Light-emitting device for vehicles

Abstract

Light-emitting device (1A, 1B) for vehicles, provided at the left and right rear end of a vehicle (C) and functioning as the rear light of the vehicle (C) and configured to emit light towards the outside of the vehicle (C), wherein the light-emitting device (1A, 1B) comprises: a light source (2A); a light guide plate (11A) provided at the rear end of the vehicle, comprising a light-emitting surface (11a), a rear surface (11b) opposite the light-emitting surface (11a), and end surfaces (11c, 11d, 11e, 11f) connecting the light-emitting surface (11a) and the rear surface (11b), where the light source (2A) is arranged on one of the end faces (11c, 11d, 11e, 11f) and emits light to the light guide plate (11A, 11B), wherein the light guide plate (11A) is configured to direct light entering from the light source (2A) such that the light exits the light-emitting surface (11a) and produces a virtual stereoscopic image (I) in an image-generating plane (P1) that is further inside or outside the vehicle (C) than the light guide plate (11A, 11B) relative to an observer outside the vehicle (C), wherein beam-path-changing sections (13), which change a beam path of the light entering from the light source (2A), are formed on the back surface (11b), and the virtual stereoscopic image (I) in the image-generating plane (P1) is formed by the light whose beam path is changed by the beam-path-changing sections (13), and wherein the light-emitting device (1A, 1B) comprises a further light guide plate (11B) which, together with the light guide plate (11A), forms a plurality of light guide plates (11A, 11B), wherein the light guide plates (11A, 11B) are stacked one above the other in a direction perpendicular to their light-emitting surfaces (11a), and the further light guide plate has a further light source (2B), so that each light guide plate of the plurality of light guide plates (11A, 11B) has a light source (2A, 2B), wherein the further light guide plate (11B) has a back surface (11b) on which beam path-changing sections (13) are formed which change a beam path of the light entering from the further light source (2B); and a lighting control device (20A, 20B) configured to control the emission status of the light source (2A, 2B) according to a braking operation, a lighting operation, a direction signaling operation or a steering operation, wherein the lighting control device (20A, 20B) switches between the light guide plates (11A, 11B) according to the details of the operation / processes of the vehicle (C) in such a way as to which of the light guide plates (11A, 11B) emits light, and wherein the lighting control device (20A, 20B) stacks virtual stereoscopic images (I1, I2) by causing the different light guide plates (11A, 11B) to emit light simultaneously according to the details of the operation / processes of the vehicle (C), whereby one virtual stereoscopic image (I1) is produced by the light source (2A) and the light guide plate (11A) in the stereoscopic image-generating plane (P1) and another stereoscopic image (I2) is produced by the light source (2B) and the further light guide plate (11B) in a further stereoscopic image-generating plane (P2), so that the stereoscopic images (I1, I2) appear overlapping from a viewing position behind the vehicle (C).

Description

Technical area

[0001] The present invention relates to a light emitting device provided for a vehicle. State of the art

[0002] A light-emitting device may be provided as disclosed in Japanese Patent Publication JP 2011-25 738 A (published on February 10, 2011).

[0003] The light-emitting device disclosed in JP 2011-25738 A includes a reflection device that produces a first reflection light and a second reflection light from light incident at the incident portion of a light guide element. The first reflection light is reflected by a first surface of the reflection device toward a reflector (which is a reflection surface), and the second reflection light is reflected toward the interior of the vehicle cabin. The above-mentioned reflection device illuminates the front surface of the light guide element with the second reflection light. The curved reflection surface orients the first reflection light toward the light guide element, and this re-emitted light illuminates a distance proportional to the distance to and from the reflector arranged on the rear surface of the light guide element, making it visible. Thus, the illumination creates a sense of depth.

[0004] Further prior art can be found in the documents US 6 100 943 A, DE 10 2010 017 494 A1 and US 8 564 205 B2. Technical problem

[0005]

[0005] However, the techniques disclosed in JP 2011 - 25 738 A require a complicated configuration since a light guide plate and a reflector are required.

[0006] Embodiments of the present invention are directed to implementing a simply configured light-emitting device for vehicles. OVERVIEW

[0007] To overcome the above disadvantages, a light-emitting device according to claim 1 is provided. Preferred embodiments are subject of the dependent claims.

[0008] A light-emitting device for vehicles according to one aspect of the present invention is configured to emit light toward the exterior of the vehicle, the light-emitting device including: a light source; a light guide plate including a light-emitting surface and configured to guide light entering from the light source so that the light exits from the light-emitting surface and forms an image or a virtual stereoscopic image in a space; and a lighting control device configured to control the emission status of the light source according to an operation of the vehicle.

[0009] The above configuration allows the light guide plate to generate images that respond to the vehicle's operation. As a result, information is provided to a viewer outside the vehicle. Furthermore, the configuration is simple, as only one light source and one light guide plate are required.

[0010] The light-emitting device for vehicles includes a plurality of light guide plates, the light guide plates being stacked one on top of the other in a direction perpendicular to their light-emitting surfaces; and the lighting control device switches the light guide plate emitting light according to the details of the operation of the vehicle.

[0011] The above configuration makes it possible to present a plurality of images by providing a plurality of light guide plates.

[0012] In the light-emitting device for vehicles according to the invention, the lighting control device causes different light guide plates to layer the light emitted simultaneously by them according to the details of the operation of the vehicle.

[0013] The above configuration makes it possible to present a multitude of information to a viewer in a single region.

[0014] The light-emitting device for vehicles according to an embodiment may be configured such that the distances from the light-emitting surface of the light guide plate closest to the outside of the vehicle to the images formed by each of the light guide plates are different from each other.

[0015] The above configuration according to the invention makes it possible to make the generated images appear as if they have depth.

[0016] The light-emitting device for vehicles according to one embodiment is configured such that the lighting control device switches where the image is generated during a particular operation of the vehicle.

[0017] In another embodiment, the light-emitting device for vehicles includes a plurality of light guide plates, the light guide plates being stacked one on top of the other in a direction perpendicular to one of their surfaces; the illumination control device switches where the image is formed by switching the light guide plate that emits light.

[0018] According to the invention, the light guide plate at the left and right rear ends of the vehicle functions as a taillight; and the lighting control device controls the emission status of a light source according to at least one of the following: a braking operation, a lighting operation, a direction signaling operation, and a steering operation within the operation of the vehicle.

[0019] According to the invention, the lighting control device causes a light guide plate to form an image further inside the vehicle than the light guide plate relative to a viewer outside the vehicle, in controlling the emission status of a light source according to at least one of the following: the braking operation, the lighting operation, and the direction signaling operation within the operation of the vehicle.

[0020] According to the invention, the lighting control device alternatively causes a light guide plate to form an image further outside the vehicle than the light guide plate relative to a viewer outside the vehicle when the emission status of a light source is controlled according to the steering operation within the scope of the operation of the vehicle.

[0021] To overcome the above disadvantages, a light-emitting device for vehicles according to further embodiments serving as comparative examples is provided for a vehicle and is configured to emit light toward the interior of the vehicle, the light-emitting device including: a light source; a light guide plate including a light-emitting surface and configured to guide light entering from the light source so that the light exits from the light-emitting surface and forms an image in a space; and a lighting control device configured to control the emission status of the light source according to an operation of the vehicle.

[0022] The above configuration allows the light guide plate to generate images that respond to the vehicle's operation. As a result, information can be provided to a viewer inside the vehicle (e.g., the driver). Furthermore, the configuration is simple, requiring only one light source and one light guide plate.

[0023] In another embodiment, the lighting control device switches the emission status of the light source to change the image when a door of the vehicle is locked or unlocked as part of the operation of the vehicle.

[0024] The above configuration allows a user to recognize that the activation or deactivation of a vehicle lock has been detected by observing that the image changes. According to the invention, optical path-changing sections that change the optical path of the light entering from the light source are formed on the corresponding rear surface of the light guide plate, and the virtual stereoscopic image is formed in the image formation plane by the light whose optical path is changed by the optical path-changing sections.

[0025] In another embodiment, the light-emitting device for vehicles may further include a plurality of lights of the light sources for one of the light guide plates; and the lighting control device changes the light source that is activated to change the image.

[0026] In another embodiment, the light guide plate may be provided at the rear end of the vehicle. Effects

[0027] Embodiments of the present invention have the effect of achieving a simply configured light-emitting device for vehicles. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to a first embodiment of the present invention; Fig. 2 is a plan view of the above-mentioned vehicle; Fig. 3 is a perspective view of the above-mentioned light-emitting device; Fig. 4 illustrates the above-mentioned light-emitting device as viewed from above; Fig. 5 shows a stereoscopic image produced by the above-mentioned light-emitting device; Fig. 6 illustrates a modified example of the above-mentioned light-emitting device and is a perspective view thereof; Fig. 7 is a cross-sectional view of a configuration of the above-mentioned light-emitting device; Fig. 8 is a plan view of a configuration of the above-mentioned light-emitting device; Fig. 9 is a perspective view showing an optical path changing portion in the above-mentioned light-emitting device; Fig. 10 is a perspective view showing a distribution of the above-mentioned optical path changing portions; Fig. Fig. 11 is a perspective view showing how the above-mentioned light-emitting device produces a stereoscopic image; Fig. 12 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to a second embodiment of the present invention; Fig. 13 illustrates the above-mentioned light-emitting device as viewed from above; Fig. 14A and Fig. 14B are used to describe a function of the above-mentioned light-emitting device; Fig. 15 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to a third embodiment of the present invention; Fig. 16A and Fig. 16B are used to describe a function of the above-mentioned light-emitting device; Fig. 17A and Fig. 17B are used to describe another function of the above-mentioned light-emitting device; Fig. 18 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to a fourth embodiment of the present invention; Fig. 19 illustrates the above-mentioned light-emitting device as viewed from above; Fig. 20A to Fig. 20F are used to describe a function of the above-mentioned light-emitting device; Fig. 21 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to a fifth embodiment of the present invention; Fig. 22A to Fig. 22D are used to describe a function of the above-mentioned light-emitting device; Fig. 23 is a block diagram showing the main components of a modification example of the light-emitting device, the light-emitting device being provided for a vehicle; Fig. 24 is a perspective view of the above-mentioned light-emitting device; Fig. 25 is a cross-sectional view of a configuration of the above-mentioned light-emitting device; Fig. 26 is a rear view of a vehicle according to a comparative example; Fig. Fig. 27 is a plan view of a 2D image display device provided in the above-mentioned vehicle; Fig. Fig. 28 is a cross-sectional view of the above-mentioned 2D image display device; Fig. 29A to Fig. 29C are used to describe the shape of the optical path changing portions in the above-mentioned 2D image display device; Fig. 30 illustrates a vehicle C according to another comparative example; Fig. 31A to Fig. 31D illustrate examples of a stereoscopic image produced by using the above-mentioned light-emitting device; Fig. 32 illustrates the light-emitting device installed in a vehicle side window; Fig. 33 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to an eighth embodiment of the present invention; Fig. 34A to Fig. 34C are used to describe a function of the above-mentioned light-emitting device; Fig. 35 is a block diagram showing the main components of a vehicle equipped with a light-emitting device according to a ninth embodiment of the present invention; and Fig. 36A to Fig. 36D are used to describe a function of the above-mentioned light-emitting device; DETAILED DESCRIPTIONFirst embodiment

[0028] A light-emitting device 1A according to a first embodiment of the present invention (ie, a light-emitting device for a vehicle) will be described in detail below with reference to the drawings. Configuration of the light-emitting device 1A

[0029] Fig. 1 is a block diagram showing the main components of a vehicle equipped with a light-emitting device 1A; Fig. 2 is a plan view of the above-mentioned vehicle; Fig. 3 is a perspective view of the light-emitting device 1A; and Fig. 4 illustrates the light-emitting device 1A as viewed from above. It should be noted that in the following description, for the sake of simplicity, the positive X-axis direction, the negative X-axis direction, the positive Y-axis direction, the negative Y-axis direction, the positive Z-axis direction and the negative Z-axis direction are Fig. 2 can be described as backward, upward, downward, right or left.

[0030] As in Fig. As shown in Figure 2, a light-emitting device 1A is provided at the left and right rear portions of a vehicle C and functions as a taillight (also referred to as a tail lamp) and a brake light, respectively. There are no particular restrictions on the vehicle C; for example, the vehicle C may be a typical automobile, a bus, a truck, or a motorcycle. As shown in Fig. 1 and Fig. 3, the light-emitting device 1A includes a light guide plate 11A, a light source 2A and a control device 20A (lighting control device).

[0031] As in Fig. 3, the light guide plate 11A is a curved panel shaped so that its cross section, taken in a plane perpendicular to the vertical direction (Y-axis), coincides with the rear part of the vehicle C. The light guide plate 11A is made of a resin material having a relatively high refractive index. For example, the light guide plate 11A may be made of a polycarbonate resin, a polymethyl methacrylate resin, glass, or the like. The light guide plate 11A has an emission surface 11a (i.e., a light-emitting surface) that emits light, a rear surface 11b opposite to the emission surface 11a, and end surfaces 11c, 11d, 11e, 11f that are connected to the emission surface 11a and the rear surface 11b. The end surface 11c is an incident surface at which light emitted from the light source 2A enters the light guide plate 11A.The emission surface 11a and the end surface 11c, which is the incident surface, do not face each other. The light guide plate 11A diffuses and guides the light from the light source 2A along the Z-axis direction between the emission surface 11a and the rear surface 11b.

[0032] The light source 2A emits light to the light guide plate 11A. The light source 2A can be, for example, a light-emitting diode. The light source 2A can be placed on the end surface 11c, which is the lower surface of the light guide plate 11A.

[0033] Next, the method of how the light-emitting device 1A generates a stereoscopic image I will be described. As in Fig. 3 and Fig. 4, the light-emitting device 1A forms a virtual stereoscopic image I in a stereoscopic image formation plane P in front of the light-emitting device 1A; that is, the image is formed toward the inside of the vehicle C, that is, toward the rear surface 11b of the light guide plate 11A.

[0034] A plurality of groups of optical path-changing sections 13 are formed on the rear surface 11b of the light guide plate 11A. The groups of optical path-changing sections 13 are formed sequentially along the Z-axis direction for the most part. In other words, the plurality of groups of optical path-changing sections 13 are formed in a plane parallel to the emission surface 11a along predetermined lines parallel to the Z-axis direction. The groups of optical path-changing sections 13 can be made of a part of a Fresnel lens. For the sake of simplicity, Fig. 3, only one group of optical path changing sections 13 is shown. The light output from the light source 2A and guided through the light guide plate 11A enters the positions of the group of optical path changing sections 13 along the Z-axis direction. A group of optical path changing sections 13 changes the optical path of the light entering at the positions of the group of optical path changing sections 13 so that most of the light radiates from a fixed point corresponding to the group of optical path changing sections 13. (Note that the fixed point is referred to as the convergence point PA hereinafter.) The light reflected from a specific point in the group of optical path changing sections 13 travels in a direction along a straight line connecting the points and the convergence point PA.The group of optical path changing sections 13 modifies the optical path of the light, and then the radiated light L from the emission surface 11a exits the light guide plate 11A toward the outside of the vehicle C.

[0035] Fig. 5 shows a stereoscopic image generated by the light-emitting device 1A.

[0036] The plurality of groups of optical path-changing sections 13 are formed on the rear surface 11b of the light guide plate 11A and have different convergence points from each other. Thus, as shown in Fig. 4 and Fig. 5, by grouping a plurality of convergence points corresponding to the groups of optical path changing sections 13, a virtual image is produced in the stereoscopic image forming plane P, which functions as the stereoscopic image I. In other words, the light emitted from the light guide plate 11A functions as the tail light and the brake light for the vehicle C.

[0037] The control device 20A controls when the light source 2A emits light. Specifically, the control device 20A acquires the operating states of the brakes B and the headlights HL in the vehicle C and controls the emission status of the light source 2A according to the aforementioned operating states.

[0038] More specifically, the control device deactivates the light source 2A when neither the brakes B nor the headlights HL are in operation (i.e. the driver has not applied the brakes or switched on the headlights).

[0039] The control device 20A turns on the light source 2A when the brakes B are applied (i.e., when the driver has applied the brakes). This creates a stereoscopic image I, and the brake light on the vehicle C appears illuminated.

[0040] The control device 20A turns on the light source 2A at a lower intensity, as if the brakes were being applied, when the brakes are not being applied and the headlights are on (ie, the driver has not applied the brakes and has turned on the headlights). This creates a stereoscopic image I, and the taillight on the vehicle C appears illuminated.

[0041] As described above, a light-emitting device 1A in the present embodiment includes a light source 2A, a light guide plate 11A, and a controller 20A; the controller 20A controls the emission status of the light source 2A according to the operation of the vehicle C, and the light guide plate directs light incident thereon from the light source 2A so that the light exits from the emission surface 11a.

[0042] The above configuration enables the light guide plate 11A to generate a stereoscopic image I corresponding to the operation of the vehicle C (i.e., the braking operation and the lighting operation). As a result, information can be provided to a viewer outside the vehicle C. Furthermore, the configuration is simple because only one light source and one light guide plate are provided. Note that a light-emitting device according to an embodiment of the present invention may be configured so that the stereoscopic image can be generated in a space outside the vehicle C farther away from the light guide plate 11A.

[0043] Furthermore, the light-emitting device 1A can generate the stereoscopic image at the top of the space inside the vehicle C farther away from the light guide plate 11A. This can make the brake light and the tail light appear to have depth. Modification example 1

[0044] A light-emitting device 1B will be described as an example of the modification of the light-emitting device 1A of the first embodiment. For the sake of simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0045] The light-emitting device 1B uses a different method for forming the stereoscopic image I, which is a virtual image; moreover, the light-emitting device 1B is identical to the light-emitting device 1A of the first embodiment, and therefore only the method for forming the stereoscopic image I will be described.

[0046] Fig. 6 is a perspective view of a light-emitting device 1B. Fig. 7 is a cross-sectional view of a configuration of the light-emitting device 1B; Fig. 8 is a plan view of a configuration of the light-emitting device 1B; Fig. 9 is a perspective view showing an optical path changing portion 16 in the light emitting device 1B.

[0047] As in Fig. 6 and Fig. As shown in Figure 7, the light-emitting device 1B is equipped with the light guide plate 15 instead of the light guide plate 11A of the first embodiment. Note that, for simplicity, the light guide plate 15 is rectangular as described.

[0048] The light guide plate 15 guides light entering from the light source 2A (i.e., incident light). The light guide plate 15 is made of a resin material with a relatively high refractive index. The light guide plate 15 can be made of, for example, a polycarbonate resin, a polymethyl methacrylate resin, glass, or the like. In this modification example, the light guide plate 15 is made of a polymethyl methacrylate resin. The light guide plate 15 has an emitting surface 15a that emits light, a rear surface 15b opposite the emitting surface 15a, and end surfaces 15c, 15d, 15e, 15f that are connected to the emitting surface 15a and the rear surface 15b ( Fig. 11).

[0049] The emission surface 15a emits light, which is guided by the light guide plate 15 and modified by a light path changing portion 16. The emission surface 15a is configured as the front surface of the light guide plate 15. The rear surface 15b and the emission surface 15a are parallel to each other, and the light path changing portion 16 described later is arranged thereon. The end surface 15c is an incident surface where light emitted from the light source 2A enters the light guide plate 11A.

[0050] Light emitted from the light source 2A and entering the light guide plate 15 from the incident surface 15c is completely reflected between the emission surface 15a and the rear surface 15b and passed through the light guide plate 15.

[0051] As in Fig. As shown in Figure 7, a light path changing portion 16 is formed on the rear surface 15b within the light guide plate 15. The light path changing portion 16 changes the light path of the light passing through the light guide plate 15 and causes the light to exit from the emission surface 15a. A plurality of light path changing portions 16 are formed on the rear surface 15b of the light guide plate 15.

[0052] As in Fig. 8, the beam path changing sections 16 are arranged along a direction parallel to the end surface 15c. As shown in Fig. As shown in Figure 9, the optical path-changing portions 16 are tetrahedrons having reflection surfaces 16a that reflect (fully reflect) incident light. For example, the optical path-changing portions 16 may be recesses formed in the rear surface 15b of the light guide plate 15. Note that the optical path-changing portions 16 are not limited to being tetrahedrons. As shown in Fig. 8, the plurality of optical path changing portions 16 may consist of a plurality of groups of optical path changing portions 17a, 17b, 17c... formed on the rear surface 15b of the light guide plate 15.

[0053] Fig. 10 is a perspective view showing a distribution of the optical path changing sections 16. As shown in Fig. As shown in Figure 10, the plurality of optical path-changing sections 16 in each group of optical path-changing sections 17a, 17b, 17c... are arranged on the rear surface 15b of the light guide plate 15 such that the angles of the reflecting surfaces 16a with respect to the direction from which the light is incident are different from each other. Thus, each group of optical path-changing sections 17a, 17b, 17c.... changes the optical path of the incident light and causes the light to exit from the emitting surface 15a in different directions.

[0054] Next, with reference to Fig. 11 describes the method of how the light-emitting device 1B forms a stereoscopic image I. In this case, the plane perpendicular to the emission surface 15a of the light guide plate 15 is the stereoscopic image forming plane P, and light modified by the optical path changing portions 16 forms a stereoscopic image I as a planar image in the stereoscopic image forming plane P.

[0055] Fig. 11 is a perspective view illustrating how the light-emitting device 1B forms a stereoscopic image, which is a virtual image; note that, in the described case, the stereoscopic image I formed in the stereoscopic image forming plane 500 is a ring with an oblique line therethrough.

[0056] As in Fig. As shown in FIG. 11, the plurality of optical path-changing sections 16 belonging to a group of optical path-changing sections 17a deflect the incident light and spread the light in the YZ plane and a direction parallel thereto, thereby causing two light beams to exit from the emission surface 15a. One of the light beams exiting from the emission surface 15a as a result of the optical path-changing sections 16 belonging to a group of optical path-changing sections 17a travels along a direction connecting a point on a line 551 in the stereoscopic image formation plane P and the optical path-changing section 16 in the group of optical path-changing sections 17a.The other light beam emerging from the emission surface 15a due to the optical path changing portions 16 belonging to the group of optical path changing portions 17a travels along a direction connecting a point on a line 552 in the stereoscopic image forming plane P and the optical path changing portion 16 in the group of optical path changing portions 17a. Any one of the optical path changing sections 16 in the group of optical path changing sections 17a causes a light beam traveling along a direction connecting a point on a line 551 in the stereoscopic image forming plane P and the optical path changing sections 16 and a light beam traveling along a direction connecting a point on a line 552 in the stereoscopic image forming plane P and the optical path changing sections 16 to exit from the emission surface 15a.Lines 551 and 552 are located in a plane substantially parallel to the YZ plane and form a portion of the stereoscopic image I. Thus, each of the plurality of optical path-changing sections 16 belonging to a group of optical path-changing sections 17a diffuses the light incident on each of the optical path-changing sections 16, diffuses the light within the plane of the emission surface 15a to create a light intensity distribution along the Z-axis direction according to the image of lines 551 and 552, and causes the light to exit from the emission surface 15a. As a result, the light from the plurality of optical path-changing sections 16 arranged along the Z-axis direction and belonging to the group of optical path-changing sections 17a is the light emitted by lines 551 and 552 in the image.

[0057] The majority of the optical path changing sections 16 belonging to a group of optical path changing sections 17b deflect the incident light and spread the light in the YZ plane and a direction parallel thereto, thereby causing three light beams to emerge from the emission surface 15a.The three light beams emerging from the emission surface 15 include a light beam traveling along a direction connecting a point on a line 561 in the stereoscopic image forming plane P and the optical path changing portions 16 belonging to the group of optical path changing portions 17b; a light beam traveling along a direction connecting a point on a line 562 and the optical path changing portions 16 belonging to the group of optical path changing portions 17b; and a light beam traveling along a direction connecting a point on a line 563 and the optical path changing portions 16 belonging to the group of optical path changing portions 17b.Any one of the optical path-changing sections 16 in the group of optical path-changing sections 17b causes a light beam traveling along a direction connecting a point on a line 561 in the stereoscopic image formation plane P and the optical path-changing sections 16, a light beam traveling along a direction connecting a point on a line 562 in the stereoscopic image formation plane P and the optical path-changing sections 16, and a light beam traveling along a direction connecting a point on a line 563 in the stereoscopic image formation plane P and the optical path-changing sections 16 to exit the emission surface 15a. The lines 561, 562, and 563 are located in a plane substantially parallel to the YZ plane and form a portion of the stereoscopic image I.Thus, each of the plurality of optical path changing sections 16 belonging to a group of optical path changing sections 17b diffuses the light incident on each of the optical path changing sections, generates light with a light intensity distribution in the Z-axis direction according to the image of lines 561, 562, and 563, and causes the light to exit from the emission surface 15a. As a result, the light from the plurality of optical path changing sections 16 arranged along the Z-axis direction and belonging to the group of optical path changing sections 17b is the light emitted from lines 561, 562, and 563 in the image.

[0058] The majority of the optical path-changing sections 16 belonging to a group of optical path-changing sections 17c deflect the incident light and spread the light in the YZ plane and a direction parallel thereto, thereby causing two light beams to emerge from the emission surface 15a. The two light beams emerging from the emission surface 15a include a light beam traveling along a direction connecting a point on a line 571 in the stereoscopic image formation plane P and the optical path-changing sections 16 belonging to the group of optical path-changing sections 17c; and a light beam traveling along a direction connecting a point on a line 572 and the optical path-changing sections 16 belonging to the group of optical path-changing sections 17c.Any one of the optical path-changing sections 16 in the group of optical path-changing sections 17c causes a light beam traveling along a direction connecting a point on a line 571 in the stereoscopic image formation plane P and the optical path-changing sections 16, and a light beam traveling along a direction connecting a point on a line 572 in the stereoscopic image formation plane P and the optical path-changing sections 16, to exit the emission surface 15a. The lines 571 and 572 are located in a plane substantially parallel to the YZ plane and form a portion of the stereoscopic image I.Thus, each of the plurality of optical path-changing sections 16 belonging to a group of optical path-changing sections 17a diffuses the light incident on each of the optical path-changing sections 16, diffuses the light within the plane of the emission surface 15a to generate a light intensity distribution along the Z-axis direction according to the image of lines 571 and 572, and causes the light to exit from the emission surface 15a. As a result, the light from the plurality of optical path-changing sections 16 arranged along the Z-axis direction and belonging to the group of optical path-changing sections 17c is the light emitted from lines 571 and 572 in the image.

[0059] Thus, the light-emitting device 1B groups the light beams from a plurality of the group of optical path changing portions arranged two-dimensionally to present light beams radiated from the stereoscopic image I to a viewer.

[0060] The light-emitting device 1B includes the above-described light guide plate 15 and can thereby produce a virtual image in a stereoscopic image formation plane P, which functions as a stereoscopic image I. Thus, the light emitted from the light guide plate 11B functions as the tail light and the brake light for the vehicle C. Second embodiment

[0061] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0062] Fig. 12 is a block diagram showing the main components of a vehicle equipped with a light-emitting device 1C according to an embodiment of the present invention; Fig. 13 illustrates the light-emitting device 1C as viewed from above.

[0063] As in Fig. 12 and Fig. As shown in Fig. 13, in addition to the features of the light-emitting device 1A of the first embodiment, the light-emitting device 1C includes a light guide plate 11B and a light source 2B that outputs light to the light guide plate 11B. In other words, the light-emitting device 1C is provided with a plurality of light guide plates (i.e., the light guide plate 11A and the light guide plate 11B). The light-emitting device 1C also includes a controller 20B instead of the controller 20A of the first embodiment.

[0064] Given that the light guide plate 11B and the light source 2B are essentially the same as the light guide plate 11A and the light source 2A, only the different features will be described.

[0065] As in Fig. As shown in Figure 13, the light guide plates 11A and 11B are arranged in the light-emitting device 1C such that the emission surface 11a of the light guide plate 11A and the emission surface 11a of the light guide plate 11B are parallel. In other words, the light guide plates 11A and 11B are stacked one on top of the other in a direction perpendicular to the emission surface 11a of the light guide plate 11A.

[0066] The light-emitting device 1C utilizes a stereoscopic image formation plane P1 and a stereoscopic image formation plane P2 located at mutually different positions on the XZ plane; light emitted from the light source 11A forms an image on the stereoscopic image formation plane P1, and light emitted from the light guide plate 11B forms an image on the stereoscopic image formation plane P2. Specifically, the distance between the stereoscopic image formation plane P1 and the emission surface 11a of the light guide plate 11A is shorter than the distance between the stereoscopic image formation plane P2 and the emission surface 11a of the light guide plate 11A.

[0067] The control device 20B controls when the light source 2A and the light source 2B emit light. Specifically, the control device 20B acquires the operating states of the brakes B and the headlights HL in the vehicle C and controls the emission status of the light sources 2A and 2B according to the aforementioned operating states. That is, the control device 20B controls the emission of the light sources 2A and 2B according to the braking operation and the lighting operation of the vehicle C.

[0068] Fig. 14A and Fig. 14B are used to describe a function of the light-emitting device 1C.

[0069] The control device 20B deactivates the light sources 2A and 2B when neither the brakes B nor the headlights HL are in operation.

[0070] The control device 20B switches on the light source 2A when the brakes B are operated. This results in, as in Fig. 14A, the stereoscopic image I1 is generated in the stereoscopic image generation plane P1, so that the brake light on the vehicle C appears illuminated.

[0071] The control device 20B switches on the light source 2B when the brakes are not operated and the headlights are switched on. This, as shown in Fig. 14B, the stereoscopic image I2 is generated in the stereoscopic image generation plane P2, so that the tail light on the vehicle C appears illuminated.

[0072] Thus, the light-emitting device 1C may include a plurality of light guide plates to thereby present a plurality of stereoscopic images corresponding to the operating state of the vehicle C. A viewer may also be presented with a plurality of information because the light guide plates 11A and 11B may be stacked and illuminated simultaneously.

[0073] Furthermore, it is possible that the generated stereoscopic images I1 and I2 convey a sense of depth because the stereoscopic images I1 and I2 are generated at different stereoscopic imaging planes. Consequently, it is possible to warn the user. Third embodiment

[0074] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0075] Fig. 15 is a block diagram illustrating the main components of a vehicle C equipped with a light-emitting device 1D according to an embodiment. As shown in Fig. As shown in Figure 15, the light-emitting device 1D includes a controller 20C instead of the controller 20B of the second embodiment. The other features of the light-emitting device 1D are substantially identical to the features of the light-emitting device 1C of the second embodiment.

[0076] Light emitted from the light guide plate 11A in the light-emitting device 1D produces the stereoscopic image I1, which serves as the brake light, and light emitted from the light guide plate 11B produces the stereoscopic image I2, which serves as a turn signal ( Fig. 16, Fig. 17).

[0077] The control device 20C controls when the light source 2A and the light source 2B emit light. Specifically, the control device 20C acquires the operating states of the brakes B and a direction signal receiver W in the vehicle C and controls the emission status of the light sources 2A and 2B according to the aforementioned operating states. That is, the control device 20C controls the emission of the light sources 2A and 2B according to the braking operation and the direction signal operation of the vehicle C. The direction signal receiver W may be a component that accepts driver instructions to activate a turn signal (direction indicator) on the vehicle C. In a typical vehicle, this component is located behind the steering wheel (as viewed from the driver).

[0078] Fig. 16A and Fig. 16B are used to describe a function of the light-emitting device 1D. Fig. 17A and Fig. 1DB are used to describe another function of the light-emitting device 1D.

[0079] In the light-emitting device 1D, the control device 20C deactivates the light sources 2A and 2B when the brakes B are not operated and the direction signal receiver W is not operated (ie, no direction signaling operation).

[0080] The control device 20C switches on the light source 2A when the brakes B are not operated and the direction signal receiver W is not operated (ie, no direction signaling operation). As a result, as shown in Fig. 16A and Fig. 16B, the stereoscopic image I1 is generated in the stereoscopic image generation plane P1, so that the brake light on the vehicle C is illuminated.

[0081] The control device 20C switches on the light sources 2A and 2B when the brakes have been applied and the direction signal receiver W has been operated (e.g., when the driver indicates his intention to turn right). This creates a stereoscopic image I1 in the stereoscopic image formation plane P1 and creates a stereoscopic image I2 in the stereoscopic image formation plane P2, as shown in Fig. 17A and Fig. 17B. As a result, both the brake light and the indicator light are illuminated. As shown in Fig. 17B, ​​the stereoscopic image I1 serving as the brake light and the stereoscopic image I2 serving as the turn signal may appear overlapped at a viewing position from behind the vehicle C.

[0082] The control device 20C turns on the light source 2B when the brakes have not been applied and the direction signal receiver W has been operated (e.g., when the driver indicates his intention to turn right). This creates the stereoscopic image I2 in the stereoscopic image formation plane P2, so that the turn signal on the vehicle C is illuminated.

[0083] As described above, in the light-emitting device 1D, the light guide plate 11A and the light guide plate 11B can be stacked and illuminated according to the details of the vehicle's operation (ie, the details of the brake operation and the turn signal operation). This allows the stereoscopic image I1 serving as the brake light and the stereoscopic image I2 serving as the turn signal to be presented in the same region. Fourth embodiment

[0084] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0085] Fig. Fig. 18 is a block diagram showing the main components of a vehicle C equipped with a light-emitting device 1E according to this embodiment; and Fig. 19 illustrates the light-emitting device 1E as viewed from above.

[0086] As in Fig. 18 and Fig. As shown in Fig. 19, in addition to the features of the light-emitting device 1C of the second embodiment, the light-emitting device 1E includes a light guide plate 11C and a light source 2C that outputs light to the light guide plate 11C. In other words, the light-emitting device 1E is provided with a plurality of light guide plates (i.e., the light guide plate 11A, the light guide plate 11B, and the light guide plate 11C). The light-emitting device 1E also includes a controller 20D instead of the controller 20A of the first embodiment. The controller 20D changes where the stereoscopic image is formed during a specific operation of the vehicle C (in this embodiment, during the direction signaling operation).

[0087] Given that the light guide plate 11C and the light source 2C are essentially the same as the light guide plate 11A and the light source 2A, only the different features will be described.

[0088] As in Fig. As shown in Figure 19, the light guide plates 11A, 11B, and 11C are arranged in the light-emitting device 1E such that the emission surfaces 11a of the light guide plates 11A, 11B, and 11C are parallel. In other words, the light guide plates 11A, 11B, and 11C are stacked one on top of the other in a direction perpendicular to the emission surface 11a of the light guide plate 11A. In the light-emitting device 1E, light emitted from the light guide plates 11A, 11B, and 11C forms an image on the stereoscopic image formation plane P.

[0089] The control device 20D controls when the light sources 2A, 2B, and 2C emit light. Specifically, the control device 20D acquires the operating states of the direction signal receiver W in the vehicle C and controls the emission status of the light sources 2A, 2B, and 2C according to the aforementioned operating states.

[0090] Fig. 20A to Fig. 20F are used to describe a function of the light-emitting device 1E.

[0091] The control device 20D repeats the following operations (1) to (3) in the specified order when the direction signal receiver W is operated (e.g., when the driver indicates his intention to turn right).

[0092] (1) The light source 2A is activated for a certain period of time (e.g., one second). This causes, as shown in Fig. 20A and Fig. 20B, a stereoscopic image I is formed in the stereoscopic image formation plane P as a portion of the blinker.

[0093] (2) The light sources 2A and 2B are activated for a certain period of time (e.g., one second). This causes, as shown in Fig. 20C and Fig. 20D, a stereoscopic image I1 and a stereoscopic image I2 are formed in the stereoscopic image formation plane P as a portion of the blinker.

[0094] (3) The light sources 2A, 2B and 2C are activated for a certain period of time (e.g. one second). This causes, as shown in Fig. 20E and Fig. 20F, the stereoscopic images I1, I2 and I3 are generated in the stereoscopic image formation plane P as a section of the blinker.

[0095] Here, the stereoscopic images I1 to I3 are aligned along the Z-axis direction (i.e., along the width of the vehicle C), as shown in Fig. 20E and Fig. 20F. The control device 20D in the light-emitting device 1D repeats the above operations in the specified order to thereby present a flowing turn signal at the rear of the vehicle C. That is, the light-emitting device 1E implements a so-called flowing turn signal (sequential turn signal) in the vehicle C. Fifth embodiment

[0096] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0097] Fig. Fig. 21 is a block diagram showing the main components of a vehicle C equipped with a light-emitting device 1F according to this embodiment. As shown in Fig. As shown in Fig. 21, the light-emitting device 1D includes a control device 20C instead of the control device 20B of the second embodiment. The other features of the light-emitting device 1D are substantially identical to the features of the light-emitting device 1C of the second embodiment. However, the light guide plates 11A, 11B, and 11C form a stereoscopic image in the space behind the emitting surface 11a (i.e., near the location where the emitting surface 11a emits light toward the outside of the vehicle C).

[0098] The light-emitting device 1F generates a stereoscopic image representing the traveling direction of the vehicle C by emitting light from the light guide plates 11A, 11B, and 11C when the vehicle C is reversing (ie, traveling in reverse).

[0099] The control device 20E controls when the light sources 2A, 2B, and 2C emit light. Specifically, the control device 20E obtains the steering status of the steering wheel H in the vehicle C (i.e., information about the rotation angle applied by the driver to the steering wheel H) and controls the emission status of the light sources 2A, 2B, and 2C according to the aforementioned operating state.

[0100] Fig. 22A to Fig. 22D are used to describe a function of the light-emitting device 1F.

[0101] As in Fig. 22A, the control device 20E in the light-emitting device 1F turns on the light source 2A when the vehicle C is reversing at a small angle relative to its longitudinal direction; that is, the control device 20E turns on the light source 2A when the driver turns the steering wheel H proportionally to an angle smaller than a predetermined angle and the vehicle C is reversing. As a result, the light emitted from the light guide plate 11A forms a true stereoscopic image I1, as shown in Fig. 22B. The stereoscopic image I1 shows the route along which the tires of the vehicle C move while the vehicle C reverses with the steering wheel H at the current turning angle.

[0102] As in Fig. 22C, the control device 20E turns on the light source 2C when the vehicle C is reversing at a large angle relative to its longitudinal direction; that is, the control device 20E turns on the light source 2C when the driver turns the steering wheel H proportionally to an angle greater than a predetermined angle and the vehicle C is reversing. As a result, the light emitted from the light guide plate 11C creates a true stereoscopic image I2, as shown in Fig. 22D. The stereoscopic image I2 shows the route along which the tires of the vehicle C move while the vehicle C reverses with the steering wheel H at the current turning angle.

[0103] It should be noted that, although not shown, the control device 20E turns on the light source 2B when the vehicle is reversing at an angle that is between the angle of the tires relative to the longitudinal direction in Fig. 22A and the angle of the tires in relation to the longitudinal direction in Fig. 22C. The light emitted from the light guide plate 11B creates a stereoscopic image showing the route along which the tires of the vehicle C move while the vehicle C reverses with the steering wheel H at the current turning angle.

[0104] As described above, the light-emitting device 1F displays a stereoscopic image showing the route along which the tires of the vehicle C move to correspond to the steering status of the steering wheel H (ie, to correspond to the steering operation). This alerts a person around the vehicle C.

[0105] Note that although the light-emitting device 1F in this embodiment is provided at the rear of the vehicle C, a light-emitting device according to the present invention is not limited thereto. A light-emitting device according to an embodiment of the present invention may be installed at the front of the vehicle C and generate a stereoscopic image showing the route along which the tires of the vehicle C move while the vehicle C is moving forward with the steering wheel H at the current turning angle. In addition, the light-emitting

[0106] Device 1F in this embodiment represents the traveling direction of the tires of vehicle C with lines, but a light-emitting device according to the present invention is not limited to this. In another embodiment of the light-emitting device, the stereoscopic image may be an arrow indicating the general direction of the tires of vehicle C. Modification example 2

[0107] A light-emitting device 1G will be described as an example of the modification of the light-emitting device 1F of the first embodiment. For the sake of simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0108] Fig. 23 is a block diagram showing the main components of a vehicle equipped with a light-emitting device 1G; Fig. 24 is a perspective view of the light-emitting device 1G; and Fig. 25 is a cross-sectional view of a configuration of the light-emitting device 1G.

[0109] As in Fig. 23 to Fig. As shown in FIG. 25, the light-emitting device 1G includes an image display device 81, an image forming lens 82, a collimator lens 83, a light guide plate 84 (i.e., a first light guide plate), and a mask 85. The image display device 81, the image forming lens 82, the collimator lens 83, and the light guide plate 84 are arranged in this order along the Y-axis direction. In addition, the light guide plate 84 and the mask 85 are arranged in this order toward the positive X-axis direction. The light-emitting device 1G also includes a controller 20F instead of the controller 20E of the fifth embodiment.

[0110] The image display device 81 presents a two-dimensional image projected by the light-emitting device 1G in a space in the display area according to an image signal received from a control device (not shown). The image display device 81 is, for example, a typical liquid crystal display capable of outputting image light by displaying an image in a display region. In the shown example, the display region of the image display device 81 and the incident surface 84a facing the display region in the light guide plate 84 are both arranged parallel to the XZ plane. The rear surface 84b and the emission surface 84c (i.e., a light-emitting surface) in the light guide plate 84 are arranged parallel to the YZ plane. The emission surface 84b, which emits light onto the mask 85, faces the rear surface 84c on which prisms 141 (described below) are provided.In addition, the surface on which slits 151 are provided in the mask 85 (described below) is parallel to the YZ plane. Note that the display region in the image display device 81 and the incident surface 84a in the light guide plate 84 may face each other, or the display region in the image display device 81 may be inclined relative to the incident surface 84a.

[0111] The image-forming lens 82 is arranged between the image display device 81 and the incident surface 84a. Image light exits the image display device 81 and enters the image-forming lens 82, which focuses the image light in the XZ plane; the image light exits the image-forming lens 82 and enters the collimator lens 83. Note that the XZ plane is parallel to the length of the incident surface 84a. The image-forming lens 82 can be of any type as long as it is capable of focusing the image light. The image-forming lens 82 can be a solid lens, a Fresnel lens, a diffraction lens, or the like. The image-forming lens 82 can also be a combination of a plurality of lenses arranged along the Z-axis direction.

[0112] The collimator lens 83 is arranged between the image display device 81 and the incident surface 84a. The collimator lens 83 collimates the image light focused by the image-forming lens 82 onto the XY plane; the XY plane is orthogonal to the length of the incident surface 84a. Collimated light exiting the collimator lens 83 enters the incident surface 84a of the light guide plate 84. Like the image-forming lens 82, the collimator lens 83 can be a solid lens or a Fresnel lens. The image-forming lens 82 and the collimator lens 83 can be arranged in the reverse order. Furthermore, the functions of the image-forming lens 82 and the collimator lens 83 can be achieved by a single lens or by a combination of multiple lenses.In other words, the combination of the image forming lens 83 and the collimator lens 81 can be configured in any manner as long as the light output from the display region of the image display device 82 is converged in the XY plane and collimated in the YZ plane.

[0113] The light guide plate 84 is made of a transparent resin; image light collimated by the collimator lens 83 enters the light guide plate 84 at the incident surface 84a and exits the light guide plate 84 at the emitting surface 84. In the example shown, the light guide plate 84 is a flat rectangular panel, where the surface facing the collimator lens 83 and parallel to the XZ plane is assumed to be the incident surface 84a. The rear surface is assumed to be the surface parallel to the YZ plane and located in the negative X-axis direction, while the emitting surface 84c is assumed to be the surface parallel to the YZ plane and facing the rear surface 84b. A plurality of prisms 141 (i.e., emitting structures, optical path changing portions) are provided in the light guide plate 84.

[0114] The plurality of prisms 141 reflect the image light entering the light guide plate from the incident surface 84a. The prisms 141 are provided on the rear surface 84b of the light guide plate 84 and protrude therefrom toward the emission surface 84c. For example, when image light travels along the Y-axis direction, the plurality of prisms 141 may consist essentially of triangular grooves with a predetermined width in the Y-axis direction (e.g., 10 μm) arranged at a predetermined interval along the Y-axis direction (e.g., 1 mm). The prisms 141 include a reflection surface 141a, which is the optical surface located closer to the incident surface 84a with respect to the direction along which the image light travels (i.e., the positive Y-axis direction). In the example shown, the plurality of prisms 141 are provided parallel to the Z-axis on the rear surface 84b.Thus, the reflection surfaces 141a in the plurality of prisms 141 are provided parallel to the Z-axis and orthogonal to the Y-axis; the reflection surfaces 141a reflect the image light entering from the incident surface 84a and traveling along the Y-axis direction. Each of the plurality of prisms 141 causes light emitted from mutually different positions in the display region of the image display device 81 along the direction orthogonal to the length of the incident surface 84a (i.e., the Z-axis) to exit from the emission surface 84c. That is, the prisms 141 allow the image light to exit from one surface of the light guide plate 84 to a predetermined viewpoint 100. Details of the reflection surfaces 141a will be described later.

[0115] The mask 85 is configured from a material opaque to visible light and includes a plurality of slits 151. The mask 85 allows only light emitted from the emission surface 84c of the light guide plate 84 and oriented toward the image formation point 101 in a plane 102 to pass through the plurality of slits 151.

[0116] The plurality of slits 151 only allows light emitted from the emission surface 84c of the light guide plate 84 and oriented toward the image formation point 101 in a plane 102 to pass through. In the example shown, the plurality of slits 151 are provided parallel to the Z-axis. Individual slits 151 can also correspond to any prism 141 in the plurality of prisms 141.

[0117] In the configuration described above, the light-emitting device 1G generates the image presented by the image display device 81 and projects it onto an imaginary plane 102 outside the light-emitting device 1G. Specifically, the light emitted from the display region in the image display device 81 passes through the image forming lens 82 and the collimator lens 83, after which the image light enters the incident surface 84a, which is an end surface of the light guide plate 84. Subsequently, the image light incident on the light guide plate 84 passes through the light guide plate 84 and reaches the prisms 141 provided on the rear surface 84b of the light guide plate 84. The reflection surfaces 141a reflect the image light reaching the prisms 141 toward the negative X-axis direction, thereby causing the image light to leave the light guide plate 84 from the emission surface 84c, which is parallel to the YZ plane.The light emitted from the emission surface 84c and passing through the slits 151 of the mask 85 forms an image of the image formation point 101 on the plane 102. In other words, the image light emanating from points in the display region of the image display device 81 converges on the YZ plane, collimates on the XY plane, and then arrives at an image formation point 101 on a plane 102. The light-emitting device 1G processes all the points in the display region in the aforementioned manner to thereby project an image output in the display region of the image display device 81 onto the plane 102. Thus, a user viewing this imaginary plane 102 from a viewpoint 100 perceives the image projected in the air.Note that the plane 102 on which the projected image is generated is a virtual plane; however, a screen may be disposed in the plane 102 to improve visibility. Thus, the light-emitting device 1G generates the image presented by the image display device 81 as a stereoscopic image I.

[0118] The control device 20F controls the image display device 81. Specifically, the control device 20F acquires the steering status of the steering wheel H in the vehicle C (i.e., information on the rotation angle applied by the driver to the steering wheel H) and changes the image presented by the image display device 81 according to the aforementioned operating state. In other words, the control device 20F causes the image display device 81 to present an image showing the route along which the tires of the vehicle C are moving to correspond to the steering status of the steering wheel H (i.e., to correspond to the steering operation). Thereby, the light-emitting device 1G generates a stereoscopic image showing the route along which the tires of the vehicle C are moving. This alerts a person around the vehicle C.

[0119] Note that the light-emitting device 1G in this embodiment is configured to form an image by the image light emitted from the emission surface 84c passing through the slits 151 in a mask 85. However, the configuration may be omitted from the mask 85 and the slits 151, if possible, to form an image from the image light at an image formation point 101 in the virtual plane 102.

[0120] For example, the angle between the reflecting surfaces on the prisms 141 and the rear surface 84b can be set to increase with increasing distance from the incident surface 84j to form an image with image light at an image formation point 101 in the virtual plane 102. Note that the angle of the prism 141 located farthest from the incident surface 84a is preferably an angle that causes total internal reflection of light in the image display device 81.

[0121] Light is emitted from a point on the display region of the image display device 81 and is oriented toward a predetermined viewpoint; the angles are configured as described above: the closer this emission point is to the rear surface 84b (i.e., farther to the negative X-axis direction), the farther the prism 141 is from the incident surface 84a that reflects this light. However, without being limited to this configuration, it is sufficient to assign a location in the X-axis direction in the display region of the image display device 81 to a prism 141. Furthermore, light reflected by a prism 141 is increasingly oriented toward the incident surface 84a as the distance of the prism 141 from the incident surface 84a increases; whereas light reflected by a prism 141 is increasingly oriented away from the incident surface 84a as the proximity of the prism 141 to the incident surface 84a increases.Therefore, a light-emitting device according to an embodiment of the present invention is capable of emitting light from the image display device 81 toward a specific viewpoint even without the mask 85. Light emerging from the light guide plate 84 forms an image on the plane onto which the image is projected and diffuses according to the distance from the plane in the Z-axis direction. As a result, a parallax effect can be generated in the Z-axis direction, allowing a viewer to align both eyes along the Z-axis direction to stereoscopically view an image projected in the Z-axis direction.

[0122] Given that, in the above-mentioned configuration, no light reflected by the prisms 141 and oriented toward the viewpoint is blocked, a viewer can see an image presented on the image display device 81 and projected into the air even when the viewer's viewpoint moves along the Y-axis direction. However, the angle between light rays from the prisms 141 oriented toward the viewpoint and the reflection surface of the prisms 141 changes with the position of the viewpoint along the Y-axis direction; therefore, the position of the viewpoint in the image display device 81 corresponding to the light beam also changes with the position of the viewpoint along the Y-axis direction. Furthermore, in this example, light from each of the points in the image display device 81 is also generated in the Y-axis direction to some extent by the prisms 141.Therefore, a viewer whose both eyes are aligned along the Y direction can also see a stereoscopic image.

[0123] Furthermore, the above configuration eliminates the need for the mask 85, thus reducing the loss of light intensity and allowing a brighter image to be projected into a room. Furthermore, since no mask is used, a viewer can see both an object behind the light guide plate 84 (not shown) and the projected image. Sixth embodiment

[0124] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0125] Fig. Fig. 26 is a rear view of a vehicle C according to an embodiment; in this embodiment, the vehicle C has, in addition to the functions of the vehicle C in the first embodiment, a 2D image display device 200 as shown in Fig. 26 shown.

[0126] Fig. 27 is a plan view of the 2D image display device 200; and Fig. 28 is a cross-sectional view of the above-mentioned 2D image display device 200.

[0127] As in Fig. 26, the 2D image display device 200 is installed in the rear window of the vehicle C. The 2D image display device 200 includes a light source 201 and a light guide plate 211, as shown in Fig. 27 and Fig. 28. The light source 201 may, for example, be a light-emitting diode.

[0128] The light guide plate 211 is made of a transparent resin material with a relatively high refractive index. The light guide plate 211 can be made of, for example, a polycarbonate resin, a polymethyl methacrylate resin, glass, or the like. The light guide plate 211 has an emission surface 211a (i.e., a light-emitting surface) that emits light, a rear surface 211b opposite the emission surface 211a, and an incident surface 211c through which light emitted from the light source 201 enters the light guide plate 211. The light guide plate 211 guides the light from the light source 201 so that the light propagates in a planar form on a plane parallel to the emission surface 211a.

[0129] As in Fig. 27 and Fig. As shown in Figure 28, the rear surface 211b of the light guide plate 211 includes a plurality of optical path-changing portions 212 formed thereon. The optical path-changing portions 212 reflect light transmitted through the light guide plate 211 and cause the light to exit from the emission surface 211a. A driver in a vehicle following the vehicle C can see an image represented by the light emitted from the emission surface 211a.

[0130] Fig. 29A to Fig. 29C are used to describe the shape of the beam path changing sections 212. The beam path changing sections 212 may be prisms containing two reflection surfaces, as in Fig. 29A, or prisms containing a single reflecting surface, as in Fig. 29B and Fig. 29C. In addition, the optical path changing portions 212 may be employed as the groups of optical path changing portions 13 formed on the rear surface 11b of the light guide plate 11A, as described with respect to the first embodiment.

[0131] The plurality of optical path changing portions 212 are formed on the back surface 211b of the light guide plate 211 in the 2D image display device 200 to display a specific image, for example, the letters STOP and the triangle as shown in Fig. 26 shown.

[0132] The vehicle C in the present embodiment can present a two-dimensional image through the 2D image display device 200 in addition to displaying the stereoscopic image I through the light-emitting device 1A. Thus, the stereoscopic image presented by the light-emitting device 1A can be displayed more effectively. Furthermore, since the light guide plate 211 is transparent, the driver of the vehicle C can see behind the vehicle C without obstructing the driver's field of vision.

[0133] It should be noted that in the embodiment, the 2D image display device 200 is not limited to including only one light guide plate 211. The 2D image display device, which is an embodiment of the present invention, may include a plurality of light guide plates and present a different image via each of the light guide plates. This allows the presented image to change according to the operation of the vehicle C. For example, a particular light guide plate may display the letters "ON AUTOPILOT." In addition, another light guide plate may display an arrow to provide a warning that the vehicle C is turning.

[0134] In some situations, it may be desirable to display an image by the 2D image display device 200 only for a specific direction. In this case, the beam path-changing sections 212 must cause the light to exit in the specific direction.

[0135] For example, groups of optical path-changing sections 13 formed on the rear surface 11b of the light guide plate 11A may serve as the optical path-changing sections 212; in this case, the optical path-changing sections 212 may cause the light to exit in a specific direction by forming only a portion of a region of the groups of optical path-changing sections 13 on the rear surface 211b and using this portion as the optical path-changing sections 212. For example, the central region of the groups of optical path-changing sections 13 may be formed on the rear surface 211b, thereby allowing only a viewer in a direction orthogonal to the emission surface 211a (i.e., a viewer behind the vehicle C) to view the image.

[0136] As another example, the optical path-changing sections 212 can be formed such that the reflective surfaces thereon are oriented in a specific direction. Furthermore, a plurality of light sources 201 can be provided for the light guide plate 11 to thereby adjust or modify the propagation angle of the light emitted by the light sources. The light source 201 can also be provided with a collimator lens to ensure that the light hits the optical path-changing sections 212 from a single direction.

[0137] The 2D image display device according to the embodiments may include a plurality of light sources and present a different image using the light emitted by the light sources. This allows the light source to be selectively activated according to the respective situation, thereby enabling the presentation of an image corresponding to the said situation; for example, an image may be presented that responds to the rotation angle of the steering wheel H, as described in connection with the fifth embodiment. Seventh embodiment

[0138] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0139] Fig. 30 illustrates how the light-emitting device 1G may be installed in a vehicle C. Fig. 31A to Fig. 31D show examples of a stereoscopic image formed by the light-emitting device 1G.

[0140] In the embodiment, the light-emitting device 1G is installed in the front windshield F, and the light emerging from the light-emitting device 1G is radiated toward the driver in the vehicle C, as shown in Fig. 30. In other words, a driver can see the stereoscopic image I generated by the light-emitting device 1G.

[0141] For example, the light-emitting device 1G can generate a stereoscopic image I presented in relation to the width of the vehicle C ( Fig. 31A). Typically, bumper corner guides may be provided at a front end of the vehicle C so that the driver can have an idea of ​​the width of the vehicle C. In contrast, in this example, the driver can have an idea of ​​the width of the vehicle C through the stereoscopic image I generated by the light-emitting device 1G. In this example, bumper corner guides do not need to be installed on the vehicle C, and thus the driver can determine the width of the vehicle without compromising the design quality of the vehicle C.

[0142] The light-emitting device 1G can also generate a stereoscopic image that presents, for example, the traveling position of the vehicle C; ie, the light-emitting device 1G generates a stereoscopic image that indicates where the vehicle C is traveling ( Fig. 31B). Specifically, the light-emitting device 1G can obtain the steering status information of the steering wheel H in the vehicle C and change the stereoscopic image I indicating the driving position depending on the steering status. More specifically, the light-emitting device 1G can obtain information about the rotation angle of the steering wheel H operated by the driver and cause the stereoscopic image I to change depending on the steering status. The driver can thus recognize where the vehicle C is traveling. As a result, the driver can drive safely.

[0143] A navigation system may be installed in the vehicle C; in this case, the light-emitting device 1G may obtain information from this navigation system and generate a stereoscopic image based on this information. For example, if information is obtained from the navigation system that prompts the driver to turn, the light-emitting device 1G may generate an arrow as a stereoscopic image I ( Fig. 31C). In addition, when information informing a temporary stop is received from the navigation system, the light-emitting device 1G can generate a character as the stereoscopic image I indicating a temporary stop ( Fig. 31D). In this example, using the stereoscopic image I, the driver can obtain information from the navigation system while looking forward, instead of having to look at the vehicle navigation system's display unit, which is typically located in the center console. As a result, the driver can drive safely.

[0144] Fig. 32 illustrates the light-emitting device 1A installed in the side window glass (side window) of the vehicle C. In this embodiment, the light-emitting device 1A may be installed in a side window glass (side window). For example, a sensor may be used to detect that an object (e.g., another vehicle or an obstacle) is adjacent to and outside the vehicle C closer than a predetermined distance; in this case, the light-emitting device 1A may generate a stereoscopic image I (e.g., an arrow) to provide a warning of an approaching object. The driver can thus be warned of a hazard that is not visible by simply looking in the side mirror with the stereoscopic image I.

[0145] The light-emitting device 1G may also be installed inside the vehicle C; e.g., in the dashboard, glove compartment, center console, armrests, door trim, storage compartment trim, or the back of the front seat. The light-emitting device 1G may generate an image serving as an ornament. For example, the light-emitting device 1G may generate a stereoscopic image displaying the vehicle manufacturer's logo on the vehicle C. Note that in this example, the stereoscopic image generated by the light-emitting device 1G may be visible to both the driver and other passengers. Eighth embodiment

[0146] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0147] Fig. 33 is a block diagram showing the main components of a vehicle C equipped with a light-emitting device 1H according to this embodiment; and Fig. 34A to Fig. 34C are used to describe a function of the light-emitting device 1H. As in Fig. 33 and Fig. 34, the vehicle C includes a detector D that detects when the user of a remote key sends an instruction to lock or unlock the vehicle C. The light-emitting device 1H may also include a light source 3A and a light source 4A in addition to the features of the light-emitting device 1A of the first embodiment. The light-emitting device 1H includes a controller 20G instead of the controller 20A of the first embodiment. The light-emitting device 1H in this embodiment functions as a so-called entry light.

[0148] The structure of the light sources 3A and 4A is identical to the structure of the light source 2A. The light sources 3A and 4A can be arranged on the end surface 11c of the light guide plate 11A. Specifically, the light sources 3A, 2A, and 4A are arranged in order from left to right along the end surface 11c of the light guide plate 11A. The light sources 2A, 3A, and 4A irradiate the groups of optical path-changing sections 13 with light.

[0149] The control device 20G obtains information from a lock intervention detector D as to whether an instruction to lock or unlock the vehicle C has been sent by a user with a remote key. The control device 20G causes the light sources 2A, 3A, and 4A to emit light to express the following states (i) to (iii).

[0150] (i) The control device 20G switches on the light source 2A while the light sources 3A and 4A are off; thus, a stereoscopic image I4 is formed as shown in Fig. 34A. Fig. 34A shows a single group of optical path changing sections 13 and the optical path of the light when the above-mentioned group of optical path changing sections 13 changes the optical path of the light so that the light appears to radiate from one point in the stereoscopic image I4 ( Fig. 34B and Fig. 34C).

[0151] (ii) The control device 20G switches on the light source 3A while the light sources 2A and 4A are off; thus, a stereoscopic image I5 is formed as shown in Fig. 34B. As described above, the light source 3A is located farther to the left than the light source 2A on the end surface 11c of the light guide plate 11A. Therefore, light emitted from the light source 3A and modified by the group of optical path changing sections 13 converges at a different location than light emitted from the light source 2A and modified by the group of optical path changing sections 13. Consequently, the stereoscopic images I4 and I5 are formed as different stereoscopic images in the same region. Specifically, the stereoscopic images I4 and I5 are inclined relative to each other with respect to a horizontal plane (i.e., the XZ plane); in other words, the stereoscopic images I4 and I5 have different orientations from each other.

[0152] (iii) The control device 20G switches on the light source 4A while the light sources 2A and 3A are off; thus, a stereoscopic image I6 is formed as shown in Fig. 34C. As described above, the light source 4A is located farther to the left than the light sources 2A and 3A on the end surface 11c of the light guide plate 11A. Therefore, light emitted from the light source 4A and modified by the group of optical path changing sections 13 converges at a different location than light emitted from the light sources 2A and 3A and modified by the group of optical path changing sections 13. Consequently, the stereoscopic image I6 is formed as a different stereoscopic image in the same region as the stereoscopic images I4 and I5. Specifically, the stereoscopic images I4, I5, and I6 are inclined with respect to a horizontal plane (i.e., the XZ plane); in other words, the stereoscopic images I4, I5, and I6 have different orientations from each other.

[0153] As described above, the light guide plate 11 of the light-emitting device 1H has three light sources (i.e., light sources 2A, 3A, and 4A), and the controller 20G changes the associated light source to thereby change the stereoscopic image that is generated. As a result, by viewing images I4 to I6, the user can determine whether the vehicle C has recognized the instruction to lock or unlock the vehicle. The light-emitting device 1H can also provide highly attractive entry lighting because the stereoscopic image changes.

[0154] Although the light-emitting device 1H in this embodiment includes three light sources (light sources 2A, 3A, and 4A) for a single light guide plate (ie, the light guide plate 11A), a light-emitting device according to the present invention is not limited thereto. A light-emitting device according to an embodiment of the present invention may be configured with two light sources or with four or more light sources for a single light guide plate.

[0155] The light-emitting device 1H in this embodiment includes three light sources (light sources 2A, 3A, and 4A) for a single light guide plate (i.e., the light guide plate 11A), and changes the light source that is activated to change where the stereoscopic image is formed. However, a light-emitting device according to the present invention is not limited to such a configuration. A light-emitting device according to an embodiment of the present invention may include a single light source for a single light guide plate 11A and be configured to change where the stereoscopic image is formed by moving the light source laterally along the end surface 11c of the light guide plate 11A. The controller 20G in the light-emitting device 1H according to the embodiment may change the light emission intensity of the light sources 2A to 4A upon activation of the light sources 2A to 4A.This allows changing the brightness of the stereoscopic images I4 to I6.

[0156] Note that although the light-emitting device 1H in this embodiment is installed at the rear (i.e., at the taillight location) of the vehicle C, a light-emitting device according to the present invention is not limited thereto. A light-emitting device according to the present invention may be installed at another location in the vehicle, such as the outside rearview mirror or the like. Ninth embodiment

[0157] The following is a description of another embodiment. For simplicity, components previously described in an embodiment that have an identical function are given the same reference numerals, and the corresponding explanations are omitted.

[0158] Fig. 35 is a block diagram showing the main components of a vehicle C equipped with a light-emitting device 1I according to this embodiment; and Fig. 36A to Fig. 36D are used to describe a function of the light-emitting device 1I. As in Fig. 35 and Fig. As shown in Fig. 36, the light-emitting device 1I is equipped with the light guide plate 11D instead of the light guide plate 11A in the light-emitting device 1H of the eighth embodiment. The light-emitting device 1I includes a controller 20H instead of the controller 20G of the eighth embodiment.

[0159] As in Fig. 36A to Fig. 36D, groups of optical path changing portions 13A, 13B and 13C are formed on the rear surface 11b of the light guide plate 11D. Fig. 36A to Fig. 36D shows a single group of optical path changing sections (the group of optical path changing sections 13A, 13B, and 13C) and the optical path of the light when the above-mentioned group of optical path changing sections changes the optical path of the light so that the light appears to radiate from one point in the stereoscopic image. The groups of optical path changing sections 13A, 13B, and 13C are configured identically to the group of optical path changing sections 13 described for the first embodiment. The group of optical path changing sections 13A changes the optical path of the light originating from and incident on the light source 3A to form a stereoscopic image 17. The group of optical path changing sections 13B changes the optical path of the light originating from and incident on the light source 3A to produce a stereoscopic image I8.The group of optical path changing sections 13C changes the optical path of the light originating from and incident on the light source 3A to produce a stereoscopic image I9.

[0160] The control device 20H obtains information from a lock intervention detector D as to whether an instruction to lock or unlock the vehicle C has been sent by a user with a remote key. The control device 20H causes the light sources 2A, 3A, and 4A to emit light to express the following states (i) to (iii). (i) The control device 20H switches on the light source 3A while the light sources 2A and 4A are off; thus, a stereoscopic image I7 is formed as shown in Fig. 36A. (ii) The control device 20H switches on the light source 2A while the light sources 3A and 4A are off; thus, a stereoscopic image I8 is formed as shown in Fig. 36B. (iii) The control device 20H switches on the light source 4A while the light sources 2A and 3A are off; thus, a stereoscopic image I9 is ​​formed as shown in Fig. 34C shown.

[0161] As described above, the groups of optical path-changing sections 13A, 13B, and 13C are aligned laterally along the rear surface 11b of the light guide plate 11D. Therefore, the stereoscopic images I7, I8, and I9 generated by the groups of optical path-changing sections 13A, 13B, and 13C are formed at different locations from each other. Thus, as described in cases (i) to (iii) above, the light sources 2A to 4A are sequentially activated, so that the stereoscopic image appears to change, and more specifically, so that the stereoscopic image appears to move. As a result, by viewing the images I7 to I9, the user can determine whether the vehicle C has recognized the instruction to lock or unlock the vehicle. The light-emitting device 1I can also provide highly attractive entry lighting because the stereoscopic image changes.

[0162] The control device 20H can activate the light sources 2A to 4A when the vehicle C is traveling to generate the stereoscopic images I7 to I9, as shown in Fig. 36D shown.

[0163] The light-emitting device 1I in the embodiment produces stereoscopic images I7 to I9 having identical shapes; however, the light-emitting device according to the present invention is not limited to this. A light-emitting device according to the present invention can produce stereoscopic images I7 to I9 having different shapes from each other.

[0164] The groups of optical path-changing sections 13A, 13B, and 13C of the light-emitting device 1I in this embodiment include a corresponding light source; however, a light-emitting device according to the present invention is not limited thereto. A light-emitting device according to an embodiment of the present invention may be configured with a plurality of light sources corresponding to a single group of optical path-changing sections. In this case, as described in connection with the eighth embodiment, when presenting a stereoscopic image corresponding to the above-mentioned single group of optical path-changing sections of the embodiment, the configuration may be such that the generated stereoscopic image changes by sequentially activating a plurality of light sources.The control device 20H in the light-emitting device 1I according to the embodiment can change the light emission intensity of the light sources 2A to 4A upon activation of the light sources 2A to 4A. This enables changing the brightness of the stereoscopic images I7 to I9.

[0165] The present invention is not limited to any specific embodiment described above and may be modified in various ways while still remaining within the scope of the claims. The technical means disclosed in each of the various embodiments may be combined as needed, and an embodiment obtained in such a manner still remains within the technical scope of the present invention.

Claims

[1] A light-emitting device (1A, 1B) for vehicles, provided at the left and right rear ends of a vehicle (C) and functioning as a taillight of the vehicle (C) and configured to emit light toward the outside of the vehicle (C), the light-emitting device (1A, 1B) comprising: a light source (2A); a light guide plate (11A) provided at the rear end of the vehicle and including a light-emitting surface (11a), a rear surface (11b) opposite the light-emitting surface (11a), and end surfaces (11c, 11d, 11e, 11f) connecting the light-emitting surface (11a) and the rear surface (11b), where the light source (2A) is arranged on one of the end surfaces (11c, 11d, 11e, 11f) and emits light to the light guide plate (11A, 11B), wherein the light guide plate (11A) is configured to direct light entering from the light source (2A) such that the light exits the light-emitting surface (11a) and creates a virtual stereoscopic image (I) in an image formation plane (P1) that is further inside or outside the vehicle (C) than the light guide plate (11A, 11B) relative to a viewer outside the vehicle (C), wherein optical path-changing sections (13) which change an optical path of the light entering from the light source (2A) are formed on the rear surface (11b), and the virtual stereoscopic image (I) is formed in the image formation plane (P1) by the light whose optical path is changed by the optical path-changing sections (13), and wherein the light-emitting device (1A, 1B) comprises a further light guide plate (11B) which forms a plurality of light guide plates (11A, 11B) with the light guide plate (11A), wherein the light guide plates (11A, 11B) are stacked one above the other in a direction perpendicular to their light-emitting surfaces (11a), and the further light guide plate has a further light source (2B), so that each light guide plate of the plurality of light guide plates (11A, 11B) has a light source (2A, 2B), wherein the further light guide plate (11B) has a rear surface (11b) on which optical path-changing sections (13) which change an optical path of the light entering from the further light source (2B) are formed; and a lighting control device (20A, 20B) configured to control the emission status of the light source (2A, 2B) according to a braking operation, a lighting operation, a direction signaling operation, or a steering operation, wherein the lighting control device (20A, 20B) switches between the light guide plates (11A, 11B) according to the details of the operation / operations of the vehicle (C) as to which of the light guide plates (11A, 11B) emits light, and wherein the illumination control device (20A, 20B) layers virtual stereoscopic images (I1, I2) by causing the different light guide plates (11A, 11B) to simultaneously emit light corresponding to the details of the operation / operations of the vehicle (C), whereby one virtual stereoscopic image (I1) is formed by the light source (2A) and the light guide plate (11A) in the stereoscopic image formation plane (P1) and another stereoscopic image (I2) is formed by the light source (2B) and the further light guide plate (11B) in a further stereoscopic image formation plane (P2), so that the stereoscopic images (I1, I2) appear to overlap from a viewing position behind the vehicle (C). [2] The light-emitting device (1A, 1B) for vehicles according to claim 1, wherein distances from the light-emitting surface (11a) of the light guide plate (11A, 11B) located closest to the outside of the vehicle (C) to the virtual stereoscopic images (I1, I2) formed by each of the light guide plates (11A, 11B) are different from each other because distances of the light-emitting surfaces of the light guide plates (11A, 11B) with the light guide plate located closest to the outside of the vehicle (C) to the image formation planes (P1, P2) in which the virtual stereoscopic images (I1, I2) corresponding to the respective light guide plates (11A, 11B) are formed are different from each other. [3] A light-emitting device (1A, 1B) for vehicles according to claim 1, wherein the lighting control means (20A, 20B), during a direction signaling operation of the vehicle (C), switches the respective virtual stereoscopic image (I1, I2) generated by the respective light guide plate (11A, 11B) by switching which of the light sources (2A, 2B) emits light.

Images