Backlight and display device

Abstract

To enable reduction in thickness of a backlight with a simple structure.SOLUTION: A backlight 12 includes: a light guide plate 16 which includes a surface 18 and a rear surface 20, which includes an end surface 22 for connecting one end of the surface 18 and one end of the rear surface 20, and in which at least part of the end surface 22 is inclined at an angle excluding a right angle with respect to the surface 18; and a light source 26 which is allowed to emit light L, which is arranged so as to emit the light L in parallel with the surface 18 toward at least part of the end surface 22 of the light guide plate 16, in which the light L enters at least part of the end surface 22 and refracts, in which the light L propagates inside the light guide plate 16, and in which the light L reflects on the rear surface 20 and is emitted in a planar manner from the surface 18.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a backlight and a display device. [Background technology]

[0002] In an edge-light type backlight, light is incident from an edge surface of a light guide plate. If the edge surface of the light guide plate is tilted, the light incident surface can be enlarged (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-126811 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a structure in which light is incident on a slanted end face along the normal to the end face, the light source is placed at an angle to the light-emitting surface of the light guide plate, making the structure complicated. Also, the bottom end of the light source protrudes lower than the bottom end of the end face, which makes it difficult to make the backlight thinner.

[0005] An object of the present invention is to enable a thinner backlight with a simple structure. [Means for solving the problem]

[0006] The backlight comprises: a light guide plate including a front surface and a back surface, and including an end surface connecting one end of the front surface and one end of the back surface, at least a portion of the end surface being inclined at an angle other than a right angle with respect to the front surface; and a light source configured to emit light and arranged to emit the light parallel to the front surface toward at least a portion of the end surface of the light guide plate, the light entering and refracting at least a portion of the end surface, the light propagating inside the light guide plate, and the light being reflected by the back surface and emitted in a planar form from the front surface.

[0007] The display device includes the backlight and a display panel arranged so that the light emitted from the backlight is incident on the rear surface of the display panel. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a display device according to a first embodiment. [Diagram 2] FIG. [Diagram 3] FIG. 13 is a diagram showing the relationship between the end face angle γ and the propagation angle θ. [Figure 4] FIG. 11 is a cross-sectional view of a backlight according to a first modified example of the first embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of a backlight according to Modification 2 of the first embodiment. [Figure 6] FIG. 11 is a cross-sectional view of a backlight according to a second embodiment. [Figure 7] FIG. [Figure 8] FIG. 11 is a cross-sectional view of a backlight according to a first modified example of the second embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a backlight according to Modification 2 of the second embodiment. [Figure 10] FIG. 11 is a cross-sectional view of a backlight according to a third embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a backlight according to a modified example of the third embodiment. [Figure 12] FIG. 11 is a cross-sectional view of a backlight according to a fourth embodiment. [Figure 13] FIG. 11 is a cross-sectional view of a backlight according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention can be embodied in various forms without departing from the spirit of the present invention, and the present invention should not be construed as being limited to the description of the embodiment exemplified below.

[0010] In order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. In this specification and each drawing, elements having the same functions as those explained in the previous drawings may be given the same reference numerals, and duplicate explanations may be omitted.

[0011] Furthermore, in the detailed description of the present invention, when defining the positional relationship between a certain component and another component, "above" and "below" do not only mean a component being located directly above or below another component, but also include a component being located between the other components, unless otherwise specified.

[0012] [First embodiment] 1 is a cross-sectional view of a display device according to a first embodiment. The display device has a display panel 10 (e.g., a liquid crystal display panel). The display panel 10 is arranged so that light emitted from a backlight 12 enters from the rear surface of the display panel 10. An optical sheet 14 is interposed between the rear surface of the display panel 10 and the backlight 12.

[0013] [Light guide plate] The backlight 12 has a light guide plate 16. The light guide plate 16 is a plurality of light guide plates 16 overlapping each other. The light guide plate 16 includes a front surface 18 and a rear surface 20. The light guide plate 16 includes an end surface 22 connecting one end of the front surface 18 and one end of the rear surface 20. The light guide plate 16 includes a vertical end surface 24 perpendicular to the front surface 18 on the opposite side to the end surface 22. One end surface 22 and the other end surface 22 of the plurality of light guide plates 16 are opposite to each other. At least a part of the end surface 22 faces in an obliquely downward direction that is a combination of a lateral direction outward from one end of the front surface 18 and a downward direction opposite to the front surface 18.

[0014] [light source] As shown in FIG. 1, the backlight 12 has a light source 26. The light source 26 is a laser diode (semiconductor laser) that emits light L. The light source 26 may be a plurality of point light sources arranged in a line (not shown), or may be one line light source. The light source 26 is each of the plurality of light sources 26. Each of the plurality of light sources 26 is arranged so that the light L can be incident on at least a part of a corresponding one of the end faces 22 of the plurality of light guide plates 16. One of the plurality of light sources 26 and the other one are opposite to each other. Therefore, since the light L is incident in the opposite direction, it is possible to reduce luminance unevenness due to the distance from the light source 26. The light source 26 is arranged so that the light L can be emitted parallel to the surface 18 toward at least a part of the end face 22 of the light guide plate 16.

[0015] 2 is a detailed view of the light guide plate 16. Light L is incident on at least a portion of the end face 22 and refracted. The light L propagates inside the light guide plate 16. The light L is reflected by the rear surface 20 and emitted in a planar form from the front surface 18. A reflective sheet 28 (FIG. 1) is disposed below the light guide plate 16 (the side opposite the display panel 10). The light L that has passed through the rear surface 20 is reflected by the reflective sheet 28 and returns to the inside of the light guide plate 16.

[0016] 2, at least a portion (e.g., the entirety) of the end face 22 is inclined at an angle γ (inside the light guide plate 16) other than a right angle with respect to the surface 18. The angle of incidence of the light L is π / 2-γ. The light L propagates at an angle θ with respect to the surface 18 of the light guide plate 16. The angle θ is optimally 26.5°. The refraction angle of the light L is π / 2-γ-θ.

[0017] 3 is a diagram showing the relationship between the angle γ of the end face 22 and the propagation angle θ. According to Snell's law, the following equation is established.

number

[0018] By modifying the above equation, the angle θ can be obtained as follows:

number

[0019] When the refractive index n of the light guide plate 16 is 1.496, the optimal angle γ of the end face 22 corresponding to the optimal angle θ of 26.5° in terms of luminous efficiency is 26.9° inside the light guide plate 16. A preferable angle θ is 36.5° to 16.5°, and correspondingly, a preferable angle γ of the end face 22 is 12.8° to 45.6° inside the light guide plate 16.

[0020] According to this embodiment, the end face 22 is inclined, so that the incident surface for the light L can be increased. The light source 26 is arranged so as to be able to emit the light L parallel to the surface 18 of the light guide plate 16, so that the lower end of the light source 26 does not protrude downward. Therefore, as shown in FIG. 1, the thickness T does not become large, and the backlight 12 can be made thinner with a simple structure.

[0021] [Modification 1 of the first embodiment] 4 is a cross-sectional view of a backlight according to Modification 1 of the first embodiment. The backlight 12A has an anti-glare film 30A that overlaps at least a portion of the end face 22A in the downward direction. The anti-glare film 30A may be a light-shielding film or a light-shielding tape. The anti-glare film 30A prevents the light L reflected by the end face 22A from returning to the light guide plate 16A.

[0022] The anti-glare film 30A does not overlap the back surface 20A of the corresponding light guide plate 16A. The anti-glare film 30A may be attached to the front surface 18A of another light guide plate 16A below the light guide plate 16A. Below the lowest light guide plate 16A, the anti-glare film 30A and the reflective sheet 28A may be adjacent to each other (in contact with each other), or the anti-glare film 30A may overlap the reflective sheet 28A.

[0023] [Modification 2 of the first embodiment] 5 is a cross-sectional view of a backlight according to Modification 2 of the first embodiment. The multiple light guide plates are a first light guide plate 32B and a second light guide plate 34B. The second light guide plate 34B is located below the first light guide plate 32B. The end face 22B of the first light guide plate 32B and the end face 22B of the second light guide plate 34B are located on opposite sides to each other. The multiple light sources are a first light source 36B and a second light source 38B. The first light source 36B and the second light source 38B are located on opposite sides to each other.

[0024] At least a part of the end face 22B of the first light guide plate 32B faces in an obliquely downward direction that is a combination of a lateral direction outward from one end of the surface 18B and a downward direction opposite to the surface 18B. The backlight 12B has an anti-glare film 30B that overlaps at least a part of the end face 22B of the first light guide plate 32B in the downward direction.

[0025] The light L of the first light source 36B spreads radially to some extent even if its optical axis is parallel to the surface 18B of the first light guide plate 32B. The light L', which has a large angle of incidence on the end face 22B, also has a large reflection angle with the end face 22B, and travels from directly below the end face 22B to directly below the back face 20B. Since the reflecting sheet 28B is located directly below the back face 20B, the light L' travels in an undesirable direction (for example, perpendicular to the display panel 10B) when reflected by the reflecting sheet 28B. Therefore, the anti-glare film 30B extends below the back face 20B of the second light guide plate 34B in a direction from directly below the end face 22B of the first light guide plate 32B to directly below the back face 20B.

[0026] [Second embodiment] 6 is a cross-sectional view of a backlight according to the second embodiment. At least a part of the end face 222 faces in an obliquely upward direction that is a combination of a lateral direction outward from one end of the surface 218 and the upward direction in which the surface 218 faces. At least a part (e.g., the entirety) of the end face 222 is inclined at an angle other than a right angle with respect to the surface 218.

[0027] FIG. 7 is a detailed view of the light guide plate 216. As in the first embodiment, the angle θ can be obtained from Snell's law. The optimal angle γ of the end face 222 corresponding to the optimal angle θ of 26.5° in terms of luminous efficiency is 26.9° on the outside of the inside of the light guide plate 216. The preferred angle θ is 36.5° to 16.5°, and the corresponding preferred angle γ of the end face 222 is 12.8° to 45.6° on the outside of the inside of the light guide plate 216. The contents described in the first embodiment are applicable to this embodiment.

[0028] [Modification 1 of the second embodiment] FIG. 8 is a cross-sectional view of a backlight according to a first modified example of the second embodiment. The backlight 212A has a light-shielding film 240A or a diffraction grating that overlaps at least a part of the end surface 222A in the upward direction. The light-shielding film 240A may be a light-shielding tape. The light-shielding film 240A blocks the passage of light L. The light-shielding film 240A or the diffraction grating is below the optical sheet 214A. The light-shielding film 240A or the diffraction grating does not overlap the surface 218A of the corresponding light guide plate 216A. The light-shielding film 240A or the diffraction grating may be attached to the back surface 220A of another light guide plate 216A that is above the light guide plate 216A.

[0029] [Modification 2 of the second embodiment] 9 is a cross-sectional view of a backlight according to Modification 2 of the second embodiment. The multiple light guide plates are a first light guide plate 232B and a second light guide plate 234B. The first light guide plate 232B is on the second light guide plate 234B. An end face 222B of the first light guide plate 232B and an end face 222B of the second light guide plate 234B are on opposite sides to each other. The multiple light sources are a first light source 236B and a second light source 238B. The first light source 236B and the second light source 238B are on opposite sides to each other.

[0030] At least a part of the end surface 222B of the second light guide plate 234B faces in an obliquely upward direction that is a combination of a lateral direction outward from one end of the surface 218B and the upward direction in which the surface 218B faces. The backlight 212B has a light-shielding film 240B or a diffraction grating that overlaps at least a part of the end surface 222B of the second light guide plate 234B in the upward direction.

[0031] The light L of the second light source 238B spreads radially to some extent even if its optical axis is parallel to the surface 218B of the second light guide plate 234B. The light L' having a large angle of incidence on the end face 222B also has a large reflection angle with the end face 222B. The light L' reflected by the end face 222B travels in an undesirable direction (for example, perpendicular to the display panel). Therefore, the light-shielding film 240B or the diffraction grating extends above the surface 218B of the first light guide plate 232B in a direction from directly above the end face 222B of the second light guide plate 234B to directly above the surface 218B.

[0032] [Third embodiment] 10 is a cross-sectional view of a backlight according to a third embodiment. The plurality of light guide plates are a first light guide plate 332 and a second light guide plate 334. The second light guide plate 334 is located below the first light guide plate 332. An end surface 322 of the first light guide plate 332 and an end surface 322 of the second light guide plate 334 are located opposite each other. The plurality of light sources are a first light source 336 and a second light source 338. The first light source 336 and the second light source 338 are located opposite each other.

[0033] At least a part of end face 322 of first light guide plate 332 faces in an obliquely upward direction resulting from a combination of a lateral direction outward from one end of surface 318 and the upward direction in which surface 318 faces. At least a part of end face 322 of second light guide plate 334 faces in an obliquely downward direction resulting from a combination of a lateral direction outward from one end of surface 318 and a downward direction opposite surface 318. The contents described in the first and second embodiments are applicable to this embodiment.

[0034] [Modification of the third embodiment] 11 is a cross-sectional view of a backlight according to a modification of the third embodiment. The back surface 320A of the first light guide plate 332A and the front surface 318A of the second light guide plate 334A face each other. The first light source 336A is disposed so that light L is incident on a position closer to the back surface 320A than the midpoint between the front surface 318A and the back surface 320A. The second light source 338A is disposed so that light L is incident on a position closer to the front surface 318A than the midpoint between the front surface 318A and the back surface 320A.

[0035] According to this embodiment, the thickness T of the backlight 312A can be made thinner than the thickness t of a backlight that directs light into the middle between the front surface 318A and the back surface 320A.

[0036] [Fourth embodiment] 12 is a cross-sectional view of a backlight according to a fourth embodiment. The multiple light guide plates are a first light guide plate 432 and a second light guide plate 434. A rear surface 420 of the first light guide plate 432 and a front surface 418 of the second light guide plate 434 face each other. An end surface 422 of the first light guide plate 432 and an end surface 422 of the second light guide plate 434 are on opposite sides to each other. The multiple light sources are a first light source 436 and a second light source 438. The first light source 436 and the second light source 438 are on opposite sides to each other.

[0037] At least a portion of the end surface 422 of the first light guide plate 432 is a first inclined surface 442 that connects to the rear surface 420. The end surface 422 of the first light guide plate 432 further includes a first upright surface 444 that stands upright and connects to the front surface 418. The first upright surface 444 can widen the front surface 418, thereby ensuring a wide support surface.

[0038] At least a part of the end surface 422 of the second light guide plate 434 is a second inclined surface 446 that connects to the front surface 418. The end surface 422 of the second light guide plate 434 further includes a second upright surface 448 that stands upright and connects to the rear surface 420. The second upright surface 448 can widen the rear surface 420, thereby ensuring a wide support surface. The contents described in the third embodiment can be applied to this embodiment.

[0039] [Fifth embodiment] 13 is a cross-sectional view of a backlight according to a fifth embodiment. The multiple light guide plates are a first light guide plate 532 and a second light guide plate 534. A rear surface 520 of the first light guide plate 532 and a front surface 518 of the second light guide plate 534 face each other. An end surface 522 of the first light guide plate 532 and an end surface 522 of the second light guide plate 534 are on opposite sides to each other. The multiple light sources are a first light source 536 and a second light source 538. The first light source 536 and the second light source 538 are on opposite sides to each other.

[0040] At least a portion of the end surface 522 of the first light guide plate 532 is a first inclined surface 542 that connects to the rear surface 520. The end surface 522 of the first light guide plate 532 further includes a first reverse inclined surface 550 that connects to the front surface 518. The first inclined surface 542 and the first reverse inclined surface 550 form a first recess 552. The first reverse inclined surface 550 can widen the front surface 518, ensuring a wide support surface.

[0041] At least a part of the end surface 522 of the second light guide plate 534 is a second inclined surface 546 that connects to the front surface 518. The end surface 522 of the second light guide plate 534 further includes a second reverse inclined surface 554 that connects to the back surface 520. The second inclined surface 546 and the second reverse inclined surface 554 form a second recess 556. The second reverse inclined surface 554 can widen the back surface 520, and a wide support surface can be secured. The contents described in the third embodiment are applicable to this embodiment.

[0042] [Overview of the embodiment] (1) A backlight 12 comprising: a light guide plate 16 including a front surface 18 and a back surface 20, and including an end surface 22 connecting one end of the front surface 18 and one end of the back surface 20, at least a portion of the end surface 22 being inclined at an angle other than a right angle with respect to the front surface 18; and a light source 26 configured to emit light L and arranged to be able to emit the light L parallel to the front surface 18 toward at least a portion of the end surface 22 of the light guide plate 16, the light L being incident on at least a portion of the end surface 22 and refracted, the light L propagating inside the light guide plate 16, and the light L being reflected by the back surface 20 and emitted in a planar form from the front surface 18. Since the end face 22 is inclined, it is possible to increase the incident surface for the light L. Since the light source 26 is arranged so as to be able to emit the light L parallel to the surface 18 of the light guide plate 16, the lower end of the light source 26 does not protrude downward, and it is possible to make the backlight 12 thinner with a simple structure. (2) The backlight 12 described in (1), wherein the light guide plate 16 further includes a vertical end face 24 perpendicular to the surface 18 on the side opposite the end face 22. (3) In the backlight 12 described in (1) or (2), the light guide plate 16 is each of a plurality of light guide plates 16 stacked on top of each other, the light source 26 is each of a plurality of light sources 26, and each of the plurality of light sources 26 is arranged so that light L can be incident on at least a portion of a corresponding one of the end faces 22 of the plurality of light guide plates 16. (4) In the backlight 12 described in (3), the plurality of light guide plates 16 are a first light guide plate 32 and a second light guide plate 34, and the end face 22 of the first light guide plate 32 and the end face 22 of the second light guide plate 34 are opposite each other, and the plurality of light sources 26 are a first light source 36 and a second light source 38, and the first light source 36 and the second light source 38 are opposite each other. (5) A backlight 12 according to any one of (1) to (3), in which at least a portion of the end face 22 faces in a diagonally downward direction that is a combination of a lateral direction outward from one end of the surface 18 and a downward direction opposite to the surface 18. (6) The backlight 12 according to (5), wherein the angle inside the light guide plate 16 is 12.8° or more and 45.6° or less. (7) The backlight 12A according to (5) or (6), further comprising an anti-glare film 30A overlapping downwardly at least a portion of the end face 22A. (8) A backlight 212 according to any one of (1) to (3), wherein at least a portion of the end face 222 faces in a diagonally upward direction that is a combination of a lateral direction outward from one end of the surface 218 and the upward direction in which the surface 218 faces. (9) The backlight 212 according to (8), wherein the angle, from the inside to the outside of the light guide plate 216, is 12.8° or more and 45.6° or less. (10) The backlight 212A according to (8) or (9), further comprising a light-shielding film 240A or a diffraction grating overlapping at least a portion of the end surface 222A in the upward direction. (11) A backlight 12B as described in (4), in which at least a portion of an end face 22B of a first light guide plate 32B faces in a diagonally downward direction that is a combination of a lateral direction outward from one end of a surface 18B and a downward direction opposite to the surface 18B. (12) The backlight 12B described in (11) further includes an anti-glare film 30B overlapping at least a portion of the end face 22B of the first light guide plate 32B in a downward direction, the second light guide plate 34B is located below the first light guide plate 32B, and the anti-glare film 30B extends below the back face 20B of the second light guide plate 34B in a direction from directly below the end face 22B of the first light guide plate 32B to directly below the back face 20B. (13) A backlight 212B as described in (4), in which at least a portion of an end face 222B of a second light guide plate 234B faces in an obliquely upward direction that is a combination of a lateral direction outward from one end of a surface 218B and the upward direction in which the surface 218B faces. (14) A backlight 212B described in (13), further comprising a light-shielding film 240B or a diffraction grating overlapping at least a portion of the end face 222B of the second light guide plate 234B in the upward direction, the first light guide plate 232B being on the second light guide plate 234B, and the light-shielding film 240B or the diffraction grating extending in a direction from directly above the end face 222B of the second light guide plate 234B to directly above the surface 218B above the surface 218B of the first light guide plate 232B. (15) In the backlight 312 described in (4), at least a part of the end face 322 of the first light guide plate 332 faces in an obliquely upward direction that is a combination of a lateral direction outward from one end of the surface 318 and the upward direction in which the surface 318 faces, and at least a part of the end face 322 of the second light guide plate 334 faces in an obliquely downward direction that is a combination of a lateral direction outward from one end of the surface 318 and a downward direction opposite to the surface 318. (16) A backlight 312A described in (15), in which the back surface 320A of the first light guide plate 332A and the front surface 318A of the second light guide plate 334A face each other, the first light source 336A is arranged so that light L is incident on a position closer to the back surface 320A than the midpoint between the front surface 318A and the back surface 320A, and the second light source 338A is arranged so that light L is incident on a position closer to the front surface 318A than the midpoint between the front surface 318A and the back surface 320A. (17) In the backlight 412 described in (16), at least a portion of the end face 422 of the first light guide plate 432 is a first inclined surface 442 connecting to the back surface 420, the end face 422 of the first light guide plate 432 further includes a first upright surface 444 standing upright and connecting to the front surface 418, at least a portion of the end face 422 of the second light guide plate 434 is a second inclined surface 446 connecting to the front surface 418, and the end face 422 of the second light guide plate 434 further includes a second upright surface 448 standing upright and connecting to the back surface 420. (18) In the backlight 512 described in (16), at least a part of the end face 522 of the first light guide plate 532 is a first inclined surface 542 connected to the back surface 520, the end face 522 of the first light guide plate 532 further includes a first reverse inclined surface 550 connected to the front surface 518, the first inclined surface 542 and the first reverse inclined surface 550 forming a first recess 552, at least a part of the end face 522 of the second light guide plate 534 is a second inclined surface 546 connected to the front surface 518, the end face 522 of the second light guide plate 534 further includes a second reverse inclined surface 554 connected to the back surface 520, and the second inclined surface 546 and the second reverse inclined surface 554 form a second recess 556. (19) A display device having a backlight 12 according to any one of (1) to (18) and a display panel 10 arranged so that light L emitted from the backlight 12 is incident on the back surface.

[0043] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations described in the embodiments can be replaced with substantially the same configurations, configurations that provide the same effects, or configurations that can achieve the same purpose. [Explanation of symbols]

[0044] 10 display panel, 10B display panel, 12 backlight, 12A backlight, 12B backlight, 14 optical sheet, 16 light guide plate, 16A light guide plate, 18 front surface, 18A front surface, 18B front surface, 20 rear surface, 20A rear surface, 20B rear surface, 22 end surface, 22A end surface, 22B end surface, 24 vertical end surface, 26 light source, 28 reflective sheet, 28A reflective sheet, 28B reflective sheet, 30A anti-glare film, 30B anti-glare film, 32 first light guide plate, 32B first light guide plate, 34 second light guide plate, 34B second light guide plate, 36 first light source, 36B first light source, 38 second light source, 38B second light source, 212 backlight, 212A backlight, 212B backlight, 214A Optical sheet, 216 light guide plate, 216A light guide plate, 218 surface, 218A surface, 218B surface, 220A back surface, 222 end surface, 222A end surface, 222B end surface, 232B first light guide plate, 234B second light guide plate, 236B first light source, 238B second light source, 240A light shielding film, 240B light shielding film, 312 backlight, 312A backlight, 318 surface, 318A surface, 320A back surface, 322 end surface, 332 first light guide plate, 332A first light guide plate, 334 second light guide plate, 334A second light guide plate, 336 first light source, 336A first light source, 338 second light source, 338A second light source, 412 backlight, 418 Front surface, 420, rear surface, 422, end surface, 432, first light guide plate, 434, second light guide plate, 436, first light source, 438, second light source, 442, first inclined surface, 444, first upright surface, 446, second inclined surface, 448, second upright surface, 512, backlight, 518, front surface, 520, rear surface, 522, end surface, 532, first light guide plate, 534, second light guide plate, 536, first light source, 538, second light source, 542, first inclined surface, 546, second inclined surface, 550, first inverted surface, 552, first recess, 554, second inverted surface, 556, second recess, L, light, L', light, T, thickness, t, thickness.

Claims

1. a light guide plate including a front surface and a back surface, and including an end surface connecting one end of the front surface and one end of the back surface, at least a part of the end surface being inclined at an angle other than a right angle with respect to the front surface; a light source that emits light and is arranged to be able to emit the light parallel to the front surface toward at least the part of the end surface of the light guide plate, the light being incident on the at least the part of the end surface and refracted, the light being propagated inside the light guide plate, the light being reflected by the back surface, and being emitted planarly from the front surface; Having a backlight.

2. 2. The backlight according to claim 1, The light guide plate further includes a vertical end surface perpendicular to the surface on the opposite side to the end surface.

3. 2. The backlight according to claim 1, The light guide plate is each of a plurality of light guide plates stacked on top of each other, the light source is each of a plurality of light sources; A backlight, in which each of the plurality of light sources is arranged so that the light can be incident on at least the portion of the end surface of a corresponding one of the plurality of light guide plates.

4. 4. The backlight according to claim 3, the plurality of light guide plates are a first light guide plate and a second light guide plate, the end surface of the first light guide plate and the end surface of the second light guide plate are opposite to each other, the plurality of light sources are a first light source and a second light source, The first light source and the second light source are on opposite sides of the backlight.

5. 2. The backlight according to claim 1, A backlight, wherein at least the portion of the end face faces in an obliquely downward direction that is a combination of a lateral direction outward from the one end of the surface and a downward direction opposite to the surface.

6. 6. The backlight according to claim 5, The backlight, wherein the angle is greater than or equal to 12.8° and less than or equal to 45.6° within the interior of the light guide plate.

7. 6. The backlight according to claim 5, The backlight further comprises an anti-glare film overlapping said at least a portion of said edge surface in said downward direction.

8. 2. The backlight according to claim 1, A backlight, wherein the at least a portion of the end face faces in an obliquely upward direction that is a combination of a lateral direction outward from the one end of the surface and an upward direction in which the surface faces.

9. 9. The backlight according to claim 8, The backlight, wherein the angle is greater than or equal to 12.8° and less than or equal to 45.6° outside the interior of the light guide plate.

10. 9. The backlight according to claim 8, The backlight further comprises a light blocking film or a diffraction grating overlapping said at least a portion of said edge surface in said upward direction.

11. 5. The backlight according to claim 4, A backlight, wherein the at least a portion of the end face of the first light guide plate faces an obliquely downward direction that is a combination of a lateral direction outward from the one end of the surface and a downward direction opposite to the surface.

12. 12. The backlight according to claim 11, an anti-glare film overlapping at least a portion of the end surface of the first light guide plate in the downward direction; the second light guide plate is located below the first light guide plate, The anti-glare film extends below the rear surface of the second light guide plate in a direction from directly below the end surface of the first light guide plate to directly below the rear surface.

13. 5. The backlight according to claim 4, a backlight in which the at least a portion of the end face of the second light guide plate faces an obliquely upward direction that is a combination of a lateral direction outward from the one end of the surface and an upward direction in which the surface faces.

14. 14. The backlight according to claim 13, The second light guide plate further includes a light-shielding film or a diffraction grating overlapping at least a portion of the end surface of the second light guide plate in the upward direction; the first light guide plate is located above the second light guide plate; A backlight, wherein the light-shielding film or the diffraction grating extends above the surface of the first light guide plate in a direction from directly above the end face of the second light guide plate to directly above the surface.

15. 5. The backlight according to claim 4, the at least a portion of the end surface of the first light guide plate faces an obliquely upward direction that is a combination of a lateral direction outward from the one end of the surface and an upward direction to which the surface faces, A backlight, wherein the at least a portion of the end face of the second light guide plate faces an obliquely downward direction that is a combination of a lateral direction outward from the one end of the surface and a downward direction opposite to the surface.

16. 16. The backlight according to claim 15, the rear surface of the first light guide plate faces the front surface of the second light guide plate, the first light source is disposed so that the light is incident on a position closer to the rear surface than a midpoint between the front surface and the rear surface; The second light source is a backlight arranged so that the light is incident on a position closer to the front surface than the middle between the front surface and the back surface.

17. 17. The backlight according to claim 16, the at least a portion of the end surface of the first light guide plate is a first inclined surface connected to the back surface, The end surface of the first light guide plate further includes a first upright surface that stands upright and connects to the surface; the at least a portion of the end surface of the second light guide plate is a second inclined surface connected to the front surface; The end surface of the second light guide plate further includes a second upright surface that stands upright and connects to the rear surface.

18. 17. The backlight according to claim 16, the at least a portion of the end surface of the first light guide plate is a first inclined surface connected to the back surface, The end surface of the first light guide plate further includes a first reverse inclined surface connected to the surface; the first inclined surface and the first reverse inclined surface constitute a first recess; the at least a portion of the end surface of the second light guide plate is a second inclined surface connected to the front surface; The end surface of the second light guide plate further includes a second inclined surface connected to the back surface, The backlight, in which the second inclined surface and the second reverse inclined surface form a second recess.

19. A backlight according to any one of claims 1 to 18; a display panel arranged so that the light emitted from the backlight is incident on the rear surface of the display panel; A display device having the above configuration.

Images