JP2011103236A - Lighting system and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of preventing a situation that a difference of luminance between a central part and both ends of a light out-going surface becomes extremely large. <P>SOLUTION: The lighting system includes: a plurality of LED light sources 33; and a light guide plate 18 having a light-incident surface 18e, on which the light from the plurality of LED light sources 33 is incident, and a light out-going surface 18a, from which the light goes out and which is formed into a rectangular shape in plan view. The light guide plate 18 is structured so that, when the light of the same luminance in the whole range in one side direction of the light out-going surface 18a is made to enter the light-incident surface 18e, the luminance of the light going out from both end sides in the one side direction of the light out-going surface 18a is lower than the luminance of the light going out from a central side in the one side direction of the light out-going surface 18a. The plurality of LED light sources 33 are arranged along the one side direction of the light out-going surface 18a so that the luminance of the LED light sources 33 arranged in both end sides in the one side direction of the light out-going surface 18a is higher than the luminance of the LED light sources 33 arranged in the central side in the one side direction of the light out-going surface 18a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lighting device and a display device.

  In recent years, thin display elements such as liquid crystal panels and plasma display panels have been used as display elements of image display devices, which enables thinning of image display devices. When a liquid crystal panel is used as the display element, the liquid crystal panel does not emit light, and thus a backlight device is separately required as a lighting device.

  As an example of the backlight device, one described in Patent Document 1 below is known. The backlight device includes a plurality of LEDs (light sources) arranged on a side end (side edge) of the backlight device and a light guide plate that emits light from the LEDs toward a display surface of the liquid crystal panel. Prepare. More specifically, the plurality of LEDs are arranged so as to face the light incident surface of the light guide plate, and light incident from the light incident surface is guided by repeating total reflection in the light guide plate. The light is emitted from the entire emission surface.

JP 2001-92370 A

  In the liquid crystal display device described above, there is a case where the luminance of the peripheral portion of the display surface is made lower than the luminance of the central portion for the purpose of improving visibility. In order to obtain such a configuration, the luminance of the peripheral portion may be made lower than the luminance of the central portion on the light emitting surface of the light guide plate. The luminance distribution of the light exit surface is mainly determined by the characteristics of the light guide plate and each brightness of the plurality of light sources. At the design stage, it is assumed that the brightness of the plurality of light sources is all the same, The light guide plate is designed so that the luminance at the peripheral portion is lower than the luminance at the central portion.

  By the way, light sources such as LEDs are ranked according to differences in luminance, for example, and it is common to purchase LEDs having a desired rank when manufacturing a lighting device. At the time of purchase, it is easier to reduce the purchase cost if the LEDs of a plurality of ranks are purchased together rather than purchasing only the LEDs of the same rank (that is, the same luminance). For these reasons, there are cases in which LEDs of different ranks are mixedly used in the lighting device while being within the required luminance range. For this reason, for example, when a low-luminance LED is arranged at a position corresponding to the end of the light emitting surface among the plurality of LEDs, the luminance on the end side is combined with the characteristics of the light guide plate described above. However, the luminance is extremely lower than the luminance at the center, which may cause luminance unevenness.

  The present invention has been completed on the basis of the above situation, and the difference in luminance between the central portion and both end portions on the light exit surface becomes extremely large while using light sources having different luminances. It is an object of the present invention to provide a lighting device that can be suppressed and a display device using such a lighting device.

  The present invention includes a light guide plate having a plurality of light sources, a light incident surface on which light from the plurality of light sources is incident, and a light emitting surface for emitting the light, wherein the light emitting surface has a rectangular shape in plan view. The light guide plate is emitted from both end sides in the one side direction of the light emitting surface when light having the same luminance is incident on the light incident surface in the entire range of one side direction of the light emitting surface. And the light sources are arranged along the one side direction of the light emitting surface. And the luminance of the light source arranged on both ends in the one side direction of the light emitting surface is arranged to be higher than the luminance of the light source arranged on the center side in the one side direction of the light emitting surface. It has the characteristics in that.

  In the present invention, the light guide plate is configured such that when light having the same luminance is incident on the light incident surface in the entire range in one side direction, the luminance of the light emitted from both ends in the one side direction of the light emitting surface is It is set as the structure which becomes lower than the brightness | luminance of the light radiate | emitted from the center side in one side direction. On the other hand, the plurality of light sources are arranged in such a manner that the luminance of the light sources arranged on both ends in the one side direction of the light emitting surface is higher than the luminance of the light sources arranged on the central side in the one side direction of the light emitting surface. Yes. Accordingly, it is possible to suppress a situation in which an extreme difference occurs in the luminance of the emitted light between the central side in one side direction of the light emitting surface and both end sides thereof, while using light sources having different luminances. Although the light emission surface is rectangular in plan view, the “rectangular shape” includes a square.

  In the above configuration, in the light guide plate, a light reflecting portion that scatters and reflects light is formed on a surface opposite to the light emitting surface, and the light reflecting portions on both ends in the one side direction of the light emitting surface. Is set lower than the density distribution of the light reflecting portion on the center side in the one side direction of the light emitting surface.

  With such a configuration, on the surface opposite to the light emission surface, the side corresponding to both end sides in the one side direction of the light emission surface has a lower function of scattering and reflecting light than the center side. If the function of scattering and reflecting light is reduced, the proportion of light that is totally reflected by the light exit surface (light that is not emitted) increases, and the amount of emitted light is relatively reduced. As a result, it is possible to reduce the luminance on both ends in the direction of one side of the light exit surface compared to the luminance on the center side.

  Moreover, the said light reflection part shall be comprised by a dot pattern. In this way, it is possible to easily control the density distribution of the light reflecting portion by setting the mode (area, arrangement interval, etc.) of each dot.

  A surface opposite to the light emitting surface may be covered with a reflecting member that reflects light from the plurality of light sources toward the light emitting surface. With such a configuration, the light emitted from the light guide plate to the reflecting member side can be reflected again to the light emitting surface side, and the light utilization efficiency can be increased.

  Next, in order to solve the above-described problem, a display device of the present invention includes the above-described illumination device and a display panel that performs display using light from the illumination device.

  The display panel can be exemplified by a liquid crystal panel. Such a display device can be applied as a liquid crystal display device to various uses, for example, a display screen of a car navigation system.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the illuminating device which can suppress the situation where the difference in the brightness | luminance of the center part and both ends in a light-projection surface becomes extremely large, and a display apparatus using such an illuminating device. It becomes.

1 is an exploded perspective view showing a schematic configuration of a liquid crystal display device according to an embodiment of the present invention. Sectional drawing which shows the cross-sectional structure along the short side direction of the liquid crystal display device of FIG. Sectional drawing which shows the cross-sectional structure along the long side direction of the liquid crystal display device of FIG. The top view which shows the structure of a light-guide plate and an LED light source. The perspective view which shows a LED light source. The top view which shows the surface on the opposite side to the light-projection surface of a light-guide plate. Schematic which shows the relationship between the arrangement | sequence of the LED light source which concerns on this embodiment, and the luminance distribution in a light-projection surface. Schematic which shows the relationship between the arrangement | sequence of the LED light source in a comparative example, and the luminance distribution in a light-projection surface.

  The configuration of the liquid crystal display device 10 according to the embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device 10 of the present embodiment is used for, for example, a car navigation device, a portable terminal, a television receiver, and the like. The long side direction of the liquid crystal display device 10 (and the chassis 14) is the X-axis direction, the short side direction is the Y-axis direction, and the vertical direction in FIGS. 2 and 3 is the Z-axis direction (front and back direction).

  As shown in FIG. 1, the liquid crystal display device 10 (display device) according to the present embodiment has a horizontally long rectangular shape (rectangular shape) as a whole. For example, in a state where the short side direction matches the vertical direction. Installed. The liquid crystal display device 10 includes a liquid crystal panel 11 (display panel) and a backlight device 12 (illumination device) that is an external light source, and these are integrally held by a frame-like bezel 13 or the like. Yes.

  Next, the liquid crystal panel 11 and the backlight device 12 constituting the liquid crystal display device 10 will be described. The liquid crystal panel 11 is configured such that a pair of glass substrates are bonded together with a predetermined gap therebetween, and a liquid crystal layer is sandwiched between both glass substrates. One glass substrate is provided with a switching element (for example, TFT) connected to a source wiring and a gate wiring orthogonal to each other, a pixel electrode connected to the switching element, an alignment film, and the like. The substrate is provided with a color filter and counter electrodes in which colored portions such as R (red), G (green), and B (blue) are arranged in a predetermined arrangement, and an alignment film. In addition, polarizing plates 11a and 11b are disposed outside both substrates (see FIGS. 2 and 3).

  As shown in FIG. 2, the backlight device 12 includes a substantially box-shaped chassis 14 opened on the light emitting surface side (the liquid crystal panel 11 side), and an optical member 15 attached so as to cover the opening of the chassis 14. A frame 16 that is disposed along the long side of the chassis 14 and holds the long side edge of the optical member 15 between the frame 14 and the chassis 14. In the chassis 14, an LED substrate 17 that emits light, a light guide plate 18 that guides light generated from the LED substrate 17 to the liquid crystal panel 11 side, and a holder 20 on which an edge of the optical member 15 is placed are disposed. Has been. In other words, in the present embodiment, the backlight device 12 employs an edge light system in which the light source is arranged on the edge of the chassis 14.

  The chassis 14 is made of, for example, iron and is formed of a rectangular bottom plate 14a and a shallow outer edge portion 21 (short side outer edge portion 21a and long side outer edge portion 21b) that rises from each side and is folded back into a substantially U shape. Sheet metal is formed into a substantially box shape. As shown in FIG. 3, a fixing hole 14c is formed in the upper surface of the long-side outer edge portion 21b of the chassis 14, and the bezel 13, the frame 16, the chassis 14 and the like can be integrated with, for example, screws. It is possible. In the present embodiment, the chassis 14 is made of iron in order to ensure rigidity. However, for example, when higher thermal conductivity is required, the chassis 14 may be made of a metal such as an aluminum-based material.

  An optical member 15 including a diffusion plate 15a and an optical sheet 15b is disposed on the opening side of the chassis 14. The diffusing plate 15a has a function of diffusing light emitted from the LED substrate 17 and guided by the light guide plate 18 by dispersing and blending light scattering particles in a synthetic resin plate-like member. The short side edge of the diffusion plate 15a is placed on the holder 20 and is not subjected to vertical restraining force (see FIG. 3). On the other hand, the long side edge of the diffusion plate 15a is sandwiched between the chassis 14 and the frame 16 as shown in FIG.

  The optical sheet 15b disposed on the diffusion plate 15a is a laminate of a diffusion sheet, a lens sheet, and a reflective polarizing plate in order from the diffusion plate 15a side, and is emitted from the LED substrate 17 and passes through the diffusion plate 15a. It has a function to make the light into a planar light. The liquid crystal panel 11 is installed on the upper surface side of the optical sheet 15 b, and the optical sheet 15 b is sandwiched between the diffusion plate 15 a and the liquid crystal panel 11.

  As shown in FIG. 5, the LED substrate 17 has three LED chips 32 that emit R (red), G (green), and B (blue) in a single color on a substrate portion 31 that has a resin plate shape. The LED light sources 33 (light sources) thus arranged are arranged in a line. The LED substrate 17 is attached to the long side outer edge portion 21b of the chassis 14 by, for example, screwing. Further, a power supply circuit board 22 that generates electric power for driving the LED board 17 and a control circuit board 23 that controls the driving of the LED board 17 are attached to the bottom plate 14a of the chassis 14 on the center side. ing.

  The light guide plate 18 is a rectangular plate-like member, and is formed of a resin having high translucency (high transparency) such as acrylic. As shown in FIG. 2, the light guide plate 18 is arranged in such a manner that the main plate surface (light emitting surface 18 a) faces the diffusion plate 15 a side and one of the side plate surfaces (light incident surface 18 e) faces each LED light source 33. Has been. In other words, the light emitting surface 18a of the light guide plate 18 has a rectangular shape in plan view, and each LED light source 33 is arranged along the long side direction (one side direction) of the light emitting surface 18a.

  The light generated from the LED light source 33 enters from the light incident surface 18e of the light guide plate 18, is guided in the light guide plate 18 by total reflection, and is emitted from the entire surface of the light emitting surface 18a facing the diffusion plate 15a. And the emitted light from the light emission surface 18a is irradiated to the back side of the liquid crystal panel 11. Further, a light reflection sheet 19 (reflection member) is laid on the bottom plate 14 a of the chassis 14. The light reflecting sheet 19 is arranged so as to cover the surface 18d on the back side of the light guide plate 18 (surface opposite to the light emitting surface 18a). By this light reflecting sheet 19, the light emitted from the light guide plate 18 to the light reflecting sheet 19 side can be reflected again to the light emitting surface 18a side, and the light utilization efficiency can be increased.

  On the back surface 18d of the light guide plate 18 (the surface opposite to the light emitting surface 18a), as shown in FIG. 3, a light reflecting portion 27 formed of a white dot pattern is formed. The light reflecting portion 27 has a function of scattering and reflecting light. Therefore, the light that is scattered and reflected by the light reflecting portion 27 and travels toward the light exit surface 18a generates light whose incident angle with respect to the light exit surface 18a does not exceed the critical angle (light that is not totally reflected), and thus emits the light. The light can be emitted from the surface 18a to the liquid crystal panel 11 side.

  As shown in FIG. 6, the light reflecting portion 27 is configured by arranging a plurality of dots 27 a having a round shape in a plan view, for example, in a zigzag shape (staggered shape, staggered shape). Each dot 27a is formed, for example, by printing a paste containing a metal oxide on the back surface 18d of each light guide plate 18. As the printing means, screen printing, ink jet printing and the like are suitable.

  In the light guide plate 18 of the present embodiment, by changing the density distribution of the light reflecting portion 27 on the back surface 18d, the light emission amount (and thus the luminance distribution) from the light emission surface 18a is changed to the light emission surface 18a. It is configured to change in the plane. Specifically, if light of the same luminance is incident on the light incident surface 18e in the entire range in the long side direction (one side direction) of the light emitting surface 18a, the peripheral portion (in other words, the long side of the light emitting surface 18a) The brightness of light emitted from both ends in the side direction or the short side direction is lower than the brightness of light emitted from the center side of the light exit surface 18a (in other words, the center part in the long side direction or the short side direction). It is set as the composition. This is to improve the visibility of the liquid crystal display device 10 in consideration of human visual characteristics.

  More specifically, on the back surface 18d, the density distribution of the light reflecting portion 27 in the long side direction of the light emitting surface 18a is the density distribution of the central light reflecting portion 27 in the long side direction of the light emitting surface 18a. Is set lower. As a result, the side corresponding to the both end sides in the long side direction of the light emitting surface 18a has a lower function of scattering and reflecting light than the center side. If the function of scattering and reflecting light is reduced, the proportion of light totally reflected by the light emitting surface 18a increases, and the amount of light emitted is relatively reduced. As a result, it is possible to reduce the luminance at both ends in the long side direction of the light exit surface 18a compared to the luminance at the center. The density distribution of the light reflecting portion 27 can be set by appropriately setting the area or arrangement interval of the dots 27a constituting the light reflecting portion 27.

  As described above, the light guide plate 18 according to the present embodiment has a predetermined luminance distribution (from the central portion) when light having the same luminance is incident on the entire long side direction (one side direction) of the light emitting surface 18a. The distribution is such that the luminance of the peripheral portion is reduced). In other words, the light guide plate 18 is designed on the assumption that all the LED light sources 33 have the same luminance. However, if it is actually desired to secure only a predetermined number of LED light sources 33 having the same luminance, a predetermined number or more of LED light sources 33 must be produced in consideration of manufacturing errors and the like, leading to an increase in cost.

  Therefore, in practice, LED light sources 33 having different luminances may be mixed and used while falling within a predetermined luminance range. For this reason, depending on the arrangement of the LED light sources 33, the luminance of the peripheral portion becomes extremely lower than the luminance of the central portion of the light emitting surface 18a in combination with the characteristics of the light guide plate 18 described above. There is concern about the situation.

  Next, the relationship between the arrangement of the LED light sources 33 and the luminance distribution will be described. 7 and 8 are schematic diagrams showing the relationship between the luminance of each LED light source 33 and the luminance distribution on the light exit surface of the light guide plate 18. FIG. 7 shows the configuration of this embodiment, and FIG. 8 shows the configuration of a comparative example.

7 and 8, the relative luminance (%) of each LED light source 33 is given below each LED light source 33. Each point (indicated by points A1 to A9) on the light exit surface 18a of the light guide plate 18 is given the relative luminance (%) of the emitted light measured at each point. 7 and 8 exemplify the case where, for example, three types of LED light sources 33 having different luminances are mixed and used.
Specifically, assuming that the luminance of the LED light source 33 set at the time of designing the light guide plate 18 is 100%, the LED light source 33A having a relative luminance of 90%, the LED light source 33B having 100%, and the LED light source 33C having 110%. Used.

  In the comparative example of FIG. 8, among the LED light sources 33, the LED light sources 33A having a low relative luminance are arranged on both ends in the long side direction (X-axis direction) of the light emitting surface 18a, and the LED light sources having a high relative luminance. 33C is arranged on the center side. In other words, the luminance of the LED light source 33 disposed on both ends in the long side direction of the light emitting surface 18a is lower than the luminance of the LED light source 33 disposed on the central side in the long side direction of the light emitting surface 18a. It is arranged with. In this comparative example, in addition to the characteristics of the light guide plate 18, the low-brightness LED light sources 33 are arranged on both ends in the long side direction. As a result, the luminance (110%) of the central portion (point A5) of the light exit surface 18a On the other hand, the luminance (65%) of the peripheral portion (for example, point A1) is reduced by about 60%. With such an arrangement of the LED light source 33, the difference in luminance between the central portion and the peripheral portion becomes extremely large on the light emitting surface 18a, and luminance unevenness increases.

  Therefore, in the present embodiment, as shown in FIG. 7, among the LED light sources 33, the LED light source 33A having a relatively low luminance is arranged on the center side, and the LED light source 33C having a relatively high luminance is arranged on both ends. It was decided to. In other words, the luminance of the LED light source 33 disposed on both ends in the long side direction of the light emitting surface 18a is higher than the luminance of the LED light source 33 disposed on the center side in the long side direction of the light emitting surface 18a. It is arranged with. In this way, as shown in the luminance distribution of FIG. 7, it is possible to suppress the peripheral luminance of the light exit surface 18a from being significantly reduced. In the present embodiment, the luminance (75%) of the peripheral portion (for example, point A1) is only about 75% lower than the luminance (100%) of the central portion (point A5), which is compared with the comparative example of FIG. It can be seen that the luminance unevenness is reduced.

  7 and 8, the number of LED light sources 33 is less than that in FIGS. 1 to 4 described above for easy understanding. Even if the number of the LED light sources 33 is changed, the above-described array of the LED light sources 33 (an array in which the peripheral portion has high luminance) can be applied.

  In the present embodiment, it is necessary to check the luminance of each LED light source 33 when the LED light source 33 is mounted. As a method for confirming the brightness of each LED light source 33, for example, when the LED light source 33 is purchased and used, the brightness is classified according to the brightness of the LED light source 33. You can confirm. Of course, you may measure the brightness | luminance of each LED light source 33 separately.

  As described above, in the backlight device 12 of the present embodiment, even when the LED light sources 33 having different luminances are mixed and used for the purpose of reducing the cost related to the LED light sources 33, the light emitting surface is used. Therefore, it is possible to suppress a situation in which an extreme difference in luminance (brightness unevenness) occurs between both end sides in the one side direction and the center side thereof.

  In addition, after securing the LED light sources 33 with different luminances, the LED light sources 33 are sorted for each luminance and assigned to each backlight device for use (that is, the LED light sources 33 with different luminances are used without mixing them). ) Is also conceivable, but in this case, the luminance of each backlight device varies, which is not preferable.

  Further, in the backlight device 12 according to the present embodiment, a light reflecting portion 27 that scatters and reflects light is formed on the surface 18d of the light guide plate 18 opposite to the light emitting surface 18a. The density distribution of the light reflecting portions 27 on both ends in the long side direction (one side direction) is set lower than the density distribution of the light reflecting portions 27 on the center side in the long side direction (one side direction) of the light emitting surface 18a. .

  With such a configuration, on the opposite surface 18d, the side corresponding to both end sides in the long side direction of the light emitting surface 18a has a lower function of scattering and reflecting light than the center side. If the function of scattering and reflecting light is reduced, the proportion of light that is totally reflected by the light exit surface 18a (light that is not emitted) increases, and the amount of emitted light is relatively reduced. As a result, it is possible to reduce the luminance at both ends in the long side direction of the light exit surface 18a compared to the luminance at the center.

  Moreover, the light reflection part 27 can be comprised by a dot pattern. In this way, it is possible to easily control the density distribution of the light reflecting portion 27 by setting the mode (area, arrangement interval, etc.) of each dot 27a.

  A light reflecting sheet 19 that reflects light from the plurality of LED light sources 33 toward the light emitting surface 18a is covered with the surface 18d opposite to the light emitting surface 18a. With such a configuration, the light emitted from the light guide plate 18 to the light reflecting sheet 19 side can be reflected again to the light emitting surface 18a side, and the light utilization efficiency can be increased.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the above-described embodiment, the LED light sources 33 are illustrated as being arranged along the long side direction of the light emitting surface 18a, but are arranged along the short side direction of the light emitting surface 18a. It may be a configuration. When the light emitting surface 18a is arranged along the short side direction, the LED light source 33A having a relatively low luminance is arranged on the center side in the short side direction, and the LED light source 33C having a relatively high luminance is arranged on the short side. What is necessary is just to set it as the structure distribute | arranged to the both ends in a direction. Moreover, each LED light source 33 may be arranged along both the long side direction and the short side direction.

  (2) In the above embodiment, the light reflecting unit 27 is configured by printing a dot pattern, but the present invention is not limited to this. The light reflection unit 27 may be configured to scatter and reflect light, and the back surface 18d of the light guide plate 18 may be formed in, for example, an uneven shape or a lens shape to scatter and reflect light.

  (3) The number of LED light sources 33 arranged, the arrangement interval, the type of luminance, and the like are not limited to those of the above embodiment, and can be changed as appropriate.

  (4) In the above embodiment, the light reflecting portion 27 is formed on the surface 18d of the light guide plate 18 opposite to the light exit surface 18a, so that the light guide plate 18 has predetermined characteristics (from both ends of the light exit surface 18a). Although the characteristic that the luminance of the emitted light is lower than the luminance of the light emitted from the center side) is given, it is not limited to this. For example, a dot pattern that reflects light (that is, does not transmit light) is formed on the light exit surface 18a, and the distribution density of the dot pattern is changed at the central portion and the peripheral portion on the light exit surface 18a. The amount of light emitted from the emission surface 18a may be adjusted to give the predetermined characteristics described above.

  (5) In each of the above-described embodiments, the case where the LED light source 33 is configured by combining three LED chips 32 that emit R (red), G (green), and B (blue) in a single color has been shown. It is not limited to this. For example, an LED chip that emits blue light in a single color may be incorporated and white light may be emitted by a phosphor. Moreover, it is also possible to apply light sources other than LED as a light source.

  (6) In the above-described embodiment, the TFT is used as the switching element of the liquid crystal display device. However, the present invention can also be applied to a liquid crystal display device using a switching element other than TFT (for example, a thin film diode (TFD)), and color display. In addition to the liquid crystal display device, the present invention can be applied to a liquid crystal display device that displays black and white.

  (7) In the above-described embodiment, the liquid crystal display device using the liquid crystal panel as the display panel has been exemplified. However, the present invention can also be applied to display devices using other types of display panels.

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device (display device), 11 ... Liquid crystal panel (display panel), 12 ... Backlight device (illumination device), 18 ... Light guide plate, 18a ... Light emission surface, 18d ... Light emission surface opposite side Surface, 18e ... light incident surface, 19 ... light reflecting sheet (reflective member), 27a ... dot (light reflecting portion, part of dot pattern), 33 ... LED light source (light source), 33A ... LED light source (light emitting surface) Light source disposed on the center side in one side direction), 33C... LED light source (light sources disposed on both end sides in the one side direction of the light emitting surface)

Claims (6)

Multiple light sources;
A light incident surface on which light from the plurality of light sources is incident and a light guide surface that emits the light, and the light emission surface has a rectangular shape in plan view, and
In the light guide plate, when light having the same luminance is incident on the light incident surface in the entire range in one side direction of the light emitting surface, the luminance of light emitted from both end sides in the one side direction of the light emitting surface is The light emission surface is configured to be lower than the luminance of the light emitted from the center side in the one side direction,
The plurality of light sources are arranged along the one side direction of the light emitting surface, and the luminance of the light sources arranged on both ends in the one side direction of the light emitting surface is set in the one side direction of the light emitting surface. A lighting device, wherein the lighting device is arranged in a form that is higher than the luminance of the light source disposed on the center side. In the light guide plate, a light reflecting portion that scatters and reflects light is formed on a surface opposite to the light emitting surface.
The density distribution of the light reflecting portions on both ends in the one side direction of the light emitting surface is set lower than the density distribution of the light reflecting portions on the center side in the one side direction of the light emitting surface. The lighting device according to claim 1.   The lighting device according to claim 2, wherein the light reflecting portion is configured by a dot pattern.   4. The reflecting member for reflecting light from the plurality of light sources toward the light emitting surface side is covered on a surface opposite to the light emitting surface. The lighting device according to claim 1. The lighting device according to any one of claims 1 to 4,
And a display panel that performs display using light from the lighting device.   The display device according to claim 5, wherein the display panel is a liquid crystal panel using liquid crystal.

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