Light guide plate, display device, game machine, and in-vehicle display unit

Abstract

To realize a light guide plate with a high translucency.SOLUTION: A light guide plate (10A) includes: an entrance surface (11a) in which light from a light source (20) enters; an exit surface (11c) from which light is emitted; and a plurality of light deflection units (12) for emitting light which entered from the entrance surface and was introduced, from the exit surface. The light deflection units are arranged on alignment lines (13) as a linear alignment region and at least one of the alignment lines includes a region which is not parallel to the entrance surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a light guide plate, a display device, a gaming machine, and an in-vehicle display device that display a stereoscopic image using parallax. [Background technology]

[0002] Patent Document 1 discloses a light guide plate that displays a stereoscopic image by parallax. The light guide plate includes a plurality of deflection sections, each of which has an inclined surface that reflects light guided from a light source through an entrance surface, which is a side surface, and that reflects the light while being totally reflected inside and emits it from an exit surface, for each row parallel to the entrance surface. The orientation of the inclined surface of each row changes depending on the distance from the entrance surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-139176 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as will be described in detail later, in the light guide plate of Patent Document 1, in the region where a stereoscopic image close to parallel to the incident surface is displayed, the spacing between the rows of the deflection section for displaying the stereoscopic image needs to be narrowed. In such a region, the density of the deflection section increases, which causes a problem of reducing the transparency of the light guide plate. In addition, when a stereoscopic image with a very high degree of parallelism to the incident surface is to be displayed, there is also a problem that it becomes difficult to display the stereoscopic image as a continuous line image.

[0005] An object of one embodiment of the present disclosure is to provide a light guide plate or the like that is capable of clearly displaying a stereoscopic image nearly parallel to the incidence surface and that has high transparency. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a light guide plate according to one aspect of the present disclosure is a light guide plate that displays a stereoscopic image using parallax, and includes an entrance surface into which light from a light source is incident, an exit surface from which the light is emitted, and a plurality of light deflection units that deflect the light that is incident and guided from the entrance surface to emit it from the exit surface, the plurality of light deflection units being arranged on an arrangement line that is a linear arrangement region, and the exit surface being configured to emit a first exit light deflected by the light deflection units into an angle range in which one eye of an observer who observes the exit surface from within a predetermined range of observation space and the vicinity thereof are irradiated. If a point on the surface is defined as a first exit point, and a point on the exit surface from which the second exit light deflected by the light deflection unit is emitted into an angular range in which the other eye of the observer and its vicinity is irradiated is defined as a second exit point, a plurality of the light deflection units are arranged on the array line so that a straight line passing through the first exit point and the center of the one eye and a straight line passing through the second exit point and the center of the other eye intersect with each other to form an intersection, and a plurality of the array lines are provided, and at least one of the array lines includes an area that is not parallel to the entrance surface.

[0007] According to the above configuration, an intersection point between a straight line passing through the first exit point and the center of one eye and a straight line passing through the second exit point and the center of the other eye is formed for each array line. By including an area where the multiple array lines are not parallel to the incident surface, when a stereoscopic image close to parallel to the incident surface is displayed, the interval between the array lines for displaying the stereoscopic image can be widened, and the density of the light deflection section can be reduced. Therefore, a light guide plate having high transparency can be realized even when a stereoscopic image close to parallel to the incident surface is displayed.

[0008] In the light guide plate according to the aspect of the present disclosure, the intersection may be located on the rear side of the exit surface as viewed from the observer.

[0009] According to the above configuration, a stereoscopic image can be displayed on the rear side of the emission surface.

[0010] Furthermore, in the light guide plate according to one embodiment of the present disclosure, each of the plurality of alignment lines may be a straight line, a curved line, a combination of two or more straight lines, a combination of two or more curved lines, or a combination of one or more straight lines and one or more curved lines.

[0011] According to the above configuration, the degree of freedom in moving a stereoscopic image is improved by switching the position of the light source that makes light incident on the light guide plate or by moving the position at which the observer views the stereoscopic image.

[0012] In the light guide plate according to the aspect of the present disclosure, each of the plurality of arrangement lines may include a branching point or a joining point of the plurality of lines.

[0013] According to the above configuration, by switching the position of the light source that inputs light to the light guide plate or by moving the position from which the observer views the stereoscopic image, it is possible to realize an appearance in which the stereoscopic image splits or merges along the array line.

[0014] In the light guide plate according to the aspect of the present disclosure, each of the plurality of arrangement lines may include linear regions that are not parallel to each other.

[0015] According to the above configuration, by switching the position of the light source that makes light enter the light guide plate or by moving the position from which the observer views the stereoscopic image, it is possible to realize an appearance in which the stereoscopic image expands or shrinks along the array line.

[0016] Furthermore, in a light guide plate according to one embodiment of the present disclosure, the stereoscopic image includes a first stereoscopic image displayed by the optical deflection unit in a first partial region that is a partial region of the light guide plate, and a second stereoscopic image displayed by the optical deflection unit in a second partial region that is a region different from the first partial region, and the optical deflection unit may be arranged so that the first stereoscopic image and the second stereoscopic image are observable from within the same observation space.

[0017] According to the above configuration, the viewer can view the first stereoscopic image and the second stereoscopic image from within the same viewing space.

[0018] Furthermore, in a light guide plate according to one embodiment of the present disclosure, the stereoscopic image includes a first stereoscopic image displayed by the optical deflection unit in a first partial region that is a partial region of the light guide plate, and a second stereoscopic image displayed by the optical deflection unit in a second partial region that is a region different from the first partial region, and the optical deflection unit is provided such that the observation space in which the first stereoscopic image can be observed and the observation space in which the second stereoscopic image can be observed are located at different positions from each other.

[0019] According to the above configuration, when a viewer views one of the first stereoscopic image and the second stereoscopic image, the reflection of the other can be reduced.

[0020] In the light guide plate according to the aspect of the present disclosure, an angle formed between the incident surface and a region of each of the plurality of arrangement lines that is not parallel to the incident surface may be 2.5° or more.

[0021] According to the above configuration, the visibility of a stereoscopic image parallel to the incidence surface is improved.

[0022] A display device according to an aspect of the present disclosure includes the above-described light guide plate, a plurality of light sources that cause light to enter the light guide plate from the incident surface, and a controller that controls the plurality of light sources.

[0023] According to the above configuration, the control unit controls the multiple light sources, so that the position of the light source that emits light into the light guide plate can be changed.

[0024] In addition, in a display device according to one aspect of the present disclosure, the multiple light sources may be arranged in a line, and the control unit may control the multiple light sources to be turned on and off sequentially from one end of the linear area to the other end.

[0025] According to the above configuration, it is possible to realize control such that the position of the light source that causes light to be incident on the light guide plate moves from one end to the other end of the area in which the plurality of light sources are linearly arranged.

[0026] In addition, in a display device according to one aspect of the present disclosure, the multiple light sources may be arranged in a line, and the control unit may control the multiple light sources to be turned on and off sequentially from an arbitrary point that is not one end or the other end of the linear region to both one end and the other end.

[0027] According to the above configuration, it is possible to realize control such that the positions of the light sources that cause light to enter the light guide plate move from other than both ends to both ends of the area in which the multiple light sources are linearly arranged.

[0028] Furthermore, a gaming machine according to one aspect of the present disclosure includes the above-mentioned display device.

[0029] According to the above configuration, the same effects as those of the above display device are achieved.

[0030] Moreover, an in-vehicle display device according to one aspect of the present disclosure includes the above-mentioned display device.

[0031] According to the above configuration, the same effects as those of the above display device are achieved. Effect of the Invention

[0032] According to one aspect of the present disclosure, it is possible to realize a light guide plate or the like that is capable of clearly displaying a stereoscopic image nearly parallel to the incidence surface and that has high transparency. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a plan view illustrating a configuration of a display device according to an embodiment of the present disclosure. [Diagram 2] 4 is a cross-sectional view showing the path of light guided by a light guide plate. FIG. [Diagram 3] 4 is a perspective view for explaining the directivity of light emitted from an exit surface of a light guide plate. FIG. [Figure 4] FIG. 2 is a perspective view illustrating the principle of stereoscopic display based on parallax, showing the intersection point where a straight line passing through a first exit point and the center of one of the observer's eyes intersects with a straight line passing through a second exit point and the center of the other observer's eye. [Diagram 5] 1 is a perspective view showing a gaming machine equipped with a display device of embodiment 1. FIG. [Figure 6] 11 is a diagram showing an example of a case where a stereoscopic image having a portion nearly parallel to the incidence surface is displayed in a display device as a comparative example. FIG. [Figure 7] 4 is a diagram showing an example of the relationship between the angle between an arrangement line and an incidence surface and the display of a stereoscopic image in the display device of the first embodiment. FIG. [Figure 8] 11A and 11B are diagrams illustrating specific examples of the arrangement of light deflection portions in a light guide plate. [Figure 9] 11A and 11B are diagrams illustrating more specific examples of the arrangement of light deflection units in a light guide plate. [Figure 10] FIG. 11 is a plan view showing an example of a display device according to a second embodiment. [Figure 11] FIG. 11 is a plan view showing an example of a display device according to a third embodiment. [Figure 12] FIG. 11 is a plan view showing another example of the display device according to the third embodiment. [Figure 13] FIG. 11 is a plan view showing still another example of the display device according to the third embodiment. [Figure 14] FIG. 13 is a diagram showing a display device according to a first modified example of the third embodiment. [Figure 15] FIG. 13 is a diagram showing a display device according to a second modified example of the third embodiment. [Figure 16] FIG. 13 is a diagram showing a display device according to a third modified example of the third embodiment. [Figure 17] FIG. 13 is a diagram showing a display device according to a fourth modified example of the third embodiment. [Figure 18] FIG. 11 is a diagram showing a display device according to a fourth embodiment. [Figure 19] FIG. 13 is a diagram showing a display device according to a modified example of the fourth embodiment. [Figure 20] FIG. 20 is a diagram showing a display device according to another modified example of the fourth embodiment, different from the one shown in FIG. [Figure 21] FIG. 13 is a diagram showing an example of an arrangement line according to the fifth embodiment. [Figure 22] 13 is a diagram showing an example of a light guide plate according to a fifth embodiment. FIG. [Diagram 23] FIG. 23 is a diagram showing an example of an arrangement line according to the sixth embodiment. [Figure 24] 13 is a diagram showing an example of a light guide plate according to a sixth embodiment. FIG. [Diagram 25] FIG. 13 is a diagram showing an example of an arrangement line according to a seventh embodiment. [Figure 26] 13 is a diagram showing an example of a light guide plate according to a seventh embodiment. FIG. [Figure 27] 11A and 11B are diagrams illustrating a specific example of control of a light source by a control unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] [Embodiment 1] An embodiment of the present disclosure will be described in detail below. In the following description, "A to B" indicating a numerical range means "A or more and B or less" unless otherwise specified. In addition, in each drawing, among multiple components appearing, only some of the components may be labeled with a symbol.

[0035] (Examples) Fig. 1 is a plan view showing a configuration of a display device 1A according to one embodiment of the present disclosure. First, an example of a situation to which the present disclosure is applied will be described with reference to Fig. 1. As shown in Fig. 1, the display device 1A according to the present disclosure includes a light guide plate 10A, a light source 20, and a control unit 30. For simplicity, the control unit 30 is omitted in Fig. 1 and other figures.

[0036] The light guide plate 10A displays a stereoscopic image SI by parallax. In this application example, the light guide plate 10A has a rectangular plate shape in a plan view. In other words, the light guide plate 10A has a rectangular parallelepiped shape. However, the shape of the light guide plate 10A is not limited to this. The material of the light guide plate 10A may be, for example, polycarbonate, acrylic, other translucent resin, or glass.

[0037] The three-dimensional image SI includes one or more line segments or curves, etc. The three-dimensional image SI expresses characters, figures, pictures, etc. by a combination of line segments or curves.

[0038] The light guide plate 10A has an incident surface 11a. The incident surface 11a is a surface through which light from the light source 20 enters the light guide plate 10A. The incident surface 11a is one of the side surfaces of the light guide plate 10A, which has a rectangular parallelepiped shape. When the surface with the largest area in the rectangular parallelepiped shape is referred to as the main surface, the side surface is a surface adjacent to the main surface.

[0039] Furthermore, the light guide plate 10A has another side surface 11b opposite to the incident surface 11a. In the display device 1A, a light source 20 may also be disposed on the side surface 11b, and light may enter the light guide plate 10A from the side surface 11b.

[0040] Furthermore, light guide plate 10A has exit surface 11c. Exit surface 11c is a surface from which light guided inside light guide plate 10A is emitted from light guide plate 10A. Exit surface 11c is one of the main surfaces of light guide plate 10A, which has a rectangular parallelepiped shape.

[0041] The light guide plate 10A also has a plurality of light deflection sections 12. The light deflection sections 12 deflect the light that is incident on the light guide plate 10A from the incident surface 11a and guided through the light guide plate 10A, causing the light to exit from the exit surface 11c. The light deflection sections 12 in this embodiment have a V-groove structure that extends in a direction corresponding to the position of the observation space relative to the light guide plate 10A and the display position of the stereoscopic image SI, and are formed in a plurality of rows in the incident direction. For ease of explanation, the drawings show a smaller number of light deflection sections 12 formed on the light guide plate 10A than the actual number.

[0042] Fig. 2 is a cross-sectional view showing the path of light guided by light guide plate 10A. As shown in Fig. 2, light deflection unit 12 is provided on rear surface 11d of light guide plate 10A. Rear surface 11d is the other main surface of light guide plate 10A having a rectangular parallelepiped shape, facing exit surface 11c.

[0043] The light deflection unit 12 has an inclined surface 12a as a reflecting surface that reflects the light from the light source 20 that is incident from the incident surface 11a toward the exit surface 11c. In this embodiment, in order to reflect the light L that is incident from the incident surface 11a, the light deflection unit 12 has an inclined surface 12a that corresponds to the incident surface 11a. In the case where light is also incident from the side surface 11b, the light guide plate 10A further includes a light deflection unit 12 on which an inclined surface 12a that corresponds to the light from the side surface 11b is formed. In addition to the inclined surface 12a, the light deflection unit 12 may further have a surface for reflecting the light that is incident on the light deflection unit 12 from a direction other than the intended direction in a direction that cannot be recognized by an observer.

[0044] In the light guide plate 10A, the light L incident from the incident surface 11a is guided while being totally reflected between the exit surface 11c and the back surface 11d. The light L incident on the light deflection unit 12 is reflected by the inclined surface 12a and enters the exit surface 11c at an angle of incidence smaller than the angle of incidence at which the light L is totally reflected on the exit surface 11c. As a result, the light L is emitted from the exit surface 11c. However, the deflection of light by the light deflection unit 12 is not limited to reflection, and may be, for example, refraction.

[0045] The size of the light deflection unit 12 may be, for example, 30 μm to 300 μm in a direction perpendicular to the incident direction of light from the light source 20. The angle of the inclined surface 12a with respect to the rear surface 11d may be, for example, 30° to 60°. The shape of the light deflection unit 12 in a plan view seen from a direction perpendicular to the rear surface 11d may be a quadrangular shape such as a rectangle, or may be a spindle shape. In particular, the latter shape improves the moldability of the light deflection unit 12 compared to the former shape. However, the size and shape of the light deflection unit 12 are not limited to these.

[0046] Fig. 3 is a perspective view for explaining the directivity of the light emitted from the exit surface 11c of the light guide plate 10A. Fig. 4 is a perspective view showing the principle of stereoscopic display based on parallax, and shows an intersection point where a straight line passing through the first exit point P1 and the center of one eye E1 of the observer intersects with a straight line passing through the second exit point P2 and the center of the other eye E2 of the observer. For simplicity, Figs. 3 and 4 show only one light source 20.

[0047] 3 shows a state in which an observer is observing the display device 1A from within a predetermined range of observation space. The observation space is a space in which at least a part of the stereoscopic image SI displayed by the display device 1A can be observed.

[0048] The light emitted within an angular range to irradiate one eye E1 of the observer and its vicinity is referred to as the first emitted light L1, and the point on the emission surface 11c from which the first emitted light L1 is emitted is referred to as the first emitted point P1. The light emitted within an angular range to irradiate the other eye E2 of the observer and its vicinity is referred to as the second emitted light L2, and the point on the emission surface 11c from which the second emitted light L2 is emitted is referred to as the second emitted point P2.

[0049] The first outgoing light L1 emitted from the first outgoing point P1 is viewed by one eye E1 of the observer. On the other hand, the first outgoing light L1 is not viewed by the other eye E2, or the amount of light viewed by the other eye E2 is very small compared to the amount of light viewed by the one eye E1. As a result, the first outgoing light L1 has directionality.

[0050] The second exit light L2 from the second exit point P2 is viewed by the other eye E2 of the observer. On the other hand, the second exit light L2 is not viewed by the one eye E1, or the amount of light viewed by the one eye E1 is very small compared to the amount of light viewed by the other eye E2. As a result, the second exit light L2 has directionality.

[0051] 4, a straight line passing through the first emission point P1 and the center of one eye E1, i.e., the pupil and the crystalline lens, and a straight line passing through the second emission point P2 and the center of the other eye E2 intersect at intersection C. In other words, the optical axis of the first emission light L1 viewed by one eye E1 of the observer and the optical axis of the second emission light L2 viewed by the other eye E2 of the observer intersect at intersection C. Therefore, the observer has the illusion that a light emitting point exists at intersection C.

[0052] When intersection C is located on the observer's side with respect to exit surface 11c, the observer sees the light emitting point popping out from exit surface 11c. On the other hand, when intersection C is located on the opposite side of exit surface 11c from the observer, the observer sees the light emitting point to be located further back than exit surface 11c. In this embodiment, intersection C is located on the further back side of exit surface 11c as seen by the observer. This causes the observer to perceive a sense of depth.

[0053] In this way, when the first outgoing light L1 is emitted within an angular range toward one eye E1 of the observer and its vicinity, and the second outgoing light L2 is emitted within an angular range toward the other eye E2 of the observer and its vicinity, and the optical axis of the first outgoing light L1 and the optical axis of the second outgoing light L2 have an intersection C, the observer has the illusion that a light emitting point exists at the intersection C. Therefore, by forming such an intersection C as a set of consecutive points such as a plurality of intersections C1, C2, ..., the observer can perceive a three-dimensional stereoscopic image SI that is, for example, a straight line.

[0054] The light source 20 is a light-emitting element that causes light to enter the light guide plate 10A. The light source 20 may be a point light source. An example of the light source 20 is an LED (Light Emitting Diode). However, the light source 20 is not limited to this, and may be other light sources such as a fluorescent lamp. In FIG. 1, the display device 1A includes two light sources 20. However, the display device 1A may include three or more light sources 20. The multiple light sources 20 may be arranged at intervals of, for example, 10 mm, but the intervals between the light sources 20 are not limited to this.

[0055] As described above, the shape of the light guide plate 10A is not limited to the rectangular parallelepiped shape. For example, the light guide plate 10A may have a rectangular shape in a plan view perpendicular to the exit surface 11c, so that the entrance surface 11a is not flush and has a stepped shape. In this case, the light source 20 may be arranged along each of the non-flush entrance surfaces 11a.

[0056] The control unit 30 controls the turning on and off of the light source 20. The specific contents of the control by the control unit 30 will be described later.

[0057] (Configuration example) FIG. 5 is a perspective view showing a gaming machine 100 equipped with a display device 1A according to the present embodiment. As shown in FIG. 5, the gaming machine 100, for example, a pachinko machine or a slot machine, is provided with the display device 1A. The display device 1A is disposed near the center of the gaming machine 100. The display device 1A displays images for various effects, such as an effect image showing a big win or an effect image showing the expectation of a big win. Specifically, the display device 1A displays a stereoscopic image SI in a stereoscopic manner as an image display. The control unit 30 controls whether or not to display the stereoscopic image SI, controls to switch the light source 20 to be turned on at a predetermined timing, or controls to switch the multiple light sources 20 that emit different colors from each other at a predetermined timing.

[0058] The gaming machine 100 is merely one application example of the display device 1A of the present embodiment, and does not limit the application range of the display device 1A. The display device 1A of the present embodiment may be applied to any object having a function of displaying an image. Another example of an object to which the display device 1A is applied is an in-vehicle display.

[0059] As shown in Fig. 1, in the display device 1A, the light deflection section 12 is arranged on an arrangement line 13. The arrangement line 13 is a linear arrangement region provided in plurality on the light guide plate 10A. In Fig. 1, the arrangement line 13 is a plurality of straight lines parallel to one another. However, the shape of the arrangement line 13 is not limited thereto. Other examples of the shape of the arrangement line 13 will be described later.

[0060] 6 is a diagram showing an example of a case where a stereoscopic image SI having a portion nearly parallel to the incident surface 11a is displayed in a display device 1X as a comparative example. The display device 1X has the same configuration as the display device 1A, except that it has a light guide plate 10X instead of the light guide plate 10A. The light guide plate 10X differs from the light guide plate 10A in that the arrangement lines 13 are parallel to the incident surface 11a.

[0061] In FIG. 6, the stereoscopic image SI is an image of a broken line having two bending points. The direction of the line segment between the two bending points of the stereoscopic image SI is nearly parallel to the incident surface 11a. In the region of the light guide plate 10X where such a line segment is displayed, the interval between the array lines 13 needs to be narrowed. This increases the density of the light deflection parts 12 in the region, and the transparency of the light guide plate 10X may decrease. In addition, as described later, in the display device 1X having the light guide plate 10X, it may be difficult to display the line segment nearly parallel to the incident surface 11a as a continuous line image.

[0062] In the light guide plate 10A, the arrangement lines 13 are not parallel to the incident surface 11a. Therefore, even in a region of the light guide plate 10A where a stereoscopic image is displayed that is nearly parallel to the incident surface 11a, the interval between the arrangement lines 13 can be increased and the density of the light deflection sections 12 can be reduced. Therefore, a light guide plate 10A having higher transparency can be realized compared to a case where the arrangement lines 13 are parallel to the incident surface 11a.

[0063] Furthermore, since the arrangement lines 13 of the light guide plate 10A are not parallel to the incident surface 11a, the visibility of the portions of the three-dimensional image SI displayed by the light deflection section 12 arranged in that region that are parallel to the incident surface 11a can be improved.

[0064] FIG. 7 is a diagram showing an example of the relationship between the angle between the arrangement line 13 and the incident surface 11a and the display of the stereoscopic image SI in the display device 1A. In the example of FIG. 7, an image of the letter "A" is displayed as the stereoscopic image SI. In FIG. 7, reference numeral 701 indicates a case where the angle between the arrangement line 13 and the incident surface 11a is 0°. Reference numeral 702 indicates a case where the angle between the arrangement line 13 and the incident surface 11a is 1°. Reference numeral 703 indicates a case where the angle between the arrangement line 13 and the incident surface 11a is 2°. Reference numeral 704 indicates a case where the angle between the arrangement line 13 and the incident surface 11a is 3°. Reference numeral 705 indicates a case where the angle between the arrangement line 13 and the incident surface 11a is 4°. Reference numeral 706 indicates a case where the angle between the arrangement line 13 and the incident surface 11a is 5°. Reference numeral 707 indicates a case where the angle between the arrangement line 13 and the incidence surface 11a is 10°.

[0065] The image of the letter "A" includes two oblique line images and one horizontal line image. Of these, the horizontal line image is an image parallel to the incident surface 11a. As shown by reference numeral 701, when the angle between the arrangement line 13 and the incident surface 11a is 0°, the image of the horizontal line is barely visible. As shown by reference numeral 702, when the angle between the arrangement line 13 and the incident surface 11a is 1°, the image of the horizontal line is faintly visible. From reference numeral 703 onwards, as the angle between the arrangement line 13 and the incident surface 11a increases, the visibility of the image of the horizontal line improves.

[0066] In the light guide plate 10A, all the regions of all the arrangement lines 13 do not necessarily have to be regions that are not parallel to the incident surface 11a. In the display device 1A, it is sufficient that at least one arrangement line 13 includes a region that is not parallel to the incident surface 11a. In particular, it is sufficient that a region involved in displaying a portion of the stereoscopic image SI that is close to parallel to the incident surface 11a or parallel to the incident surface 11a is a region that is not parallel to the incident surface 11a. By including a region in which the arrangement lines 13 are not parallel to the incident surface 11a as described above, it is possible to improve the transparency of the light guide plate 10A and the visibility of the portion of the stereoscopic image SI that is parallel to the incident surface 11a.

[0067] Fig. 8 is a diagram showing a specific example of the arrangement of the light deflection section 12 in the light guide plate 10A. In Fig. 8, reference numerals 801 and 802 indicate different specific examples. In both examples, a matrix 14 is defined for the region where the light deflection section 12 is arranged, and the light deflection section 12 is arranged within the matrix 14.

[0068] In the example indicated by reference numeral 801, the matrix 14 is arranged along a direction parallel to the incident surface 11a and a direction perpendicular to the incident surface 11a. In this case, the optical deflection units 12 can be arranged along the arrangement line 13 by arranging the optical deflection units 12 only in the matrix 14 located on the arrangement line 13.

[0069] In the example indicated by the reference numeral 802, the matrices 14 are arranged in a direction along the arrangement lines 13. In this case, by arranging the optical deflection units 12 in any of the matrices 14, the optical deflection units 12 can be arranged along the arrangement lines 13.

[0070] Fig. 9 is a diagram showing a more specific example of the arrangement of the light deflection section 12 in the light guide plate 10A. In Fig. 9, reference numerals 901 and 902 indicate different examples. Fig. 9 shows an example in which an image of the letter "A" is displayed. In Fig. 9, a three-dimensional image SI, which is the image of the letter "A", is divided into two oblique line images SI1 and SI2 and one horizontal line image SI3.

[0071] In the example indicated by the reference numeral 901, an optical deflection unit 121 for displaying an image SI1 of oblique lines, an optical deflection unit 122 for displaying an image SI2 of oblique lines, and an optical deflection unit 123 for displaying an image SI3 of horizontal lines are shown as the optical deflection unit 12. The optical deflection unit 121 and the optical deflection unit 122 may be arranged in different matrices 14 on the arrangement line 13. Furthermore, the optical deflection unit 123 may be arranged in yet another matrix 14 parallel to the arrangement line 13.

[0072] Furthermore, the light deflection unit 12 may display two or more of the images SI1 and SI2 of diagonal lines and the image SI3 of horizontal lines. In the example indicated by the reference numeral 902, the light deflection unit 12 includes a light deflection unit 124 for displaying the images SI1 and SI2 of diagonal lines and the image SI3 of horizontal lines, and a light deflection unit 125 for displaying the images SI1 and SI2 of diagonal lines. The light deflection unit 124 and the light deflection unit 125 may be arranged in different matrices 14 on the arrangement line 13.

[0073] When multiple images are displayed by the light deflection unit 12, the light deflection unit 12 has a portion corresponding to each of the multiple images. In this case, the light deflection unit 12 may be formed so that there are more convex portions than concave portions relative to the incident direction of light. In this case, stray light caused by light being reflected multiple times by the light deflection unit 12 can be reduced compared to the case where there are more concave portions than convex portions relative to the incident direction of light.

[0074] In the display device 1A, the control unit 30 may switch the positions of the light sources 20 that emit light into the light guide plate 10A among the multiple light sources 20. For example, the control unit 30 may sequentially turn on and off the multiple light sources 20. This makes it possible to create an effect in which the three-dimensional image SI appears to move. At this time, the three-dimensional image SI moves in a direction along the arrangement line 13.

[0075] In the example indicated by reference numeral 801, the pitch of the matrix 14 is equal in the direction parallel to the incident surface 11a and in the direction perpendicular to the incident surface 11a. In this case, the angle formed between each of the arrangement lines 13 and the incident surface 11a may be 2.5° or more. Also, the angle formed between each of the arrangement lines 13 and the incident surface 11a may be 5° or more. This sufficiently improves the visibility of the portion of the stereoscopic image SI parallel to the incident surface 11a.

[0076] The display device 1A may also include a plurality of light guide plates 10A that are stacked such that their main surfaces are parallel to each other. In this case, in a region in which the arrangement lines 13 are parallel to the incident surface 11a, there is a possibility that interference fringes will be generated by the light deflection units 12 arranged along the arrangement lines 13. When the display device 1A includes a plurality of light guide plates 10A, the inclinations of the arrangement lines 13 in each of the light guide plates 10A can be made different from each other to reduce the generation of interference fringes.

[0077] The display device 1A may be used by being superimposed on a flat display such as a liquid crystal display device. In this case, a display system can be provided that can simultaneously provide display by the flat display and stereoscopic image display by the display device 1A. In such a display system, the occurrence of interference fringes can be reduced by making the arrangement direction of the pixels of the flat display and the inclination of the arrangement line 13 different from each other.

[0078] The pitch of the matrix 14 may be changed as appropriate depending on the purpose. For example, in order to move the stereoscopic image SI smoothly in a direction parallel to the incident surface 11a, the pitch of the matrix 14 in the direction may be reduced to increase the resolution. In addition, in order to improve the visibility of the portion of the stereoscopic image SI parallel to the incident surface 11a, the pitch of the matrix 14 in the direction perpendicular to the incident surface 11a may be reduced to increase the resolution.

[0079] Furthermore, the light source 20 may be a so-called RGB LED that is capable of adjusting the color of light. In this case, the control unit 30 may control the color of light emitted by the light source 20. The control unit 30 can achieve an effective effect by, for example, making the colors of light of adjacent light sources 20 different from each other.

[0080] Furthermore, the control unit 30 can superimpose multiple stereoscopic images of different colors to achieve a stronger effect through color mixing. For example, by superimposing a stereoscopic image of (R,G,B)=(255,0,0) and a stereoscopic image of (R,G,B)=(0,255,255), the overlapping portion can be colored (R,G,B)=(255,255,255), i.e., white. Furthermore, the control unit 30 may superimpose three or more stereoscopic images.

[0081] In the light guide plate 10A, the number of light deflection units 12 arranged on the arrangement line 13 varies depending on which position of the stereoscopic image SI the arrangement line 13 corresponds to. For example, when an image of the letter "A" is displayed as the stereoscopic image SI, the light deflection units 12 for displaying an image of two diagonal lines are arranged on the arrangement line 13 corresponding to the upper and lower parts of the stereoscopic image SI. On the other hand, the light deflection units 12 for displaying an image of two diagonal lines and an image of a horizontal line are arranged on the arrangement line 13 corresponding to the vicinity of the center of the stereoscopic image SI. In this way, the number of light deflection units 12 arranged on the arrangement line 13 varies depending on the shape of the stereoscopic image SI, and therefore the density of the light deflection units 12 varies depending on the position on the light guide plate 10A.

[0082] When the shape of the light deflection units 12 is constant, there is a possibility that the transparency of the light guide plate 10A varies depending on the density of the light deflection units 12. In order to reduce the variation, the shape, etc. of the light deflection units 12 may be changed as appropriate. Alternatively, dummy light deflection units 12 that are not related to the display of the stereoscopic image SI may be disposed in an area where the density of the light deflection units 12 is low.

[0083] [Embodiment 2] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be given to members having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0084] 10 is a plan view showing an example of a display device 1B according to embodiment 2. The display device 1B differs from the display device 1A in that the display device 1B includes a light guide plate 10B instead of the light guide plate 10A. A light entrance section 15 is provided on the light entrance surface 11a of the light guide plate 10B near the light source 20. The light entrance section 15 is a portion of the light entrance surface 11a formed into a concave shape.

[0085] In the light guide plate 10A that does not have the light entrance portion 15, the spread of the light incident from the incident surface 11a is at most about 40° with respect to the optical axis, depending on the material of the light guide plate 10A. For this reason, it is difficult to display a stereoscopic image SI, which is large in size in the direction perpendicular to the optical axis, in the vicinity of the light source 20. For example, if the stereoscopic image SI has a size of 20 mm in the direction perpendicular to the optical axis, the position where the optical deflection unit 12 is disposed needs to be separated from the light source 20 by 10 mm or more in the direction along the optical axis. However, the actual position where the optical deflection unit 12 is disposed is also affected by conditions such as the shape of the stereoscopic image SI.

[0086] In the display device 1B, light from the light source 20 enters the light guide plate 10B from the light entrance portion 15. Therefore, the spread of the light incident from the light entrance portion 15 in the display device 1B in a plane parallel to the main surface of the light guide plate 10B is larger than the spread of the light incident from the flat incident surface 11a to the light guide plate 10A in the display device 1A. That is, in the light guide plate 10B, the area that the light can reach near the incident surface 11a is wider than the area that the light can reach near the incident surface 11a of the light guide plate 10A. This improves the degree of freedom in designing the light guide plate 10B.

[0087] The light entrance portion 15 may be a slit, a lens array, a diffusion member, or the like disposed between the light source 20 and the incident surface 11a, in addition to the above-mentioned concave portion. An example of the diffusion member is frosted glass.

[0088] Furthermore, as in another embodiment described later, in the display device 1B, light may be incident on the light guide plate 10B from another side surface adjacent to the incident surface 11a. In this case, however, the light from the other side surface may be incident on the light deflection section 12 located near the light entrance section 15 and having a large inclination with respect to the incident surface 11a, which may cause unintended light emission (crosstalk). For this reason, the shape, size, etc. of the light deflection section 12 located near the light entrance section 15 may be appropriately adjusted so as to reduce crosstalk.

[0089] [Embodiment 3] FIG. 11 is a plan view showing an example of a display device 1C according to the third embodiment. In FIG. 11, reference numerals 1101, 1102, and 1103 show different examples of the display device 1C. In the example shown in FIG. 11, the display device 1C differs from the display device 1A in that the display device 1C includes a light guide plate 10C instead of the light guide plate 10A. The light guide plate 10C can display a plurality of stereoscopic images SIA and SIB by light incident from a light source 20. In FIG. 11, the stereoscopic image SIA is an image of the letter "A", and the plurality of stereoscopic images SIB are images of the letter "B". In FIG. 11, the display device 1C displays the stereoscopic images SIA and SIB by light from the same light source 20.

[0090] The stereoscopic images SIA and SIB may be adjacent to each other in a direction along the light incidence direction, as indicated by reference numeral 1101. The stereoscopic images SIA and SIB may also be adjacent to each other in a direction perpendicular to the light incidence direction, as indicated by reference numeral 1102. The stereoscopic images SIA and SIB may also be adjacent to each other in a direction different from both the light incidence direction and the direction perpendicular thereto, as indicated by reference numeral 1103.

[0091] Fig. 12 is a plan view showing another example of the display device 1C. In Fig. 12, reference numerals 1201 and 1202 indicate different examples of the display device 1C. In the example shown in Fig. 12, the display device 1C includes, as the light source 20, a light source 21 that makes light incident from the incident surface 11a and a light source 22 that makes light incident from another side surface 11e adjacent to the incident surface 11a. In the display device 1C, a stereoscopic image SIA is displayed by the light from the light source 21, and a stereoscopic image SIB is displayed by the light from the light source 22.

[0092] The optical deflection unit 12 for displaying the stereoscopic image SIA and the optical deflection unit 12 for displaying the stereoscopic image SIB may be arranged in regions separated from each other, as indicated by reference numeral 1201. The optical deflection unit 12 for displaying the stereoscopic image SIA and the optical deflection unit 12 for displaying the stereoscopic image SIB may be arranged in the same region, as indicated by reference numeral 1202. In particular, in the case of the example indicated by reference numeral 1202, by switching which of the light source 21 and the light source 22 is turned on, it becomes possible to switch whether the display device 1C displays the stereoscopic image SIA or the stereoscopic image SIB.

[0093] Fig. 13 is a plan view showing yet another example of a display device 1C. In the example shown in Fig. 13, the display device 1C displays a plurality of stereoscopic images SIA and SIB by light incident from an incident surface 11a of a light guide plate 10C. In the example shown in Fig. 13, a light source 20 for displaying the stereoscopic image SIA and a light source 20 for displaying the stereoscopic image SIB are separate from each other.

[0094] In the example shown in FIG. 13, the display device 1C has a structure that narrows the spread of light incident on the light guide plate 10C. For example, a convex lens (not shown) may be disposed between the light source 20 and the light guide plate 10C. Alternatively, the light source 20 may be a light source with high directivity, such as a bullet LED. Alternatively, the entrance surface 11a may have a shape that narrows the spread of the incident light. This reduces the possibility that, when the display device 1C displays only one of the stereoscopic images SIA and SIB, the other will be unintentionally displayed.

[0095] In addition, in the display device 1C, the stereoscopic images SIA and SIB are displayed by the optical deflection units 12 in different partial regions of the light guide plate 10C. In other words, the stereoscopic image displayed by the display device 1C includes a stereoscopic image SIA (a first stereoscopic image) displayed by the optical deflection units 12 in a first partial region that is a partial region of the light guide plate 10C, and a stereoscopic image SIB (a second stereoscopic image) displayed by the optical deflection units 12 in a second partial region that is a region different from the first partial region of the light guide plate 10C.

[0096] In such a display device 1C, the light deflection unit 12 may be provided so that the stereoscopic image SIA and the stereoscopic image SIB are observable from the same observation space. In this case, the observer can observe the first stereoscopic image SIA and the second stereoscopic image SIB from the same observation space.

[0097] In addition, by making the observation space in which the first stereoscopic image SIA and the second stereoscopic image SIB are observable a relatively narrow limited space, the first stereoscopic image SIA and the second stereoscopic image SIB can be displayed so that they can be observed only from the limited space. On the other hand, by making the observation space in which the first stereoscopic image SIA and the second stereoscopic image SIB are observable a relatively wide wide area space, the first stereoscopic image SIA and the second stereoscopic image SIB can be displayed so that they can be observed from a wide range. This wide area space may include a position at an infinite distance from the light guide plate 10C.

[0098] In addition, in the display device 1C, the optical deflection unit 12 may be provided so that the observation space in which the stereoscopic image SIA can be observed and the observation space in which the stereoscopic image SIB can be observed are disposed at different positions from each other. In this case, when a viewer observes one of the stereoscopic images SIA and SIB, the reflection of the other can be reduced.

[0099] (Variation 1) Fig. 14 is a diagram showing a display device 1CA according to a first modified example of embodiment 3. In the example shown in Fig. 14, the distance between the light sources 20 is closer than in other examples. Furthermore, the display device 1CA displays a plurality of stereoscopic images SIA1 and SIA2. The stereoscopic images SIA1 and SIA2 are images of the letter "A" and have shapes that can be considered to be identical to each other.

[0100] In this state, by appropriately adjusting the brightness of each of the light sources 20, it is possible to present the stereoscopic images SIA1 and SIA2 as if one were the shadow of the other, thereby allowing the observer to sense a sense of front and back.

[0101] (Variation 2) FIG. 15 is a diagram showing a display device 1CB according to a second modified example of the third embodiment. In the example shown by reference numerals 1501, 1502, and 1503 in FIG. 15, the display device 1CB performs a so-called dissolve effect in which a plurality of stereoscopic images SIA and SIB are switched while moving. In other words, the control unit 30 switches the positions of the light sources 20 to be turned on so as to move the display positions of the stereoscopic images SIA and SIB. For simplicity, the light sources 20 that are not turned on are omitted in FIG. 15. In FIG. 15, reference numeral 1501 indicates a display when the movement of the display position starts, reference numeral 1502 indicates a display during the movement of the display position, and reference numeral 1503 indicates a display when the movement of the display position ends.

[0102] However, the display position of the stereoscopic images SIA and SIB while the display position is being moved is not limited to the example shown by reference numeral 1502. While the display position is being moved, the display device 1CB may display the stereoscopic images SIA and SIB at a display position other than that shown by reference numeral 1502. Moreover, while the display position is being moved, the display device 1CB does not necessarily have to display the stereoscopic images SIA and SIB at the display position shown by reference numeral 1502.

[0103] As shown by reference numeral 1501, when the movement of the display position starts, only the stereoscopic image SIA is displayed. As shown by reference numeral 1502, during the movement of the display position, the stereoscopic images SIA and SIB are displayed superimposed on each other. At this time, the size, inclination angle, density, etc. of the light deflection unit 12 are adjusted so that the image that is primarily viewed changes from the stereoscopic image SIA to the stereoscopic image SIB as the movement of the display position progresses. As shown by reference numeral 1503, when the movement of the display position ends, only the stereoscopic image SIB is displayed. The display device 1CB makes it possible to perform an impactful performance in which the stereoscopic image gradually changes from the stereoscopic image SIA to the stereoscopic image SIB as the display position moves.

[0104] Also, in Fig. 15, reference numeral 1504 is a diagram showing another example of a display device 1CB according to a second modified example of the third embodiment, different from the reference numerals 1501 to 1503. In the example shown by reference numeral 1504 in Fig. 15, the display device 1CB sequentially displays three types of stereoscopic images SIC, SID, and SIE at different positions. For simplicity, reference numeral 1504 shows the stereoscopic images SIC, SID, and SIE in a single drawing.

[0105] In the example indicated by reference numeral 1504 in Fig. 15, the stereoscopic image SIC is an image of an ellipse. The stereoscopic image SIE is an image of a diamond. The stereoscopic image SID is an image of a shape intermediate between an ellipse and a diamond. In this example, the display device 1CB performs a so-called morphing effect in which the stereoscopic image SIC moves and transforms into the stereoscopic images SID and SIE in sequence.

[0106] (Variation 3) Fig. 16 is a diagram showing a display device 1CC according to a third modified example of the third embodiment. In the example shown in Fig. 16, the display device 1CC displays a stereoscopic image SIA and a planar image PI. In Fig. 16, reference numerals 1601 and 1602 indicate display devices 1CC in which the light sources 20 are turned on in different states. For simplicity, the light sources 20 that are not turned on are omitted in Fig. 16.

[0107] As indicated by reference numerals 1601 and 1602 in Fig. 16, the display position of the stereoscopic image SIA moves by switching the position of the lit light source 20. On the other hand, the flat image PI is displayed at a fixed position on the emission surface 11c or the rear surface 11d, regardless of the position of the lit light source 20. In the example of Fig. 16, the display content of the flat image PI is switched depending on the position of the lit light source 20. However, the display content of the flat image PI may be always constant, regardless of the position of the lit light source 20.

[0108] In this way, by combining the stereoscopic image SIA and the planar image PI in the display device 1CC, it is possible to produce a more impactful presentation. Also, by an observer referring to the planar image PI displayed on the exit surface 11c or the back surface 11d, the sense of depth of the stereoscopic image SIA displayed on the back side of the light guide plate 10C is further emphasized.

[0109] (Variation 4) Fig. 17 is a diagram showing a display device 1CD according to a fourth modified example of the third embodiment. In Fig. 17, reference numerals 1701 and 1702 indicate display devices 1CD in which the light sources 20 are turned on in different states. For simplicity, the light sources 20 that are not turned on are omitted in Fig. 17.

[0110] The display device 1CD includes a light guide plate 10CD and light sources 21, 22, 23, and 24 as the light source 20. The light guide plate 10CD displays the stereoscopic images SIA and SIB. The light sources 21, 22, 23, and 24 are arranged in this order along the incident surface 11a of the light guide plate 10CD. The light sources 21 and 22 cause light for displaying the stereoscopic image SIA to enter the light guide plate 10CD. The light sources 23 and 24 cause light for displaying the stereoscopic image SIB to enter the light guide plate 10CD. For simplicity, the light sources 20 that are not lit are omitted in FIG. 17.

[0111] In the display device 1CD, the display position of the stereoscopic image SIA in the direction along the incident surface 11a is shifted toward the light sources 23 and 24 from the optical axes of the light sources 21 and 22. In addition, in the display device 1CD, the display position of the stereoscopic image SIB is shifted toward the light sources 21 and 22 from the optical axes of the light sources 23 and 24. In particular, the display positions of the stereoscopic image SIA displayed by the light source 22 and the stereoscopic image SIB displayed by the light source 23 in the direction along the incident surface 11a may be considered to be substantially the same. In addition, the display position of the stereoscopic image SIA in the direction perpendicular to the incident surface 11a is farther from the incident surface 11a than the display position of the stereoscopic image SIB in that direction.

[0112] In the display device 1CD, the control unit 30 may first turn on the light sources 21 and 24, and then turn on the light sources 22 and 23. This makes it possible to present the stereoscopic images SIA and SIB as if they were gathering near the center of the light guide plate 10CD. In addition, by making the lights emitted by the light sources 22 and 23 different colors, the stereoscopic images SIA and SIB can be displayed in different colors.

[0113] [Embodiment 4] Fig. 18 is a diagram showing display devices 1DA, 1DB, and 1DC according to embodiment 4. In Fig. 18, reference numeral 1801 is a perspective view showing an outline of the display device 1DA, reference numeral 1802 is a perspective view showing an outline of the display device 1DB, and reference numeral 1803 is a perspective view showing an outline of the display device 1DC.

[0114] As indicated by reference numeral 1801, the display device 1DA includes an auxiliary light guide 16A in addition to the configuration of the display device 1A. The auxiliary light guide 16A may have the same configuration as the light guide plate 10A, except that it does not include the light deflection section 12.

[0115] The display device 1DA further includes a light source 41 which is a light source different from the light source 20. The light emitted from the light source 41 enters the light guide plate 10A via the auxiliary light guide 16A and is emitted from the emission surface 11c. The distance from the light source 41 to the emission surface 11c is longer than the distance from the light source 20 to the emission surface 11c by the auxiliary light guide 16A. Therefore, in the display device 1DA, an intersection CA1 for the light from the light source 20 and an intersection CA2 for the light from the light source 41 are generated. The intersection CA1 and the intersection CA2 have different depths from the light guide plate 10A, i.e., different distances from the light guide plate 10A.

[0116] As indicated by reference numeral 1802, the display device 1DB differs from the display device 1A in that it includes a light guide plate 10DB instead of the light guide plate 10A. The light guide plate 10DB differs from the light guide plate 10A in that it includes a recess 16B. The recess 16B is a recess formed in the rear surface 11d of the light guide plate 10DB.

[0117] The display device 1DB further includes a light source 42 that is a light source different from the light source 20. The light source 20 is omitted in the reference numeral 1802. The light source 42 is accommodated in the recess 16B. The distance from the light source 42 to the emission surface 11c is shorter than the distance from the light source 20 to the emission surface 11c by the distance between the entrance surface 11a and the recess 16B. Therefore, in the display device 1DB, an intersection CA1 (see reference numeral 1801) for the light from the light source 20 and an intersection CA3 for the light from the light source 42 are generated. The intersection CA1 and the intersection CA3 have different depths from each other with respect to the light guide plate 10DB.

[0118] As indicated by reference numeral 1803, the display device 1DC differs from the display device 1A in that it includes a light guide plate 10DC instead of the light guide plate 10A. The light guide plate 10DC differs from the light guide plate 10A in that an intermediate light entrance portion 16C is formed. The intermediate light entrance portion 16C is a portion that is provided on the side surface 11e of the light guide plate 10DC adjacent to the incident surface 11a, and that allows light to enter the light guide plate 10DC.

[0119] The display device 1DC further includes a light source 43 which is a light source different from the light source 20. The light source 43 causes light to enter the light guide plate 10DC from the intermediate light entrance portion 16C. The light source 20 in the display device 1DC is disposed near the side surface 11e so that the optical axis of the light from the light source 20 passes through the light source 43. The distance from the light source 43 to the exit surface 11c is shorter than the distance from the light source 20 to the exit surface 11c by the distance between the entrance surface 11a and the intermediate light entrance portion 16C. Therefore, in the display device 1DC, an intersection CA1 (see reference numeral 1801) for the light from the light source 20 and an intersection CA4 for the light from the light source 43 are generated. The intersection CA1 and the intersection CA4 have different depths from each other with respect to the light guide plate 10DC.

[0120] As described above, in each of the display devices 1DA, 1DB, and 1DC, a plurality of intersections with mutually different amounts of depth are generated for each array line 13. Therefore, each of the display devices 1DA, 1DB, and 1DC can, as a whole, display a plurality of stereoscopic images with mutually different amounts of depth.

[0121] (Modification) Fig. 19 is a diagram showing display devices 1DD, 1DE, and 1DF according to a modified example of embodiment 4. In Fig. 19, reference numeral 1901 is a perspective view showing an outline of the display device 1DD, reference numeral 1902 is a perspective view showing an outline of the display device 1DE, and reference numeral 1903 is a perspective view showing an outline of the display device 1DF.

[0122] As indicated by reference numeral 1901, the display device 1DD includes, in addition to the configuration of the display device 1A, a lens 16D and a light source 44 that makes light incident on the light guide plate 10A via the lens 16D. The display device 1DD also includes a light source 20, although this is not shown in reference numeral 1901. In this type of display device 1DD, an intersection CA1 (see reference numeral 1801) for the light from the light source 20 and an intersection CA5 for the light from the light source 44 are generated.

[0123] Intersection CA1 and intersection CA5 have different depth amounts relative to light guide plate 10DC. Depending on the characteristics of lens 16D, intersection CA5 may occur closer to the viewer than light guide plate 10A, as indicated by reference numeral 1901. Such a display device 1DD can also display a plurality of stereoscopic images having different depth amounts.

[0124] As indicated by reference numeral 1902, the display device 1DE differs from the display device 1A in that the display device 1DE includes a light guide plate 10DE instead of the light guide plate 10A. The light guide plate 10DE differs from the light guide plate 10A in that a retroreflective structure 16E is formed on the side surface 11b, which is the side surface opposite to the incident surface 11a.

[0125] The retroreflective structure 16E reflects the light incident on the side surface 11b in a direction that can be regarded as substantially the same as the incident direction. However, the display device 1DE may have a structure in which a separate retroreflective member having the same function as the retroreflective structure 16E is attached to the side surface 11b of the light guide plate 10A, instead of having the light guide plate 10DE.

[0126] In the display device 1DE, an intersection CA6 different from the intersection CA1 is formed by the light reflected by the side surface 11b. The intersection CA6 is located closer to the viewer than the light guide plate 10DE as indicated by reference numeral 1902, depending on the shape of the light deflection unit 12. Such a display device 1DE can also display a plurality of stereoscopic images with different amounts of depth.

[0127] As shown by reference numeral 1903, the display device 1DF includes a retroreflector 16F in addition to the configuration of the display device 1A. The retroreflector 16F reflects incident light in a direction that can be considered to be substantially the same as the incident direction. The retroreflector 16F is disposed on the exit surface 11c side of the light guide plate 10A. In consideration of visibility, the positional relationship between the exit surface 11c and the back surface 11d in reference numeral 1903 is reversed from that in other figures.

[0128] In this modification, the viewer views the display device 1DF from the rear surface 11d side. The light reflected by the retroreflector 16F forms an intersection CA7 on the viewer side relative to the light guide plate 10A. Therefore, the display device 1DF can display a stereoscopic image using the light guide plate 10A at a position closer to the viewer than the light guide plate 10A. That is, the viewer can view a stereoscopic image projecting forward from the light guide plate 10A.

[0129] Fig. 20 is a diagram showing display devices 1DG and 1DH according to another modified example of the fourth embodiment different from that shown in Fig. 19. In Fig. 20, reference numeral 2001 is a perspective view showing an outline of the display device 1DG, and reference numeral 2002 is a perspective view showing an outline of the display device 1DH.

[0130] As indicated by the reference symbol 2001, the display device 1DG includes a light source 45 in addition to the light source 20 in addition to the configuration of the display device 1A. The light source 45 causes light to enter the light guide plate 10A from the side surface 11b opposite to the incident surface 11a. Such a display device 1DG also achieves the same effects as the display device 1A and the like.

[0131] As indicated by the reference numeral 2002, the display device 1DH differs from the display device 1A in that it includes a light guide plate 10DH instead of the light guide plate 10A. The light guide plate 10DH differs from the light guide plate 10A in that the light entrance surface 11a is provided with positions other than the position where the light from the light source 20 is incident, and the side surface 11b are provided as reflective surfaces that reflect light.

[0132] In the display device 1DH, of the light incident on the light guide plate 10DH from the light source 20, the light incident on the side surface 11b is reflected and further guided within the light guide plate 10DH. The light reflected on the side surface 11b behaves as light from a virtual light source 46 located on the opposite side of the side surface 11b from the light source 20, and forms an intersection point CA8 that is different from the intersection point CA1. Such a display device 1DH also exerts the same effects as the display device 1A and the like.

[0133] [Embodiment 5] Fig. 21 is a diagram showing an example of the arrangement lines 13 according to the fifth embodiment. In the above-mentioned embodiment, the arrangement lines 13 are a plurality of straight lines parallel to each other, but the arrangement lines 13 are not limited to this. The arrangement lines 13 may be straight lines, curved lines, a combination of two or more straight lines, a combination of two or more curved lines, or a combination of one or more straight lines and one or more curved lines. Specific examples of such arrangement lines 13 are shown by reference numerals 2101-2101-2103 in Fig. 21.

[0134] In the display device 1A or the like, when the arrangement line 13 has such a shape, it is possible to express the stereoscopic image SI moving along the arrangement line 13 by switching the positions of the light sources 20 that are turned on or by moving the position where the observer observes the stereoscopic image SI. Therefore, the degree of freedom in expressing the stereoscopic image SI is improved.

[0135] FIG. 22 is a diagram showing an example of a light guide plate 10E according to the fifth embodiment. The light guide plate 10E differs from the light guide plate 10A in that it has an arrangement line 13 that is not linear. In FIG. 22, reference numerals 2201 and 2202 denote different examples of the light guide plate 10E. In FIG. 22, the stereoscopic images SIA and SIB that appear at multiple positions during the movement are shown in a single drawing. Also, in FIG. 22, the arrangement line 13 is shown as an arrow indicating the movement direction of the stereoscopic images SIA and SIB.

[0136] In the light guide plate 10E shown by reference numeral 2201, the arrangement line 13 on which the light deflection units 12 for displaying the stereoscopic image SIA are arranged has a shape that combines a curved line that is convex in a direction away from the incident surface 11a and a curved line that is convex in a direction toward the incident surface 11a. In this light guide plate 10E, the stereoscopic image SIA oscillates in a direction perpendicular to the incident surface 11a while moving in a direction along the incident surface 11a, as shown by reference numeral 2201. By reducing the width and period of the oscillation in the direction perpendicular to the incident surface 11a, it is possible to present the stereoscopic image SIA as if it were moving linearly in a direction along the incident surface 11a.

[0137] In the light guide plate 10E shown by reference numeral 2202, the arrangement line 13 on which the light deflection units 12 for displaying the stereoscopic image SIA are arranged has a curved shape that is convex in a direction approaching the incident surface 11a. On the other hand, the arrangement line 13 on which the light deflection units 12 for displaying the stereoscopic image SIB are arranged has a curved shape that is convex in a direction away from the incident surface 11a. The arrangement line 13 on which the light deflection units 12 for displaying the stereoscopic image SIA are arranged and the arrangement line 13 on which the light deflection units 12 for displaying the stereoscopic image SIB are arranged intersect with each other. In this light guide plate 10E, the stereoscopic images SIA and SIB temporarily switch positions in a direction perpendicular to the incident surface 11a while moving in a direction along the incident surface 11a, as shown by reference numeral 2202.

[0138] [Embodiment 6] FIG. 23 is a diagram showing an example of the arrangement line 13 according to the sixth embodiment. In the above-mentioned embodiment, the start point and the end point of each of the arrangement lines 13 are each a single line, but the arrangement line 13 is not limited to this. The arrangement line 13 may include a branch point or a junction point of a plurality of lines. Specific examples of such an arrangement line 13 are shown by reference numerals 2301, 2302, and 2303 in FIG. 23.

[0139] In the display device 1A or the like, when the arrangement line 13 has such a shape, by switching the position of the lit light source 20 or by moving the position where the observer observes the stereoscopic image SI, it becomes possible to express the stereoscopic image SI as if it were split or merged along the arrangement line 13. Therefore, the degree of freedom in expressing the stereoscopic image SI is improved.

[0140] FIG. 24 is a diagram showing an example of a light guide plate 10F according to the sixth embodiment. The light guide plate 10F differs from the light guide plate 10A in that the arrangement lines 13 include a branching point or a merging point of a plurality of lines. In FIG. 24, reference numerals 2401 and 2402 denote different examples of the light guide plate 10F. In FIG. 24, a stereoscopic image SIA that appears at a plurality of positions during the movement is shown in a single drawing. Also, in FIG. 24, the arrangement lines 13 are shown as arrows indicating the movement direction of the stereoscopic image SIA.

[0141] 24, the array lines 13 have a shape that branches in two directions from one end. In this case, the stereoscopic image SIA is a single image at the start of its movement, but it moves by splitting into two.

[0142] 24, the arrangement lines 13 have a shape that branches in four directions from one end. In this case, the stereoscopic image SIA is a single image at the start of its movement, but it moves by splitting into four.

[0143] In all of the examples shown in Fig. 24, the stereoscopic image SIA is split into multiple images. However, as described above, according to the arrangement line 13 of the sixth embodiment, multiple stereoscopic images can be merged. For example, in the example shown in Fig. 24, by reversing one end and the other end, two or four stereoscopic images SIA can be merged.

[0144] [Embodiment 7] Fig. 25 is a diagram showing an example of the arrangement line 13 according to the seventh embodiment. In Fig. 25, reference numerals 2501 and 2502 denote different examples of the arrangement line 13 according to the seventh embodiment.

[0145] For example, as shown by reference numeral 2501 in Fig. 25, the array lines 13 may include linear regions that are not parallel to each other. In the display device 1A or the like, when the array lines 13 have such a shape, it is possible to express the stereoscopic image SI as if it were enlarged or reduced along the array lines 13 by switching the positions of the light sources 20 that are turned on or by moving the position at which the observer observes the stereoscopic image SI. This improves the degree of freedom in expressing the stereoscopic image SI.

[0146] Furthermore, if there is a region in which the spacing between the array lines 13 is excessively wide due to the array lines 13 not being parallel to each other, an auxiliary array line 17 may be added to that region, as shown by reference numeral 2501 in Fig. 25. In this case, it is possible to suppress degradation in the image quality of the stereoscopic image SI while maintaining the freedom of expression of the stereoscopic image SI.

[0147] Fig. 26 is a diagram showing an example of a light guide plate 10G according to the seventh embodiment. The light guide plate 10G differs from the light guide plate 10A in that the arrangement lines 13 are not parallel to each other. In Fig. 26, a stereoscopic image SIA that appears at a plurality of positions during the movement is shown in a single drawing. Also, in Fig. 26, the arrangement lines 13 are shown as arrows indicating the movement direction of the stereoscopic image SIA.

[0148] In the light guide plate 10G shown in Fig. 26, the intervals between the multiple array lines 13 increase as the stereoscopic image SIA moves from the start point to the end point. In this case, the stereoscopic image SIA is enlarged as it moves along the array lines 13. In addition, in the light guide plate 10G, the intervals between the multiple array lines 13 may decrease as the stereoscopic image SIA moves from the start point to the end point, contrary to the example of Fig. 26. In this case, the stereoscopic image SIA is reduced as it moves along the array lines 13.

[0149] [Embodiment 8] Fig. 27 is a diagram showing a specific example of the control of the light source 20 by the control unit 30. In Fig. 27, reference numerals 2701 and 2702 denote different examples of the control of the light source 20 by the control unit 30. In Fig. 27, a stereoscopic image SIA that appears at a plurality of positions during the course of movement is shown in a single drawing. Also, in Fig. 27, the arrangement line 13 is shown as an arrow indicating the movement direction of the stereoscopic image SIA.

[0150] 27, the control unit 30 controls turning on and off of five light sources 21, 22, 23, 24, and 25 that constitute the light source 20. The light sources 21, 22, 23, 24, and 25 are arranged linearly in this order.

[0151] The control unit 30 may control the light sources 21, 22, 23, 24, and 25 to be turned on and off sequentially from one end of the linear region to the other end. For example, as shown by reference numeral 2701 in FIG. 27, the control unit 30 first turns on only the light source 21. Next, the control unit 30 turns off the light source 21 and turns on the light source 22. Thereafter, the control unit 30 turns off the light source 22 and turns on the light source 23, turns off the light source 23 and turns on the light source 24, and turns off the light source 24 and turns on the light source 25, in that order. By such control, it is possible to realize control such that the position of the light source 20 that emits light into the light guide plate 10A moves from one end to the other end of the region in which the light sources 20 are linearly arranged.

[0152] Furthermore, the control unit 30 may control the light sources 21, 22, 23, 24, and 25 to turn on and off sequentially from any point other than one end and the other end of the linear area to both one end and the other end.

[0153] 27, for example, the control unit 30 first turns on only the light source 23. Next, the control unit 30 turns off the light source 23 and turns on the light sources 22 and 24. Furthermore, the control unit 30 turns off the light sources 22 and 24 and turns on the light sources 21 and 25. By such control, it is possible to realize control such that the position of the light source 20 that makes light incident on the light guide plate 10A moves from the ends other than the ends of the area in which the light sources 20 are linearly arranged to the ends.

[0154] The number of light sources 20 controlled by the control unit 30 is not limited to the above. The control unit 30 may cause the light sources 20 to emit light one by one, or may cause multiple light sources 20 to emit light one by one. Furthermore, the control unit 30 may gradually increase or decrease the number of light sources 20 that emit light simultaneously.

[0155] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure.

[0156] 〔summary〕 The present disclosure can also be expressed as follows.

[0157] A light guide plate according to a first aspect of the present disclosure is a light guide plate for displaying a stereoscopic image using parallax, and includes an entrance surface into which light from a light source is incident, an exit surface from which the light is emitted, and a plurality of light deflection units for deflecting the light incident and guided from the entrance surface to emit the light from the exit surface, the plurality of light deflection units being arranged on an array line that is a linear array area, and a first point on the exit surface from which a first exit light deflected by the light deflection units is emitted into an angle range in which the first exit light is irradiated to one eye of an observer observing the exit surface from within a predetermined range of an observation space and its vicinity. If the first exit point is defined as an exit point, and the point on the exit surface from which the second exit light deflected by the light deflection unit is emitted into an angular range in which the other eye of the observer and its vicinity is irradiated is defined as a second exit point, a plurality of the light deflection units are arranged on the array line so that a straight line passing through the first exit point and the center of the one eye and a straight line passing through the second exit point and the center of the other eye intersect with each other to form an intersection, and a plurality of the array lines are provided, and at least one of the array lines includes an area that is not parallel to the entrance surface.

[0158] A light guide plate according to a second aspect of the present disclosure is similar to the first aspect, in that the intersection is located on the rear side of the exit surface as viewed from the observer.

[0159] A light guide plate according to aspect 3 of the present disclosure is in aspect 1 or 2, wherein each of the plurality of alignment lines is a straight line, a curved line, a combination of two or more straight lines, a combination of two or more curved lines, or a combination of one or more straight lines and one or more curved lines.

[0160] A light guide plate according to a fourth aspect of the present disclosure is the light guide plate of any one of the first to third aspects, wherein each of the plurality of alignment lines includes a branching point or a joining point of the plurality of lines.

[0161] A light guide plate according to a fifth aspect of the present disclosure is the light guide plate of any one of the first to fourth aspects, wherein each of the plurality of alignment lines includes linear regions that are not parallel to each other.

[0162] A light guide plate according to aspect 6 of the present disclosure is, in any one of aspects 1 to 5, such that the stereoscopic image includes a first stereoscopic image displayed by the optical deflection unit in a first partial region that is a partial region of the light guide plate, and a second stereoscopic image displayed by the optical deflection unit in a second partial region that is a region other than the first partial region, and the optical deflection unit is arranged so that the first stereoscopic image and the second stereoscopic image are observable from within the same observation space.

[0163] A light guide plate according to aspect 7 of the present disclosure is, in any one of aspects 1 to 5, such that the stereoscopic image includes a first stereoscopic image displayed by the optical deflection unit in a first partial region that is a partial region of the light guide plate, and a second stereoscopic image displayed by the optical deflection unit in a second partial region that is a region other than the first partial region, and the optical deflection unit is provided such that the observation space in which the first stereoscopic image can be observed and the observation space in which the second stereoscopic image can be observed are located at different positions from each other.

[0164] A light guide plate according to an eighth aspect of the present disclosure is any one of the first to seventh aspects, wherein an angle formed between the incident surface and a region of each of the plurality of arrangement lines that is not parallel to the incident surface is 2.5° or more.

[0165] A display device according to a ninth aspect of the present disclosure includes a light guide plate according to any one of the first to eighth aspects, a plurality of light sources that cause light to enter the light guide plate from the incident surface, and a control unit that controls the plurality of light sources.

[0166] A display device according to aspect 10 of the present disclosure is similar to aspect 9, in that the multiple light sources are arranged in a line, and the control unit controls the multiple light sources to turn on and off sequentially from one end of the linear area to the other end.

[0167] A display device according to aspect 11 of the present disclosure is similar to aspect 9 in that the multiple light sources are arranged in a line, and the control unit controls the multiple light sources to turn on and off sequentially from any point other than one end or the other end of the linear area to both one end and the other end.

[0168] An amusement machine according to an eleventh aspect of the present disclosure includes a display device according to any one of aspects 9 to 11.

[0169] An in-vehicle display device according to a thirteenth aspect of the present disclosure includes the display device according to any one of the ninth to eleventh aspects. [Explanation of symbols]

[0170] 1A, 1B, 1C, 1CA, 1CB, 1CC, 1CD, 1DA, 1DB, 1DC, 1DD, 1DE, 1DF, 1DG, 1DH Display device 10A, 10B, 10C, 10CD, 10DB, 10DC, 10DE, 10DH, 10E, 10F, 10G light guide plate 11a Incidence plane 11c Output surface 12, 121, 122, 123, 124, 125 Light deflection section 13, 17 Array lines 20, 21, 22, 23, 24, 25, 41, 42, 43, 44, 45, 46 light source 30 Control section 100 Gaming Machines

Claims

1. A light guide plate for displaying a stereoscopic image using parallax, an incident surface on which light from a light source is incident; an exit surface from which the light is emitted; a plurality of light deflection units that deflect the light that is incident on the entrance surface and guided thereto, thereby causing the light to exit from the exit surface; The plurality of light deflection units are arranged on an array line which is a linear array area, a first exit point is a point on the exit surface from which a first exit light deflected by the optical deflection unit is emitted into an angular range in which one eye of an observer observing the exit surface from within a predetermined range of observation space and the vicinity thereof is irradiated, and a second exit point is a point on the exit surface from which a second exit light deflected by the optical deflection unit is emitted into an angular range in which the other eye of the observer and the vicinity thereof is irradiated, a plurality of the optical deflection units are arranged on the arrangement line such that a straight line passing through the first exit point and the center of the one eye and a straight line passing through the second exit point and the center of the other eye intersect with each other to form an intersection, A light guide plate comprising a plurality of the arrangement lines, and at least one of the arrangement lines includes a region that is not parallel to the incident surface.

2. The light guide plate according to claim 1 , wherein the intersection is located on a rear side of the exit surface as viewed from the observer.

3. The light guide plate according to claim 1 , wherein each of the plurality of alignment lines is a straight line, a curved line, a combination of two or more straight lines, a combination of two or more curved lines, or a combination of one or more straight lines and one or more curved lines.

4. The light guide plate according to claim 1 , wherein each of the plurality of alignment lines includes a branching point or a joining point of the plurality of lines.

5. The light guide plate according to claim 1 , wherein each of the plurality of alignment lines includes linear regions that are not parallel to each other.

6. the stereoscopic image includes a first stereoscopic image displayed by the light deflection unit in a first partial region that is a partial region of the light guide plate, and a second stereoscopic image displayed by the light deflection unit in a second partial region that is a region different from the first partial region, The light guide plate according to claim 1 , wherein the light deflection section is provided so that the first stereoscopic image and the second stereoscopic image are observable from within the same observation space.

7. the stereoscopic image includes a first stereoscopic image displayed by the light deflection unit in a first partial region that is a partial region of the light guide plate, and a second stereoscopic image displayed by the light deflection unit in a second partial region that is a region different from the first partial region, The light guide plate according to claim 1 , wherein the light deflection section is provided so that the observation space in which the first stereoscopic image can be observed and the observation space in which the second stereoscopic image can be observed are disposed at positions different from each other.

8. The light guide plate according to claim 1 , wherein an angle formed between the incident surface and a region of each of the plurality of alignment lines that is not parallel to the incident surface is equal to or larger than 2.5°.

9. The light guide plate according to claim 1 ; A plurality of light sources that cause light to enter the light guide plate from the entrance surface; A control unit that controls the plurality of light sources.

10. The plurality of light sources are arranged in a line, The display device according to claim 9 , wherein the control unit controls the plurality of light sources to be turned on and off in sequence from one end of the line to the other end.

11. The plurality of light sources are arranged in a line, The display device according to claim 9 , wherein the control unit controls the plurality of light sources to be turned on and off sequentially from an arbitrary point other than one end and the other end of the line to both the one end and the other end.

12. A gaming machine comprising the display device according to any one of claims 9 to 11.

13. An in-vehicle display comprising the display device according to any one of claims 9 to 11.

Images