WO2012053262A1

WO2012053262A1 - Lighting apparatus, and display apparatus provided with same

Info

Publication number: WO2012053262A1
Application number: PCT/JP2011/066325
Authority: WO
Inventors: 進大山
Original assignee: シャープ株式会社
Priority date: 2010-10-19
Filing date: 2011-07-19
Publication date: 2012-04-26

Abstract

Provided is a lighting apparatus, wherein a light guiding plate can be made to be thinner without decreasing the light-entering rate of light radiated from a light source into the light guiding plate. The lighting apparatus (1) is provided with a light source (10), and a light guiding plate (20) for guiding light radiated by the light source (10). At least a portion of a circumferential edge section at the front face (201) side of the light guiding plate (20) is cut towards the rear face (202) side thereof, and a reflection member (30) for mirror-reflecting light is arranged facing the cut face. The light source (10) is arranged at the rear face (202) side of the light guiding plate (20), along the cut portion.

Description

Illumination device and display device including the same

The present invention relates to an illuminating device and a display device, and more particularly to an illuminating device having a light guide plate that guides light emitted from a light source, and a display device including the illuminating device.

For example, a display device such as a liquid crystal display device includes an illumination device that emits light toward the display panel. This type of illuminating device includes a so-called “directly-type” illuminating device in which a light source emits substantially planar light directly under the display panel (back side), and a light source substantially along the side surface of the display panel. It is roughly classified into so-called “edge light type” lighting devices arranged so as to emit linear light.

In recent years, since display devices can be made thinner, display devices using “edge light type” lighting devices are increasing. A general “edge light type” lighting device uses a light guide plate that guides light emitted from a light source disposed along a side surface of the panel. The light guide plate plays a role of diffusing light from the light source and making the luminance distribution of the light irradiated to the display panel uniform.

In such an “edge light type” lighting device, an attempt has been made to make the light guide plate as thin as possible in order to make the lighting device (display device) thinner, cost reduction, and weight reduction. However, when the light guide plate is made thin, there is a problem that the utilization efficiency of light emitted from the light source is lowered. That is, as shown in FIG. 7 (hatching is omitted), in the general “edge light type” lighting device 100, the light source 102 is disposed to face the side surface 1041 of the light guide plate 104, and thus the light guide plate 104 is thin. When the width (area) of the side surface 1041 of the light guide plate 104 is reduced, there is a problem that light that does not enter the light guide plate 104 increases, and the light use efficiency decreases.

For such a problem, it is conceivable to reduce the amount of light that does not enter the light guide plate 104 by bringing the light source 102 close to the side surface 1041 of the light guide plate 104. However, when such a configuration is adopted, there is a risk that the light source 102 and the light guide plate 104 come into contact with each other due to thermal expansion of the light guide plate 104. That is, it is necessary to set a certain clearance in consideration of expansion of the light guide plate 104 between the light source 102 and the side surface 1041 of the light guide plate 104, and there is a limit in bringing both into close proximity.

For example, as described in Patent Document 1, if a concave portion is formed on the side surface of the light guide plate and a light source is disposed in the concave portion, light that does not enter the light guide plate can be reduced. However, in such a configuration, the thickness of the light guide plate capable of forming a recess capable of accommodating the light source is required, which hinders the thinning of the light guide plate.

For this reason, in the conventional “edge light type” lighting device, the light incident rate of the light emitted from the light source to the light guide plate may be significantly reduced. Only the light guide plate could be made thin.

JP 2007-250458 A

In view of the above situation, the problem to be solved by the present invention is an illumination device capable of thinning the light guide plate without reducing the light incident rate of the light emitted from the light source to the light guide plate, and thus Another object of the present invention is to provide a display device including a simple lighting device.

In order to solve the above-mentioned problems, the present invention is an illuminating device including a light source and a light guide plate that guides light emitted from the light source, and at least one of peripheral portions on the front side of the light guide plate. The part is notched toward the back side, and a reflecting member for specularly reflecting light is disposed opposite to the notched surface, and the light source is along the notched part, The gist is that it is arranged on the back side of the light guide plate.

In this case, the notched surface may be an inclined surface inclined at a certain angle.

The light source may be an LED light source. In this case, the LED light sources may be arranged in a plurality of rows in the plane direction of the light guide plate.

Further, the thickness of the light guide plate may be made smaller than the width of the light exit surface of the light source.

In addition, a concave portion that is depressed on the front surface side is formed on the back surface of the light guide plate, and the light source may be disposed in the concave portion.

Further, the reflective member may be a metal layer deposited on the cut surface.

Further, it is only necessary that the housing further includes a housing member that houses the light guide plate and the light source, and the LED light source is attached to the inner bottom surface of the housing member via a heat dissipation member.

On the other hand, the gist of the display device according to the present invention is that it includes any one of the illumination devices described above and a display panel disposed on the front side of the illumination device.

In the illumination device according to the present invention and the display device including the illumination device, at least a part of the peripheral edge portion of the front surface of the light guide plate is cut out toward the back surface, and the reflection member is disposed so as to face the cut surface. Is done. The light source is disposed on the back side of the light guide plate (periphery of the back surface of the light guide plate) along the cut-out portion, that is, the portion where the reflection member is disposed. That is, the light emitted from the light source enters the light guide plate from the peripheral edge of the back surface of the light guide plate and is reflected by the reflecting member to guide the light guide plate toward the center of the light guide plate. Thus, since the light emitted from the light source enters from the back side of the light guide plate, the light incident rate to the light guide plate does not decrease even if the light guide plate is thinned.

If the notched portion is an inclined surface inclined at a certain angle, not only the light guide plate (notch) can be easily formed, but also the light reflected by the reflecting member can be efficiently reflected. Guided to the center.

In the present invention, when the light source is an LED light source, the LED light sources can be arranged in a plurality of rows in the planar direction of the light guide plate. In other words, in the case of the conventional edge light type “illumination device”, the light incident surface is the side surface of the light guide plate having a narrow width. On the other hand, since the present invention is configured to allow light to enter the light guide plate from the peripheral portion on the back surface of the light guide plate, there is no possibility that the light input rate is lowered even if the LED light sources are arranged in a plurality of rows.

In the present invention, since the light emitted from the light source enters from the back side of the light guide plate, the thickness of the light guide plate can be made smaller than the width of the light emission surface of the light source.

In addition, if a concave portion is formed on the back surface of the light guide plate and a light source is arranged in the concave portion, the amount of light that leaks outside without entering the light guide plate out of the light emitted from the LED light source. Can be reduced. That is, the light use efficiency is improved. Further, since the light source is arranged so as to overlap the light guide plate in the thickness direction of the light guide plate, the lighting device can be made thinner.

Moreover, if the metal layer deposited on the cut-out surface of the light guide plate is used as the reflection member, there is no gap between the cut-out surface and the reflection member. Therefore, the light is efficiently directed toward the center of the light guide plate. Can be reflected. In addition, the reflective member can be easily formed.

Further, if the light source is attached to the inner bottom surface of the housing member via the heat radiating member, the heat generated from the light source is released to the outside mainly from the back surface of the housing member through the heat radiating member. That is, the heat dissipation efficiency of the heat generated from the light source is excellent.

Further, if the lighting device is applied to a display device having a display panel, the display device can be thinned, reduced in cost, and reduced in weight.

It is a disassembled perspective view of the illuminating device concerning one Embodiment of this invention. It is sectional drawing of the illuminating device shown in FIG. 1 (the angle of an inclined surface is 45 degree | times). It is sectional drawing of the illuminating device shown in FIG. 1, Comprising: It is sectional drawing in case the angle which the back surface and inclined surface of a light-guide plate make is 45 degree | times or more. It is sectional drawing of the illuminating device concerning a 1st modification. It is sectional drawing of the illuminating device concerning a 2nd modification. It is a disassembled perspective view of the display apparatus concerning one Embodiment of this invention. It is sectional drawing of the conventional "edge light type" illuminating device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a lighting device 1 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the lighting device 1. Unless otherwise specified, the front side (upward direction) in the following description means the upper side in FIG. 2 (FIGS. 3 to 5), and the back side (downward direction) means FIG. 2 (FIGS. 3 to 5). The lower side in 5). In order to make the figure easy to understand, hatching is omitted in each of the cross-sectional views (FIGS. 2 to 5).

The lighting device 1 according to the present embodiment is an LED backlight using an LED (light emitting diode) as a light source. The lighting device 1 includes an LED light source 10, a light guide plate 20, a reflection member 30, an optical sheet such as a reflection sheet 32, and a frame 42 and a chassis plate 44 that are accommodation members 40 that accommodate these.

The LED light source 10 is disposed on the back side of the light guide plate. Specifically, the LED light source 10 faces the peripheral edge of the back surface 202 of the light guide plate 20 along the longitudinal direction of the light guide plate 20 (in other words, the light emission direction of the LED light source 10 is the light guide plate). 20 facing the back 202). Note that the “peripheral portion” in the light guide plate 20 refers to a range of a predetermined width from the edge of the light guide plate 20 where an inclined surface 22 described later is formed (notched).

When the lighting device 1 according to the present embodiment is compared with a general “edge light type” lighting device, the light source is arranged approximately along the periphery of the light guide plate as viewed in the entire device (so-called “ This is the same in that a planar light source opposed to the entire back surface of the light guide plate is not provided as in the “direct-type” lighting device. However, in a general “edge light type” lighting device, the light source is arranged so that the light emission direction faces the “side surface” of the light guide plate (the light source and the side surface of the light guide plate face each other). On the other hand, in the illuminating device 1 concerning this embodiment, both differ by the point from which the LED light source 10 is arrange | positioned so that the output direction of light may face the "back surface" 202 of the light-guide plate 20. FIG.

The LED light source 10 is mounted on the LED substrate 12 and attached to the chassis plate 44 with the heat dissipation member 14 interposed between the LED substrate 12 and the inner bottom surface of the chassis plate 44. The heat radiating member 14 is not particularly limited as long as it is formed of a material having excellent thermal conductivity. It is preferable to use a heat dissipation sheet in which an adhesive layer is formed on a member having excellent thermal conductivity because the LED light source 10 can be easily attached. *

The LED light source 10 is a so-called white LED that emits white light. Although various things are known as white LED, white LED applicable to this embodiment is not limited to a specific thing. For example, a white LED formed by sealing an LED chip that emits blue light with a transparent resin mixed with a yellow phosphor can be used.

The light guide plate 20 is a plate-shaped (substantially rectangular shape in plan view) formed of, for example, acrylic resin. As shown in FIG. 2, at least a part of the peripheral portion on the front surface 201 side in the circumferential direction of the light guide plate 20 is notched at a certain angle (details will be described later) toward the back surface 202 side of the light guide plate 20. It is. In the present embodiment, since the LED light source 10 is disposed along the longitudinal direction of the light guide plate 20, the peripheral edge portion along the longitudinal direction of the front surface 201 of the light guide plate 20 is notched.

Further, a reflecting member 30 is provided so as to face the cut-out surface (hereinafter referred to as an inclined surface 22) of the light guide plate 20. The reflecting member 30 has a mirror surface on the side facing the inclined surface 22, and plays a role of reflecting the light that is about to escape from the inclined surface 22 to the inside of the light guide plate 20. The reflecting member 30 may be a sheet-like member whose surface facing the inclined surface 22 is a mirror surface, or a reflecting member formed of a metal layer formed by depositing metal (for example, aluminum or silver) on the inclined surface 22. 30 may be configured. In addition, another configuration may be adopted as long as the light that is about to escape from the inclined surface 22 is specularly reflected.

On the back surface 202 of the light guide plate 20 on which such an inclined surface 22 is formed, a reflection pattern 24 is formed to diffuse and diffuse the light incident on the light guide plate 20. The reflective pattern 24 is formed by printing white ink containing, for example, titanium dioxide by an inkjet method. On the other hand, the surface of the light guide plate 20 opposite to the back surface 202 on which the reflection pattern 24 is formed, that is, the front surface 201 of the light guide plate 20 is a light emitting surface from which light uniformized in the plane direction by the reflection pattern 24 and the like is emitted. It has become. When the illuminating device 1 is used for a liquid crystal display device, the light emitted from the light emitting surface is irradiated from the back side (array substrate side) of the liquid crystal display panel.

The reflection sheet 32 is an optical sheet laid under the light guide plate 20. The reflection sheet 32 efficiently reflects the light emitted from the LED light source 10 toward the front surface 201 side of the light guide plate 20. That is, the light reflected by the reflection sheet 32 is spread in a planar shape by the light guide plate 20 and emitted upward from the light emission surface. The LED light source 10 mounted on the LED substrate 12 is disposed outside the reflection sheet 32.

Also, the number and type of the optical sheets 34 arranged on the light guide plate 20 can be appropriately changed according to the characteristics of the lighting device 1 (display device using the lighting device 1). For example, a diffusion sheet that further uniformizes the luminance in the surface direction of the light emitted from the light emitting surface of the light guide plate 20 is used. The light guide plate 20 and the optical sheet such as the reflection sheet 32 can improve the luminance of light emitted from the lighting device 1 and make the luminance uniform in the surface direction.

The housing member 40 that houses these members includes a frame 42 and a chassis plate 44. The frame 42 is a substantially rectangular frame. A cross section of each side constituting the frame is formed in a substantially L shape. The frame 42 is for holding the light guide plate 20 and various optical sheets laminated on the chassis plate 44 in the chassis plate 44. That is, the light guide plate 20 and the various optical sheets are disposed in a space formed by the frame 42 and the chassis plate 44.

The chassis plate 44 is a member formed in a shallow box shape made of, for example, aluminum or an aluminum alloy. As described above, the LED light source 10 mounted on the LED substrate 12 is attached to the inner bottom surface of the chassis plate 44 with the heat dissipation member 14 interposed therebetween. Specifically, a groove is formed on the inner bottom surface of the chassis plate 44 along both sides in the longitudinal direction, and the LED light source 10 is attached in the groove. The mounting structure of the LED light source 10 is an example, and the mounting structure of the LED light source 10 is applicable as long as the LED light source 10 is arranged so as to face the peripheral portion of the back surface 202 of the light guide plate 20. Can be appropriately changed. A reflective sheet 32 is laid on the inner bottom surface of the chassis plate 44 inside the LED light source 10, and the light guide plate 20 is placed on the reflective sheet 32.

The lighting device 1 having such a configuration operates as follows. A control means (control board) (not shown) supplies power to the LED light source 10 via the LED board 12. As a result, the LED light source 10 is turned on and emits light toward the peripheral edge of the back surface 202 of the light guide plate 20. The emitted light enters the light guide plate 20 (the periphery of the light guide plate 20). As described above, the inclined surface 22 is formed on the peripheral portion of the light guide plate 20, and the reflecting member 30 is disposed so as to face the inclined surface 22, so that the incident light is specularly reflected by the reflecting member 30. And guided toward the center of the light guide plate 20. The light guided in the central direction of the light guide plate 20 in this way is diffused by the reflection pattern 24 formed on the back surface 202 of the light guide plate 20, the reflection sheet 32, and the like, and becomes light in a planar form. The light is emitted from the emission surface.

As described above, in the present embodiment, the light emitted from the LED light source 10 is specularly reflected by the reflecting member 30 and guided toward the center of the light guide plate 20. That is, the angle of the inclined surface 22 (the width of the peripheral edge of the light guide plate 20) is set to a shape such that the reflected light reflected by the reflecting member 30 is reliably guided to the center of the light guide plate 20. For example, if the reflected light reflected by the reflecting member 30 returns in the direction of the LED light source 10 and interferes with the light emitted from the LED light source 10 or leaks from the gap between the LED light source 10 and the reflecting sheet 32, Since utilization efficiency falls, it is not preferable.

Therefore, the angle of the inclined surface 22 is preferably set so that the traveling direction of the reflected light reflected by the reflecting member 30 faces the front surface 201 side of the light guide plate 20 rather than the planar direction (horizontal direction) of the light guide plate 20. Specifically, the angle formed between the back surface 202 of the light guide plate 20 and the inclined surface 22 is desirably 45 degrees or more. The light emitted from the LED light source 10 is an ideal linear light, and the reflection of the light by the reflecting member 30 is an ideal specular reflection (the reflection law that the incident angle and the reflection angle are equal holds). Assuming that the angle θ1 formed by the back surface 202 of the light guide plate 20 and the inclined surface 22 is 45 degrees as shown in FIG. 2, the traveling direction of the reflected light is the plane direction (horizontal direction) of the light guide plate 20, and FIG. 3, when the angle θ <b> 2 formed by the back surface 202 of the light guide plate 20 and the inclined surface 22 is 45 degrees or more, the traveling direction of the reflected light is greater than the planar direction (horizontal direction) of the light guide plate 20. This is because it is on the front surface 201 side (since most of the reflected light travels toward the front surface 201 side of the light guide plate 20 rather than the planar direction (horizontal direction) of the light guide plate 20).

By reducing the reflected light returning to the back surface 202 side of the light guide plate 20 in this way, light that interferes with the light emitted from the LED light source 10 or leaks from the gap between the LED light source 10 and the reflective sheet 32 is reduced. Therefore, the light utilization efficiency is improved.

According to the illuminating device 1 concerning this embodiment demonstrated above, there exist the following effects.

In the illuminating device 1 according to the present invention, the light emitted from the LED light source 10 enters the light guide plate 20 from the peripheral edge of the back surface 202 of the light guide plate 20 and is disposed so as to face the inclined surface 22. By being reflected by 30, the inside of the light guide plate 20 is guided toward the center of the light guide plate 20. Thus, since the light emitted from the LED light source 10 enters from the back surface 202 side of the light guide plate 20, even if the light guide plate 20 is thinned, the light incident rate to the light guide plate 20 does not decrease. .

In addition, since the LED light source 10 is configured to face the back surface 202 of the light guide plate 20, the conventional “edge light type” lighting device in which the light source is arranged to face the side surface of the light guide plate 20, There is also an advantage that the light source can be arranged close to the light guide plate 20. That is, the light guide plate 20 having a flat plate shape is longer than the length extending in the thickness direction in the plane direction due to thermal expansion, and thus the present embodiment is arranged to face the back surface 202 of the light guide plate 20. The lighting device 1 can bring the light source closer to the light guide plate 20. Therefore, the light emitted from the light source can surely enter the light guide plate 20.

Further, if the reflecting member 30 is formed of a metal layer formed by depositing metal on the inclined surface 22 of the light guide plate 20, there is no gap between the inclined surface 22 and the reflecting member 30, so that the center of the light guide plate 20 can be efficiently obtained. The light can be reflected toward the. In addition, the reflective member 30 can be easily formed.

In addition, since the LED light source 10 is attached to the inner bottom surface of the chassis plate 44 that is the housing member 40 via the heat radiating member 14, the heat generated from the LED light source 10 is mainly transmitted through the heat radiating member 14 to the chassis plate 44. It is discharged to the outside from the back. Therefore, the heat dissipation efficiency of the heat generated from the LED light source 10 is excellent. In addition, it is easy to provide a heat dissipation mechanism such as fins on the rear surface of the chassis plate as compared with a conventional “edge light type” lighting device.

Next, the present invention will be described using a modification of the lighting device 1. In the following description of the modified examples, the same reference numerals are given to the same components as those of the illumination device 1 according to the above embodiment, and the description thereof is omitted.

The lighting device 1a according to the first modified example shown in FIG. 4 includes LED light sources 10 arranged in two rows in the plane direction of the light guide plate 20. In the present invention, as in the first modification, the LED light sources 10 may be arranged in a plurality of rows in the planar direction of the light guide plate 20. That is, as in the conventional “edge light type” lighting device, the light incident surface is not the side surface of the light guide plate 20 that is narrow, but the light incident surface is the back surface 202 of the light guide plate 20. Even if the LED light sources 10 are arranged in a plurality of rows, the light incident efficiency is not significantly reduced. Thus, in this invention, since the LED light source 10 can be arrange | positioned in multiple rows, the width | variety of an illuminating device design spreads. For example, it is easy to simply increase the number of LED light sources 10 to increase the amount of light (improve the brightness).

From another point of view, according to the present invention, the light incident efficiency into the light guide plate 20 does not decrease even if the width of the light emission surface of the LED light source 10 is increased. Therefore, the thickness of the light guide plate can be made smaller than the width of the light emission surface of the LED light source 10. If the LED light source 10 shown in FIG. 2 or FIG. 3 has a single row, the width of the light emission surface is the width X1 (see FIG. 2) of the light emission surface of one LED light source 10. If the LED light source 10 shown in FIG. 4 is configured in a plurality of rows, the side edge of the LED light source 10 arranged on the side from the center edge of the LED light source 10 arranged on the side is located. This is the distance X2 to the part.

FIG. 5 shows an illumination device 1b according to a second modification. In the illumination device 1b according to the second modification, a recessed portion 26 that is recessed toward the front surface 201 is formed on the back surface 202 of the light guide plate 20, and the LED light source 10 is disposed in the recessed portion 26. As described above, if the LED light source 10 is disposed in the recess 26 of the light guide plate 20, the LED light source 10 is surrounded by the light guide plate 20, so that light out of the light emitted from the LED light source 10 is guided. The amount of light that does not reach the optical plate 20 and leaks to the outside can be reduced, and the light utilization efficiency is improved.

Further, when the LED light source 10 is disposed in the concave portion 26 of the light guide plate 20, the LED light source 10 overlaps the light guide plate 20 in the thickness direction of the light guide plate 20, which contributes to thinning of the lighting device. Specifically, if the size of the concave portion 26 is made larger than that of the LED light source 10 and the LED light source 10 is completely accommodated in the concave portion 26, the accommodating space in which the light guide plate 20 can be accommodated in the chassis plate 44. Since the LED light source 10 can be accommodated together with the light guide plate 20, the lighting device can be made thinner. As in the configuration shown in FIG. 5, depending on the design, the LED light source 10 is housed in the concave portion 26 of the light guide plate 20, so that it is not necessary to form a groove for housing the LED light source 10 in the chassis plate 44. , Leading to thinner lighting devices and reduced manufacturing costs.

Next, the display device 2 according to an embodiment of the present invention will be described. The display device 2 according to the present embodiment described below is a liquid crystal display device in which a liquid crystal display panel is used as the display panel 50.

The display device 2 shown in FIG. 6 includes the illumination device 1 (the

illumination devices

1a and 1b according to the first and second modifications are also applicable) and the display panel 50. The display panel 50 includes a thin film transistor (TFT) array substrate 52 (hereinafter simply referred to as an array substrate 52) and a color filter (CF) substrate 54, and is fixed by a bezel 60 having a frame shape. The array substrate 52 and the color filter substrate 54 face each other with a predetermined cell gap, and a liquid crystal is filled between the substrates.

The array substrate 52 is obtained by forming TFTs and pixel electrodes in a matrix on a glass substrate. Around these TFTs and pixel electrodes, gate signal lines and source signal lines are formed in a lattice pattern. Among these, the pixel electrode is electrically connected to the drain electrode of the TFT, the source signal line is electrically connected to the source electrode of the TFT, and the gate signal line is electrically connected to the gate electrode of the TFT. Note that a substrate (source substrate or the like) or a driver IC (source driver or the like) for driving the panel is usually attached to the display panel 50, but is omitted in FIG.

The color filter substrate 54 is formed by forming a plurality of color filters in a matrix on a glass substrate having the same size as the array substrate 52 and forming a transparent common electrode on almost the entire surface of the substrate. The orientation of the liquid crystal filled between the two substrates is controlled by changing the voltage applied between the pixel electrode and the common electrode.

The lighting device 1 is arranged on the back side of the display panel 50 having such a configuration. Of the light emitted from the illumination device 1 toward the display panel 50, the light that has passed through the liquid crystal layer in the display panel 50 and the color filter of the color filter substrate 54 is visually recognized as a color image.

According to the display device 2 according to the present embodiment having such a configuration, the same operational effects as those of the lighting device 1 can be obtained.

Although the liquid crystal display device has been described as an example of the display device 2 according to the embodiment of the present invention, the present invention is not limited to this. The display device other than the liquid crystal display device is also included in the present invention as long as the illumination device 1 that emits light toward the display panel 50 is used.

The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, although it has been described that the light source used in the illumination device 1 and the display device 2 is the LED light source 10, other light sources such as a cold cathode tube can also be applied.

Claims

An illumination device comprising a light source and a light guide plate that guides light emitted from the light source,
At least a part of the peripheral portion on the front side of the light guide plate is cut out toward the back side thereof, and a reflecting member that mirror-reflects light is arranged facing the cut-out surface,
The light source is disposed on the back side of the light guide plate along the cut-out portion.
The lighting device according to claim 1, wherein the cut-out surface is an inclined surface inclined at a constant angle.
The lighting device according to claim 1 or 2, wherein the light source is an LED light source.
The lighting device according to any one of claims 3 to 4, wherein the LED light sources are arranged in a plurality of rows in a planar direction of the light guide plate.
The lighting device according to any one of claims 1 to 4, wherein a thickness of the light guide plate is smaller than a width of a light emission surface of the light source.
6. The recess according to claim 1, wherein a recess recessed on the front side is formed on a rear surface of the light guide plate, and the light source is disposed in the recess. Lighting device.
The lighting device according to any one of claims 1 to 6, wherein the reflecting member is a metal layer deposited on the cut-out surface.
A housing member for housing the light guide plate and the light source;
The lighting device according to any one of claims 3 to 7, wherein the LED light source is attached to an inner bottom surface of the housing member via a heat dissipation member.
A display device comprising: the lighting device according to any one of claims 1 to 8; and a display panel disposed on a front side of the lighting device.