Luminaire and display device

Abstract

To provide a luminaire and a display device which emit light whose luminance distribution is uniform, without increasing manufacturing cost.SOLUTION: A luminaire and a display device include: a light guide plate which includes a first side and a second side extending in a first direction, a third side and a fourth side extending in a second direction crossing the first direction, a fifth side provided between the first side and the third side, and a sixth side provided between the second side and the third side; and a plurality of light source elements provided close to the fourth side. The fifth side has a first short side extending in the first direction and a second short side extending in the second direction which are arranged alternately. The sixth side has a third short side extending in the first direction and a fourth short side extending in the second direction which are arranged alternately.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present embodiment relates to a display device. [Background technology]

[0002] 2. Description of the Related Art In recent years, attention has been focused on a technology that provides, for example, virtual reality (VR) using a display device called a head mounted display (HMD) that is worn on a user's head. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-063088 A Summary of the Invention [Problem to be solved by the invention]

[0004] The object of this embodiment is to provide an illumination device that emits light with a uniform brightness distribution, and a display device that emits image light with a uniform brightness distribution when illuminated by the illumination light, without increasing manufacturing costs. [Means for solving the problem]

[0005] An illumination device according to an embodiment includes: a light guide plate having a first side and a second side extending in a first direction, a third side and a fourth side extending in a second direction intersecting the first direction, a fifth side provided between the first side and the third side, and a sixth side provided between the second side and the third side; A plurality of light source elements provided adjacent to the fourth side; Equipped with The fifth side has a first short side extending in the first direction and a second short side extending in the second direction, which are alternately arranged, The sixth side has a third short side extending in the first direction and a fourth short side extending in the second direction, which are alternately arranged.

[0006] Moreover, the display device according to one embodiment includes: A display device including a display panel and an illumination device, The lighting device includes: a light guide plate having a first side and a second side extending in a first direction, a third side and a fourth side extending in a second direction intersecting the first direction, a fifth side provided between the first side and the third side, and a sixth side provided between the second side and the third side; A plurality of light source elements provided adjacent to the fourth side; Equipped with The fifth side includes a first short side extending in the first direction and a second short side extending in the second direction, which are alternately arranged. and a second short side extending The sixth side is a third short side extending in the first direction and a fourth short side extending in the second direction. and a fourth short side extending in the direction of the fourth short side. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing an example of the appearance of a display device according to this embodiment. [Diagram 2] FIG. 2 is a perspective view showing a schematic configuration of a display panel provided in the display device according to this embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of a schematic configuration of a display device. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a schematic configuration of a lighting device. [Diagram 5] FIG. 5 is a plan view showing one schematic configuration example of a display device of Comparative Example 1. As shown in FIG. [Figure 6] FIG. 6 is a plan view showing a schematic configuration example of a display device of Comparative Example 2. As shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment. [Figure 8] FIG. 8 is a plan view showing a schematic configuration of the light guide plate LG1. [Figure 9] FIG. 9 is a plan view showing another configuration example of the illumination device used in the display device in the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Note that the disclosure is merely an example, and those who are skilled in the art can easily come up with appropriate modifications while maintaining the gist of the invention, which are naturally included in the scope of the present invention. In addition, in order to make the explanation clearer, 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 addition, in this specification and each figure, elements similar to those described above with respect to the previous figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments described in this specification are not general, but are embodiments describing the same or corresponding special technical features of the present invention.

[0010] In this embodiment, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other, but may intersect at an angle other than 90 degrees. The direction toward the tip of the arrow of the third direction Z is defined as up or upward, and the direction opposite to the direction toward the tip of the arrow of the third direction Z is defined as down or downward. The first direction X, the second direction Y, and the third direction Z may also be called the X direction, the Y direction, and the Z direction, respectively.

[0011] Furthermore, in the case of "a second member above the first member" and "a second member below the first member," the second member may be in contact with the first member or may be located away from the first member. In the latter case, a third member may be interposed between the first and second members. On the other hand, in the case of "a second member above the first member" and "a second member below the first member," the second member is in contact with the first member.

[0012] Also, it is assumed that an observation position for observing the display device is located at the tip side of the arrow in the third direction Z, and a planar view refers to a view from this observation position toward the XY plane defined by the first direction X and the second direction Y. A cross-sectional view refers to a view of a cross section of the display device in the XZ plane defined by the first direction X and the third direction Z, or in the YZ plane defined by the second direction Y and the third direction Z.

[0013] [Embodiment] 1 is a perspective view showing an example of the appearance of a display device according to the present embodiment. In the present embodiment, the display device includes a head mounted display (HMD) that is worn on the head of a user when in use. Such a display device is used to provide, for example, virtual reality (VR) to a user wearing the display device on his or her head.

[0014] As shown in Fig. 1, the display device HMD includes a display panel PNL1 and a display panel PNL2. The display panels PNL1 and PNL2 are sometimes called a first display panel and a second display panel, respectively. The display panels PNL1 and PNL2 are each an independent display panel.

[0015] The display panels PNL1 and PNL2 are arranged so as to be located in front of the left and right eyes of the user USR when the user USR wears the display device HMD on his / her head. In this embodiment, the display panels PNL1 and PNL2 are liquid crystal display panels having a liquid crystal layer. In FIG. 1, the display panel PNL1 is for the left eye, and the display panel PNL2 is for the right eye.

[0016] 2 is a perspective view showing a schematic configuration of a display panel provided in the display device according to this embodiment. Here, the configuration of the display panel PNL1 will be mainly described.

[0017] 2 includes a first substrate SUB1 and a second substrate SUB2 opposed to the first substrate SUB1. The display panel PNL1 has a display area DA for displaying an image. The display panel PNL1 further includes a plurality of pixels PX arranged in a matrix in the display area DA.

[0018] The display panel PNL1 also includes a drive IC chip IC1 that drives the display panel PNL1, and a flexible wiring board FPC1 that transmits control signals to the display panel PNL1. The flexible wiring board FPC1 is connected to a control module (host computer) that controls the operation of the display device HMD.

[0019] In the example shown in FIG. 2, the first substrate SUB1 and the second substrate SUB2 each have a long side along the first direction X and a short side along the second direction Y. The first substrate SUB1 and the second substrate SUB2 each have an octagonal shape in a plan view. This shape can also be said to be a shape with the corners of a rectangle cut out. The shape of the display panel PNL1 in a plan view is an octagonal shape. However, the shapes of the display panels PNL1 and PNL2 are not limited to this, and may be polygonal. The shape of the display panel may be any shape that prevents it from hitting the nose of a user USR described later, and may be any shape in which the corners close to the nose of the user USR are cut out.

[0020] Here, consider that the display panels PNL1 and PNL2 are rectangular. In other words, the display panels PNL1 and PNL2 have no cut-out corners. In this case, the display panels PNL1 and PNL2 would hit the nose of the user USR. For this reason, a rectangular display panel without cut-out corners is not preferable as the display panels PNL1 and PNL2 of the display device HMD.

[0021] 3 is a cross-sectional view showing an example of a schematic configuration of a display device. The display panel PNL1 further includes a seal material SAL and a liquid crystal layer LC in addition to the above-mentioned first substrate SUB1 and second substrate SUB2. In the display panel PNL1, the first substrate SUB1 and the second substrate SUB2 are bonded together with the seal material SAL. The liquid crystal layer LC is sealed between the seal material SAL and the first substrate SUB1 and the second substrate SUB2.

[0022] In the display device HMD, a first polarizing plate PL1 is attached to the lower surface (surface not facing the second substrate SUB2) of the first substrate SUB1. A second polarizing plate PL2 is attached to the upper surface (surface not facing the first substrate SUB1) of the second substrate SUB2. The polarization axes of the first polarizing plate PL1 and the second polarizing plate PL2 are perpendicular to each other.

[0023] The display device HMD includes an illumination device ILD (also called a backlight unit) on the rear side (i.e., the side opposite to the display surface) of the display panel PNL1. The illumination device ILD is connected to a control module. In the display device HMD, the illumination device ILD illuminates the display panel PNL1, thereby allowing an image to be displayed on the display panel PNL1.

[0024] The display device HMD includes a prism sheet PS between the display panel PNL1 and the illumination device ILD. The display device HMD also includes a diffusion sheet DS (diffusion layer) between the prism sheet PS and the display panel PNL1. The prism sheet PS includes a number of prisms extending, for example, parallel to the second direction Y. These prisms are formed, for example, on the lower surface of the prism sheet PS (the surface facing the illumination device ILD). However, these prisms may also be formed on the upper surface of the prism sheet PS (the surface facing the display panel PNL1).

[0025] The prism sheet PS converts the light illuminated by the illumination device ILD into light substantially parallel to the third direction Z. Here, "light substantially parallel to the third direction Z" includes not only light strictly parallel to the third direction Z, but also light converted by the prism sheet PS such that the inclination with respect to the third direction Z is sufficiently smaller than that when illuminated by the illumination device ILD. From the viewpoint of maintaining the polarization of the light illuminated by the illumination device ILD, it is preferable that the prisms of the prism sheet PS are formed on the lower surface. The light that passes through the prism sheet PS is diffused by the diffusion sheet DS and illuminates the display panel PNL1. Even if the viewing angle of the light that passes through the prism sheet PS is narrow, the viewing angle can be widened by diffusing this light by the diffusion sheet DS.

[0026] Although the display panel PNL1 has been described with reference to FIGS. 2 and 3, the display panel PNL2 also has a similar configuration to the display panel PNL1 described with reference to FIGS.

[0027] 4 is a cross-sectional view showing an example of a schematic configuration of an illumination device. The light guide plate LG of the illumination device ILD has a first main surface F1 facing the display panel PNL1, a second main surface F2 opposite the first main surface F1, a first side surface F3, and a second side surface F4 opposite the first side surface F3. The light source element LS1 faces a slope F5 between the second main surface F2 and the first side surface F3. An optical element such as a lens may be further disposed between the light source element LS1 and the slope F5 to adjust the width and angle of the light from the light source element LS1.

[0028] The illumination device ILD has a reflector REF1 facing the second side surface F4, and a reflector REF2 facing the second main surface F2.

[0029] The second main surface F2 of the light guide plate LG has a first region A1, a second region A2, and a third region A3. In this embodiment, the first region A1, the second region A2, and the third region A3 are provided along the first direction X from the side closer to the light source element LS1. The lengths of the respective regions along the first direction X are longer in the order of the first region A1, the third region A3, and the second region A2. The reflector REF2 has a portion P1 corresponding to the second region A2 and a portion P2 corresponding to the third region A3.

[0030] A distance d1, which is the thickness of the light guide plate LG in the first region A1, increases from the first side surface F3 toward the boundary between the first region A1 and the second region A2. A distance d2, which is the thickness of the light guide plate LG in the second region A2, increases from the boundary between the first region A1 and the second region A2 toward the boundary between the second region A2 and the third region A3. In the example shown in Fig. 4, a distance d3, which is the thickness of the light guide plate LG in the third region A3, is constant. The distance d3 is longer than the distances d1 and d2 at the positions of the first region A1 and the second region A2, respectively (d3>d1, d3>d2).

[0031] The first region A1 is inclined at a first angle θ1 with respect to the first main surface F1. The second region A2 is inclined at a second angle θ2 with respect to the first main surface F1. Both angles θ1 and θ2 are acute angles. The angle θ1 is greater than the angle θ2. Note that, although the angle θ1 is an acute angle in this embodiment, the angle θ1 is not limited to this and may be 90° or an obtuse angle.

[0032] By providing the third region A3, the luminance distribution of the light emitted from the first main surface F1 can be made uniform. Consider the case where the third region A3 is not provided, that is, where the flat portion is not provided. The light incident on the light guide plate LG from the light source element LS1 propagates inside the light guide plate LG and is reflected by the reflector REF1. When the third region A3 is not provided, the light reflected by the reflector REF1 is reflected by a convex portion (also called a groove or a prism) provided below the light guide plate LG, and does not satisfy the total reflection condition of the first main surface F1, and is emitted as the emitted light LO from the first main surface F1 of the light guide plate LG. At this time, when the third region A3 is not provided, the light reflected by the convex portion near the reflector REF1 travels in the opposite direction to the first direction X and is emitted from the first main surface F1. That is, light is not emitted from the vicinity of the reflector REF1 of the first main surface F1, and there is a risk of uneven luminance of the emitted light on the first main surface F1.

[0033] However, when the third region A3 is provided, the light reflected by the convex portion of the third region A3 near the second region A2 is reflected by the upper part of the reflector REF1 and then emitted from the first main surface F1 near the reflector REF1. This makes it possible to suppress uneven brightness of the emitted light and improve the uniformity of the brightness distribution.

[0034] Here, the optical path of the light generated by the light source element until it is emitted from the lighting device ILD will be described. The emitted light emitted from the light source element LS1 enters the light guide plate LG from the inclined surface F5. The incident light LT is repeatedly totally reflected between the first main surface F1 and the second main surface F2 of the light guide plate LG and extends along the first direction X. The light LT that reaches the reflector REF1 is reflected by the reflector REF1. The reflected light LT extends in the opposite direction to the first direction X. The light LT that enters a convex portion (also called a groove or a prism) provided below the light guide plate LG no longer satisfies the total reflection condition, and is emitted as the emitted light LO from the first main surface F1 of the light guide plate LG. The luminance of the light LT that reaches the reflector REF1 is sufficiently diffused and uniformed in the second direction Y. Therefore, the luminance of the emitted light LO emitted from the first main surface F1 is uniform in the second direction Y. The emitted light LO is the illumination light of the lighting device ILD.

[0035] The light source element LS1 may be a laser light source (laser diode) such as a semiconductor laser that emits laser light. The laser light may be a diffused light having a spread centered on the irradiation direction, or may be a polarized laser light.

[0036] As described above, the display device HMD of this embodiment requires two display panels PNL1 and PNL2. The shape of each display panel with a notched corner can prevent the display panel from hitting the nose of the user USR.

[0037] However, at the cut-out corner, there is a risk that the reflected light at the cut-out portion will be non-uniform. Therefore, by forming the cut-out portion in a stepped shape, it is possible to uniformize the luminance distribution of the reflected light. By uniformizing the luminance distribution of the reflected light, it is possible to uniformize the luminance distribution of the illumination light emitted from the illumination device ILD and the image light obtained by modulating the illumination light by the display panel.

[0038] However, the shape of the display panel PNL1 of the display device HMD and the shape of the lighting device that illuminates it, as well as the shape of the display panel PNL2 and the shape of the lighting device ILD2, are symmetrical and not identical. When the display panel having the above-mentioned notched corner or the display panel having the stepped corner is used as the display panel PNL1 and the display panel PNL2, it is necessary to prepare two display panels. The lighting devices that illuminate the display panel PNL1 and the display panel PNL2 are also symmetrical and not identical. As for the lighting devices, it is necessary to prepare a lighting device for the display panel PNL1 and a lighting device for the display panel PNL2 separately.

[0039] 5 is a plan view showing one schematic configuration example of the display device of Comparative Example 1. The display device HMDr1 has a display panel PNL1r1 and a display panel PNL2r1. The display panel PNL1r1 and the display panel PNL2r1 are arranged symmetrically with respect to a virtual line KS.

[0040] The display panel PNL1r1 is formed in a polygonal shape, for example, an octagonal shape. The display panel PNL1r1 has sides EH11 and EH21 extending in a direction parallel to the first direction X, sides EV11 and EV21 extending in a direction parallel to the second direction Y, and a side EB11 provided on the sides EH11 and EV11 and extending in a direction having an acute angle with the first direction X. The direction having an acute angle with the first direction X is also referred to as a fourth direction. However, when the third direction Z is omitted, the direction is also referred to as a third direction.

[0041] An illumination device ILD1r1 is provided below the display panel PNL1r1. A light guide plate LG1r1 of the illumination device ILD1r1 has sides LH11, LH21, LV11, and LB11 extending in directions parallel to sides EH11, EH21, EV11, EV21, and EB11, respectively.

[0042] A reflector REF11 is provided along the sides EH21, EV21, and EB21. The reflector REF11 has a portion RV11 and a portion RB11 extending in directions parallel to the sides EV21 and EB11, respectively.

[0043] Side EH11, side EH21, side LH11, and side LH21 extend along the first direction X. Side EV11, side EV21, side LV11, side LV21, and portion RV11 extend along the second direction Y. Side EB11, side LB11, and portion RB11 extend in a direction forming an acute angle with the first direction X.

[0044] A plurality of light source elements LS11 are provided adjacent to a side EV11 of the display panel PNL1r1 and a side LV31 of the light guide plate LG1r1. The plurality of light source elements LS11 include a light source element LSr1 that emits red light, a light source element LSg1 that emits green light, and a light source element LSb1 that emits blue light. The light source element LSr1, the light source element LSg1, and the light source element LSb1 are arranged in this order along the second direction Y.

[0045] Sides LV11 and LV21 shown in Fig. 5 correspond to the first side face F3 and the second side face F4 shown in Fig. 4, respectively. Side LV31 of the light guide plate LG1, which extends in a direction parallel to the second direction Y, is located between sides LV11 and EV11. The area between sides EV11 and LV31 corresponds to the slope F5 shown in Fig. 4.

[0046] The display panel PNL2r1 is formed in a polygonal shape, for example, an octagonal shape. The display panel PNL2r1 has sides EH12 and EH22 extending in a direction parallel to the first direction X, sides EV12 and EV22 extending in a direction parallel to the second direction Y, and a side EB12 provided on the sides EH12 and EV12 and extending in a direction having an acute angle with the first direction X. The direction having an acute angle with the first direction X is also referred to as a fifth direction. However, when the third direction Z is omitted, the direction is also referred to as a fourth direction.

[0047] An illumination device ILD2r1 is provided below the display panel PNL2r1. The light guide plate LG2r1 of the illumination device ILD2r1 has sides LH12, LH22, LV12, and LB12 that extend in directions parallel to the sides EH12, EH22, EV12, EV22, and EB12, respectively.

[0048] A reflector REF12 is provided along the sides EH22, EV22, and EB22. The reflector REF12 has a portion RV12 and a portion RB12 extending in directions parallel to the sides EV22 and EB12, respectively.

[0049] Side EH12, side EH22, side LH12, and side LH22 extend along the first direction X. Side EV12, side EV22, side LV12, side LV22, and portion RV12 extend along the second direction Y. Side EB12, side LB12, and portion RB12 extend in a direction forming an acute angle with the first direction X.

[0050] A plurality of light source elements LS12 are provided adjacent to a side EV12 of the display panel PNL2r1 and a side LV32 of the light guide plate LG2r1. The plurality of light source elements LS12 include a light source element LSr2 that emits red light, a light source element LSg2 that emits green light, and a light source element LSb2 that emits blue light. The light source element LSr2, the light source element LSg2, and the light source element LSb2 are arranged in this order along the second direction Y.

[0051] In the display panel PNL1r1, the light LT emitted from the light source element LS11 enters the light guide plate LG1r1 from the side EV11. The main optical path of the light reflected by the portion RB11 becomes non-parallel to the first direction X. For this reason, there is a risk that the luminance distribution of the reflected light will not be uniform.

[0052] In the display panel PNL2r1, similarly to the display panel PNL1r1, the light LT emitted from the light source element LS12 enters the inside of the light guide plate LG2r1 from the side EV12. The main optical path of the light reflected by the portion RB12 becomes non-parallel to the first direction X. For this reason, there is a risk that the luminance distribution of the reflected light will not be uniform.

[0053] Therefore, the side LB11 of the light guide plate LG1r1 and the portion RB11 of the reflector REF11, and the side LB12 of the light guide plate LG1r2 and the portion RB12 of the reflector REF12 are each formed in a stepped shape to uniformize the luminance distribution of the reflected light. By uniformizing the luminance distribution of the reflected light, it is possible to uniformize the luminance distribution of the illumination light emitted from each of the illumination devices ILD1r1 and ILD2r1, and the image light obtained by modulating the illumination light by the display panel.

[0054] Fig. 6 is a plan view showing one schematic configuration example of a display device of Comparative Example 2. The display device HMDr2 shown in Fig. 6 differs from the display device HMDr1 shown in Fig. 5 in that a light guide plate is provided with stepped edges.

[0055] The display device HMDr2 has a display panel PNL1r2 and a display panel PNL2r2. The display panel PNL1r2 and the display panel PNL2r2 are arranged symmetrically with respect to a virtual line KS.

[0056] The lighting device ILD1r2 has a side LB11 between the side LV21 and the side LH11 of the light guide plate LG1r2. The side LB11 includes a side LB1a1 parallel to the first direction X and a side LB1b1 parallel to the second direction Y. The sides LB1a1 and LB1b1 are alternately arranged to configure the side LB11 in a staircase shape as a whole. Note that the sides LB1a1 and LB1b1 may be referred to as short sides to distinguish them from the other sides.

[0057] The portions RB1a1 and RB1b1 of the reflector REF11 are disposed opposite the sides LB1a1 and LB1b1. The portions RB1a1 and RB1b1 can be considered to be segments disposed parallel to the first direction X and the second direction Y, respectively. The portions RB1a1 and RB1b1 are disposed alternately one on top of the other, and as a whole constitute the portion RB11 having a staircase shape.

[0058] The lighting device ILD2r2 has a side LB12 between the side LV22 and the side LH12 of the light guide plate LG2r2. The side LB12 includes a side LB1a2 parallel to the first direction X and a side LB1b2 parallel to the second direction Y. The sides LB1a2 and LB1b2 are alternately arranged to configure the side LB12 in a staircase shape as a whole. Note that the sides LB1a2 and LB1b2 are sometimes called short sides to distinguish them from the other sides.

[0059] The portions RB1a2 and RB1b2 of the reflector REF12 are disposed opposite the sides LB1a2 and LB1b2. The portions RB1a2 and RB1b2 can be considered to be segments disposed parallel to the first direction X and the second direction Y, respectively. The portions RB1a2 and RB1b2 are alternately disposed one on top of the other, and as a whole constitute the portion RB12 having a staircase shape.

[0060] The shapes of the light guide plates LG1r1 and LG2r1 shown in Fig. 5 are line symmetrical to each other but are not identical. The shapes of the light guide plates LG1r2 and LG2r2 shown in Fig. 6 are line symmetrical to each other but are not identical. Therefore, two light guide plates must be prepared for one display device HMD, which may increase manufacturing costs.

[0061] In this embodiment, by providing a light guide plate that is symmetrical above and below, it is possible to obtain an illumination device that can be used for both the display panel PNL1 and the display panel PNL2. This makes it possible to reduce the manufacturing cost of the display device HMD.

[0062] Fig. 7 is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment. The display device HMD shown in Fig. 7 includes display panels PNL1 and PNL2, and illumination devices ILD1 and ILD2 facing the display panels PNL1 and PNL2, respectively.

[0063] The illumination device ILD1 shown in Fig. 7 differs from the illumination device ILD1r2 shown in Fig. 6 in that it has a side LB21 between the sides LV21 and LH21 of the light guide plate LG1. The side LB21 includes a side LB2a1 parallel to the first direction X and a side LB2b1 parallel to the second direction Y. The sides LB2a1 and LB2b1 are alternately arranged to form a staircase-shaped side LB21 as a whole.

[0064] The light guide plate LG1 has a step-shaped side LB21 at the top of the page and a step-shaped side LB11 at the bottom of the page. A virtual line passing through the center of the side LV21 of the light guide plate LG1 is defined as a virtual line CS. The light guide plate LG1 is vertically symmetrical with respect to the virtual line CS.

[0065] The illumination device ILD2 shown in Fig. 7 differs from the illumination device ILD2r2 shown in Fig. 6 in that it has a side LB22 between the sides LV22 and LH22 of the light guide plate LG2. The side LB22 includes a side LB2a2 parallel to the first direction X and a side LB2b2 parallel to the second direction Y. The sides LB2a2 and LB2b2 are alternately arranged to form a staircase-shaped side LB22 as a whole.

[0066] The light guide plate LG2 has a step-shaped side LB22 at the top of the page and a step-shaped side LB12 at the bottom of the page. The above-mentioned imaginary line CS passes through the center of the side LV22 of the light guide plate LG2. The light guide plate LG2 is vertically symmetrical with respect to the imaginary line CS, similar to the light guide plate LG1.

[0067] It is preferable that sides LB1a1, LB1a2, LB2a1, and LB2a2 have the same length along the first direction X. It is preferable that sides LB1b1, LB1b2, LB2b1, and LB2b2 have the same length along the second direction Y. It is preferable that sides LV21 and LV22 have the same length along the second direction Y. It is preferable that sides LH11, LH12, LH21, and LH22 have the same length along the first direction X.

[0068] The display panel PNL1 and the illumination device ILD1, and the display panel PNL2 and the illumination device ILD2 have the same shape. That is, the display panel PNL1 is the same as the display panel PNL2, and the illumination device ILD1 is the same as the illumination device ILD2. The display panel PNL1 and the illumination device ILD1 are rotated 180 degrees to obtain the display panel PNL2 and the illumination device ILD2. Alternatively, it can be said that the display panel PNL2 and the illumination device ILD2 are the display panel PNL1 and the illumination device ILD1 arranged symmetrically.

[0069] Therefore, one set of display panel and lighting device can be used as a combination of the display panel PNL1 and the lighting device ILD1, and as a combination of the display panel PNL2 and the lighting device ILD2. Unlike the above-mentioned Comparative Example 1 and Comparative Example 2, it is only necessary to provide a light guide plate of one shape, so that it is possible to reduce manufacturing costs.

[0070] The pitch of the staircase shape of the light guide plate LG1 and the light guide plate LG2, in other words, the length of the side LB1b1, the side LB2b1, the side LB2b1, and the side LB2b2, is preferably, for example, 4 mm or more and 5 mm or less, more specifically, 5 mm. However, the pitch is not limited to this and may be determined according to the pitch of the light source element LS11 and the light source element LS12.

[0071] The reflector REF11 is provided with not only the step-shaped portion RB11 but also the step-shaped portion RB21. The reflector REF11 is provided with the portions RB2a1 and RB2b1 facing the sides LB2a1 and LB2b1. The portions RB2a1 and RB2b1 can be said to be segments arranged parallel to the first direction X and the second direction Y, respectively. The portions RB2a1 and RB2b1 are arranged alternately and overlap each other to form the step-shaped portion RB21 as a whole.

[0072] The reflector REF12 is provided with a step-shaped portion RB21 and a step-shaped portion RB22. The reflector REF12 is provided with a portion RB1a2 and a portion RB1b2 facing the side LB1a2 and the side LB1b2. The portion RB1a2 and the portion RB1b2 can be said to be segments arranged parallel to the first direction X and the second direction Y, respectively. The portions RB1a2 and the portions RB1b2 are arranged alternately and overlap each other to form the step-shaped portion RB12 as a whole.

[0073] The reflector REF12 has a portion RB2a2 and a portion RB2b2 disposed opposite the side LB2a2 and the side LB2b2. The portion RB2a2 and the portion RB2b2 can be considered to be segments disposed parallel to the first direction X and the second direction Y, respectively. The portions RB2a2 and the portions RB2b2 are alternately disposed one on top of the other, and as a whole constitute the portion RB22 having a staircase shape.

[0074] Fig. 8 is a plan view showing a schematic configuration of the light guide plate LG1. Fig. 8 shows a flexible wiring board FPC2 connected to the light source element LS11 in addition to the configuration of the lighting device ILD1 shown in Fig. 7. The flexible wiring board FPC2 is provided close to the side LV31 of the light guide plate LG1.

[0075] The display device HMD of this embodiment has a light guide plate with two rectangular corners that are stepped and are vertically symmetrical. The lighting device having such a light guide plate also has a vertically symmetrical shape. Furthermore, the display panel also has a vertically symmetrical shape. By arranging two sets of such combinations of a display panel and a lighting device symmetrically, a display panel and a lighting device suitable for the display device HMD can be obtained.

[0076] <Configuration example 1> Fig. 9 is a plan view showing another example of the configuration of the illumination device used in the display device in the embodiment. The example shown in Fig. 9 is different from the example shown in Fig. 8 in that the corner on the side where the light source element is provided is also shaped like a staircase.

[0077] 9, the light guide plate LG1 of the lighting device ILD1 has a side LB31 between the sides LH11 and LV31 of the light guide plate LG1. The side LB31 includes a side LB3a1 parallel to the first direction X and a side LB3b1 parallel to the second direction Y. The sides LB3a1 and LB3b1 are alternately arranged to form the side LB31 in a staircase shape as a whole.

[0078] The light guide plate LG1 has a side LB41 between the side LH21 and the side LV31 of the light guide plate LG1. The side LB41 includes a side LB4a1 parallel to the first direction X and a side LB4b1 parallel to the second direction Y. The sides LB4a1 and LB4b1 are alternately arranged to configure the side LB41 in a staircase shape as a whole.

[0079] The side LB31 faces the side LB11 along the first direction X. The side LB41 faces the side LB21 along the first direction X. The sides LB31 and LB41 are arranged line-symmetrically with respect to a virtual line CS that passes through the center of the side LV21 of the light guide plate LG1.

[0080] From the side LH11 to the side LH21, a plurality of sides LB3a1, a plurality of sides LB3b1, a side LV31, a plurality of sides LB4a1, and a plurality of sides LB4b1 are provided along the second direction Y. From the side LH11 to the side LH21, a flexible wiring board FPC21, a flexible wiring board FPC22, a flexible wiring board FPC23, a flexible wiring board FPC24, and a flexible wiring board FPC25 are provided from the bottom to the top of the page.

[0081] The light source elements LS11 (light source elements LSr1, LSg1, and LSb1) adjacent to the sides LB31 and LB41, respectively, are arranged in a stepped manner. The flexible wiring boards FPC21 to FPC25 adjacent to the sides LB31 and LB41, respectively, are arranged in a stepped manner.

[0082] The light source element LSb1 is provided adjacent to the side LB3b1 connected to the side LH11. The light source element LSb1 is connected to a flexible wiring board FPC21 provided adjacent to the side LB3b1.

[0083] Light source element LSg1 is provided adjacent to the light source element LSb1 along the second direction Y. Light source element LSg1 is provided adjacent to another side LB3b1. Light source element LSg1 is connected to a flexible wiring board FPC22 provided adjacent to the side LB3b1.

[0084] The light source element LSr1 is provided adjacent to the side LB4b1 connected to the side LH21. The light source element LSr1 is connected to a flexible printed circuit FPC25 provided adjacent to the side LB4b1.

[0085] Light source element LSg1 is provided adjacent to light source element LSr1 along the opposite direction to the second direction Y. Light source element LSg1 is provided adjacent to another side LB4b1. Light source element LSg1 is connected to a flexible wiring board FPC24 provided adjacent to side LB4b1.

[0086] Light source element LSb1, light source element LSr1, light source element LSg1, light source element LSb1, and light source element LSr1 are provided adjacent to side LV31. Light source element LSb1, light source element LSr1, light source element LSg1, light source element LSb1, and light source element LSr1 adjacent to side LV31 are connected to flexible printed circuit board FPC23.

[0087] It is preferable that the distance between the side LB1b1 and the side LB3b1, the distance between the side LV21 and the side LV31, and the distance between the side LB2b1 and the side LB4b1 are all the same along the first direction X. This distance is defined as a length w1.

[0088] By making the distance between sides LB1b1 and LB3b1, the distance between sides LV21 and LV31, and the distance between sides LB2b1 and LB4b1 all the same length w1, it is possible to make the pattern provided on the light guide plate LG1 uniform.

[0089] The pattern provided on the light guide plate LG1 is, for example, a plurality of grooves extending along the first direction X. Each of the plurality of grooves has a V-shaped or U-shaped cross section. By providing a plurality of grooves, the light incident from the light source element LS11 can be efficiently guided to the opposite light incident side.

[0090] Fig. 10 is a cross-sectional view showing an example of a schematic configuration of a display device according to an embodiment. The display device HMD shown in Fig. 10 is different from the display device HMD shown in Fig. 7 in that the corner of the side of the light guide plate on which the light source element is provided is also stepped. Fig. 10 shows a more detailed configuration of the illumination device ILD1 shown in Fig. 9. However, in order to make the drawing easier to see, a flexible wiring board connected to the light source element is omitted in Fig. 10.

[0091] The light guide plate LG1 of the illumination device ILD1 shown in FIG. 10 has sides LB51 and LB61 in addition to the sides LB31 and LB41 described in FIG.

[0092] The side LB51 is provided between the side LH11 and the side LV11 of the light guide plate LG1. The side LB51 includes a side LB5a1 parallel to the first direction X and a side LB5b1 parallel to the second direction Y. The sides LB5a1 and LB5b1 are alternately arranged to form the side LB51 in a staircase shape as a whole.

[0093] The side LB61 is provided between the side LH21 and the side LV11 of the light guide plate LG1. The side LB61 includes a side LB6a1 parallel to the first direction X and a side LB6b1 parallel to the second direction Y. The sides LB6a1 and LB6b1 are alternately arranged to form the side LB61 in a staircase shape as a whole.

[0094] The light source elements LS11 (light source elements LSr1, light source elements LSg1, and light source elements LSb1) adjacent to the sides LB31 and LB41, respectively, are arranged in a stepped manner.

[0095] A light guide plate LG2 of an illumination device ILD2 shown in FIG. 10 has a side LB32, a side LB42, a side LB52, and a side LB62, similar to the light guide plate LG1.

[0096] Side LB32 is provided between sides LH12 and LV32 of light guide plate LG2. Side LB32 includes a side LB3a2 parallel to the first direction X and a side LB3b2 parallel to the second direction Y. Sides LB3a2 and LB3b2 are alternately arranged to form side LB32 having a staircase shape as a whole.

[0097] Side LB42 is provided between sides LH22 and LV32 of light guide plate LG2. Side LB42 includes a side LB4a2 parallel to the first direction X and a side LB4b2 parallel to the second direction Y. Sides LB4a2 and LB4b2 are alternately arranged to form side LB42 having a staircase shape as a whole.

[0098] The side LB52 is provided between the side LH12 and the side LV12 of the light guide plate LG2. The side LB52 includes a side LB5a2 parallel to the first direction X and a side LB5b2 parallel to the second direction Y. The sides LB5a2 and LB5b2 are alternately arranged to form the side LB52 in a staircase shape as a whole.

[0099] The side LB62 is provided between the side LH22 and the side LV12 of the light guide plate LG2. The side LB62 includes a side LB6a2 parallel to the first direction X and a side LB6b2 parallel to the second direction Y. The sides LB6a2 and LB6b2 are alternately arranged to form the side LB62 in a staircase shape as a whole.

[0100] The light source elements LS12 (light source elements LSr2, light source elements LSg2, and light source elements LSb2) adjacent to the sides LB32 and LB42, respectively, are arranged in a stepped manner.

[0101] It is preferable that the distances along the first direction X between sides LB1b1 and LB3b1, between sides LV21 and LV31, between sides LB2b1 and LB4b1, between sides LB1b2 and LB3b2, between sides LV22 and LV32, and between sides LB2b2 and LB4b2 are all the same.

[0102] Alternatively, sides LB51, LB61, LB52, and LB62 may not be provided, and only sides LV11 and LV12 may be provided along the second direction Y. That is, in light guide plates LG1 and LG2, the outermost sides on the sides where the light source elements are provided may not have a stepped shape, but may simply be straight sides.

[0103] The display panel PNL2 and the illumination device ILD2 are obtained by rotating the display panel PNL1 and the illumination device ILD1 by 180 degrees. Alternatively, the display panel PNL2 and the illumination device ILD2 can be said to be obtained by arranging the display panel PNL1 and the illumination device ILD1 symmetrically. In this way, one set of a display panel and an illumination device can be used as another combination of a display panel and an illumination device. Therefore, it is not necessary to manufacture the display panels and illumination devices for the right eye and the left eye separately, and the manufacturing cost can be reduced.

[0104] In this disclosure, the sides LH11 and LH12 shown in Figures 7 and 8 are referred to as the first and second sides, respectively. The sides LV21 and LV31 are referred to as the third and fourth sides, respectively. The sides LB11 and LB21 are referred to as the fifth and sixth sides, respectively.

[0105] The sides LB1a1 and LB1b1 of the side LB11 are referred to as the first short side and the second short side, respectively. The sides LB2a1 and LB2b1 of the side LB21 are referred to as the third short side and the fourth short side, respectively.

[0106] 9 and 10 are referred to as the seventh and eighth sides. Sides LB3a1 and LB3b1 of side LB31 are referred to as the fifth and sixth short sides. Sides LB4a1 and LB4b1 of side LB41 are referred to as the seventh and eighth short sides.

[0107] The portions RV11, RB11, and RB21 of the reflector REF11 shown in Fig. 7 and Fig. 10 are also referred to as the first portion, the second portion, and the third portion, respectively. The portions RB1a1 and RB1b1 are also referred to as the first segment and the second segment, respectively. The portions RB2a1 and RB2b1 are also referred to as the third segment and the fourth segment, respectively.

[0108] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0109] EB11...side, EB21...side, EH11...side, EH21...side, EV11...side, EV21...side, HMD...display device, ILD1...illumination device, LB11...side, LG1...light guide plate, LS11...light source element, LV11...side, PNL1...display panel, PX...pixel, RB11...portion, REF11...reflector, RV11...portion

Claims

1. a light guide plate having a first side and a second side extending in a first direction, a third side and a fourth side extending in a second direction intersecting the first direction, a fifth side provided between the first side and the third side, and a sixth side provided between the second side and the third side; A plurality of light source elements provided adjacent to the fourth side; Equipped with The fifth side has a first short side extending in the first direction and a second short side extending in the second direction, which are alternately arranged, The sixth side has a third short side extending in the first direction and a fourth short side extending in the second direction, which are alternately arranged.

2. The lighting device according to claim 1 , wherein the light source elements are arranged adjacent to the fourth side.

3. the light guide plate further includes a seventh side provided between the fourth side and the third side, and an eighth side provided between the fourth side and the third side, The seventh side has a fifth short side extending in the first direction and a sixth short side extending in the second direction, which are alternately arranged, The lighting device according to claim 1 , wherein the eighth side includes a seventh short side extending in the first direction and an eighth short side extending in the second direction, the seventh short side being alternately arranged.

4. The lighting device according to claim 3 , wherein the light source elements are arranged adjacent to the sixth short side, the fourth short side, and the eighth short side.

5. The illumination device according to claim 1 , wherein each of the light source elements is a laser light source that emits laser light.

6. a reflector including a first portion parallel to the third side, a second portion having a staircase shape, and a third portion having a staircase shape; The second portion has first segments extending in the first direction and second segments extending in the second direction, the first segments being arranged alternately; The lighting device of claim 1 , wherein the third portion includes third segments extending in the first direction and fourth segments extending in the second direction, the third segments being arranged alternately.

7. the first segment and the second segment face the first short side and the second short side, respectively; The lighting device according to claim 6 , wherein the third segment and the fourth segment face the third short side and the fourth short side, respectively.

8. A display device including a display panel and an illumination device, The lighting device includes: a light guide plate having a first side and a second side extending in a first direction, a third side and a fourth side extending in a second direction intersecting the first direction, a fifth side provided between the first side and the third side, and a sixth side provided between the second side and the third side; A plurality of light source elements provided adjacent to the fourth side; Equipped with The fifth side includes a first short side extending in the first direction and a second short side extending in the second direction, which are alternately arranged. and a second short side extending The sixth side includes a third short side extending in the first direction and a third short side extending in the second direction, which are alternately arranged. and a fourth short side extending in the direction of the first short side.

9. The display device according to claim 8 , wherein the plurality of light source elements are arranged adjacent to the fourth side.

10. the light guide plate further includes a seventh side provided between the fourth side and the third side, and an eighth side provided between the fourth side and the third side, The seventh side has a fifth short side extending in the first direction and a sixth short side extending in the second direction, which are alternately arranged, The display device according to claim 8 , wherein the eighth side includes a seventh short side extending in the first direction and an eighth short side extending in the second direction, the seventh short side being alternately arranged.

11. The display device according to claim 10 , wherein the light source elements are arranged adjacent to the sixth short side, the fourth short side, and the eighth short side.

12. The display device according to claim 8 , wherein each of the light source elements is a laser light source that emits laser light.

13. a reflector including a first portion parallel to the third side, a second portion having a staircase shape, and a third portion having a staircase shape; The second portion has first segments extending in the first direction and second segments extending in the second direction, the first segments being arranged alternately; The display device according to claim 8 , wherein the third portion has third segments extending in the first direction and fourth segments extending in the second direction, the third segments being arranged alternately.

14. the first segment and the second segment face the first short side and the second short side, respectively; The display device according to claim 13 , wherein the third segment and the fourth segment face the third short side and the fourth short side, respectively.

15. The display device according to claim 8 , wherein the display panel is a polygonal display panel.

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