Lighting device and display device

Abstract

The lighting device includes a light guide plate, a plurality of light source elements, and a reflection plate including a first portion parallel to a second edge of the light guide plate and a second portion parallel to a third edge of the light guide plate, the third edge having first short edges extending in the first direction and second short edges extending in the second direction alternately arranged, the second portion having first slices extending in the first direction and second slices extending in the second direction alternately overlapped.

Description

[0001] Cross-references to related applications

[0002] This application is based on and asserts the priority of Japanese Patent Application No. 2021-173377, filed on October 22, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present invention relate to lighting devices and display devices. Background Technology

[0004] In recent years, technologies that use head-mounted displays (HMDs) worn on the user's head to provide virtual reality (VR) have gained attention. Summary of the Invention

[0005] The purpose of this embodiment is to provide an illumination device that emits light with uniform brightness distribution, and a display device that emits image light with uniform brightness distribution by being illuminated by the illumination light.

[0006] One embodiment of the lighting device includes:

[0007] A light guide plate has a first side extending along a first direction, a second side extending along a second direction intersecting the first direction, and a third side disposed between the first side and the second side;

[0008] Multiple light source elements are positioned opposite the fourth side of the light guide plate, which is opposite the second side; and

[0009] The reflector has a first portion parallel to the second side and a second portion parallel to the third side.

[0010] The third side has alternating short sides extending along the first direction and short sides extending along the second direction.

[0011] The second part has alternating overlapping first slices extending along the first direction and second slices extending along the second direction.

[0012] In another embodiment, the display device includes a lighting device and an octagonal display panel.

[0013] The lighting device includes:

[0014] A light guide plate has a first side extending along a first direction, a second side extending along a second direction intersecting the first direction, and a third side disposed between the first side and the second side;

[0015] Multiple light source elements are positioned opposite the fourth side of the light guide plate, which is opposite the second side; and

[0016] The reflector has a first portion parallel to the second side and a second portion parallel to the third side.

[0017] The octagonal display panel is a display panel in which a first rectangular region and two second trapezoidal regions sandwiching the first region are arranged along the second direction.

[0018] The third side has alternating short sides extending along the first direction and short sides extending along the second direction.

[0019] The second part has alternating overlapping first slices extending along the first direction and second slices extending along the second direction.

[0020] One embodiment of the display device includes a lighting device and an octagonal display panel.

[0021] The lighting device includes:

[0022] A light guide plate has a first side extending along a first direction, a second side extending along a second direction intersecting the first direction, and a third side disposed between the first side and the second side;

[0023] Multiple light source elements are positioned opposite the fourth side of the light guide plate, which is opposite the second side; and

[0024] The reflector has a first portion parallel to the second side and a second portion parallel to the third side.

[0025] The octagonal display panel is a display panel in which a first rectangular region and two second trapezoidal regions sandwiching the first region are arranged along the second direction.

[0026] The third side has alternating short sides extending along the first direction and short sides extending along the second direction.

[0027] The second part has a plurality of slices that extend along the second direction and are separated from each other. Attached Figure Description

[0028] Figure 1 This is a perspective view showing an example of the appearance of the display device according to this embodiment.

[0029] Figure 2 This is a perspective view showing the schematic structure of the display panel provided by the display device of this embodiment.

[0030] Figure 3 This is a cross-sectional view showing an example of the general structure of a display device.

[0031] Figure 4 This is a cross-sectional view showing an example of the general structure of a lighting device.

[0032] Figure 5 This is a top view of one of the schematic structural examples of a display device for comparison.

[0033] Figure 6 This is a top view showing an example of the general structure of a display device.

[0034] Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0035] Figure 8 This is a top view showing an example of the structure of the display device in the embodiment.

[0036] Figure 9A It means along Figure 8 A cross-sectional view of an example of the schematic structure of the light guide plate with lines AA1-AA2.

[0037] Figure 9B It means along Figure 8 A cross-sectional view of an example of the schematic structure of the light guide plate along lines AB1-AB2.

[0038] Figure 10 This is a top view showing an example of the structure of the display device in the embodiment.

[0039] Figure 11 yes Figure 10 A magnified view of a portion of the image. Detailed Implementation

[0040] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the disclosure is merely an example, and suitable modifications that are more readily conceived by those skilled in the art while maintaining the spirit of the invention are naturally included within the scope of the present invention. Additionally, to make the description clearer, the drawings sometimes schematically show the width, thickness, shape, etc., of various parts compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in this specification and the various drawings, the same reference numerals are used for elements that are the same as those previously described with respect to the figures, and detailed descriptions are appropriately omitted.

[0041] Hereinafter, a display device according to one embodiment will be described in detail with reference to the accompanying drawings.

[0042] In this embodiment, the first direction X, the second direction Y, and the third direction Z are orthogonal to each other, but they may also intersect at an angle other than 90 degrees. The direction towards the tip of the arrow pointing towards the third direction Z is defined as up or above, and the direction opposite to the tip of the arrow pointing towards the third direction Z is defined as down or below. In addition, the first direction X, the second direction Y, and the third direction Z are sometimes referred to as the X direction, the Y direction, and the Z direction, respectively.

[0043] Furthermore, when designated as "a second component above the first component" or "a second component below the first component," the second component may be in contact with the first component, or it may be located in a position separate from the first component. In the latter case, a third component may be sandwiched between the first component and the second component. On the other hand, when designated as "a second component above the first component" or "a second component below the first component," the second component is in contact with the first component.

[0044] Furthermore, assuming an observation position where the display device is observed at the tip of the arrow pointing in the third direction Z, the view taken from this position toward the XY plane defined by the first direction X and the second direction Y is called a top view. Observing 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, is called a sectional view.

[0045] [Implementation Method]

[0046] Figure 1 This is a perspective view showing an example of the appearance of the display device according to this embodiment. In this embodiment, the display device includes a head-mounted display (HMD) worn on a user's head. Such a display device is used to provide, for example, virtual reality (VR) to a user wearing the display device on their head.

[0047] like Figure 1 As shown, the display device HMD includes display panel PNL1 and display panel PNL2. Sometimes, display panels PNL1 and PNL2 are also referred to as the first display panel and the second display panel, respectively. Display panels PNL1 and PNL2 are independent display panels.

[0048] Display panels PNL1 and PNL2 are respectively configured to be positioned in front of the user's left and right eyes when the user's USR is wearing the display device HMD on their head. In this embodiment, display panels PNL1 and PNL2 are assumed to be liquid crystal display panels with liquid crystal layers.

[0049] Figure 2 This is a perspective view showing the schematic structure of the display panel included in the display device of this embodiment. Here, the structure of the display panel PNL1 will be mainly described.

[0050] Figure 2 The display panel PNL1 shown includes a first substrate SUB1 and a second substrate SUB2 opposite to the first substrate SUB1. Furthermore, the display panel PNL1 has a display area DA for displaying images. Moreover, the display panel PNL1 includes a plurality of pixels PX arranged in a matrix, for example, within the display area DA.

[0051] In addition, the display panel PNL1 includes: a driver IC chip IC1 that drives the display panel PNL1 and a flexible circuit board FPC1 that transmits control signals to the display panel PNL1. The flexible circuit board FPC1 is connected to a control module (host computer) that controls the operation of the display device HMD.

[0052] exist Figure 2 In the example shown, 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 top view of the first substrate SUB1 and the second substrate SUB2 is octagonal. This shape can also be described as the shape after the corners of a rectangle have been cut off. The top view of the display panel PNL1 is octagonal. However, the shapes of the display panels PNL1 and PNL2 are not limited to this; they can be polygonal as long as they are not. The shape of the display panel is only required to prevent contact with the nose of the user USR (described later), and only requires that the corners approaching the nose of the user USR have been cut off.

[0053] Figure 3 This is a cross-sectional view illustrating an example of the schematic structure of a display device. In addition to the first substrate SUB1 and the second substrate SUB2 described above, the display panel PNL1 also includes a sealing element SAL and a liquid crystal layer LC. In the display panel PNL1, the first substrate SUB1 and the second substrate SUB2 are bonded together by the sealing element SAL. The liquid crystal layer LC is sealed between the sealing element SAL and each of the substrates SUB1 and SUB2.

[0054] In a display device (HMD), a first polarizing plate PL1 is attached to the lower surface of a first substrate SUB1 (the surface not opposite to the second substrate SUB2). A second polarizing plate PL2 is attached to the upper surface of the second substrate SUB2 (the surface not opposite to the first substrate SUB1). The polarization axes of the first polarizing plate PL1 and the second polarizing plate PL2 are orthogonal to each other.

[0055] The display device HMD has an illumination unit ILD (also called a backlight unit) on the back side of the display panel PNL1 (i.e., the opposite side of the display surface). The illumination unit ILD is connected to the control module. In the display device HMD, by illuminating the display panel PNL1 with the illumination unit ILD, images can be displayed on the display panel PNL1.

[0056] The display device HMD includes a prism sheet PS between the display panel PNL1 and the illumination device ILD. Additionally, the display device HMD includes a diffuser sheet DS (diffuse layer) between the prism sheet PS and the display panel PNL1. The prism sheet PS, for example, includes multiple prisms extending parallel to the second direction Y. These prisms are formed, for example, on the lower surface of the prism sheet PS (the surface opposite the illumination device ILD). However, these prisms may also be formed on the upper surface of the prism sheet PS (the surface opposite the display panel PNL1).

[0057] The prism sheet PS transforms the light illuminated by the illumination device ILD into light substantially parallel to the third direction Z. Here, "substantially parallel to the third direction Z" includes not only light that is strictly parallel to the third direction Z, but also light whose tilt relative to the third direction Z is significantly smaller by the prism sheet PS compared to when illuminated by the illumination device ILD. Furthermore, from the viewpoint of maintaining the polarization of the light illuminated by the illumination device ILD, the prism of the prism sheet PS is preferably formed on its lower surface. The light after passing through the prism sheet PS is diffused by the diffuser DS and illuminates the display panel PNL1. Even when the field of view of the light passing through the prism sheet PS is narrow, the field of view can be widened by using the diffuser DS to diffuse the light.

[0058] In addition, Figure 2 and Figure 3 The text describes display panel PNL1, but also mentions display panel PNL2, which has similar characteristics. Figure 2 and Figure 3 The same structure as described in the text.

[0059] Figure 4 This is a cross-sectional view illustrating an example of the schematic structure of a lighting device. The light guide plate LG of the lighting device ILD has a first main surface F1 opposite to the display panel PNL1, a second main surface F2 opposite to the first main surface F1, a first side surface F3, and a second side surface F4 opposite to the first side surface F3. The light source element LS1 is opposite to the inclined surface F5 between the second main surface F2 and the first side surface F3. Optical elements such as lenses can also be further arranged between the light source element LS1 and the inclined surface F5 to adjust the width and angle of the light from the light source element LS1.

[0060] The lighting device ILD has a reflector REF1 opposite to the second side F4 and a reflector REF2 opposite to the second main surface F2.

[0061] 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, starting from the direction closest to the light source element LS1. The length of each region along the first direction X increases in the order of the first region A1, the third region A3, and the second region A2.

[0062] The thickness, i.e., distance d1, of the light guide plate LG in the first region A1 increases from the first side F3 towards the boundary between the first region A1 and the second region A2. The thickness, i.e., distance d2, 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 towards the boundary between the second region A2 and the third region A3. Figure 4 In the example shown, the thickness of the light guide plate LG in the third region A3, i.e., the distance d3, is constant. The distance d3 is longer than the distances d1 and d2 of the positions in the first region A1 and the second region A2, respectively (d3 > d1, d3 > d2).

[0063] The first region A1 is inclined at a first angle θ1 relative to the first main surface F1. The second region A2 is inclined at a second angle θ2 relative to the first main surface F1. Both angles θ1 and θ2 are acute angles. Angle θ1 is greater than angle θ2. In addition, in this embodiment, angle θ1 is an acute angle, but it is not limited to this; angle θ1 can also be 90° or an obtuse angle.

[0064] By setting the third region A3, the brightness distribution of light emitted from the first main surface F1 can be made more uniform. Consider the case where the third region A3 is not set, i.e., the case where the flat portion is not set. Light incident from the light source element LS1 onto the light guide plate LG propagates inside the light guide plate LG and is reflected by the reflector REF1. Without the third region A3, the light reflected by the reflector REF1 is reflected by the protrusion (also called a groove or prism) provided below the light guide plate LG, and the total internal reflection condition of the first main surface F1 is not satisfied. It is emitted from the first main surface F1 of the light guide plate LG as the emitted light LO. At this time, without the third region A3, the light reflected by the protrusion near the reflector REF1 travels in the opposite direction to the first direction X before being emitted from the first main surface F1. That is, no light is emitted from the vicinity of the reflector REF1 on the first main surface F1, which may result in uneven brightness of the emitted light on the first main surface F1.

[0065] However, when the third region A3 is provided, the light reflected from the protrusion near the second region A2 in the third region A3 is reflected again at the top of the reflector REF1 and then emitted from near the reflector REF1 of the first main surface F1. This suppresses uneven brightness of the emitted light and improves the uniformity of the brightness distribution.

[0066] Here, the optical path from the light source element emitted from the illumination device ILD is described. The emitted light from the light source element LS1 is incident on the light guide plate LG via the inclined plane F5. The incident light LT undergoes repeated total internal reflection between the first principal surface F1 and the second principal surface F2 of the light guide plate LG, extending along the first direction X. The light LT reaching the reflector REF1 is reflected by the reflector REF1. The reflected light LT extends in the direction opposite to the first direction X. The light LT incident on the protrusion (also called a groove or prism) provided below the light guide plate LG does not satisfy the total internal reflection condition and is emitted as the emitted light LO from the first principal surface F1 of the light guide plate LG. The brightness of the light LT reaching the reflector REF1 is sufficiently diffused and homogenized in the second direction Y. Therefore, the brightness of the light LO emitted from the first principal surface F1 becomes uniform in the second direction Y. The emitted light LO is the illumination light of the illumination device ILD.

[0067] The light source element LS1 can use a laser source such as a semiconductor laser (laser diode) that emits laser light. The laser can be diffuse light that extends centered on the direction of illumination, or it can be a polarized laser.

[0068] In the display device HMD of this embodiment, as described above, two display panels, PNL1 and PNL2, are required. The shape of each display panel after its corners have been cut off prevents the display panel from contacting the nose of the user (USR).

[0069] However, at the corner that has been cut off, the reflected light may become uneven. Figure 5 This is a top view showing one of the schematic structural examples of a comparative display device. In the display device HMDr, the polygonal, for example octagonal, display panel PNL1 has: sides EH1 and EH2 extending in a direction parallel to the first direction X, sides EV1 and EV2 extending in a direction parallel to the second direction Y, and a side EB1 provided on sides EH1 and EV1 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 the fourth direction. However, when the third direction Z is omitted, this direction is also referred to as the third direction.

[0070] An illumination device ILD is provided below the display panel PNL1. The light guide plate LG of the illumination device ILD has edges LH1, LH2, LV1 and LB1 extending in directions parallel to edges EH1, EH2, EV1, EV2 and EB1 respectively.

[0071] A reflector REF1 is provided along edges EH2, EV2, and EB2. The reflector REF1 has portions RV1 and RB1 extending in directions parallel to edges EV2 and EB1, respectively.

[0072] Edges EH1, EH2, LH1, and LH2 extend along the first direction X. Edges EV1, EV2, LV1, LV2, and a portion of RV1 extend along the second direction Y. Edges EB1, LB1, and a portion of RB1 extend along a direction having an acute angle with the first direction X.

[0073] A plurality of light source elements LS1 are disposed adjacent to the edge EV1 of the display panel PNL1 and the edge LV3 of the light guide plate LG. The plurality of light source elements LS1 include a light source element LSR that emits red light, a light source element LSg that emits green light, and a light source element LSb that emits blue light. The light source elements LSR, LSg, and LSb are arranged sequentially along the second direction Y.

[0074] Figure 5 The edges LV1 and LV2 shown are respectively with Figure 4 The first side F3 and the second side F4 shown correspond to each other. Between side LV1 and side EV1, there exists a light guide plate LG with side EV3 extending in a direction parallel to the second direction Y. The region between side EV1 and side EV3 corresponds to Figure 4 The inclined plane F5 is shown.

[0075] Light LT emitted from light source element LS1 enters the interior of light guide plate LG from edge EV2. For example... Figure 4 As explained, the light LT1, reflected by reflector REF1, is emitted upwards (in the third direction Z) as illumination. The main optical path of light LT1, after partial reflection by RV1 in reflector REF1, is parallel to the first direction X. Therefore, light LT1 becomes an emitted light with a uniform brightness distribution. However, the main optical path of light LT2, after partial reflection by RB1, is not parallel to the first direction X. Therefore, the brightness distribution of light LT2 may not achieve uniformity.

[0076] In this embodiment, by making the edge LB1 of the light guide plate LG and part RB1 of the reflector REF1 into a stepped shape, the brightness distribution of the reflected light is made uniform. By achieving uniformity in the brightness distribution of the reflected light, it is possible to achieve uniformity in the brightness distribution of the illumination light emitted from the illumination device ILD and the image light obtained by modulating the illumination light using the display panel.

[0077] Figure 6 This is a top view illustrating an example of the schematic structure of a display device. Figure 6 In the HMD display device shown, there is a side LB1 between side LV2 and side LH1 of the light guide plate LG1. Side LB1 includes side LB1a, which is parallel to the first direction X, and side LB1b, which is parallel to the second direction Y. Sides LB1a and LB1b are arranged alternately to form a stepped shape as a whole. In addition, to distinguish them from other sides, sides LB1a and LB1b are sometimes referred to as short sides.

[0078] Parts RB1a and RB1b, which are opposite to edges LB1a and LB1b, are arranged with reflectors REF1. Parts RB1a and RB1b can be described as slices arranged parallel to the first direction X and the second direction Y, respectively. Parts RB1a and RB1b are alternately overlapped, forming a stepped shape of part RB1.

[0079] Figure 7 yes Figure 6 A magnified view of a portion of the image. Light LT, propagating along the first direction X, is reflected at part of RB1b. The reflected light LTa also propagates in the opposite direction to the first direction X. Similar to light LT1, light LTa is emitted above the light guide plate LG as a uniformly bright emitted light.

[0080] The light LT actually propagates in the light guide plate LG at a slightly tilted angle relative to the first direction X. In this case, it is also emitted from the edge LB1b of the light guide plate LG toward the reflector REF1. The emitted light LTa is partially reflected by RB1b and then re-enters the light guide plate LG.

[0081] Light LT propagates in the light guide plate LG at a slightly tilted angle relative to the first direction X, and thus sometimes reaches edge LB1a before reaching edge LB1b of the light guide plate LG. In this case, light LT is totally internally reflected at edge LB1a of the light guide plate LG. After total internal reflection, light LT is emitted from edge LB1b of the light guide plate LG toward reflector REF1. The emitted light LTb is partially reflected at RB1b and re-enters the light guide plate LG.

[0082] In both LTa and LTb, light is emitted above the light guide plate LG in the same direction as light LT1.

[0083] Part of RB1b extends in a direction parallel to the second direction Y, just like part of RV1. The main optical paths of the light LTa and LTb reflected from part of RB1b are approximately parallel to the first direction X. Therefore, the brightness distribution of light LTa and LTb becomes uniform.

[0084] In this embodiment, the lengths dx1 of edge LB1a and dy1 of edge LB1b of the light guide plate LG are both 1 mm. The overall length of the stepped edge LB1 along the first direction X and along the second direction Y is 10 mm. However, these lengths are not limited to these and can be determined appropriately as needed.

[0085] According to this embodiment, an illumination device that emits light with uniform brightness distribution and a display device that emits image light with uniform brightness distribution by being illuminated by the illumination light can be obtained.

[0086] <Structure Example 1>

[0087] Figure 8 This is a top view illustrating other structural examples of the display device in the embodiment. Figure 8 In the structural example shown, with Figure 6 Compared to the structural example shown, the difference lies in that the output of the light source element is changed based on the shape of the display panel.

[0088] The display panel PNL1 has a polygonal shape. For example, a polygon can be exemplified by the shape of a rectangle with its corners cut off, i.e., an octagon. An octagon can be described as consisting of a rectangle and two trapezoids enclosing that rectangle. Figure 8 In this diagram, rectangular and trapezoidal regions are designated as AR1 and AR2, respectively. Regions AR2, AR1, and AR2 are arranged along the second direction Y. In other words, it can be said that region AR1 is sandwiched between two regions AR2 along the second direction Y.

[0089] Region AR1 includes edge EV1 and edge EV2. Region AR2 includes edge EH1, edge EH2, edge EB1, and edge EV2.

[0090] Furthermore, in this structural example, an octagonal shape is listed as an example of a polygonal shape, but the shape of the display panel PNL1 is not limited to this. In addition to the octagon, a pentagonal shape obtained by cutting off one corner of a rectangle can also be given.

[0091] The light source element arranged adjacent to region AR1 is designated as light source element LS11. Light source element LS11 includes light source element LSR11 that emits red light, light source element LSg11 that emits green light, and light source element LSb11 that emits blue light.

[0092] The light source element configured adjacent to region AR2 is designated as light source element LS12. Light source element LS12 includes light source element LSR12 that emits red light, light source element LSg12 that emits green light, and light source element LSb12 that emits blue light.

[0093] Light emitted from light source element LS11 is emitted from region AR1, and light emitted from light source element LS12 is emitted from region AR2. Since the area of ​​region AR1 is larger than that of region AR2, the brightness of region AR2 is higher when the light emitted from light source element LS11 and light emitted from light source element LS12 have the same intensity.

[0094] Therefore, in this structural example, the intensity of the light emitted from the light source element LS12 is less than the intensity of the light emitted from the light source element LS11. As a result, the brightness of regions AR1 and AR2 is equal, enabling uniform display throughout the display panel PNL1.

[0095] To ensure uniform brightness in both regions AR1 and AR2, the height of the protrusions (grooves) of the light guide plate LG is varied.

[0096] Figure 9A It means along Figure 8 A cross-sectional view of an example of the schematic structure of the light guide plate with lines AA1-AA2. Figure 9B It means along Figure 8 A cross-sectional view of an example of the schematic structure of the light guide plate along lines AB1-AB2. That is, Figure 9A The cross-sectional structure of region LR1 of the light guide plate LG that overlaps with region AR1 is shown. Figure 9B This shows the cross-sectional structure of region LR2 of the light guide plate LG that overlaps with region AR2.

[0097] A protrusion CX extending along the second direction Y is provided on the second main surface F2 of the light guide plate LG. For example... Figure 9A As shown, the height of the protrusion CX on the light source element side (also known as the light input side) of region LR1 of the light guide plate LG is set to HXA1. The height of the protrusion CX on the side opposite to the light source element side (also known as the opposite side of the light source element or the reverse input side) of region LR1 is set to HXA2. The so-called light source element side refers to the area near the inclined surface F5 and the first side surface F3, and the opposite side of the light source element refers to the area near the second side surface F4.

[0098] like Figure 9B As shown, the height of the protrusion CX on the light source element side of region LR2 of the light guide plate LG is set to HXB1. The height of the protrusion CX on the opposite side of the light source element of region LR2 is set to HXB2. On the light source element side, regarding the heights of the protrusion CX of regions LR1 and LR2 located at the same position in the first direction X, region LR2 is higher. That is, HXB1 > HXB1. On the other hand, on the opposite side of the light source element, regarding the heights of the protrusion CX of regions LR1 and LR2 located at the same position in the first direction X, region LR2 is lower. That is, HXB2 <HXA2。

[0099] To achieve uniform brightness in region AR1, the height of the protrusion CX in region LR1 of the light guide plate LG is higher on the light source element side and lower on the opposite side. Similarly, the height of the protrusion CX in region LR2 of the light guide plate LG is also higher on the light source element side and lower on the opposite side. However, the height distribution of the protrusion CX used to achieve uniform brightness in regions AR1 and AR2 is different in regions LR1 and LR2. As described above, if HXB1 > HXA1 and HXB2 < HXA2, uniform light emission can be obtained in regions AR1 and AR2.

[0100] Furthermore, since the display area of ​​the display panel PNL1 is insufficient in area LR2, the protrusion CX is not required in this part.

[0101] In this structural example, it also achieves the same effect as the implementation method.

[0102] <Structure Example 2>

[0103] Figure 10 This is a top view illustrating other structural examples of the display device in the embodiment. Figure 10 In the structural example shown, with Figure 8 Compared to the structural example shown, the difference is that only the portion of the reflector extending along the second direction Y is provided. Figure 11 yes Figure 10 A magnified view of a portion of the image.

[0104] exist Figure 6 In the process, the reflector REF1 has a portion RB1a extending along a first direction X and a portion RB1b extending along a second direction Y. On the other hand, in Figure 10 In this configuration, portion RB1a is not provided. That is, the reflector REF1 is composed of portion RV1 extending along the second direction Y and shorter slices, i.e., portions RB1b, extending along the second direction Y. Multiple portions RB1b are provided separately from each other.

[0105] like Figure 7 As explained, only a portion RB1b of the reflector REF1 is reflected by the light LT. Therefore, the light LT does not incident on the portion RB1a of the reflector REF1. Thus, in this structural example, the portion RB1 of the reflector REF1 is composed only of the portion RB1b, without the portion RB1a. In this structure, light emitted from the edge LB1b of the light guide plate LG can also be reflected by the portion RB1b and re-incidentally onto the light guide plate LG.

[0106] In this structural example, it also achieves the same effect as the implementation method.

[0107] In this embodiment, edges LH1, LV2, LB1, and LV3 of the light guide plate LG are referred to as the first edge, the second edge, the third edge, and the fourth edge, respectively. Edges LB1a and LB1b of the light guide plate LG are also referred to as the first short edge and the second short edge, respectively.

[0108] Parts RV1 and RB1 of the reflector REF1 are also referred to as the first part and the second part, respectively. Parts RB1a and RB1b are also referred to as the first slice and the second slice, respectively.

[0109] Several embodiments of the present invention have been described, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope or spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

Claims

1. An illumination device comprising: a light guide plate having a first edge extending in a first direction, a second edge extending in a second direction intersecting the first direction, and a third edge disposed between the first edge and the second edge; a plurality of light source elements opposing a fourth edge of the light guide plate opposite the second edge; and a reflection plate having a first portion parallel to the second edge and a second portion parallel to the third edge, wherein the third edge has first short edges extending in the first direction and second short edges extending in the second direction alternately arranged, and wherein the second portion has first slices extending in the first direction and second slices extending in the second direction alternately and overlappingly arranged in the first direction or the second direction.

2. The illumination device according to claim 1, wherein the plurality of light source elements are each a laser light source emitting laser light.

3. A display device comprising an illumination device and a display panel of a polygonal shape, wherein the illumination device comprises: a light guide plate having a first edge extending in a first direction, a second edge extending in a second direction intersecting the first direction, and a third edge disposed between the first edge and the second edge; a plurality of light source elements opposing a fourth edge of the light guide plate opposite the second edge; and a reflection plate having a first portion parallel to the second edge and a second portion parallel to the third edge, wherein the display panel of the polygonal shape is a display panel in which a rectangular first region and two trapezoidal second regions sandwiching the first region are arranged along the second direction, wherein the third edge has first short edges extending in the first direction and second short edges extending in the second direction alternately arranged, and wherein the second portion has first slices extending in the first direction and second slices extending in the second direction alternately and overlappingly arranged in the first direction or the second direction.

4. The display device according to claim 3, wherein the plurality of light source elements are each a laser light source emitting laser light.

5. The display device according to claim 3, wherein a first light source element of the plurality of light source elements illuminating the first region has a higher light emission luminance than a second light source element illuminating the second region.

6. The display device according to claim 5, wherein the light guide plate has a plurality of protrusions extending in the second direction, and wherein a height distribution of the protrusions disposed in a region of the light guide plate overlapping the first region is different from a height distribution of the protrusions disposed in a region of the light guide plate overlapping the second region.

7. A display device comprising an illumination device and a display panel of a polygonal shape, wherein the illumination device comprises: a light guide plate having a first edge extending in a first direction, a second edge extending in a second direction intersecting the first direction, and a third edge disposed between the first edge and the second edge; a plurality of light source elements opposing a fourth edge of the light guide plate opposite the second edge; and a reflection plate having a first portion parallel to the second edge and a second portion parallel to the third edge, wherein the display panel of the polygonal shape is a display panel in which a rectangular first region and two trapezoidal second regions sandwiching the first region are arranged along the second direction, wherein the third edge has first short edges extending in the first direction and second short edges extending in the second direction alternately arranged, and wherein the second portion has first slices extending in the first direction and second slices extending in the second direction alternately and overlappingly arranged in the first direction or the second direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A reflection plate has a first portion parallel to the second side and a second portion parallel to the third side. The polygonal display panel is a display panel in which a first region of a rectangular shape and two second regions of a trapezoidal shape sandwiching the first region are arranged along the second direction, The third side has first short sides extending in the first direction and second short sides extending in the second direction arranged alternately, The second portion has a plurality of cutouts extending in the second direction and separated from each other.

8. The display device according to claim 7, wherein The plurality of light source elements are laser light sources each emitting laser light.

9. The display device according to claim 7, wherein A first light source element of the plurality of light source elements illuminating the first region emits light at a higher luminance than a second light source element illuminating the second region.

10. The display device according to claim 9, wherein The light guide plate has a plurality of protrusions extending in the second direction, A height distribution of the protrusions provided in a region of the light guide plate overlapping the first region is different from a height distribution of the protrusions provided in a region of the light guide plate overlapping the second region.

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