Light guide plate, display device, input device and electrical equipment

Abstract

The present invention realizes a light guide plate capable of displaying a stereoscopic image with enhanced three-dimensional effect. The light guide plate includes a plurality of optical path changing portions that converge incident light to fixed points. Through the aggregation of the plurality of fixed points, a stereoscopic image (IA) is spatially formed. The stereoscopic image includes a plurality of non-parallel surfaces (A, B), each surface being composed of a plurality of points dispersed thereon, and the density of the plurality of points on each surface becomes a value corresponding to the position of that surface.

Description

Technical Field

[0001] The present invention relates to a light guide plate for spatially displaying an image, a display device including the light guide plate, an input device including the display device, and an electrical device including the above display device or input device. Background Art

[0002] Patent Document 1 discloses an optical device for forming a three-dimensional image. The optical device includes a plurality of light converging portions. Each of the light converging portions has an optical surface on which light guided by a light guide plate is incident and from which outgoing light (i) substantially converges in a direction of a single converging point or converging line in space or (ii) substantially diverges from a single converging point or converging line in space is emitted. The converging point or converging line is different between the plurality of light converging portions, and an image is formed in space by the aggregation of the plurality of converging points or converging lines.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open Gazette: JP-A-2016-114929 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in the case of forming an image having a plurality of non-parallel surfaces by the display device disclosed in Patent Document 1, when these surfaces are formed by the same aggregation of converging points or converging lines, the resulting image lacks a three-dimensional effect. A method for improving the three-dimensional effect in the case of forming such an image is not disclosed or suggested in Patent Document 1.

[0008] An object of one aspect of the present invention is to provide a light guide plate or the like that can display a three-dimensional image with an improved three-dimensional effect.

[0009] Technical Solution for Solving the Problem

[0010] To solve the above technical problem, one aspect of the present invention provides a light guide plate including a plurality of optical path changing portions that converge incident light to corresponding fixed points, and a three-dimensional image is formed in space by the aggregation of a plurality of the fixed points respectively corresponding to the plurality of the optical path changing portions, wherein the three-dimensional image includes a plurality of non-parallel surfaces, the surfaces are each composed of a plurality of points dispersed thereon, and the density of the plurality of points on each of the surfaces becomes a value corresponding to the position of the surface.

[0011] Advantages of the Invention

[0012] According to one aspect of the present invention, it is possible to provide a light guide plate or the like that can display a three-dimensional image with an improved three-dimensional effect. Description of the Drawings

[0013] Figure 1 It is a figure showing a specific example of a three - dimensional image of a light guide plate imaging representing a structural example.

[0014] Figure 2 It is a three - dimensional view for explaining the principle of the display performed by the display device.

[0015] Figure 3 It is a figure for explaining an example of a method for determining the respective brightnesses of the surfaces included in the three - dimensional image.

[0016] Figure 4 It is a coordinate diagram showing an example of the relationship between the angle and the brightness of the surface.

[0017] Figure 5 It is a coordinate diagram showing the relationship between the brightness of the surface and the density of the points.

[0018] Figure 6 It is a figure for explaining the arrangement of the points.

[0019] Figure 7 It is a figure for explaining a method for determining the brightness of the curved surface when the three - dimensional image has a curved surface.

[0020] Figure 8 It is a figure for explaining another specific example of the three - dimensional image formed by the light guide plate of the structural example.

[0021] Figure 9 It is a figure showing the surface in the three - dimensional image displayed by the display device of the first modification example.

[0022] Figure 10 It is a figure showing the three - dimensional image displayed by the display device of the second modification example.

[0023] Figure 11 It is a figure showing the input device of the third modification example.

[0024] Figure 12 It is a three - dimensional view showing an example of a game machine applying the input device.

[0025] Figure 13 It is a figure showing a case where the display device is applied to the taillight of a vehicle.

[0026] Figure 14 It is a figure showing a case where the display device is applied to the input part of an elevator.

[0027] Figure 15 It is a figure showing a case where the display device is applied to the input part of a warm - water cleaning toilet seat.

[0028] Figure 16It is a perspective view of the display device according to the fifth modification example.

[0029] Figure 17 It is a cross-sectional view showing the structure of the display device according to the fifth modification example.

[0030] Figure 18 It is a top view showing the structure of the display device according to the fifth modification example.

[0031] Figure 19 It is a perspective view showing the structure of the optical path changing unit included in the display device according to the fifth modification example.

[0032] Figure 20 It is a perspective view showing the arrangement of the optical path changing units.

[0033] Figure 21 It is a perspective view showing the imaging method of the stereoscopic image of the display device according to the fifth modification example. Detailed Embodiment

[0034] Hereinafter, embodiments of one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described based on the drawings. However, the present embodiment described below is merely an example of the present invention in all aspects. Of course, various improvements or modifications can be made without departing from the scope of the present invention.

[0035] §1 Application Example

[0036] First, the principle of the display performed by the display device including the light guide plate of the present invention will be described. In addition, hereinafter, for the sake of convenience of explanation, sometimes the Figure 2 +X direction in is set as the front direction, the -X direction as the rear direction, the +Y direction as the upper direction, the -Y direction as the lower direction, the +Z direction as the right direction, and the -Z direction as the left direction for explanation.

[0037] Figure 2 It is a perspective view for explaining the principle of the display performed by the display device 10. The display device 10 forms a stereoscopic image recognizable by the user in a space without a screen. In Figure 2 , a case where the display device 10 displays the stereoscopic image I, and more specifically, a button-shaped stereoscopic image I with the character "ON" is shown. As Figure 2 shown, the display device 10 includes a light guide plate 11 and a light source 12. According to the display device 10, an image formed by the light guide plate 11 with the light from the light source 12 can be displayed.

[0038] The light guide plate 11 guides the light incident from the light source 12 and emits it from the light emitting surface 11a, causing a stereoscopic image to be spatially formed. The light guide plate 11 is formed in a rectangular parallelepiped shape and is formed of a resin material having transparency and a relatively high refractive index. The material forming the light guide plate 11 may also be, for example, polycarbonate resin, polymethyl methacrylate resin, glass, or the like. The light guide plate 11 includes a light emitting surface 11a (light emitting surface) for emitting light, a back surface 11b on the side opposite to the light emitting surface 11a, and end surfaces 11c, 11d, 11e, and 11f that are end faces on four sides. The end surface 11c is an incident surface on which the light projected from the light source 12 is incident on the light guide plate 11. In the following description, the end surface 11c is referred to as the incident surface 11c. The end surface 11d is a surface on the side opposite to the end surface 11c. The end surface 11e is a surface on the side opposite to the end surface 11f. The light guide plate 11 guides the light from the light source 12 to expand and guide it in a plane parallel to the light emitting surface 11a. The light source 12 is a point light source that emits light into the light guide plate 11. Specifically, the light source 12 is, for example, an LED (Light Emitting Diode) light source.

[0039] A plurality of optical path changing portions 13 including an optical path changing portion 13a, an optical path changing portion 13b, and an optical path changing portion 13c are formed on the back surface 11b of the light guide plate 11. The optical path changing portions 13 are substantially continuously formed in the Z-axis direction. In other words, the plurality of optical path changing portions 13 are respectively formed along a predetermined line in a plane parallel to the light emitting surface 11a. The light projected from the light source 12 and guided by the light guide plate 11 is incident on respective positions in the Z-axis direction of the optical path changing portion 13. The optical path changing portion 13 substantially converges the light incident on respective positions of the optical path changing portion 13 to a fixed point corresponding to each optical path changing portion 13. In Figure 2 , as a part of the optical path changing portion 13, the optical path changing portion 13a, the optical path changing portion 13b, and the optical path changing portion 13c are particularly shown. In addition, in Figure 2 is shown a case where a plurality of lights emitted from the optical path changing portion 13a, the optical path changing portion 13b, and the optical path changing portion 13c respectively converge in each of the optical path changing portion 13a, the optical path changing portion 13b, and the optical path changing portion 13c.

[0040] Specifically, the optical path changing unit 13a corresponds to the fixed point PA of the stereoscopic image I. The light from each position of the optical path changing unit 13a converges at the fixed point PA. Therefore, the wavefront of the light from the optical path changing unit 13a becomes the wavefront of the light emitted from the fixed point PA. The optical path changing unit 13b corresponds to the fixed point PB on the stereoscopic image I. The light from each position of the optical path changing unit 13b converges at the fixed point PB. In this way, the light from each position of any of the optical path changing units 13 substantially converges at the fixed point corresponding to each optical path changing unit 13. Thus, it is possible to provide, through any of the optical path changing units 13, the wavefront of the light emitted from the corresponding fixed point. The fixed points corresponding to the respective optical path changing units 13 are different from each other, and through the aggregation of a plurality of fixed points respectively corresponding to the optical path changing units 13, the stereoscopic image I recognized by the user is imaged spatially (more specifically, in the space from the light guide plate 11 toward the light emitting surface 11a side).

[0041] As Figure 2 shown, the optical path changing unit 13a, the optical path changing unit 13b, and the optical path changing unit 13c are respectively formed along the line La, the line Lb, and the line Lc. Here, the line La, the line Lb, and the line Lc are straight lines substantially parallel to the Z-axis direction. Any of the optical path changing units 13 is substantially continuously formed along a straight line parallel to the Z-axis direction.

[0042] §2 Structural Example

[0043] Figure 1 is a diagram showing a specific example of the stereoscopic image I imaged by the light guide plate 11 of the present embodiment, that is, the stereoscopic image IA. As Figure 1 shown, the stereoscopic image IA has non-parallel surfaces A and B. In Figure 1 it, a state is shown in which the rectangular surfaces A and B are joined at one side of the rectangle, and this one side is inclined with respect to the paper surface.

[0044] The surfaces A and B are composed of a plurality of points dispersedly arranged on the surfaces A and B. The point is an image of a light spot that forms an image at a point in space. The density of the plurality of points on each of the surfaces A and B becomes a value corresponding to the position of the surface A and B. Therefore, according to the light guide plate 11, it is possible to easily recognize each of the surfaces A and B, and the three-dimensional effect of the stereoscopic image IA is enhanced. ...

[0045] The display device 10 can also display a stereoscopic image having more planes than the stereoscopic image IA. In addition, the display device 10 can display not only a plane but also a stereoscopic image having a curved surface such as a sphere. The curved surface can be displayed as a collection of many minute surfaces or as a single curved surface.

[0046] The density of points on each of surfaces A and B is determined according to the angle between the normal direction of the surface and a specified direction. Specifically, (i) the brightness of each of surfaces A and B is determined according to the above-mentioned angle, and (ii) the density of points on each of surfaces A and B is determined according to the above-mentioned brightness.

[0047] Figure 3 FIG. is for explaining an example of a method for determining the brightness of each of surfaces A and B. The method described below is a method for reproducing the brightness when light is irradiated on a stereoscopic image from a specified direction. In this method, as Figure 3 shown by reference numeral 3001, a virtual light source, i.e., virtual light source 100, for irradiating light 110 on the stereoscopic image IA from a specified direction is set. The virtual light source 100 is set to be at infinity with respect to the stereoscopic image IA. That is, the direction (specified direction) in which the light 110 is incident on the stereoscopic image IA from the virtual light source 100 is constant regardless of the position on the stereoscopic image IA. Moreover, as Figure 3 shown by reference numeral 3002, the angles θA and θB between the directions of the normal lines PLA and PLB of each of surfaces A and B and the direction of the light 110 are calculated.

[0048] Figure 4 FIG. is a coordinate diagram showing an example of the relationship between the angles θA and θB and the brightness of surfaces A and B. In Figure 4 , the horizontal axis represents the angle and the vertical axis represents the brightness. Figure 4 The brightness values in are values standardized with the minimum value set to 0 and the maximum value set to 1. In the example shown in Figure 4 , the smaller the angles θA and θB, the greater the brightness of surfaces A and B. By setting the brightness in this way, the irradiation mode of the light from the virtual light source 100 can be reproduced. However, the relationship between the angle and the brightness and the range of the angle defining this relationship are not limited to the Figure 4 shown curve and can be freely set.

[0049] Figure 5 FIG. is a coordinate diagram showing the relationship between the brightness of surfaces A and B and the density of points. In Figure 5 , the horizontal axis represents the brightness of surfaces A and B and the vertical axis represents the density of points. The density of points on each of surfaces A and B monotonically increases as the brightness of each of surfaces A and B increases. In the example shown in Figure 5 , the density of points is proportional to the brightness of surfaces A and B. By arranging points on each of surfaces A and B according to the density determined based on the Figure 5 shown relationship, an optical path changing portion 13 is formed on the back surface 11b of the light guide plate 11, whereby a light guide plate 11 capable of imaging the stereoscopic image IA can be manufactured.

[0050] The density of the dots is appropriately determined according to the design of the stereoscopic image IA. For example, when the stereoscopic image IA is designed to be bright as a whole, the density of the dots is increased as a whole. However, when the density of the dots on the surfaces A and B is too high, the surfaces A and B become surfaces that seem to be filled, and the three-dimensional effect of the stereoscopic image IA is reduced. The upper limit of the dot density is preferably 50%. If the upper limit of the dot density is 50%, it is possible to prevent the reduction of the three-dimensional effect of the stereoscopic image IA caused by excessive dot density.

[0051] Figure 6 This is a diagram for explaining the arrangement of the dots D. Each dot may also be arranged randomly. However, in terms of the shape of the dots, blurring is likely to occur in the direction parallel to the incident surface 11c of the light guide plate 11. Therefore, as shown by the reference numeral 6001 in Figure 6 , when the interval DD between a plurality of adjacent dots D in the direction parallel to the incident surface 11c is shorter than the distance by which the dot D spreads due to blurring, these dots D become blurred, and sometimes they are not recognized as individual dots D but as a connected line. In this case, the three-dimensional effect of the stereoscopic image IA may be reduced.

[0052] Therefore, as shown by the reference numeral 6002 in Figure 6 , the interval DD between a plurality of adjacent dots D in the direction parallel to the incident surface 11c is preferably equal to or greater than a specified threshold value. The specified threshold value only needs to be set to a distance at which the dots D do not connect to each other when a plurality of adjacent dots D in the direction parallel to the incident surface 11c become blurred. By arranging a plurality of dots D in this way, even when the dots D become blurred, it is easy to recognize the dots D individually, and therefore, the possibility of reducing the three-dimensional effect of the stereoscopic image IA can be reduced.

[0053] In addition, as described above, in the display device 10, a curved surface can be displayed. However, the normal line of a curved surface is different from that of a plane and is not uniquely determined. Therefore, the density of the dots on the curved surface is determined, for example, based on the angle between the direction represented by the curved surface and a specified direction.

[0054] Figure 7 This is a diagram for explaining a method of determining the brightness of the surface C when the stereoscopic image I has a surface C that is a curved surface. The normal lines PLC1, PLC2, PLC3, and PLC4 at four different points on the surface C are shown in Figure 7 . The directions of the normal lines PLC1 to PLC4 are different from each other. As an example of a method of determining the brightness of such a surface C, the following method can be cited: setting an arbitrary normal line direction on the surface C as the direction represented by the surface C and determining the dot density based on the angle between this direction and the direction of the light 110.

[0055] For example, consider the case where the direction of the normal line PLC3 is set to the direction represented by plane C. In this case, the angle between the direction of the normal line PLC3 and the direction of the light 110 is calculated. Moreover, the brightness determined based on the calculated angle is set as the brightness of the entire plane C, and the density of points determined based on this brightness is set as the density of points on the entire plane C.

[0056] The density of points does not necessarily need to be determined by the above method. It is also possible to freely determine the brightness of planes A and B regardless of the above method (for example, setting the brightness of plane A to 1.0 and the brightness of plane B to 0.5), and based on this brightness, Figure 5 determine the density of points through the relationship shown. Specifically, an example is to determine the brightness for each gray level of the original color of the stereoscopic image IA. Even in the case of determining the brightness in this way, by making the brightness of each plane different, it is easy to separately identify these planes. Therefore, compared with the case of imaging each plane equally, the stereoscopic effect of the stereoscopic image IA can be improved. Additionally, it can also be that two or more virtual light sources 100 that irradiate the stereoscopic image IA from different directions are set, and the brightnesses formed by each virtual light source 100 are summed as the final brightness.

[0057] §3 Operation Example

[0058] Figure 8 This is a diagram for explaining a stereoscopic image IB, which is another specific example of the stereoscopic image I that images the light guide plate 11. In Figure 8 it, the 3D model IB0 to be represented by the stereoscopic image IB is denoted by the symbol 8001. Additionally, the stereoscopic image IB1 that represents only the contour lines of the 3D model IB0 is denoted by the symbol 8002. Additionally, the stereoscopic image IB2 that fills each face of the 3D model IB0 is denoted by the symbol 8003. Additionally, the stereoscopic image IB that images the 3D model IB0 through the light guide plate 11 is denoted by the symbol 8004.

[0059] In the stereoscopic image IB1, since the faces of the 3D model IB0 are not shown, the 3D model IB0 cannot be represented. On the other hand, in the stereoscopic image IB2, since it is displayed in the same way for any face, each face cannot be separately identified, and the stereoscopic effect of the 3D model IB0 cannot be represented.

[0060] In contrast, in the stereoscopic image IB, points D are arranged at different densities for each face. That is, the multiple faces are displayed by points D arranged at mutually different densities. Therefore, based on the stereoscopic image IB, compared with the stereoscopic images IB1 and IB2, it is easier to individually recognize each face of the 3D model composed of multiple faces, and a sense of three-dimensionality is more easily felt. In other words, it is possible to form an image of the stereoscopic image IB with an enhanced sense of three-dimensionality compared to the stereoscopic images IB1 and IB2 through the light guide plate 11. Therefore, based on the light guide plate 11, the expression range of the stereoscopic image IB is expanded compared with conventional light guide plates.

[0061] §4 Modification Example

[0062] The embodiments of the present invention have been described in detail above, but the above descriptions are merely examples of the present invention in all aspects. Of course, various improvements or modifications can be made without departing from the scope of the present invention. For example, the following changes can be made. In addition, hereinafter, the same reference numerals are used for the same components as those in the above embodiments, and the same points as those in the above embodiments are appropriately omitted from the description. The following modification examples can be combined as appropriate.

[0063] <4.1>

[0064] Figure 9 It is a diagram showing face A in the stereoscopic image IA displayed by the display device 10 of the first modification example. In the above structural example, the points representing face A are randomly arranged. In contrast, in the first modification example, as Figure 9 shown, when face A is divided into triangular regions A1 to A8, points D1 to D8 are arranged at the centroid of each triangle. By arranging the points regularly in this way, the appearance of face A can be improved.

[0065] However, as described above, it is preferable that the multiple points are arranged at mutually different positions in the direction perpendicular to the incident surface 11c. Therefore, when the positions of the multiple points are repeated in the direction perpendicular to the incident surface 11c due to the method of arranging points in the first modification example, it is preferable to appropriately change the positions.

[0066] In Figure 9 the shown example, considering visibility, face A is divided into eight regions A1 to A8. However, in practice, the number of divided faces can be appropriately determined according to the point density and size of the face. In addition, the shape of each region is not limited to a triangle.

[0067] In addition, the randomly arranged points as in the above structural example and the regularly arranged points as in the first modification example can also coexist on face A. In this case, it is possible to arrange the points evenly while moderately maintaining randomness, and the appearance can be further improved.

[0068] <4.2>

[0069] Figure 10 1 is a diagram showing a stereoscopic image IB displayed by the display device 10 according to the second modification. Figure 10 As shown, in the second modified example, the stereoscopic image IB includes not only points D representing each surface of the 3D model IB0 but also outlines OL of each surface. According to the second modified example, the details of the surfaces of the stereoscopic image IB can be clearly displayed. Furthermore, the clear outlines of each surface enhance the three-dimensional effect of the stereoscopic image IB.

[0070] <4.3>

[0071] Figure 11 FIG. 2 is a diagram showing an input device 20 according to a third modified example. Figure 11 As shown in FIG. 1 , the input device 20 includes a display device 10 and a sensor 24. The sensor 24 detects an object in a non-contact manner in a space where a stereoscopic image I is displayed by the display device 10. Figure 11 In the example shown, the sensor 24 is a photoelectric sensor that irradiates light toward the stereo image I and detects an object by the reflected light. However, the sensor 24 may also be a photoelectric sensor that Figure 11 The example shown is a photoelectric sensor of a different type. In addition, the sensor 24 may be a sensor other than a photoelectric sensor.

[0072] In addition, Figure 11 In the example shown, the sensor 24 is located on the opposite side of the display device 10 from the stereoscopic image I. However, the sensor 24 is not limited to this position, and may be located on the same side of the display device 10 as the stereoscopic image I, or at any position above, below, left, or right with respect to the stereoscopic image I.

[0073] When a user uses a pointer F, such as a finger, to input a stereoscopic image I displayed on the display device 10, the input device 20 receives the input by detecting the pointer F via the sensor 24. The input device 20 realizes a contactless switch. Furthermore, the input device 20 can create a stereoscopic image I with enhanced stereoscopic effect on the display device 10, prompting the user to input.

[0074] <4.4>

[0075] The following describes an example of an electrical device including a display device 10 or an input device 20. In the following description, examples may be described in which only one of the display device 10 and the input device 20 is applied to the electrical device. However, it goes without saying that the other may also be applied depending on the purpose of the electrical device.

[0076] Figure 12 2 is a perspective view showing an example of a game machine to which the input device 20 is applied. Figure 12In the figure, the illustration of the input device 20 is omitted. The input device 20 can be applied to an input device used in an entertainment device such as a game machine like a pachinko machine or an amusement machine. As described above, the input device 20 includes a display device 10 and a sensor 24. When a user performs an input operation on the image displayed on the display device 10 with an indicator such as a finger, the input device 20 receives the input by detecting the indicator with the sensor 24.

[0077] As Figure 12 shown by the symbol 12001 in, on the operation panel where the user operates the game machine M1 (electrical equipment), at least one three-dimensional image I of the switches as the user operation can also be imaged by the display device 10. Further, as Figure 12 shown by the symbol 12002 in, in the game machine M2 (electrical equipment), imaging can be performed in a manner overlapping with the screen for displaying the performance image for the user, and the three-dimensional image I as the switch that becomes the operation object of the user can be imaged by the display device 10. In this case, the display device 10 can also display the three-dimensional image I only when required for the performance. Further, only the display device 10 instead of the input device 20 can be applied as the display device for displaying the performance image to the game machine. Further, the display device 10 can also be applied to the game machines installed in a game arcade or a casino, etc.

[0078] Figure 13 is a diagram showing a case where the display device 10 is applied to the tail lamp of the vehicle C. For example, as Figure 13 shown by the symbol 13001 in, the display device 10 can be applied to the tail lamp 1A (electrical equipment) of the vehicle C. In this case, as Figure 13 shown by the symbol 13002 in, the display device 10 includes a light guide plate 11A and a light source group 12. The light guide plate 11A is different from the light guide plate 11 in that it has a shape bent according to the shape of the vehicle C. The light incident from the light source group 12 is changed in optical path by the optical path changing unit 13 formed in the light guide plate 11A, thereby displaying the three-dimensional image I. Further, the display device 10 can also be applied to vehicle lamps or vehicle display devices other than the tail lamp.

[0079] Figure 14 is a diagram showing a case where the display device 10 is applied to the input unit of an elevator. As Figure 14As shown by symbol 14001, the display device 10 can be applied to, for example, the input unit 200 of an elevator. Specifically, the input unit 200 displays three-dimensional images I1 to I12 through the display device 10. The three-dimensional images I1 to I12 are three-dimensional images obtained by imaging a display (three-dimensional images I1 to I10) that receives an input from a user designating the destination (floor) of the elevator or a display (three-dimensional images I11 / I12) that receives an instruction for opening / closing the elevator door. When the input unit 200 receives an input from the user for any one of the three-dimensional images I, the imaging state of that three-dimensional image I changes (for example, the color of the three-dimensional image I changes), and at the same time, an instruction corresponding to the input is output to the control unit of the elevator. The display of the three-dimensional image I by the input unit 200 may be performed only when a person approaches the input unit 200. In addition, the input unit 200 may be disposed inside the elevator wall.

[0080] In the input unit 200 of the elevator, for example, when there are many people in the elevator, it is possible that a part of the user's body is located at the imaging position of the three-dimensional image I, and the input unit 200 receives an unintended input from the user. Therefore, in the input unit 200, the display device 10 may also display, for example, a three-dimensional image I that reminds the user of a rotation operation as shown by symbol 14002. In this case, the input unit 200 may receive an input from the user only when, for example, a rotation operation on the three-dimensional image I is received through a motion sensor. Since a rotation operation is an operation that a user generally does not perform unintentionally, it is possible to prevent the input unit 200 from receiving an unintended input from the user. In addition, as shown by symbol 14003, the structure may be such that the three-dimensional image I is displayed in a recess provided in the inner wall of the elevator. Thus, since an input to the three-dimensional image I is performed only when a user's finger or the like is inserted into the above-mentioned recess, it is possible to prevent the input unit 200 from receiving an unintended input from the user. Figure 14 As shown by symbol 14002, the display device 10 can be applied to, for example, the input unit 200 of an elevator. Specifically, the input unit 200 displays three-dimensional images I1 to I12 through the display device 10. The three-dimensional images I1 to I12 are three-dimensional images obtained by imaging a display (three-dimensional images I1 to I10) that receives an input from a user designating the destination (floor) of the elevator or a display (three-dimensional images I11 / I12) that receives an instruction for opening / closing the elevator door. When the input unit 200 receives an input from the user for any one of the three-dimensional images I, the imaging state of that three-dimensional image I changes (for example, the color of the three-dimensional image I changes), and at the same time, an instruction corresponding to the input is output to the control unit of the elevator. The display of the three-dimensional image I by the input unit 200 may be performed only when a person approaches the input unit 200. In addition, the input unit 200 may be disposed inside the elevator wall. Figure 14 As shown by symbol 14003, the structure may be such that the three-dimensional image I is displayed in a recess provided in the inner wall of the elevator. Thus, since an input to the three-dimensional image I is performed only when a user's finger or the like is inserted into the above-mentioned recess, it is possible to prevent the input unit 200 from receiving an unintended input from the user.

[0081] Figure 15 This is a diagram showing a case where the display device 10 is applied to the input unit of a bidet toilet. As Figure 15As shown, the display device 10 can be applied to, for example, the input unit 300 (operation panel unit) of a warm water cleaning toilet seat. Specifically, the input unit 300 displays stereoscopic images I1 to I4 through the display device 10. The stereoscopic images I1 to I4 are stereoscopic images obtained by imaging a display for instructing driving / stopping of the cleaning function of the warm water cleaning toilet seat. When the input unit 300 receives an input from the user for any one of the stereoscopic images I, it changes the imaging state of the stereoscopic image I (for example, changes the color of the stereoscopic image I), and at the same time outputs an instruction corresponding to the input to the control unit of the warm water cleaning toilet seat. In terms of hygiene, many users do not like to directly contact the operation panel of the warm water cleaning toilet seat. In contrast, in the input unit 300, the user can operate without directly contacting (physically contacting) the input unit 300. Therefore, the user can operate without worrying about hygiene. In addition, the input device of the present invention can also be applied to other devices that do not like direct contact in terms of hygiene. For example, the input device of the present invention is preferably applied to a queuing machine provided in a hospital or an operation unit of a moving door contacted by unspecified people. In addition, when there are multiple options such as surgery and internal medicine in the queuing machine provided in the hospital, it is preferable because stereoscopic images I corresponding to each option can be displayed. In addition, the input device of the present invention is preferably applied to a cash register or a food ticket vending machine provided in a restaurant.

[0082] In addition, the display device 10 can be applied to, for example, the input unit of an ATM (Automated Teller Machine), the input unit in a credit card reader, the input unit for unlocking a safe, the input unit of a door that performs password-based unlocking, and the like. Here, in the conventional password input device, input is performed by physically contacting the input unit with a finger. In such a case, fingerprints and temperature history remain on the input unit. Therefore, it may be possible for others to learn the password. In contrast, when the display device 10 is used as the input unit, since fingerprints and temperature history do not remain, it is possible to prevent others from knowing the password. As another example, the input device 20 can be used for a ticket vending machine provided at a station or the like.

[0083] Moreover, the display device 10 can also be applied to input devices of household appliances such as lighting switches for dressing tables, operation switches for faucets, operation switches for range hoods, operation switches for dishwashers, operation switches for refrigerators, operation switches for microwave ovens, operation switches for IH (Induction Heating) electromagnetic cookers, operation switches for electrolytic water generators, operation switches for door intercoms, lighting switches for corridors, or operation switches for compact stereo systems, or input devices of toys. By applying the display device 10 to these switches, the following advantages are generated: (i) Since the switch has no unevenness, it is easy to clean; (ii) Since a three-dimensional image can be displayed only when necessary, the designability is improved; (iii) Since there is no need to touch the switch, it is hygienic; (iv) Since there is no movable part, it is not easily damaged.

[0084] <4.5>

[0085] Refer to Figures 16 to 21 The display device 10A as the fifth modification will be described.

[0086] Figure 16 is a perspective view of the display device 10A. Figure 17 is a cross-sectional view showing the structure of the display device 10A. Figure 18 is a top view showing the structure of the display device 10A. Figure 19 is a perspective view showing the structure of the optical path changing unit 16 included in the display device 10A.

[0087] As Figure 16 and Figure 17 shown, the display device 10A includes a light source 12 and a light guide plate 15 (first light guide plate).

[0088] The light guide plate 15 is a component that guides the light (incident light) incident from the light source 12. The light guide plate 15 is formed of a transparent resin material with a relatively high refractive index. As the material for forming the light guide plate 15, for example, polycarbonate resin, polymethyl methacrylate resin, etc. can be used. In this modification, the light guide plate 15 is formed of polymethyl methacrylate resin. As Figure 17 shown, the light guide plate 15 includes an emission surface 15a (light emission surface), a back surface 15b, and an incident surface 15c.

[0089] The emission surface 15a is a surface that emits the light that is conducted inside the light guide plate 15 and whose optical path is changed by the optical path changing unit 16 described later. The emission surface 15a constitutes the front surface of the light guide plate 15. The back surface 15b is a surface parallel to the emission surface 15a and is the surface on which the optical path changing unit 16 described later is disposed. The incident surface 15c is a surface on which the light emitted from the light source 12 enters the inside of the light guide plate 15.

[0090] The light emitted from the light source 12 and incident on the light guide plate 15 from the incident surface 15c is totally reflected by the emission surface 15a or the back surface 15b and is conducted within the light guide plate 15.

[0091] As Figure 17 shown, the optical path changing portion 16 is formed on the back surface 15b inside the light guide plate 15 and is a component for changing the optical path of the light conducted within the light guide plate 15 so that it is emitted from the emission surface 15a. A plurality of optical path changing portions 16 are provided on the back surface 15b of the light guide plate 15.

[0092] As Figure 18 shown, the optical path changing portion 16 is provided along a direction parallel to the incident surface 15c. As Figure 19 shown, the optical path changing portion 16 has a triangular pyramid shape and includes a reflecting surface 16a that reflects (totally reflects) the incident light. The optical path changing portion 16 may also be, for example, a concave portion formed on the back surface 15b of the light guide plate 15. In addition, the optical path changing portion 16 is not limited to the triangular pyramid shape. As Figure 18 shown, a plurality of optical path changing portion groups 17a, 17b, 17c... each composed of a plurality of optical path changing portions 16 are formed on the back surface 15b of the light guide plate 15.

[0093] Figure 20 is a perspective view showing the arrangement of the optical path changing portions 16. As Figure 20 shown, in each of the optical path changing portion groups 17a, 17b, 17c..., the reflecting surfaces 16a of the plurality of optical path changing portions 16 are arranged on the back surface 15b of the light guide plate 15 at different angles with respect to the incident direction of the light. Thus, each of the optical path changing portion groups 17a, 17b, 17c... changes the optical path of the incident light so that it is emitted from the emission surface 15a in various directions.

[0094] Next, a method for imaging the stereoscopic image I by the display device 10A will be described with reference to Figure 21 Here, a case where the stereoscopic image I is imaged as a planar image on the stereoscopic image imaging surface P using the light whose optical path has been changed by the optical path changing portion 16 will be described.

[0095] Figure 21 is a perspective view showing the method for imaging the stereoscopic image I by the display device 10A. Here, a case where a slanted entry circular mark is imaged as the stereoscopic image I on the stereoscopic image imaging surface P will be described.

[0096] In the display device 10A, as Figure 21As shown, for example, the light whose optical path has been changed by each optical path changing unit 16 of the optical path changing unit group 17a intersects the stereoscopic image imaging surface P on lines La1 and La2. Thereby, a line image LI that is part of the stereoscopic image I is imaged on the stereoscopic image imaging surface P. The line image LI is a line image parallel to the YZ plane. In this way, the line image LI of lines La1 and La2 is imaged by the light from many optical path changing units 16 belonging to the optical path changing unit group 17a. In addition, the light that images the images of lines La1 and La2 only needs to be provided by at least two optical path changing units 16 in the optical path changing unit group 17a.

[0097] Similarly, the light whose optical path has been changed by each optical path changing unit 16 of the optical path changing unit group 17b intersects the stereoscopic image imaging surface P on lines Lb1, Lb2, and Lb3. Thereby, a line image LI that is part of the stereoscopic image I is imaged on the stereoscopic image imaging surface P.

[0098] In addition, the light whose optical path has been changed by each optical path changing unit 16 of the optical path changing unit group 17c intersects the stereoscopic image imaging surface P on lines Lc1 and Lc2. Thereby, a line image LI that is part of the stereoscopic image I is imaged on the stereoscopic image imaging surface P.

[0099] The positions of the line images LI imaged by each of the optical path changing unit groups 17a, 17b, 17c... in the X-axis direction are different from each other. In the display device 10A, by reducing the distance between the optical path changing unit groups 17a, 17b, 17c..., the distance in the X-axis direction of the line images LI imaged by each of the optical path changing unit groups 17a, 17b, 17c... can be reduced. As a result, in the display device 10A, by aggregating the multiple line images LI imaged by the light whose optical path has been changed by each optical path changing unit 16 of the optical path changing unit groups 17a, 17b, 17c..., the stereoscopic image I as a surface image is substantially imaged on the stereoscopic image imaging surface P.

[0100] The stereoscopic image imaging surface P can be a plane perpendicular to the X-axis, a plane perpendicular to the Y-axis, or a plane perpendicular to the Z-axis. In addition, the stereoscopic image imaging surface P can also be a plane that is not perpendicular to the X-axis, Y-axis, or Z-axis. Moreover, the stereoscopic image imaging surface P can also be a curved surface instead of a plane. That is, the display device 10A can image the stereoscopic image I on an arbitrary surface (plane and curved surface) in space through the optical path changing unit 16. In addition, by combining multiple surface images, a three-dimensional image can be imaged.

[0101] <4.6>

[0102] Light can also be incident on the light guide plate 11 from the end face 11e or 11f by a light source different from the light source 12. In other words, the display device 10 may further include a light source different from the light source 12 that makes light incident on the light guide plate 11 from the end face 11e or 11f. The color of the light emitted by the other light source is different from the color of the light emitted by the light source 12.

[0103] In this case, an optical path changing portion 13 corresponding to the light source 12 and an optical path changing portion 13 corresponding to the other light source are formed on the back surface 11b of the light guide plate 11. For the stereoscopic image I, by making the density of the light spots emitted by the light source 12 and the density of the light spots emitted by the other light source different for each face, the multiple faces included in the stereoscopic image I can be set to different colors from each other.

[0104] A light guide plate according to an aspect of the present invention includes a plurality of optical path changing portions that converge incident light to corresponding fixed points. By the aggregation of the plurality of fixed points respectively corresponding to the plurality of optical path changing portions, a stereoscopic image is spatially imaged. The stereoscopic image includes a plurality of non-parallel faces, each face is composed of a plurality of points dispersedly arranged on the face, and the density of the plurality of points on each of the faces becomes a value corresponding to the position of the face.

[0105] According to the above structure, the faces included in the stereoscopic image are composed of a plurality of points with densities corresponding to the positions of the faces and dispersedly arranged on the faces. The brightness of the face varies according to the density of the points. Therefore, for example, compared with the case where the face is composed of points with a certain density, a stereoscopic image with enhanced stereoscopic effect can be displayed.

[0106] In addition, based on the light guide plate according to an aspect of the present invention, preferably, the density of the plurality of points on each of the plurality of faces is determined according to the normal direction of the face or the angle between the direction represented by the face and a specified direction.

[0107] According to the above structure, the brightness of each face when it is assumed that light is incident on the stereoscopic image from a specified direction can be reproduced. Therefore, the brightness of each face in the stereoscopic image can be appropriately determined.

[0108] In addition, based on the light guide plate according to an aspect of the present invention, preferably, the upper limit of the density of the plurality of points on each of the faces is 50%.

[0109] According to the above structure, a reduction in the stereoscopic effect of the stereoscopic image caused by an excessive density of points can be prevented.

[0110] In addition, based on the light guide plate according to an aspect of the present invention, preferably, the interval between a plurality of the points adjacent to each other in a direction parallel to the incident surface where the light is incident on the light guide plate is equal to or greater than a specified threshold value.

[0111] According to the above structure, even when multiple points are blurred in the direction parallel to the incident surface, the possibility that these points are connected and recognized as a line can be reduced.

[0112] In addition, based on the light guide plate of one embodiment of the present invention, preferably, the above three-dimensional image further includes the contour lines of the above-mentioned multiple surfaces.

[0113] According to the above structure, details can be expressed at the end of the surface through the contour line.

[0114] In addition, a display device according to one embodiment of the present invention includes the above light guide plate and a light source that emits light into the above light guide plate.

[0115] According to the above structure, by emitting the light emitted by the light source into the above light guide plate, a display device that displays a three-dimensional image with enhanced stereoscopic effect can be realized.

[0116] In addition, an input device according to one embodiment of the present invention includes the above display device and a sensor that non-contact detects an object in the space where the above three-dimensional image is displayed.

[0117] According to the above structure, an input device that can detect the operation of the user on the three-dimensional image with enhanced stereoscopic effect by the sensor and receive input can be realized.

[0118] In addition, an electrical device according to one embodiment of the present invention includes the above display device or input device.

[0119] According to the above structure, the stereoscopic effect of the image displayed by the display device or input device included in the electrical device can be enhanced.

[0120] Description of Reference Numerals

[0121] 1A Tail lamp (electrical device)

[0122] 10 Display device

[0123] 11 Light guide plate

[0124] 11a, 15a Light emitting surface (light emission surface)

[0125] 11c, 15c Incident surface

[0126] 12 Light source

[0127] 13, 13a, 13b, 13c, 16 Light path changing part

[0128] 20 Input device

[0129] 24 Sensor

[0130] I, IA, IB Three-dimensional image

[0131] Surfaces A, B, and C

[0132] Points D, D1 to D8

[0133] Game consoles M1 and M2 (electrical equipment)

[0134] OL contour line

[0135] Normals PLA, PLB, PLC1, PLC2, PLC3, PLC4 and angles of θA, θB

Claims

1. A light guide plate includes a plurality of optical path changing portions that converge incident light to corresponding fixed points, and a stereoscopic image is spatially formed by the aggregation of a plurality of the fixed points respectively corresponding to the plurality of the optical path changing portions, wherein the stereoscopic image includes a plurality of non-parallel faces, the faces are composed of a plurality of points dispersedly arranged on the faces, and the density of the plurality of points on each of the faces becomes a value corresponding to the position of the face.

2. The light guide plate according to claim 1, wherein the density of the plurality of points on each of the faces is determined according to the angle between the normal direction of the face or the direction represented by the face and a specified direction, the specified direction refers to the direction in which a virtual light source irradiates light on the stereoscopic image.

3. The light guide plate according to claim 1 or 2, wherein the upper limit of the density of the plurality of points on each of the faces is 50%.

4. The light guide plate according to claim 1 or 2, wherein the interval between a plurality of the points adjacent to each other in a direction parallel to the incident surface where the light enters the light guide plate is equal to or greater than a specified threshold value.

5. The light guide plate according to claim 1 or 2, wherein the stereoscopic image further includes contour lines of the plurality of faces.

6. A display device includes: the light guide plate according to any one of claims 1 to 5; a light source that irradiates light on the light guide plate.

7. An input device includes: the display device according to claim 6; a sensor that non-contactedly detects an object in the space where the stereoscopic image is displayed.

8. An electrical device includes the display device according to claim 6 or the input device according to claim 7.

Images