and determines in the mode that positive intensity distributions becomes desirable intensity distributions.
By above-mentioned steps 1～3, can design the cross sectional shape that can realize the convex shaped part 41 of desirable intensity distributions with respect to frontal.
Because human eye etc. has certain size, therefore conventionally detect, for example using the normal direction of first side 60a of Fig. 8, as the light in the angle amplitude (± 2.5 °) of the regulation of benchmark.Thereby, in the cross sectional shape design of convex shaped part 41, also preferably for example after having designed cross sectional shape by above-mentioned steps 1～3, the intensity distributions that adds up to be obtained with the intensity in the angle amplitude of regulation becomes the mode of desirable intensity distributions, and the shape of convex shaped part 41 is revised.In addition, in the cross sectional shape design of above-mentioned convex shaped part 41, can also carry out for example oval approximate and so on curve approximation to the outline line of the cross sectional shape by illustrated design process obtains in step 1～3.
(manufacturing process)
Convex shaped part 41 based on having the cross sectional shape determining is as described above manufactured light diffusing board 40.Light diffusing board 40 for example can be manufactured by the method for cutting out from transparent material.In addition, in the situation that adopting transparent resin material as transparent material, such as manufacturing by methods such as injection molded method, extruding formation method, punching formation, photopolymerization (photopolymer) methods.
Secondly, about the action effect of light diffusing board 40, to light diffusing board 40 being applicable to the situation of planar light source device 20 and transmission image display device 1, describe.
The in the situation that of disposing light diffusing board 40 on a plurality of light sources 31 (with reference to Fig. 1), for the light from each light source 31, form respectively the intensity distributions 50 with linear change region 51 as shown in Figure 5.And, in the region on 31,31 of two light sources of adjacency, be mainly from 31,31 outputs of two light sources the light intensity by light diffusing board 40, to distribute to be piled up to form the intensity distributions that comes from two light sources 31,31.
The linear change region 51 from the intensity distributions of each light source 31 with satisfy condition (b), so 31,31 of two light sources of adjacency, be mainly that the linear change region 51 that has of the intensity distributions 50 of each light source 31 is overlapping.Its result, can seek in abutting connection with the even intensity of 31,31 of two light sources, and can reduce the impact for the relative intensity distributions of the variation with L/D.Thereby, for example, the in the situation that of being suitable for light diffusing board 40 on planar light source device 20 and transmission image display device 1, environmental changes such as temperature and along with the impact of the design alteration of the light source 31 of slimming and configuration of the distance between light diffusing board 40 and light source 31 and so on is less, can realize more stable luminance uniformity.With reference to Fig. 9, Figure 10 and Figure 11, describe particularly.
Fig. 9 means the figure of one of intensity distributions between two light sources of adjacency example.The position of the X-direction (second direction) of the position that the transverse axis in figure represents to using side's light source 31 during as benchmark.In Fig. 9, respectively at X=0, the distance L that configures 31,31 of 31,31, two light sources of light source on 50 is 50mm.The longitudinal axis represents for the maximum intensity I in the intensity distributions 50 from a light source 31 maxcarry out the standardization intensity after standardization.In addition, the solid line I in figure, II represent to come from and are configured in X=0, the intensity distributions of each light source 31 on 50.Dotted line in figure represents the equitant result of intensity distributions of two light sources 31,31.
The intensity distributions that comes from each light source 31,31 in Fig. 9 shown in solid line I, II is the intensity distributions 50 with linear change region 51, in intensity distributions separately, from maximum intensity I max(the standardization intensity 1 in figure) equals the distance of 31,31 of two light sources to the distance in the X-direction of intensity 0.Thereby, two light sources 31,31 that the intensity distributions that comes from a plurality of light sources 31,31 becomes adjacency intensity distributions separately overlapping.In addition, the distance L of 31,31 of two light sources equals in the intensity distributions 50 of each light source 31,31 from maximum intensity I maxbecome 0.5I maxx-direction on 2 times of distance.In this case, because linear change region 51 has condition (b) or (d), so the X-direction relative with light source 31 is locational from maximum intensity I maxthe part that reduces of intensity just by the light intensity from another light source 31, compensated.Its result, as shown in Figure 9, as the intensity distributions that comes from two light sources 31,31, can realize the intensity distributions of constant, can suppress brightness disproportionation.
Figure 10 means the figure of his example of the intensity distributions between two light sources of adjacency.In Figure 10, transverse axis and the longitudinal axis are identical with the situation of Fig. 9.In Figure 10, respectively at X=0, the distance L that disposes 31,31 of 31,31, two light sources of light source on 40 is 40mm.In addition, the solid line I in figure, II represent to be configured in X=0, the intensity distributions separately of the light source 31,31 on 40.Solid line III represents to come from further adjacent light source 31 that is be configured in the part of the intensity distributions of the light source 31 on X=80 (not shown) from being configured in the light source 31 X=40.Similarly, solid line IV represents to come from as the further adjacent light source 31 of the light source 31 of benchmark that is is configured in the part of the intensity distributions of the light source 31 on X=-40.Dotted line represents the intensity distributions of 31,31 of two light sources of adjacency.
In Figure 10, the intensity distributions that comes from each light source 31 is the intensity distributions identical with the intensity distributions shown in Fig. 9.Thereby, from maximum intensity I maxthe length that becomes intensity 0 is longer than the distance L of 31,31 of two light sources of adjacency.Therefore, as shown in solid line III, IV, come from and be configured in X=0, the intensity distributions of the further adjacent light source 31 of each light source 31 on 40 contributes to the intensity distributions of 31,31 of two light sources of adjacency.And then, because of the distance L of 31,31 of two light sources shorter than the situation of Fig. 9, therefore come from abutting connection with the overlapping change in the linear change region 51 of two light sources 31 intensity distributions separately large.Thereby, in abutting connection with compare with the situation of Fig. 9 tendency of increase of the intensity of 31,31 of two light sources.In Figure 10, although contribute to the intensity distributions of between X=0～40 along the intensity distributions of 4 continuous light sources 31 of directions X, but be configured in X=0, the overlapping of intensity distributions of the light source 31,31 on 40 is but to have more mastery, at overlapping neutral line region of variation 51 overlaids of these intensity distributions.Therefore, same with the situation of Fig. 9, intensity is easy to 31,31 constants that become of two light sources in adjacency.
Figure 11 means the figure of other examples of the intensity distributions between two light sources of adjacency.In Figure 11, transverse axis and the longitudinal axis are identical with the situation of Fig. 9.In Figure 11, respectively at X=0, the distance L that disposes 31,31 of 31,31, two light sources of light source on 60 is 60mm.Solid line I in figure, II represent respectively to come from the intensity distributions of two light sources 31,31 of adjacency.Dotted line represents the intensity distributions of 31,31 of two light sources of adjacency.
In Figure 11, the intensity distributions that comes from each light source 31 is the intensity distributions same with the intensity distributions shown in Fig. 9.Thereby, from maximum intensity I maxbecome the distance L of 31,31 of two light sources that are shorter in length than adjacency of intensity 0.In this case, because the overlapping of intensity distributions of 31,31 each light sources 31,31 of two light sources in adjacency diminishes, therefore 31,31 of two light sources of adjacency reduce with phase specific strength directly over each light source 31.But, owing to passing through the overlapping of linear change region 51, and the minimizing that can make to come from the intensity of a light source 31 is compensated by the intensity that comes from another light source, so situation about reducing sharp with nonlinear way with intensity is compared, can inhibition strength reduce.
As described above, for the light diffusing board 40 that possesses the convex shaped part 41 that can realize intensity distributions 50, by adjusting L/D, can realize in 31,31 of two light sources intensity distributions (with reference to Fig. 9) uniformly roughly.In addition, even if in the situation that be offset through the L/D adjusting from such, the variation (with reference to Figure 10 and Figure 11) also can inhibition strength distributing.Like this, in light diffusing board 40, because of the impact of the relative intensity distributions of the variation for L/D (or Luminance Distribution) less, therefore light diffusing board 40 has versatility.
And, because light diffusing board 40 has action effect as described above, therefore in possessing the planar light source device 20 of light diffusing board 40, can export the planar light of higher luminance uniformity, and can realize more stable luminance uniformity.In addition, light diffusing board 40 has versatility as previously mentioned, so again prepare the necessity of light diffusing board 40 according to the change of the configuration of light source 31 and light source 31 and the distance D of light diffusing board 40 etc., reduces.Thereby, in having utilized the planar light source device 20 of light diffusing board 40, can also simultaneously seek the reduction of the manufacturing cost of planar light source device 20 by the higher luminance uniformity of one side realization.In addition, in possessing the transmission image display device 1 of light diffusing board 40, due to can enough luminance uniformities the higher light transmission type image display part 10 that throws light on, so can the good image of image quality.In addition, because light diffusing board 40 has versatility as previously mentioned, so same with the situation of planar light source device 20, the necessity of again preparing light diffusing board 40 according to the change of the configuration of light source 31 and light source 31 and the distance D of light diffusing board 40 etc. reduces.Its result, the image that can also simultaneously realize good image quality shows simultaneously seeks the reduction of the manufacturing cost of transmission image display device 1.
(the 3rd embodiment)
Then,, with reference to Figure 12～Figure 39, his example of convex shaped part 41 shapes that the light diffusing board 40 shown in Fig. 1 is had describes.Convex shaped part 41 shown in Figure 12, Figure 18, Figure 24, Figure 26, Figure 28, Figure 30, Figure 32, Figure 34, Figure 36 and Figure 38 is called to convex shaped part 41A～41J.In the explanation of each convex shaped part 41A～41J, identical with the first embodiment except the cross sectional shape of convex shaped part 41A～41J, therefore as previously mentioned, to additional same reference numerals in the key element identical with the first embodiment, and the cross sectional shape as difference is described.In addition, in the following description, adopt the local xz coordinate system of similarly setting with the situation of Fig. 3 to describe.The x axle that forms xz coordinate system is the axis of the orientation (second direction) that is parallel to a plurality of convex shaped parts 41, z axle be parallel to thickness of slab direction (with first and the direction of second direction quadrature) axis.
(convex shaped part 41A)
Figure 12 means the figure of one of cross sectional shape with the bearing of trend quadrature of convex shaped part example, and a convex shaped part is amplified and represented.
In the xz of xz coordinate system face, two ends 41a, the 41a of convex shaped part 41A are positioned on x axle.The outline line of convex shaped part 41A can be represented by the z (x) that meets following formula (5).
0.95×z 0(x)≤z(x)≤1.05×z 0(x)...(5)
Wherein, in above-mentioned formula (5),
z 0 ( x ) = h a - 8 h a ( x w a ) 2 1 - k a + ( 1 - k a ) 2 + 16 k a ( x w a ) 2 · · · ( 6 )
In formula (6), w athe axial length of x of convex shaped part 41.In addition, h afrom 0.4825w a≤ h a≤ 0.521w ascope in the constant selected, k afrom-0.232≤k athe constant of selecting in≤-0.227 scope.H a, k aan example be h a=0.521w a, k a=-0.227.H acorresponding to establishing convex shaped part 41A, be z 0(x) the axial maximum height of z between two ends 41a, the 41a of convex shaped part 41A during represented shape.In addition, k amean the parameter of the sharp-pointed degree of convex shaped part 41A.H aand k athat foregoing maximum height and the parameter this point that represents sharp-pointed degree are like this too in convex shaped part 41B～41J described later.In Figure 12, be illustrated in h a=0.521w a, k ain=-0.227 situation, in the scope that meets formula (5), make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, top 41b is positioned on z axle, has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41A is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 13, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41A is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
Utilize Figure 14～Figure 17, the shape example of establishing outline line more specifically represents for shape example 1 and shape example 2.In Figure 14～Figure 17, transverse axis represents the position relative with initial point (μ m), and the longitudinal axis represents height (μ m).Figure 14 means the z in shape example 1 0(x) figure.In shape example 1, establish w a=400 μ m, h a=0.521w a, k a=-0.227.The z of these numerical value will be depended on 0(x) be referred to as for simplicity z1 0(x).In Figure 14, represent z (x)=z1 0(x) outline line shape time.By the z1 shown in Figure 14 0(x), while being made as outline line shape, the outline line shape shown in Figure 14 is identical with the illustrated outline line shape of Figure 12.Based on above-mentioned z1 0(x) the satisfied condition of outline line as shown in figure 15.Figure 15 is for the figure of the condition that the outline line of shape example 1 is satisfied is described.In Figure 15, represent z1 0(x) represented outline line, 0.95z1 0(x) represented outline line and 1.05z1 0(x) represented outline line, as long as because making outline line meet formula (5), therefore outline line is so long as pass through 0.95z1 0(x) represented outline line and 1.05z1 0(x) outline line in the region between represented outline line.
Figure 16 means the z in shape example 2 0(x) figure.In shape example 2, establish w a=400 μ m, h a=0.4825w a, k a=-0.232.In order to distinguish with the situation of shape example 1 by the z setting in shape example 2 0(x) be referred to as z2 0(x).In Figure 16, represent z (x)=z2 0(x) outline line shape time.Based on above-mentioned z2 0(x) the satisfied condition of outline line as shown in figure 17.Figure 17 is for the figure of the condition that the outline line of shape example 2 is satisfied is described.In Figure 17, represent z2 0(x) represented outline line, 0.95z2 0(x) represented outline line and 1.05z2 0(x) represented outline line, as long as because making outline line meet formula (5), therefore outline line is so long as pass through 0.95z2 0(x) represented outline line and 1.05z2 0(x) outline line in the region between represented outline line.
(convex shaped part 41B)
Figure 18 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (5) aand k ascope be different from beyond the scope this point of convex shaped part 41A, the shape of convex shaped part 41B is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41B can be represented by the z (x) that meets the formula (5) that convex shaped part 41A was illustrated.Wherein, in convex shaped part 41B, in formula (6), h afrom 0.5966w a≤ h a≤ 0.6837w ascope in the constant selected, k afrom-0.075≤k athe constant of selecting in≤-0.069 scope.H a, k aan example be h a=0.5966w a, k a=-0.075.In Figure 18, be illustrated in h a=0.5966w a, k ain=-0.075 situation, in the scope that meets formula (5), make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).
In addition, the outline line of convex shaped part 41B is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 19, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41B is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
Utilize Figure 20～Figure 23, the shape example of establishing outline line more specifically represents for shape example 3 and shape example 4.In Figure 20～Figure 23, transverse axis and the longitudinal axis are identical with the situation of Figure 14～Figure 17.Figure 20 means the z in shape example 3 0(x) figure.In shape example 3, establish w a=400 μ m, h a=0.5966w a, k a=-0.075.The z of these numerical value will be depended on 0(x) be referred to as for simplicity z3 0(x).In Figure 20, represent z (x)=z3 0(x) outline line shape time.In addition, in Figure 18, as an example, represent z3, 0(x) be made as the nemaline situation of profile.Based on above-mentioned z3 0(x) the satisfied condition of outline line as shown in figure 21.Figure 21 is for the figure of the condition that the outline line of shape example 3 is satisfied is described.In Figure 21, represent z3 0(x) represented outline line, 0.95z3 0(x) represented outline line and 1.05z3 0(x) represented outline line, meets formula (5) because needing only outline line, therefore as long as outline line passes through 0.95z3 0(x) represented outline line and 1.05z3 0(x) outline line in the region between represented outline line.
Figure 22 means the z in shape example 4 0(x) figure.In shape example 4, establish w a=400 μ m, h a=0.6837w a, k a=-0.069.In order to distinguish with the situation of shape example 3 by the z setting in shape example 4 0(x) be referred to as z4 0(x).In Figure 22, represent z (x)=z4 0(x) outline line shape time.Based on above-mentioned z4 0(x) the satisfied condition of outline line as shown in figure 23.Figure 23 is for the figure of the condition that the outline line of shape example 4 is satisfied is described.In Figure 23, represent z4 0(x) represented outline line, 0.95z4 0(x) represented outline line and 1.05z4 0(x) represented outline line, meets formula (5) because needing only outline line, therefore as long as outline line passes through 0.95z4 0(x) represented outline line and 1.05z4 0(x) outline line in the region between represented outline line.
(convex shaped part 41C)
Figure 24 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41C is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41C can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41C, formula is h in (6) a=0.434w a, k a=-0.24.In Figure 24, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41C has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41C is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 25, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41C is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41D)
Figure 26 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41D is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41D can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41D, formula is h in (6) a=0.614w a, k a=-0.17.In Figure 26, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41D has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41D is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 27, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41D is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41E)
Figure 28 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41E is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41E can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41E, formula is h in (6) a=0.588w a, k a=-0.128.In Figure 28, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41E has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41E is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 29, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41E is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41F)
Figure 30 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41F is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41F can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41F, formula is h in (6) a=0.578w a, k a=-0.081.In Figure 30, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41F has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41F is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 31, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41F is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41G)
Figure 32 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond the scope this point of convex shaped part 41A, the shape of convex shaped part 41G is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41G can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41G, formula is h in (6) a=0.550w a, k a=-0.082.In Figure 32, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41G has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41G is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 33, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41G is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41H)
Figure 34 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41H is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41H can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41H, formula is h in (6) a=0.560w a, k a=-0.127.In Figure 34, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41H has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41H is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 35, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41H is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41I)
Figure 36 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41I is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41I can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41I, formula is h in (6) a=0.578w a, k a=-0.185.In Figure 36, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41I has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41I is not limited to make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 37, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41I is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
(convex shaped part 41J)
Figure 38 means and the figure of his example of the cross sectional shape of the bearing of trend quadrature of convex shaped part, a convex shaped part is amplified and represented.Except the h in formula (6) aand k abe different from beyond convex shaped part 41A this point, the shape of convex shaped part 41J is identical with the shape of convex shaped part 41A.Centered by this difference, describe.
The outline line of convex shaped part 41J can be represented by the z (x) that meets the formula (5) illustrated to convex shaped part 41A.Wherein, in convex shaped part 41J, formula is h in (6) a=0.486w a, k a=-0.144.In Figure 38, be illustrated in the scope that meets formula (5) and make z 0(x) stretched in the z-direction and stipulated the doubly shape of (for example 1 times).In this case, two ends 41a, 41a are positioned on x axle, and top 41b is positioned on z axle.In addition, convex shaped part 41J has the axisymmetric outline line with respect to z.
In addition, the outline line of convex shaped part 41J is not limited to make z 0(x) correspondingly stipulate in the z-direction the doubly shape of (for example 1 times), as long as meet formula (5).Thereby, as shown in figure 39, for certain width w adetermined z 0(x), time, the outline line of convex shaped part 41J is so long as through 0.95z 0(x) represented outline line and 1.05z 0(x) outline line in region between represented outline line.
Width w as above-mentioned convex shaped part 41A～41J a, can illustration w a=410 μ m, w a=400 μ m, w a=353 μ m or w a=325 μ m.Equally, although establish w in the explanation of shape example 1,2,3,4 a=400 μ m.But, w avalue be not limited thereto, w preferably abe less than or equal to 800 μ m, be more preferably and be more than or equal to 10 μ m and be less than or equal to 800 μ m, be more preferably more than or equal to 20 μ m and be less than or equal to 600 μ m.
In explanation up to now, the cross sectional shape of establishing convex shaped part 41A～41J can be represented by the z (x) that meets formula (5).But if consider near the foozle both ends of convex shaped part 41A～41J and the impact that brings intensity distributions, the cross sectional shape of convex shaped part 41A～41J is at-0.5w a* 0.95≤x≤0.5w ain * 0.95, by the z (x) that meets formula (5), represented, more preferably at-0.5w a≤ x≤0.5w ain by the z (x) that meets formula (5), represented.
Above, as the 3rd embodiment, convex shaped part 41A～the 41J that further illustrates the light diffusing board 40 being applicable to shown in Fig. 1 is illustrated, but the shape example 1,2 of convex shaped part 41A, the shape example 3,4 of convex shaped part 41B and convex shaped part 41C～41J are corresponding to an example of the convex shaped part 41 of the first embodiment.In addition, in convex shaped part 41A and convex shaped part 41B, the h representing for convex shaped part 41A, 41B aand k ascope in carry out z 0(x) r doubly (number that r is 0.95～1.05) shape and for its shape, there is 0.01w athe convex shaped part of allowing amplitude of fluctuation, corresponding to the convex shaped part 41 of the first embodiment.
For possessing the light diffusing board 40 of each convex shaped part 41A～41J and thering is the planar light source device 20 of this light diffusing board 40 and the action effect of transmission image display device 1 describes.Possess the light diffusing board 40 of each convex shaped part 41A～41J and there is the planar light source device 20 of this light diffusing board 40 and transmission image display device 1 have with the first embodiment in the same action effect of illustrated action effect.Below, action effect is simply described.Convex shaped part 41A～41J is called convex shaped part 41.
The light of exporting and incide light diffusing board 40 from each light source 31 via have the represented cross sectional shape of above-mentioned z (x) convex shaped part 41 and towards transmission type image display part 10 emergent lights.By means of convex shaped part 41, have the diffusion effect that the represented cross sectional shape of z (x) causes, from the light generation diffusion of light source 31 and generate planar light, and brightness disproportionation is inhibited.Therefore, the picture of light source 31 can not project on transmission type image display part 10.And the convex shaped part 41 being represented by above-mentioned z (x) by having cross sectional shape, can also realize the luminance uniformity of higher frontal.
In addition, because the cross sectional shape of convex shaped part 41 can be represented by the z (x) that meets formula (5), so even if L/D for example, changes from setting (design load) such as the distortion causing with respect to light source 31 dislocation or heating etc. because of light diffusing board 40, also be difficult to occur brightness disproportionation, can more stably suppress brightness disproportionation.
Thereby, in possessing the planar light source device 20 of light diffusing board 40, the light that just more stably output brightness inequality is inhibited.And, in the transmission image display device 1 that comprises light diffusing board 40, the light being inhibited due to the brightness disproportionation transmission type image display part 10 that can throw light on, so can simultaneously seek the improvement of display quality, the display quality change that the distortion that one side inhibition causes with respect to light source 31 dislocation or heating etc. because of light diffusing board 40 causes.
In addition, each convex shaped part 41A～41J realizes in the illustrated intensity distributions 50 of the second embodiment, and each convex shaped part 41A～41J is at illustrated convex shaped part 41 1 embodiments of the second embodiment.Thereby, convex shaped part 41A～41J have with the second embodiment in the same action effect of illustrated action effect.Here, the situation that is applied to planar light source device 20 and transmission image display device 1 to possessing light diffusing board 40 as the convex shaped part 41A～41J in the example of the illustrated convex shaped part 41 of the second embodiment describes particularly.Convex shaped part 41A～41J is called convex shaped part 41.
In the planar light source device 20 that comprises the light diffusing board 40 that possesses convex shaped part 41 and transmission image display device 1, the light of exporting from each light source 31 of light source portion 30 directly or in the inner face 32a of lamp box 32 reflection incides light diffusing board 40.The light that incides light diffusing board 40 irradiates to transmission type image display part 10 from second 40b.Now, because be formed with a plurality of convex shaped parts 41 on second 40b of light diffusing board 40, therefore light outgoing via convex shaped part 41.Because convex shaped part 41 has the represented cross sectional shape of above-mentioned z (x), thus according to light pass through position (outgoing position), light reflects to various directions.By means of this diffusion effect, from the light generation diffusion of light source 31 and generate planar light, and the picture of light source 31 can not project on transmission type image display part 10.
And, the cross sectional shape of convex shaped part 41 is embodiments while designing in the following manner, the intensity distributions of frontal of light that incides convex shaped part 41 from a light source 31, a part that spreads all over the region of bottom at the top from intensity distributions has intensity and is the linear region (linear change region 51) changing (linear function ground).Thereby, the intensity distributions of frontal of light that incides convex shaped part 41 from light source 31, as mentioned above, there is intensity and be the linear region (linear change region 51) changing (linear function ground).Therefore, in being formed with the light diffusing board 40 of a plurality of convex shaped parts 41, from the Luminance Distribution of the light of light diffusing board 40 outgoing, becoming and be easy to homogenising, brightness disproportionation is inhibited, and the picture of above-mentioned light source 31 becomes and is more difficult to occur.In addition, owing to thering is above-mentioned intensity Distribution from the light of convex shaped part 41 outgoing, so with respect to the variation of L/D, the variation of luminance uniformity is inhibited.Its result, can more stably suppress brightness disproportionation.In addition, because the impact of the relative luminance uniformity of the variation on L/D is reduced, so light diffusing board 40 has versatility.
Thereby, in possessing the planar light source device 20 of light diffusing board 40, the light can output brightness inequality being inhibited.And then, in planar light source device 20, with respect to L/D, changing, the variation of luminance uniformity is inhibited.
And in the transmission image display device 1 that comprises light diffusing board 40, the light being inhibited due to the brightness disproportionation transmission type image display part 10 that can throw light on, so can seek the improvement of display quality.
[embodiment]
(embodiment 1～12)
With reference to embodiment 1～12 and comparative example 1, light diffusing board (Opital control board) is described particularly.In embodiment 1～12 below and the explanation of comparative example 1, for convenience of description, convex shaped part is called convex shaped part 41, additional same reference numerals in the corresponding key element of the key element with above-mentioned the first embodiment.
In embodiment 1～12 and comparative example 1, for the cross sectional shape of different separately convex shaped parts, implement the simulation based on Ray Tracing and obtain intensity distributions.
[analogy method]
Figure 40 means the schematic diagram of analogy model.As shown in figure 40, in simulation, establish light diffusing board 40 is disposed on two light sources 31,31, to exporting and observe by the light intensity of light diffusing board 40 from light source 31,31.In order simulating, to adopt 3 to be similar to, that is (i) in the face with light source 31 quadratures, implement simulation; (ii) establishing the diameter that light source 31 is pointolite that is light source is 0; And (iii) only consider direct transmitted light, and simulate by Ray Tracing.For convenience of description, two light sources 31,31 shown in Figure 40 are called to light source 31A, light source 31B.The different this point of computing method of this analogy method light quantity of incident on the per unit length at first surface 40a, identical with the analogy method in embodiment 14～17 described later.
In all simulations of embodiment 1～12 and comparative example 1, establishing two distance L between light source 31A, 31B is 45mm, thickness d 1be 1.5, the refractive index of light diffusing board 40 is 1.59.In embodiment 1～12 and comparative example 1 simulation separately, the cross sectional shape of convex shaped part 41 is set by the decision operation of cross sectional shape illustrated in the second embodiment.Specifically, implementation step 1～3 calculating after the cross sectional shape of convex shaped part 41 under these conditions, the interpolation processing of stipulating and obtain the shape of convex shaped part 41.In design, the distance D between light source 31A (or light source 31B) and light diffusing board 40 is set to the distance of regulation.As the distance D of this regulation, while being made as L=45mm, setting L/D becomes following value.That is, the distance D while setting design is as follows, in embodiment 1, and L/D=2.17; In embodiment 2, L/D=2.50; In embodiment 3, L/D=3.20; In embodiment 4, L/D=3.75; In embodiment 5, L/D=2.00; In embodiment 6～8, L/D=3.20; In embodiment 9～11, L/D=3.00; And, in embodiment 12, L/D=2.50.
Figure 41～Figure 52 represents that respectively the convex shaped part that uses in the simulation of embodiment 1～12 is at the chart of the design data of design phase.The amplitude w of convex shaped part 41 a, for embodiment 1～4, w a=400 μ m; For embodiment 5, w a=250 μ m; For embodiment 6～11, w a=355 μ m; For embodiment 12, w a=349 μ m.In Figure 41～Figure 52, x represents the position (μ m) on the x axle in the explanation of convex shaped part 41A～41J.In Figure 41～Figure 52, z represents the position (μ m) on the z axle in the explanation of convex shaped part 41A～41J, corresponding to the height (μ m) of convex shaped part 41.As shown in Figure 41～Figure 52, in the design phase based on step 1～3, designed half shape of convex shaped part 41.By the x shown in Figure 41～Figure 52, z, combine each represented data point, be illustrated in step 1～step 3 illustrated in the second embodiment the position of intersecting point of the line feature of adjacency discretely.
The simulation of embodiment 1～12 is for usining that each data point shown in Figure 41～Figure 52 is implemented 3 spline interpolations as summit and the cross sectional shape of the convex shaped part 41 that obtains is implemented.3 spline interpolations, in each figure of Figure 41～Figure 52, carry out under the following conditions, at the left end of convex shaped part 41, and namely (x, z)=(w a/ 2,0) upper, 2 subdifferentials are 0, and in the apex of convex shaped part 41, namely, on the position of x=0,1 subdifferential is 0.
The cross sectional shape of the convex shaped part in embodiment 1～12 and comparative example 1, corresponding to by the z shown in formula (4) or formula (6) 0(x) shape representing.Now, h aand k aas shown in table 9.In addition the amplitude w of the convex shaped part 41 of embodiment 1～12, aas previously mentioned, the amplitude w of the convex shaped part 41 of comparative example 1 abe all mutually 400 μ m with the situation of embodiment 1～4.At the h shown in table 9 aand k athis occasion of value, the cross sectional shape of embodiment 1 is corresponding to the shape example 2 shown in the 3rd embodiment, the cross sectional shape of embodiment 2 is corresponding to shape example 1.The cross sectional shape of embodiment 3 is corresponding to the shape example 3 shown in the 3rd embodiment, and the cross sectional shape of embodiment 4 is corresponding to shape example 4.And then the cross sectional shape of embodiment 5～12 corresponds respectively to convex shaped part 41C～41J.
[table 9]
h a k a
Embodiment 1 0.4825w a -0.232
Embodiment 2 0.5210w a -0.229
Embodiment 3 0.5966w a -0.075
Embodiment 4 0.6837w a -0.069
Embodiment 5 0.4340w a -0.240
Embodiment 6 0.6140w a -0.170
Embodiment 7 0.5880w a -0.128
Embodiment 8 0.5780w a -0.081
Embodiment 9 0.5500w a -0.082
Embodiment 10 0.5600w a -0.127
Embodiment 11 0.5780w a -0.185
Embodiment 12 0.4860w a -0.144
Comparative example 1 0.5000w a -1.000
Utilize above-mentioned analogy model, embodiment 1～12 and comparative example 1 have been implemented as Imitating A.
(simulation A)
By being set, periodic boundary condition calculates the intensity distributions in the region two light source 31A, 31B of, adjacency caused from the light of a plurality of light sources 31 outputs.Result of calculation in region on representing between two light source 31A, 31B of adjacency in the result of this simulation 3.In this simulation A, establishing distance L is on the one hand 45mm, by distance D is changed, different L/D is obtained to intensity distributions on the other hand.The frontal (θ=0) of even intensity degree (%) while then, calculating to(for) different L/D.Even intensity degree (%) calculates as " (minimum strength)/(maximum intensity) * 100 ".In addition, because the intensity relative with certain view angle θ is corresponding to brightness, therefore the even intensity degree of the intensity distributions based on relative with certain view angle θ is corresponding to luminance uniformity.
Analog result is chart as shown in Figure 53.In embodiment 1～12, can realize the even intensity degree (luminance uniformity) higher than comparative example 1.Especially,
L/D=2.17 in embodiment 1,
L/D=2.5 in embodiment 2,
L/D=3.15,3.2 in embodiment 3,
L/D=3.7,3.75 in embodiment 4,
L/D=2.0 in embodiment 5,
L/D=3.2,3.3 in embodiment 6,
L/D=3.2 in embodiment 7,8,
In embodiment 9～11 L/D=3.0 and
L/D=2.5 in embodiment 12
Time, can realize the even intensity degree (luminance uniformity) that is more than or equal to 90% so higher frontal.
(embodiment 13)
Except establishing the refractive index of light diffusing board 40, be 1.49, thickness d 1be beyond 2.25 this point, design in the same manner convex shaped part 41 with the situation of embodiment 112 and implement embodiment.In embodiment 13, establish w a=400 μ m.In the embodiment 13 corresponding with Figure 41 Figure 52 in the design data of design phase as shown in the chart of Figure 54.Predetermined distance between light source 31A in the design of the convex shaped part 41 of embodiment 13 (or light source 31B) and light diffusing board 40 is distance D, and when L=45mm, 4.00 the mode of becoming by L/D is set.In embodiment 13, for these design datas, implement in the same manner with the situation of embodiment 1～12 interpolation processing of stipulating.In embodiment 13, the cross sectional shape of convex shaped part 41 can be by the z shown in formula (4) or formula (6) 0(x), in, establish h a=0.9752w aand k a=-0.212 situation is corresponding.In addition, w abe 400 μ m as described above.The analog result of embodiment 13 is as shown in the table.
[table 10]
Figure BSA00000185539400351
According to table 10, at L/D, be 2.0 and can realize even intensity degree (luminance uniformity) at 4.0 o'clock and be more than or equal to 90% such high value, even and if at L/D for also realizing higher even intensity degree (luminance uniformity) at larger 4.0 o'clock.
(embodiment 14～17)
Then,, with reference to embodiment 14～17 and comparative example 2, light diffusing board (Opital control board) is described particularly.In embodiment 14～17 below and the explanation of comparative example 2, for convenience of description, to the additional same reference numerals of the corresponding key element of the key element with above-mentioned the first embodiment.
In embodiment 14～17 and comparative example 2, for the cross sectional shape of different separately convex shaped parts, implement the simulation based on Ray Tracing and obtain intensity distributions.Because the situation of analogy method and embodiment 1～12 grade is identical in fact, description will be omitted.In addition, as previously mentioned, the method that the light quantity of the per unit length of first surface 40a is calculated is different from the situation of embodiment 1～12.In all simulations of embodiment 14～17 and comparative example 2, establishing two distance L between light source 31A, 31B is 30mm, and the refractive index of light diffusing board 40 is 1.59.In addition, establish the thickness d of light diffusing board 40 1for 1.5mm.
In addition, in embodiment 14～17 and comparative example 2 simulation separately, be located at and on second 40b of light diffusing board 40, be formed with the convex shaped part 41 with the cross sectional shape of setting in embodiment 14～17 and comparative example 2.
Utilize above-mentioned analogy model, embodiment 14～17 and comparative example 2 have been implemented to simulation 1～3.
(simulation 1) calculates the intensity distributions of the frontal relative with the light of exporting from a light source 31A, and this light source 31A is disposed at the position of the distance D of regulation from first surface 40a.
(simulation 2) calculates the intensity distributions of the frontal relative with the light of exporting from a light source 31A, and this light source 31A is disposed at the position of 100mm from first surface 40a.
(simulation 3) similarly obtained intensity distributions to different L/D from the situation of simulation A.In simulation 3, also calculate the intensity distributions from the direction observation light time of view angle θ with respect to frontal.Then, for different L/D and different view angle θ, calculate even intensity degree (%).
[shape of convex shaped part]
In embodiment 14～17, set the distance D between light source 31A (or light source 31B) and light diffusing board 40 distance of regulation for, and to become the mode of desirable intensity distributions, design the cross sectional shape of convex shaped part 41.The distance of regulation is D=13.82mm in embodiment 14, in embodiment 15, is D=12mm, in embodiment 16, is D=9.375mm, in embodiment 17, is D=8.0mm.
In embodiment 14～17, in being implemented in the second embodiment with above-mentioned condition illustrated step 1～3 and calculate the cross sectional shape of convex shaped part 41 after, the interpolation processing of stipulating and obtain the cross sectional shape of convex shaped part 41.The amplitude of embodiment 14～17 is identical.The convex shaped part 41 using in each simulation of embodiment 14～17 is identical with the situation of embodiment 1～4 in the design data of design phase.Figure 41～Figure 44 means that the convex shaped part that uses in the simulation of embodiment 14～17 is at the chart of the design data of design phase.
Simulation in embodiment 14～17 is to implement for the following cross sectional shape of convex shaped part 41, and this cross sectional shape is to using each data point shown in Figure 41～Figure 44 as summit, to have implemented 3 spline interpolations and obtained.3 spline interpolations are in each figure of Figure 41～Figure 44, and in the left end of convex shaped part 41 that is (x, z)=(200,0), to locate 2 subdifferentials be 0, in the apex of convex shaped part 41 that is the position of x=0 1 subdifferential, be to carry out under 0 this condition.In addition, in the simulation in comparative example 2, the cross sectional shape of convex shaped part 41 is semi-circular shape.In addition, the amplitude of comparative example 2 is identical with embodiment 14～17.
In Figure 55, represent the cross sectional shape of the convex shaped part 41 that simulation is used.Figure 55 means the figure of cross sectional shape of the convex shaped part of embodiment 14～17 and comparative example 2.The transverse axis of Figure 55, corresponding to the x axle in the explanation of convex shaped part 41A～41J, represents the position of the Width of convex shaped part 41.The longitudinal axis in Figure 55, corresponding to the z axle in the explanation of convex shaped part 41A～41J, represents height.The width of the convex shaped part 41 of embodiment 14～17 and comparative example 2 is identical.And in Figure 55, the length of transverse axis and the longitudinal axis is usingd half length of two ends width of convex shaped part 41 and is carried out standardization as benchmark and represent.
The cross sectional shape of the convex shaped part of the embodiment 14～17 shown in Figure 55 corresponding in formula (4) or formula (6) by h a, k az while setting as shown in table 11ly 0(x) represented shape.In table 11, w abe 400 μ m.
[table 11]
h a k a
Embodiment 14 0.4825w a -0.232
Embodiment 15 0.5210w a -0.229
Embodiment 16 0.5966w a -0.075
Embodiment 17 0.6837w a -0.069
[analog result]
Below, the analog result of the simulation 1～3 of embodiment 14～17 and comparative example 2 is described.In the explanation of analog result, the situation of the orientation of convex shaped part 41 that is second direction and the second embodiment is called X-direction in the same manner.
(comparative example 2)
Figure 56 means the figure of the result of simulating 1 in comparative example 2.In Figure 56, the frontal intensity distributions relative with light from light source 31A while representing to establish D=12 (mm).The transverse axis of Figure 56 represents position relative with light source 31A in X-direction, and the longitudinal axis represents intensity (arbitrary unit).Figure 57 means the figure of the result of simulating 2 in comparative example 2.The transverse axis of Figure 57 represents position relative with light source 31A in X-direction, and the longitudinal axis represents with the standardization intensity after maximum intensity standardization.
As shown in Figure 56 and Figure 57, the top from intensity distributions in comparative example 2 is non-linearly and changes to terminal part intensity.That is the caused intensity distributions of light diffusing board 40 with the convex shaped part 41 of comparative example 2 does not have linear change region 51.
One of result of expression simulation 3 example in table 12.In table 12, for L/D and view angle θ, represent the relative intensity in position based on from light source 31A and calculate even intensity degree (luminance uniformity) result (%).
[table 12]
Figure BSA00000185539400381
In addition, Figure 58 (a)～Figure 58 (c) means the figure of the intensity distributions of the result of simulating 3 in example 4 based on the comparison.Figure 58 (a) is illustrated in the situation of L/D=3.5, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 58 (b) is illustrated in the situation of L/D=3.75, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 58 (c) is illustrated in the situation of L/D=4.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.
(embodiment 14)
Figure 59 means the figure of the result of simulating 1 in embodiment 14.Frontal intensity distributions while representing to establish D=13.82 (mm) in Figure 59, relative with light from light source 31A.The transverse axis of Figure 59 represents position relative with light source 31A in X-direction, and the longitudinal axis represents intensity (arbitrary unit).Figure 60 means the figure of the result of simulating 2 in embodiment 14.The transverse axis of Figure 60 represents position relative with light source 31A in X-direction, and the situation of the longitudinal axis and Figure 57 similarly represents standardization intensity.
As shown in Figure 59 and Figure 60, under the cross sectional shape of the known convex shaped part 41 at embodiment 14, from the top of intensity distributions, to terminal part, there is linear change region 51.In addition, according to Figure 60, in the present embodiment 14 under simulation 2 condition, intensity distributions in condition (a) and (b), also satisfy condition (c), (d).In addition, can say at the lower w of condition (c) 4meet and be more than or equal to w 1/ 6.
One of result of expression simulation 3 example in table 13.In table 13, for different L/D and different view angle θ, represent the relative intensity in position based on from light source 31A and calculate even intensity degree (luminance uniformity) result (%).
[table 13]
In addition, Figure 61 (a)～Figure 61 (c) means the figure based on simulating the intensity distributions of 3 result in embodiment 14.Figure 61 (a) is illustrated in the situation of L/D=2.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 61 (b) is illustrated in the situation of L/D=2.5, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 61 (c) is illustrated in the situation of L/D=3.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.
In embodiment 14, for L=30mm, D=13.87, that is L/D is about 2.17 and to obtain the mode of desirable intensity distributions, designs the cross sectional shape of convex shaped part 41.And, according to table 13 and Figure 61 (b), at L/D, be to approach 2.17 o'clock of design load, can on frontal, guarantee to approach 100% even intensity degree (luminance uniformity) (%).In addition, according to the result shown in table 13 and Figure 61 (a)～Figure 61 (c), even if L/D departs from from above-mentioned design load, it is mild that (for example, with respect to comparative example) also compared in the variation of even intensity degree (luminance uniformity), therefore can more stably reduce brightness disproportionation.And then, even if known, at view angle θ, be under 20 ° and 30 °, also can guarantee higher even intensity degree (luminance uniformity), and the variation of even intensity degree (luminance uniformity) becomes mild for the variation of L/D.
(result of embodiment 15)
Figure 62 means the figure of the result of simulating 1 in embodiment 15.In Figure 62, frontal intensity distributions while representing to establish D=12 (mm), relative with light from light source 31A.The transverse axis of Figure 62 represents position relative with light source 31A in X-direction, and the longitudinal axis represents intensity (arbitrary unit).Figure 63 means the figure of the result of simulating 2 in embodiment 15.The transverse axis of Figure 63 represents position relative with light source 31A in X-direction, and the longitudinal axis represents with the standardization intensity after maximum intensity standardization.
As shown in Figure 62 and Figure 63, under the cross sectional shape of the known convex shaped part 41 at embodiment 15, from the top of intensity distributions, to terminal part, there is linear change region 51.In addition, according to Figure 63, in the present embodiment 15 under simulation 2 condition, intensity distributions satisfy condition (a) and (b) in also satisfy condition (c), (d).In addition, can say under condition (c) w 4meet and be more than or equal to w 1/ 6.
One of result of expression simulation 3 example in table 14.In table 14, for L/D and view angle θ, represent the relative intensity in position based on from light source 31A and calculate even intensity degree (luminance uniformity) result (%).
[table 14]
Figure BSA00000185539400401
In addition, Figure 64 (a)～Figure 64 (c) means the figure based on simulating the intensity distributions of 3 result in embodiment 15.Figure 64 (a) is illustrated in the situation of L/D=2.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 64 (b) is illustrated in the situation of L/D=2.5, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 64 (c) is illustrated in the situation of L/D=3.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.
In embodiment 15, for L=30mm, D=12, that is L/D 2.5 designs the cross sectional shape of convex shaped part 41 to obtain the mode of desirable intensity distributions.And, according to table 14 and Figure 64 (b), at L/D, be design load 2.5 o'clock, can guarantee to approach 100% even intensity degree (luminance uniformity) (%) at frontal.In addition, according to the result shown in table 14 and Figure 64 (a)～Figure 64 (c), even if known L/D departs from from above-mentioned design load, the variation of even intensity degree (luminance uniformity) is also mild, therefore can more stably reduce brightness disproportionation.And then, even if known, at view angle θ, be under 20 ° and 30 °, also can guarantee higher even intensity degree (luminance uniformity), and the variation of even intensity degree (luminance uniformity) becomes mild for the variation of L/D.
(result of embodiment 16)
Figure 65 means the figure of the result of simulating 1 in embodiment 16.In Figure 65, frontal intensity distributions while representing to establish D=9.375 (mm), relative with light from light source 31A.The transverse axis of Figure 65 represents position relative with light source 31A in X-direction, and the longitudinal axis represents intensity (arbitrary unit).Figure 66 means the figure of the result of simulating 2 in embodiment 16.The transverse axis of Figure 66 represents position relative with light source 31A in X-direction, and the longitudinal axis represents with the standardization intensity after maximum intensity standardization.
As shown in Figure 65 and Figure 66, under the cross sectional shape of the known convex shaped part 41 at embodiment 16, among intensity distributions, intensity minimizing region has linear change region 51.In addition, according to Figure 66, in the present embodiment 16 under simulation 2 condition, intensity distributions satisfy condition (a) and (b) in also satisfy condition (c).In addition, can say under condition (c) w 4meet and be more than or equal to w 1/ 8.
One of result of expression simulation 3 example in table 15.In table 15, for L/D and view angle θ, represent the relative intensity in position based on from light source 31A and calculate even intensity degree (luminance uniformity) result (%).
[table 15]
Figure BSA00000185539400421
In addition, Figure 67 (a)～Figure 67 (c) means the figure based on simulating the intensity distributions of 3 result in embodiment 16.Figure 67 (a) is illustrated in the situation of L/D=3.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 67 (b) is illustrated in the situation of L/D=3.2, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 67 (c) is illustrated in the situation of L/D=3.5, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.
In embodiment 16, for L=30mm, D=9.375, that is L/D 3.2 designs the cross sectional shape of convex shaped part 41 to obtain the mode of desirable intensity distributions.And, according to table 15 and Figure 67 (b), at L/D, be design load 3.2 o'clock, can guarantee to approach 100% even intensity degree (luminance uniformity) (%) at frontal.In addition, according to the result shown in table 15 and Figure 67 (a)～Figure 67 (c), even if L/D departs from from above-mentioned design load, the variation of even intensity degree (luminance uniformity) is also mild, therefore can more stably reduce brightness disproportionation.And then, even if known, at view angle θ, be under 20 ° and 30 °, also to guarantee higher even intensity degree (luminance uniformity), and the variation of even intensity degree (luminance uniformity) become mild for the variation of L/D.
(result of embodiment 17)
Figure 68 means the figure of the result of simulating 1 in embodiment 17.In Figure 68, while representing to establish D=8.0 (mm), the frontal intensity distributions relative with light from light source 31A.The transverse axis of Figure 68 represents position relative with light source 31A in X-direction, and the longitudinal axis represents intensity (arbitrary unit).Figure 69 means the figure of the result of simulating 2 in embodiment 17.The transverse axis of Figure 69 represents position relative with light source 31A in X-direction, and the longitudinal axis represents with the standardization intensity after maximum intensity standardization.
As shown in Figure 68 and Figure 69, under the cross sectional shape of the known convex shaped part 41 at embodiment 17, among intensity distributions, intensity minimizing region has linear change region 51.In addition, according to Figure 69, in the present embodiment 17 under simulation 2 condition, intensity distributions satisfy condition (a) and (b) in also satisfy condition (c).In addition, can say at the lower w of condition (c) 4meet and be more than or equal to w 1/ 10.
One of result of expression simulation 3 example in table 16.In table 16, for L/D and view angle θ, represent the relative intensity in position based on from light source 31A and calculate even intensity degree (luminance uniformity) result (%).
[table 16]
In addition, Figure 70 (a)～Figure 70 (c) means the figure based on simulating the intensity distributions of 3 result in embodiment 17.Figure 70 (a) is illustrated in the situation of L/D=3.5, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 70 (b) is illustrated in the situation of L/D=3.75, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.Figure 70 (c) is illustrated in the situation of L/D=4.0, and usings light source 31A as the position of the benchmark intensity distributions relative with view angle θ.
In embodiment 17, for L=30mm, D=8.0, that is L/D 3.75 designs the cross sectional shape of convex shaped part 41 to obtain the mode of desirable intensity distributions.And, according to table 16 and Figure 70 (b), at L/D, be design load 3.75 o'clock, can guarantee to approach 100% even intensity degree (luminance uniformity) (%) at frontal.In addition, according to the result shown in table 16 and Figure 70 (a)～Figure 70 (c), even if L/D departs from from above-mentioned design load, the variation of even intensity degree (luminance uniformity) is also mild, therefore can more stably reduce brightness disproportionation.And then, even if known, at view angle θ, be under 20 ° and 30 °, also can guarantee higher even intensity degree (luminance uniformity), and the variation of even intensity degree (luminance uniformity) becomes mild for the variation of L/D.
(comparison of the result of embodiment 14～17 and comparative example 2)
In comparative example 2, as simulate as shown in 1,2 result, the intensity distributions relative with light source 31A do not have linear change region 51.With respect to this, in embodiment 14～17, as to simulate as shown in 1,2 result, the intensity distributions relative with light source 31A has linear change region 51.And then as can be understood in the comparison of the result of the simulation 1,2 in separately according to embodiment 14～17 and comparative example 2, even if the change of distance between light source 31A and light diffusing board 40, intensity distributions also has identical characteristic.Thereby, light source 31 is being disposed at for example, when for example leaving the intensity distributions of the position of 100mm measuring and meet certain condition (condition (a), (b)) from light diffusing board 40, the intensity distributions relative with a light source 31A who is configured in the distance D of regulation with respect to light diffusing board 40 also meets identical condition.Thereby, knownly can also leave 100mm from light diffusing board 40 and configure light source 31A, and the shape of convex shaped part 41A is checked.
The cross sectional shape of the convex shaped part 41 of using in embodiment 14～17 in addition, be establish distance D be regulation value design.This is just equivalent to design to obtain the mode of desirable intensity distributions for the L/D of regulation.And, according to simulation 3 result, in each embodiment 14～17, for the L/D of the regulation of using in design, can realize higher luminance uniformity.
And then, in thering is the embodiment 14～17 in above-mentioned linear change region 51, compare with the comparative example without linear change region 51, can make the variation of the luminance uniformity relative with the variation of L/D reduce.Therefore, the in the situation that of embodiment 14～17, even if from situation about departing from the L/D of the regulation of setting for design, also can reduce the reduction of luminance uniformity.Its result, can more stably suppress brightness disproportionation, and as a result of, the light diffusing board 40 of embodiment 14～17 has versatility.
In addition, according to the comparison of the result of embodiment 14～17, known in the situation that use has the intensity distributions in linear change region 51 and has carried out design, can make L/D strengthen, even if that is the slimming of seeking planar light source device 20 and transmission image display device 1 also can guarantee higher luminance uniformity.And in this case, even if be also that L/D variation also can suppress the reduction of luminance uniformity, this point as previously mentioned.
According to above-described embodiment and embodiment, can provide and can more stably suppress the Opital control board of brightness disproportionation and planar light source device and the transmission image display device that comprises this Opital control board.
Above, although understand embodiment of the present invention and embodiment, but the present invention is not limited to above-mentioned embodiment and embodiment.For example, although establish Opital control board, be that light diffusing board 40 is illustrated, the present invention is not limited thereto, so long as the optics of the brightness uniformity of the light that adjustment is exported from a plurality of light sources in the parallel plane plane with a plurality of light sources of configuration.For example, Opital control board can also be made as light exit side at the plate being comprised of transparent material and has brightness adjustment plate a plurality of above-mentioned convex shaped parts, the optical sheet such as prismatic lens or lens or blooming and so on.
In addition, although in explanation up to now, establish a plurality of light sources 31 that light source portion 30 has and be roughly equally spaced configured with interval L, the distance that two light source of adjacency is 31,31 can be different.In this case, can use the mean distance L at interval of 31,31 of two light sources of adjacency m, define the distance of 31 of light sources and the ratio of distances constant between light source 31 and Opital control board 40.In addition,, in the situation that the distance of 31,31 of two light sources of adjacency is different, L/D is according to position and difference.In light diffusing board 40, as previously mentioned, even if L/D changes the contribution to intensity distributions of the light also can reduce from a plurality of light sources 31.Thereby, even if in the situation that the distance of 31,31 of two light sources of adjacency is different, according to position, come modification also to reduce as the necessity of the cross sectional shape of convex shaped part 41.Therefore, the design of light diffusing board 40 and manufacture become easily, can seek the reduction of the manufacturing cost of light diffusing board 40, planar light source device 20 and transmission image display device 1.
And then, although it is identical to establish the cross sectional shape of convex shaped part 41, also can be identical.But by making its identical reduction of seeking manufacturing cost etc., this point as previously mentioned.
In addition, although in the second embodiment, establishing optical element portion is that convex shaped part 41 is illustrated, and optical element portion is so long as can realize the shape of the intensity distributions shown in Fig. 5 and just do not limit especially.

Claims (11)

1. an Opital control board, makes can, from being positioned at second outgoing with above-mentioned first surface opposition side, to it is characterized in that from the light of first surface incident:
On above-mentioned second, be formed with along first direction and extend, and a plurality of convex shaped parts that configure side by side in the second direction with above-mentioned first direction quadrature,
On the cross section at above-mentioned convex shaped part and above-mentioned first direction quadrature, if the axis at the two ends by this convex shaped part in above-mentioned second direction is x axle, be located on above-mentioned x axle center by above-mentioned two ends and with the axis of above-mentioned x axle quadrature be z axle, and the axial length of x of establishing above-mentioned convex shaped part is w atime,
On above-mentioned cross section, the contour shape of above-mentioned convex shaped part is at-0.475w a≤ x≤0.475w ascope in, by the z (x) that meets formula (1), represented,
z B(x)-0.01w a≤z(x)≤z B(x)+0.01w a...(1)
Wherein, in formula (1), z b(x)=z 0(x) * r, r is more than or equal to 0.95 and be less than or equal to 1.05 constant, z 0(x) by formula (2), represented,
z 0 ( x ) = h a - 8 h a ( x w a ) 2 1 - k a + ( 1 - k a ) 2 + 16 k a ( x w a ) 2 · · · ( 2 )
In formula (2), h ato be more than or equal to 0.27w aand be less than or equal to 1.02w aconstant, k ato be more than or equal to-0.38 and be less than or equal to 0.00 constant.
2. Opital control board according to claim 1, is characterized in that, the refractive index of above-mentioned convex shaped part is more than or equal to 1.48 and be less than or equal to 1.62.
3. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.48 and be less than 1.50,
Above-mentioned h abe more than or equal to 0.34w aand be less than or equal to 1.02w a,
Above-mentioned k abe more than or equal to-0.38 and be less than or equal to-0.06.
4. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.50 and be less than 1.52,
Above-mentioned h abe more than or equal to 0.33w aand be less than or equal to 0.99w a,
Above-mentioned k abe more than or equal to-0.35 and be less than or equal to-0.06.
5. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.52 and be less than 1.54,
Above-mentioned h abe more than or equal to 0.31w aand be less than or equal to 0.98w a,
Above-mentioned k abe more than or equal to-0.33 and be less than or equal to-0.05.
6. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.54 and be less than 1.56,
Above-mentioned h abe more than or equal to 0.30w aand be less than or equal to 0.96w a,
Above-mentioned k abe more than or equal to-0.30 and be less than or equal to-0.05.
7. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.56 and be less than 1.58,
Above-mentioned h abe more than or equal to 0.29w aand be less than or equal to 0.94w a,
Above-mentioned k abe more than or equal to-0.29 and be less than or equal to-0.03.
8. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.58 and be less than 1.60,
Above-mentioned h abe more than or equal to 0.28w aand be less than or equal to 0.92w a,
Above-mentioned k abe more than or equal to-0.27 and be less than or equal to-0.02.
9. Opital control board according to claim 1, is characterized in that:
The refractive index of above-mentioned convex shaped part is more than or equal to 1.60 and be less than or equal to 1.62,
Above-mentioned h abe more than or equal to 0.27w aand be less than or equal to 0.87w a,
Above-mentioned k abe more than or equal to-0.27 and be less than or equal to 0.00.
10. a planar light source device, is characterized in that, possesses:
Opital control board in claim 1～9 described in any one; And
Be spaced from each other and be configured, and the above-mentioned first surface of above-mentioned Opital control board is supplied with to a plurality of light sources of light.
11. 1 kinds of transmission image display devices, is characterized in that possessing:
Opital control board in claim 1～9 described in any one;
Be spaced from each other and be configured, and the above-mentioned first surface of above-mentioned Opital control board is supplied with to a plurality of light sources of light; And
By export and throw light on to show by the light of above-mentioned Opital control board the transmission type image display part of image from a plurality of above-mentioned light sources.
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