JP2005011559A - Planar light source and display device using planar light source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar light source device in which there occurs no unevenness of luminance in the vicinity of a point-shape light source even when a point-shape light source having a high directivity of outgoing light is used. <P>SOLUTION: This is a planar light source device which has a case having an opening part, a light outgoing plate arranged at the opening part, a reflecting plate for forming a hollow region between the light outgoing plate, and a plurality of point-shape light sources arranged along at least one side face part of the case. A rod-shape optical element extending in the arrangement direction of the plural point-shape light sources is provided in the hollow region. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a planar light source device for supplying light to a display device such as a liquid crystal or a signboard and a display device using the device. More specifically, a hollow-type planar light source device that does not use a light guide plate, and in particular, a planar light source device that uses a plurality of point light sources such as light emitting diodes (hereinafter simply referred to as LEDs) and the like. The present invention relates to a display device using the.
[0002]
[Prior art]
A conventional planar light source device includes a light distribution means, an LED, a reflection means provided to face the light distribution means, a hollow region formed between the light distribution means and the reflection means, and a reflector. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-258664 (page 4, left column, line 3 to page 5, left column, line 43, FIG. 1)
[0004]
[Problems to be solved by the invention]
In the conventional planar light source device, the luminance in the vicinity of the LED that is the point light source is higher than the luminance at a position far from the point light source, and uneven luminance occurs in the display, which deteriorates the display quality. There is.
[0005]
In view of the above circumstances, the present invention provides a planar light source device that does not cause uneven brightness in the vicinity of a point light source when using a point light source with high directivity of emitted light. It is an object of the present invention to provide a display device that can obtain excellent display characteristics when used.
[0006]
[Means for Solving the Problems]
The planar light source device of the present invention includes a housing having an opening, a light emitting plate disposed in the opening, a reflecting plate that forms a hollow region between the light emitting plate, and at least one of the housings. A planar light source device including a plurality of point light sources arranged along one side surface portion, and having a rod-like optical element extending in the arrangement direction of the plurality of point light sources in the hollow region. It is characterized by.
[0007]
The display device of the present invention includes the planar light source device, and a display unit that is disposed above the planar light source device and performs display using light emitted from the planar light source device. And
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a planar light source device of the present invention and a display device using the device will be described with reference to the accompanying drawings.
[0009]
Embodiment 1
FIG. 1 is a plan view showing a schematic configuration of a surface light source device according to Embodiment 1 of the present invention, FIG. 2 is a sectional view taken along line AA of the surface light source device shown in FIG. 1, and FIG. It is a LED arrangement | sequence figure which shows an example.
[0010]
As shown in FIGS. 1 to 3, the planar light source device according to the first embodiment of the present invention includes a housing 1, a light exit plate 2, a plurality of point light sources 3, a point light source substrate 4, a reflection plate 5, and the like. The reflector 7 is composed of a deflection element 8 and a rod-shaped optical element 9. A hollow region 6 is formed between the light exit plate 2 and the reflection plate 5.
[0011]
The housing 1 includes an upper surface portion 1a, a bottom surface portion 1b, and four side surface portions 1c, and an opening portion 1d is formed in the upper surface portion 1a. The housing 1 is formed so that light is not leaked to the outside as much as possible, and the reflection is reflected on the bottom surface portion 1b on the inner side of the housing 1 so that the light is reflected on the inner side and proceeds to the opening 1d. A plate 5 is provided. Thereby, light propagates in the air in the hollow region 6 formed between the reflecting plate 5 and the light outgoing plate 2.
[0012]
The light exit plate 2 is disposed so as to cover the entire opening 1 d of the housing 1. The light exit plate 2 is a plate having a function of transmitting light, such as polyethylene terephthalate (PET), a resin plate such as acrylic or polycarbonate, or a glass plate. In the first embodiment, a diffusion plate having a diffusion function is used for the light output plate 2. A planar light source device having a wide directivity can be obtained by providing a function of diffusing incident light by using a light emitting plate 2 mixed with a reflective material or a surface roughened surface. .
[0013]
As the point light source 3, an LED, a laser diode (LD), or the like can be used. The point light source 3 according to the first embodiment includes an LED and a first point light source 3a that emits red (R) light, and a second point light source 3b that emits green (G) light. , And a third point light source 3c that emits blue (B) light.
[0014]
In the first embodiment, the LED that emits red, green, or blue monochromatic light has higher luminous efficiency than the LED that emits white light, and the color filter used in the liquid crystal display device transmits red, green, and blue light. By combining the characteristics and the emission spectrum of the LED, a display device with high color reproducibility can be obtained. Moreover, the hue of the emitted light from the planar light source device can be easily changed by independently controlling the LEDs for each color.
[0015]
The point light source substrate 4 has a rectangular shape. On the point light source substrate 4, the plurality of point light sources 3 are mounted so as to be arranged along the longitudinal direction of the point light source substrate 4. The point light source substrate 4 is arranged side by side on the bottom surface portion 1 b of the housing 1 along a pair of side surface portions 1 c facing the housing 1. Accordingly, the plurality of point light sources 3 are arranged along the side surface portion 1 c of the housing 1. In the present invention, the numbers of the first point light source 3a, the second point light source 3b, and the third point light source 3c mounted on the point light source substrate 4 are not necessarily equal. The number of each of the first point light source 3a, the second point light source 3b, and the third point light source 3c is arbitrarily set so that the light transmitted through the liquid crystal display element can be optimized to a desired chromaticity. can do. For example, as shown in FIG. 4, after mounting point light sources of G, B, G, R, G, and B as a plurality of point light sources on the point light source substrate 4a in a repetitive permutation, G can be implemented.
[0016]
As shown in FIG. 2, the structure of the reflecting plate 5 is such that the gap between the light exiting plate 2 and the reflecting plate 5 increases from the point light source 3 toward the center of the opening 1d of the housing 1 and then the opening. The concave-convex shape is formed such that the distance between the light-emitting plate 2 and the reflecting plate 5 is reduced toward the center of 1d. Further, the vicinity of the point light source 3 of the reflecting plate 5 is a regular reflecting portion 5a made of a specular reflecting material in which a metal plate such as aluminum or silver is vapor-deposited on a metal plate such as aluminum or silver or a resin sheet. The central portion is a diffuse reflection portion 5b by roughening the surface of the regular reflection material, or by arranging a white resin sheet or a metal plate painted in white.
[0017]
The reflector 7 surrounds the point light source 3 except for the hollow region 6 side, and efficiently reflects light from the point light source 3 toward the hollow region 6 side. The reflector 7 is made of a material such as a metal plate such as silver or aluminum or a white resin sheet.
[0018]
In addition, it is preferable that the reflectance of the said reflecting plate 5 and the reflector 7 is 90% or more in order to suppress the reflection loss in a reflective surface. Further, by applying a white paint or the like to the inside of the housing 1, the internal reflection is further improved, so that the loss of light can be reduced. In the present embodiment, the reflector 5 and the reflector 7 are made of different members. However, the present invention is not limited to this, and the reflector 5 and the reflector 7 are made of the same member. can do. By integrally producing the same member, it is possible to reduce the number of parts and improve the assembly workability. Furthermore, by using a highly reflective material as the material of the casing 1 and integrally manufacturing the casing 1 and the reflecting plate 5 or the reflector 7, the number of parts can be reduced.
[0019]
The deflection element 8 extends in the arrangement direction of the plurality of point light sources 3 between the point light source 3 and the hollow region 6, and is substantially parallel to the bottom surface portion 1 b of the housing 1. A first inclined surface (incident surface) on the point light source 3 side connecting a surface 8b, a facing surface 8d facing substantially parallel to the parallel surface 8b, and a top line of the parallel surface 8b and facing surface 8d. 8a and a second inclined surface (outgoing surface) 8c opposite to the first inclined surface 8a. That is, the declination element 8 has a trapezoidal cross section in which the thickness increases from the light exit plate 2 side toward the bottom surface portion 1b of the housing 1, and is made of a transparent resin such as acrylic or glass.
[0020]
The rod-shaped optical element 9 extends in the arrangement direction of the plurality of point light sources 3 at the substantially central portion of the hollow region 6. The rod-shaped optical element 9 has a symmetric cross-sectional shape, and faces the surface 9b substantially parallel to the bottom surface portion 1b of the housing 1 and faces the parallel surface 9b substantially parallel to the parallel surface 9b. An opposing surface 9d having a smaller area than the flat surface 9b, a first inclined surface 9a connecting the top surface of the parallel surface 9b and the opposing surface 9d, and a second inclined surface 9c facing the first inclined surface 9a. And have. The rod-shaped optical element 9 is made of a transparent resin such as acrylic or glass and has a function of transmitting light. In FIG. 2, the first inclined surface 9 a is the incident surface with respect to the left point light source 3.
[0021]
The parallel surface 9 b is in contact with the reflecting plate 5, and the opposing surface 9 d is in contact with the light output plate 2. The parallel surface 9b is formed as a diffuse reflection surface by pasting a white reflection sheet, processing it into a rough surface (uneven surface), and depositing silver or aluminum.
[0022]
A plurality of optical sheets (not shown) are disposed on the light exit plate 2 in order to effectively use light, and liquid crystals are disposed on the light exit plate 2 via the optical sheets. A display element (not shown) is arranged.
[0023]
The optical sheets have a structure in which a lens sheet is sandwiched between diffusion sheets. In addition, when the luminance needs to be improved, a plurality of lens sheets may be combined in consideration of the direction of the prism of the sheet formed on the surface. In addition, two or more diffusion sheets can be used to improve diffusibility. Furthermore, one lens sheet may or may not be used depending on the light distribution characteristics of the lens sheet. Further, a protective sheet or a polarizing reflection sheet may be used in combination, or neither may be used.
[0024]
The liquid crystal display device which is an example of the display device of the present invention is provided with a circuit board (not shown) for driving a liquid crystal display element as display means on the top of the planar light source device according to the present embodiment. It can be configured by arranging elements.
[0025]
The liquid crystal display element includes a TFT array substrate and a counter substrate in which electrodes and wiring such as a colored layer, a light shielding layer, a thin film transistor (hereinafter referred to as TFT) serving as a switching element, a pixel electrode, and a wiring are formed on an upper or lower substrate. Spacer for holding two substrates at equal intervals, sealing material for bonding two substrates, sealing material for sealing after injecting liquid crystal between two substrates, alignment film for giving initial alignment to liquid crystal In the present invention, since an existing liquid crystal display element is used, the description thereof is omitted here.
[0026]
Next, an optical path until the light emitted from the point light source 3 is emitted from the light output plate 2 will be described.
[0027]
Red, green, and blue monochromatic light emitted from the first point light source 3a, the second point light source 3b, and the third point light source 3c, which are the point light sources 3, are reflected directly or by the reflector 7. Then, the light is incident on the first inclined surface 8 a of the deflection element 8. Next, the deflection element 8 refracts and emits incident light to the bottom surface portion 1b side of the housing 1 through the second inclined surface 8b. Thereby, in this Embodiment, the light which reaches | attains the light source vicinity of the light-emitting plate 2 can be reduced, and the bright part of the light source vicinity can be improved. Further, since the first inclined surface 8a that is the incident surface is inclined in the direction away from the point light source 3 from the bottom surface portion 1b of the housing 1 toward the opening 1d of the housing 1, the point light source 3 emits light. The reflected light is likely to be surface-reflected by the first inclined surface 8a and returns to the reflector 7 side, so that the emitted light from the light output plate 2 in the vicinity of the light source is reduced. Thereby, while improving the bright part of the vicinity of a light source, the color mixture of the light emitted from the point light source 3 advances, and the planar light source device with few color irregularities can be obtained.
[0028]
The light emitted from the second inclined surface 8 c that is the emission surface of the deflection element 8 toward the bottom surface portion 1 b of the housing 1 is reflected by the reflecting plate 5 and propagates in a direction away from the point light source 3. To do. In the present embodiment, the reflection plate 5 has an uneven shape, and the regular reflection portion 5a and the diffuse reflection portion 5b are provided, so that light reaching the light output plate 2 in the vicinity of the point light source 3 is suppressed. And since light can be guide | induced to the position far from the point light source 3, a brightness | luminance nonuniformity and a color nonuniformity can be reduced.
[0029]
The rod-shaped optical element 9 refracts or totally reflects light that has reached the vicinity of the center of the hollow region 6 toward the bottom surface portion 1b of the housing 1 by the first inclined surface 9a and the second inclined surface 9c. As a result, in the present embodiment, most of the light that has reached the vicinity of the central portion of the hollow region 6 is emitted near the central portion of the light output plate 2 via the reflection plate 5, and the luminance near the central portion, that is, the point light source 3. The surface light source device with high display quality can be obtained by increasing the luminance at a position far from the center.
[0030]
The light incident from the first inclined surface 9a of the rod-shaped optical element 9 and reaching the opposing surface 9d, or emitted from the right point-like light source 3 in FIG. 2 and incident from the second inclined surface 9c, is opposed to the opposing surface 9d. Most of the light that has reached the surface is totally reflected by the facing surface 9d, so that there is little light emitted from the region of the light exit plate 2 in contact with the facing surface 9d, and a dark part is produced. Since the diffused reflection surface is used, the light that has reached the parallel surface 9b is reflected by changing the propagation direction, and the light that reaches the opposing surface 9d with a total reflection angle of less than or equal to the outgoing angle increases, resulting in less luminance unevenness. Obtainable.
[0031]
Further, since the rod-shaped optical element 9 is in contact with the light output plate 2 and the reflection plate 5, the space between the hollow regions 6 is maintained, and a stable luminance distribution can be obtained.
[0032]
The light incident on the light exit plate 2 is divided into a light component transmitted through the light exit plate 2 and a light component reflected by particles in the light exit plate 2. Among these, the component light reflected to the bottom surface portion 1 b side of the housing 1 is reflected by the reflecting plate 5 and enters the light exiting plate 2 again. Further, the light of the component incident on and transmitted through the light exit plate 2 is radiated in all directions by the diffusion function of the light exit plate 2.
[0033]
The light emitted from the upper surface of the light exit plate 2 passes through optical sheets such as a diffusion sheet, a protective sheet, or a lens sheet and enters the liquid crystal display element. In this liquid crystal display element, the liquid crystal layer is oriented by turning on or off the voltage by the switching element, so that light incident on the liquid crystal display element is modulated in accordance with the video signal and displays each color of red, green, or blue.
[0034]
As described above, according to the planar light source device according to the first embodiment of the present invention, by providing the rod-shaped optical element 9 in the hollow region 6 so as to extend in the arrangement direction of the plurality of point light sources 3, Since the direction of light propagating through the hollow region 6 can be changed to the light output plate 2 side or the reflection plate 3 side, the light reaching the light output plate 2 or the reflection plate 5 near the center of the hollow region 6 is increased. Thus, the luminance near the center can be increased. In addition, since the luminance in the vicinity of the point light source 3 does not become higher than the luminance at a position far from the point light source 3, uneven luminance on the display surface can be suppressed.
[0035]
In addition, since the parallel surface 9b of the rod-shaped optical element 9 is a diffuse reflection surface, the light reaching the parallel surface 9b is reflected by changing the propagation direction, and the light emitted from the opposing surface 9d is increased to increase the luminance. A planar light source device with less unevenness can be obtained.
[0036]
Further, since the rod-shaped optical element 9 is in contact with the light output plate 2 and the reflection plate 5, the space between the hollow regions 6 is maintained, and a stable luminance distribution can be obtained.
[0037]
Embodiment 2
FIG. 5 is a partial cross-sectional view of a planar light source device according to Embodiment 2 of the present invention. In FIG. 5, the casing 1, the light exit plate 2, the plurality of point light sources 3, the point light source substrate 4, the reflection plate 5, the hollow region 6, the reflector 7, and the deflection element 8 are the same as those in the first embodiment. Therefore, the description thereof is omitted.
[0038]
In FIG. 5, the rod-shaped optical element 19 extends in the arrangement direction of the plurality of point light sources 3 at the substantially central portion of the hollow region 6. The rod-like optical element 9 has a symmetric cross-sectional shape, a surface 19b that is substantially parallel to the bottom surface portion 1b of the housing 1, and a surface that is substantially parallel to the parallel surface 19b and that faces the parallel surface 19b. An opposing surface 19d having a smaller area than 19b, a first inclined surface 19a connecting the top surface of the parallel surface 19b and the opposing surface 19d, and a second inclined surface 19c facing the first inclined surface 19a. Have. The rod-shaped optical element 9 is made of a transparent resin such as acrylic or glass and has a function of transmitting light. In FIG. 5, the first inclined surface 19 a is an incident surface with respect to the left point light source 3.
[0039]
The parallel surface 19b is in contact with the reflecting plate 5, and the opposing surface 19d is in contact with the light emitting plate 2. Moreover, this opposing surface 19d is formed in the uneven surface.
[0040]
The second embodiment is different from the first embodiment only in that the opposing surface 19d of the rod-shaped optical element 19 is a concavo-convex surface. The same effects as those of the first mode are obtained.
[0041]
When the opposing surface 19d is a flat surface, most of the light emitted from the point light source 3 and incident from the first inclined surface 19a or the second inclined surface 19c of the rod-like optical element 19 and reaches the opposing surface 19d. Since the light is totally reflected, there is little light emitted from the region of the light exit plate 2 in contact with the opposing surface 19d, and a dark portion is generated. However, in the second embodiment, since the facing surface 19d is an uneven surface, the light emitted from the facing surface 19d increases, and a planar light source device with little luminance unevenness can be obtained.
[0042]
In the first embodiment, as shown in FIG. 2, in order to make the parallel surface 9b a diffuse reflection surface, a white reflective sheet is attached to the parallel surface 9b, or the parallel surface 9b is roughened. It is necessary to process the surface and deposit silver or aluminum. However, in the second embodiment, as shown in FIG. 5, since the opposing surface 19d of the rod-shaped optical element 19 is an uneven surface, it is not necessary to attach the reflective sheet or to deposit silver or the like. Further, the uneven surface of the facing surface 19d can be easily manufactured integrally by injection molding or extrusion molding, and productivity can be improved.
[0043]
In the second embodiment, the opposing surface 19d of the rod-like optical element 19 is an uneven surface. However, in the present invention, the invention is not limited to this. Any of the parallel surface 19b, the first inclined surface 19a, and the second inclined surface 19c constituting the rod-shaped optical element 19 can be obtained by making the light reach below the angle and increasing the emitted light from the facing surface 19d. The light emitted from the facing surface 19d can be increased by making the surface of the surface uneven and disturbing the direction of light.
[0044]
As described above, since at least one of the surfaces constituting the rod-shaped optical element 19 is a concavo-convex surface, light can reach the opposing surface 19d at a total reflection angle or less, and is emitted from the opposing surface 19d. Thus, a planar light source device with less luminance unevenness can be obtained.
[0045]
Embodiment 3
In the first and second embodiments, the point light source substrates on which a plurality of point light sources are mounted are arranged side by side along a pair of side surfaces facing the housing. However, the point light source substrate can be disposed along at least one of the four side surfaces of the housing as long as sufficient luminance is obtained.
[0046]
In the first and second embodiments, the rod-shaped optical element is in contact with the light-emitting plate and supports the light-emitting plate. However, in the present invention, if the light-emitting plate has sufficient strength, the rod-shaped optical element and the light-emitting plate are supported. A space may be provided between In addition, by providing a space, it is possible to easily reduce luminance unevenness due to the boundary between the rod-shaped optical elements.
[0047]
In the first and second embodiments, a square column having a trapezoidal cross section is used as the rod-shaped optical element. However, in the present invention, the hollow region is formed by the rod-shaped optical element in order to increase the luminance near the center. What is necessary is just to change the direction of the light to propagate to the said light-emitting plate side or the said reflecting plate side, and it is not limited to this trapezoid shape.
[0048]
Here, assuming that the upper side of the sheet of FIG. 6 is the light emitting plate side and the lower side is the reflecting plate side, for example, as shown in FIG. 6A, a rod-shaped optical element 29a whose contour on the light emitting plate side is a curved surface. As a result, the contact area with the light-emitting plate is reduced, and uneven brightness at the center can be reduced.
[0049]
In addition, as shown in FIG. 6B, by using a rod-shaped optical element 29b having an inclined surface having a curved surface, the refraction angle can be controlled by the light arrival position, so that more precise luminance unevenness can be controlled. it can.
[0050]
Further, as shown in FIG. 6C, the light reaching the inclined surface of the rod-shaped optical element 29c is obtained by using the rod-shaped optical element 29c having a larger area on the light-emitting plate side than the surface on the reflecting plate side. Since light is totally reflected and reaches the light output plate, light can be efficiently emitted from the vicinity of the central portion.
[0051]
Further, as shown in FIG. 6D, a surface 30b that is substantially parallel to the bottom surface of the housing, a facing surface 30d that is substantially parallel to the parallel surface 30b, and a surface that faces the parallel surface 30b. A first prism array surface 30a having a plurality of grooves connecting the top lines of 30d and extending in the arrangement direction of the point light sources; and a second prism array surface 30c facing the first prism array surface 30a; By using the rod-shaped optical element 29d composed of the rod-shaped optical element 29d, the rod-shaped optical element 29d can be thinned and the weight of the apparatus can be reduced.
[0052]
Also, as shown in FIG. 6 (e), the direction of light propagating through the hollow region is changed by using a rectangular column with a rectangular parallelepiped cross section and using either surface as an uneven surface or a diffuse reflection surface as a bottom surface. By adding the function to make it possible to reduce luminance unevenness at the center. Furthermore, since the rod-shaped optical element 29e can be thinned, the weight of the apparatus can be reduced.
[0053]
Furthermore, in Embodiments 1 and 2, one rod-shaped optical element is provided at the substantially central portion of the hollow region. However, in the present invention, a plurality of rod-shaped optical elements may be provided in the hollow region. In addition, by providing a plurality of rod-shaped optical elements, the luminance distribution can be adjusted more finely.
[0054]
Embodiment 4
In the fourth embodiment, as shown in FIG. 7, elements having the same shape as the deflection element 8 are used as the two rod-shaped optical elements 39. Thereby, in this Embodiment 4, since the kind of optical component reduces, cost reduction can be achieved.
[0055]
In the present invention, the shape of the rod-shaped optical element is appropriately selected according to the directivity of light incident on the rod-shaped optical element, the refraction ratio with the surrounding medium surrounding the rod-shaped optical element, and the shape of the deflection element. Is preferred.
[0056]
In the above embodiments, the planar light source device and the liquid crystal display device using the planar light source device have been described. However, the present invention is not limited to these. For example, the present invention can be applied to a display device such as a signboard or a guide light by using a panel displaying characters and designs instead of the liquid crystal display element described above.
[0057]
【The invention's effect】
As described above, according to the present invention, since the hollow region has the rod-shaped optical element extending in the arrangement direction of the plurality of point light sources, the direction of the light propagating through the hollow region is set to the light output plate side or the reflection. By changing to the plate side, the light reaching the light-emitting plate or the reflecting plate in the vicinity of the central portion of the hollow region can be increased. For this reason, it is possible to increase the luminance in the vicinity of the central portion and to suppress uneven luminance on the display surface.
[Brief description of the drawings]
FIG. 1 is a plan view showing a schematic configuration of a planar light source device according to Embodiment 1 of the present invention.
2 is a cross-sectional view taken along line AA of the planar light source device shown in FIG.
FIG. 3 is an LED array diagram showing an example of an LED array;
FIG. 4 is an LED array diagram showing another example of an LED array;
FIG. 5 is a partial cross-sectional view of a planar light source device according to Embodiment 2 of the present invention.
FIG. 6 is a cross-sectional view of a rod-shaped optical element according to Embodiment 3 of the present invention.
FIG. 7 is a partial cross-sectional view of a planar light source device according to Embodiment 4 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 1a Upper surface part 1b Bottom surface part 1c Side surface part 1d Opening part 2 Light emission plate 3 Point light source 3a 1st point light source 3b 2nd point light source 3c 3rd point light source 4, 4a Point light source board | substrate DESCRIPTION OF SYMBOLS 5 Reflector 5a Regular reflection part 5b Diffuse reflection part 6 Hollow area | region 8 Declination element 8a 1st inclined surface 8b Parallel surface 8c 2nd inclined surface 8d Opposing surfaces 9, 19, 29, 29a,
29b, 29c,
29d, 29e, 39 Bar-shaped optical elements 9a, 19a First inclined surfaces 9b, 19b Parallel surfaces 9c, 19c Second inclined surfaces 9d, 19d Opposing surfaces

Claims (6)

A housing having an opening, a light emitting plate disposed in the opening, a reflecting plate forming a hollow region between the light emitting plate, and at least one side surface of the housing A planar light source device comprising a plurality of point light sources, wherein the hollow region has rod-like optical elements extending in an arrangement direction of the plurality of point light sources. Light source device. The planar light source device according to claim 1, wherein the rod-shaped optical element is in contact with the light output plate. The planar light source device according to claim 1, wherein a bottom surface of the rod-shaped optical element is a diffuse reflection surface. The planar light source device according to claim 1, wherein at least one surface of the rod-shaped optical element is an uneven surface. 5. A planar light source device according to claim 1, and a display means that is arranged on an upper portion of the planar light source device and performs display by light emitted from the planar light source device. Characteristic display device. 6. The display device according to claim 5, wherein the display means is a liquid crystal display element including two substrates sandwiching liquid crystal, and a drive circuit substrate connected to the liquid crystal display element.

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