Prism body, prism device, reflective display device and information display system

Abstract

To provide an information display system capable of displaying a video excellent in visibility to users, and a prism body, a prism device, and a reflective display device for realizing the information display system.SOLUTION: Prism bodies 1 are arranged over a plurality of locations on a projected surface 9 onto which light is projected from one light source, and can individually emit the light toward one predetermined direction. Each prism body has an incident / exiting surface 10, and a reflecting surface 11 facing the incident / exiting surface 10. A cross-sectional shape is formed in the shape of a convex meniscus lens, and its convex side is used as the incident / exiting surface 10, while its concave side is used as the reflecting surface 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a prism body, a prism device, a reflective display device, and an information display system. [Background technology]

[0002] Conventionally, as an information display system that displays road accident occurrence status, weather information, etc. to a user as characters, images, etc., an information display means that displays an image by reflecting image light projected from a projector on a screen has been known (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-279857 A [Patent Document 2] JP 2019-41862 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional information display means, there is a problem that the reflected light is diffused on the screen surface, so there is room for improvement in the visibility of characters, images, etc. seen by the user.

[0005] Furthermore, in the above-mentioned conventional information display means, the direction of the reflected light depends on the shape of the screen, so there is a problem in that the degree of freedom in designing the distribution of the reflected light is low.

[0006] Therefore, as a result of extensive research, the inventors have developed and completed an information display system that can emit light with a light distribution that is easily visible to the user, and ultimately display images with excellent visibility to the user, as well as a prism body, prism device, and reflective display device that realize this.

[0007] The present invention has been made to solve the above-mentioned problems in the conventional art, and aims to provide an information display system that can display images with excellent visibility to the user, as well as a prism body, prism device, and reflective display device that realize this. [Means for solving the problem]

[0008] In order to achieve the above object, the prism body described in the present application is a prism body that is arranged in a plurality of places on a projection surface onto which light is projected from a single light source, and is capable of individually reflecting the light in a predetermined direction, the prism body having an entrance / exit surface and a reflecting surface opposing the entrance / exit surface, and a cross-sectional shape formed in a convex meniscus lens shape, the convex surface side of the prism body being the entrance / exit surface, and the concave surface side being the reflecting surface. The reflecting surface is defined by a reflecting area that reflects incident light and a non-reflecting area that does not reflect the incident light. It is characterized by the above.

[0010] As another solution, The prism device described herein comprises: The projection lens is arranged in a plurality of locations on a projection surface onto which light is projected from a single light source, and is capable of emitting the light in a predetermined direction individually. The projection lens has an entrance / exit surface and a reflecting surface opposed to the entrance / exit surface, and has a cross-sectional shape formed in a convex meniscus lens shape, with the convex surface side being the entrance / exit surface and the concave surface side being the reflecting surface. The optical system is characterized by comprising a prism body and a swing shaft portion that supports the prism body behind the reflecting surface so that the prism body can swing in a direction along the curvature of the reflecting surface.

[0011] In addition, the reflective display device described in the present application is a reflective display device that displays an image by reflecting image light projected from an image source onto a screen, and is characterized in that an image reflecting section is formed on the screen by arranging a large number of the prism bodies or prism devices in a matrix pattern, and the attitude of each of the prism bodies or prism devices in the image reflecting section is adjusted so that the direction of each exit light emitted from each of the prism bodies or prism devices in the image reflecting section is the same.

[0012] In the reflective display device, the screen may be provided with an ambient light shielding portion for shielding ambient light.

[0013] In the reflective display device, at least one side end of the screen surface may be curved toward the projection side of the image light.

[0014] An information display system described in the present application is characterized by comprising the above-mentioned reflective display device, and a projector that projects image light onto the reflective display device.

[0015] In addition, in the information display system, the projector may be capable of emitting the image light in the three primary colors of RGB, and may project the image light toward the screen so that one prism body or prism device of the image reflecting unit reflects one color component, and the reflective display device may display an image composed of the three primary colors reflected by each of the individual prism bodies or prism devices. Effect of the Invention

[0016] According to the present invention, an image with excellent visibility can be displayed to a user. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view showing an embodiment of a prism body. [Diagram 2] 2 is a schematic side view showing a prism body disposed on a projection surface. FIG. [Diagram 3] FIG. 1 is a schematic perspective view showing an embodiment of a prism device. [Figure 4] 1 is a schematic front view showing an embodiment of a reflective display device. [Diagram 5] 5 is a schematic cross-sectional view showing a part of a vertical cross section of the reflective display device of FIG. 4. [Figure 6] FIG. 2 is a schematic cross-sectional view showing a cross section of a screen. [Figure 7] 7 is a schematic cross-sectional view showing a part of a vertical cross section of a modified example of the screen in FIG. 6. [Figure 8] FIG. 7 is a schematic cross-sectional view showing a transverse section of another modified example of the screen of FIG. [Figure 9] FIG. 1 is a schematic plan view showing a first embodiment of an information display system. [Figure 10] 10 is a block diagram showing a schematic configuration of the information display system of FIG. 9. [Figure 11] 1 is a schematic front view showing an example of an arrangement pattern of a prism device in an image reflecting portion of a reflective display device. [Figure 12] 1 is a schematic side view showing a state in which sunlight is reflected by a reflective display device. [Figure 13] 10 is a schematic side view showing a modified example of the information display system of FIG. 9. [Figure 14] 10 is a schematic plan view showing another modified example of the information display system in FIG. [Figure 15] FIG. 11 is a block diagram showing a schematic configuration of a second embodiment of an information display system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the same components in the embodiments described below are designated by the same reference numerals, and redundant descriptions of those components will be omitted.

[0019] - Prism body - First, the prism body 1 will be described.

[0020] (Embodiment of Prism Body) Fig. 1 is a perspective view showing one embodiment of a prism body 1. Fig. 2 is a schematic side view showing the prism body 1 arranged on a projection surface 9. In Fig. 2, the solid arrow indicates the direction of incident light, and the dashed arrow indicates the direction of outgoing light.

[0021] The prism body 1 has an incident / exit surface 10 and a reflecting surface 11 facing the incident / exit surface 10 (see Figs. 1 and 2). Hereinafter, "incident light" refers to light that is incident on the incident / exit surface 10, and "exiting light" refers to light that is emitted from the incident / exit surface 10.

[0022] The cross-sectional shape of the prism body 1 is formed into a convex meniscus lens shape, with the convex side serving as the entrance / exit surface 10 and the concave side serving as the reflecting surface 11 (see Figs. 1 and 2). In other words, the entrance / exit surface 10 is formed into a convex surface that bulges outward in a curved manner toward the light source side of the incident light, and the reflecting surface 11 is formed into a concave surface that sinks inward in a curved manner toward the entrance / exit surface 10 side.

[0023] Due to the shape of the input / output surface 10 as described above, the light reflected by the reflecting surface 11 is condensed, and the diffusion of the output light is suppressed.

[0024] In addition, due to the shape of the reflecting surface 11 as described above, the light emitted from the input / output surface 10 is emitted in one direction without being focused at one point. Here, "one direction" not only means that the directions of the light rays are the same, but also simply means that the directions of the light rays are generally the same.

[0025] Furthermore, due to the shapes of the entrance / exit surface 10 and the reflecting surface 11 as described above, when the attitude of the prism body 1 is adjusted by swinging the prism body 1 in the R direction along the curvature of the entrance / exit surface 10, the direction of the exiting light changes while maintaining the effect of suppressing the diffusion of the exiting light. Here, the "attitude" refers to the orientation in space, that is, the rotation angle in three-dimensional space.

[0026] In summary, the shapes of the incident / exit surface 10 and the reflecting surface 11 as described above make it possible to efficiently emit light in a predetermined direction.

[0027] The above-mentioned prism body 1 is suitable for use in a reflection-type display device in which light is projected from a single light source, by arranging it over a plurality of positions on a projection surface 9 onto which the light is projected (see FIG. 2). Specifically, as shown in FIG. 2, by adjusting the posture of each of the prism bodies 1 (1a to 1c) arranged on the projection surface 9 by swinging them in the R direction, the light can be emitted from the prism bodies 1 (1a to 1c) in a predetermined direction, for example, toward the user, regardless of the angle of incidence of the incident light to each of the prism bodies 1 (1a to 1c). In this way, the light emitted toward the user efficiently reaches the user's eyes, and thus has a light distribution that is easily visible to the user. Here, the "light distribution" refers to the distribution of luminous intensity. In this way, the prism bodies 1 (1a to 1c) are arranged in multiple locations on the projection surface 9, and the attitude of each of the prism bodies 1 (1a to 1c) can be adjusted to emit light with a light distribution that is easy for the user to see, and ultimately, light with excellent visibility to the user can be emitted.

[0028] In addition, in the past, when prism bodies were arranged in multiple locations on the projection surface 9 and light was to be emitted in a predetermined direction using these prism bodies, the shape of each prism body had to be changed depending on the location of the prism body, which resulted in high manufacturing costs and complicated assembly. Furthermore, since prism bodies of different shapes had to be used depending on the installation location and shape of the projection surface 9, there was a problem of low freedom in light distribution design. In the present invention, as described above, the prism body 1 is made to oscillate in a specific shape, so that the prism body 1 can efficiently emit light in a predetermined direction regardless of the angle of incidence of the incident light, regardless of where it is arranged on the projection surface 9. In other words, the prism bodies 1 of the same shape can be arranged in multiple locations on the projection surface 9 and light can be emitted in a predetermined direction using these prism bodies 1, which leads to a common shape of the prism body, which in turn reduces manufacturing costs and makes assembly easier. Furthermore, since the posture of each prism body 1 can be adjusted by swinging it so that the direction of the emitted light is in a predetermined direction depending on the installation location and shape of the projection surface 9, light can be emitted with a light distribution that is easily visible to the user regardless of the installation location and shape of the projection surface 9, thereby improving the freedom of light distribution design.

[0029] In the conventional information display means that displays images by reflecting light projected from a projector or the like on a screen, the screen reflects the light over the entire area of ​​the reflective surface. This means that in the light emitted from such a screen, low-luminosity colors, particularly black colors, tend to appear excessively bright, resulting in low contrast in the displayed image and poor visibility.

[0030] Therefore, in this embodiment, the reflective surface 11 is defined with a reflective area 12 that reflects incident light and a non-reflective area 13 that does not reflect incident light (see FIG. 1). The reflective area 12 is defined in the center of the reflective surface 11, and the non-reflective area 13 is defined outside the reflective area 12. For example, the reflective area 12 and the non-reflective area 13 are defined by applying a light absorbing material or laminating an anti-reflection film to an area other than the center of the reflective surface 11, among the areas of the reflective surface 11 formed from a reflective member such as a mirror material. The size of the reflective area 12 is set to a size that can ensure the brightness required for the outgoing light. Of the incident light, the light that hits the reflective area 12 is reflected by the reflective area 12 and is emitted from the entrance / exit surface 10 as the outgoing light, while the light that hits the non-reflective area 13 is absorbed by the non-reflective area 13.

[0031] In this way, by defining not only the reflective area 12 but also the non-reflective area 13 on the reflective surface 11, it is possible to prevent low-brightness colors, particularly black, from becoming excessively bright, compared to a case in which the entire area of ​​the reflective surface 11 reflects light. This makes it possible to improve the visibility of the emitted light.

[0032] In order to make the surface of the incident / exit surface 10 look dark when no incident light is being irradiated, a light-transmitting film or the like may be attached to the surface of the incident / exit surface 10.

[0033] The surface of the prism body 1 may be subjected to an antifouling treatment.

[0034] Furthermore, the projection surface 9 is not limited to being flat, and may be curved, for example.

[0035] -Prism device- Next, a prism device 2 including the above-mentioned prism body 1 will be described.

[0036] (Embodiment of Prism Device) FIG. 3 is a schematic perspective view showing an embodiment of the prism device 2. As shown in FIG.

[0037] The prism device 2 is an apparatus that embodies the prism body 1 so that the direction of the outgoing light can be adjusted according to the optical axis direction of the incident light, and includes the prism body 1 and a swing shaft portion 20 (see FIG. 3).

[0038] The oscillating shaft portion 20 supports the prism body 1 behind the reflecting surface 11 so that the prism body 1 can oscillate in the direction R that follows the curvature of the reflecting surface 11. In this embodiment, the oscillating shaft portion 20 is rotatably inserted into an attachment hole (not shown) formed in the outer surface behind the concave surface of the reflecting surface 11, and is driven to rotate by a drive portion (not shown) or manually. By providing such an oscillating shaft portion 20 to the prism body 1, the attitude of the prism body 1 can be easily adjusted to adjust the direction of the emitted light.

[0039] -Reflective display device- Next, a reflective display device 3 using the above prism body 1 or prism device 2 will be described.

[0040] (Embodiment of a Reflective Display Device) Fig. 4 is a schematic front view showing one embodiment of the reflective display device 3. Fig. 5 is a schematic cross-sectional view showing a part of the vertical section of the reflective display device 3. Fig. 6 is a schematic cross-sectional view showing the horizontal section of the screen 30. Fig. 7 is a schematic cross-sectional view showing a part of the vertical section of a modified example of the screen 30. Fig. 8 is a schematic cross-sectional view showing the horizontal section of another modified example of the screen 30. In Figs. 5 and 7, the solid arrow indicates the direction of incident light, and the dashed arrow indicates the direction of outgoing light.

[0041] The reflective display device 3 displays an image by reflecting image light projected from an image source, and is provided with a screen 30 for reflecting the image light (see FIG. 4). Here, "image light" refers to light modulated based on an image signal, and "image" includes still images and moving images. In this embodiment, the image source is installed on the lower left side when viewed from the front of the reflective display device 3, and the prism device 2 is disposed so that the swing shaft portion 20 is aligned horizontally with the screen 30.

[0042] A large number of prism devices 2 are arranged in a matrix on the screen 30 to form an image reflecting section 31 that reflects image light (see FIG. 4). Here, "matrix-like" does not necessarily mean a checkerboard arrangement in the row and column directions, but also includes an arrangement in accordance with any system or pattern over the entire area of ​​the screen 30. An image is formed by the light emitted from each prism device 2 in the image reflecting section 31.

[0043] The posture of each prism device 2 is adjusted so that the direction of each light emitted from each prism device 2 in the image reflecting section 31 is the same. Specifically, the swing shaft section 20 of each prism device 2 is rotated and the prism body 1 of each prism device 2 is swung in the R direction, whereby light is emitted from the image reflecting section 31 toward the user, and the light distribution of the emitted light, particularly the light distribution in the vertical direction of the screen 30, is narrowed (see Figs. 3 and 5). In other words, the posture of each prism device 2 is adjusted so that light is emitted from the image reflecting section 31 with a light distribution that is easily visible to the user.

[0044] In such a reflective display device 3, image light projected from an image source is reflected by an image reflecting section 31 composed of a number of prism devices 2, and is emitted from the image reflecting section 31 with a light distribution that is easy for the user to view. This makes it possible to display an image with excellent visibility to the user. Note that the same effect can be achieved even when the image reflecting section 31 is composed of a number of prism bodies 1 instead of a number of prism devices 2.

[0045] In this embodiment, the screen 30 is provided with a plurality of ventilation holes 33 that allow air to pass through (see FIG. 4). Such ventilation holes 33 can reduce wind resistance to the reflective display device 3, for example, when the reflective display device 3 is installed in an open outdoor environment such as on a road.

[0046] In this embodiment, the screen 30 is provided with a disturbance light shielding section 32 that shields disturbance light (see FIG. 5). Here, "disturbance light" refers to optical signals or light other than the image source, including, for example, sunlight and illumination light. The disturbance light shielding section 32 extends like an eave from the screen 30 between the individual prism devices 2 in the image reflecting section 31. By providing such disturbance light shielding section 32, it is possible to suppress a decrease in the contrast of the emitted light caused by disturbance light.

[0047] In this embodiment, the left and right ends of the screen 30 surface are curved toward the projection side of the image light (see FIG. 6). Such a shape of the screen 30 narrows the distribution of the light emitted from the image reflector 31, particularly the distribution of the light emitted in the left and right directions of the screen 30, thereby improving the visibility of the image viewed by the user.

[0048] In this embodiment, the surface of the screen 30 is subjected to an antifouling treatment.

[0049] The prism device 2 may be disposed so that the oscillating shaft portion 20 is aligned along the vertical direction of the screen 30. In this case, as shown in Fig. 7, by curving the upper end of the screen 30 surface toward the projection side of the image light, the light distribution of the emitted light in the vertical direction of the screen 30 can be narrowed, thereby improving the visibility of the image viewed by the user.

[0050] In order to adjust the direction of each light beam emitted from each prism device 2 in the image reflecting section 31 to the same direction, the screen 30 may be formed to have a plurality of wedge-shaped protrusions 35, as shown in FIG. 8.

[0051] - Information display system configuration - Further, a description will be given of an information display system 4(A, B) including the above-mentioned reflective display device 3. For convenience of description, the first and second embodiments of the information display system 4(A, B) are denoted by different reference characters such as information display system 4A and information display system 4B, respectively, but the functions of both are the same.

[0052] (First embodiment of information display system) FIG. 9 is a schematic plan view showing an information display system 4A which is a first embodiment of the information display system 4. FIG. 10 is a block diagram showing a schematic configuration of the information display system 4A. FIG. 11 is a schematic front view showing an example of an arrangement pattern of the prism device 2 in the image reflecting section 31 of the reflective display device 3. FIG. 12 is a schematic side view showing a state in which sunlight is reflected by the reflective display device 3. FIG. 13 is a schematic side view showing one modified example of the information display system 4A. FIG. 14 is a schematic plan view showing another modified example of the information display system 4A. In FIG. 9, FIG. 12, FIG. 13, and FIG. 14, the solid line arrow indicates the direction of the image light projected from the projector 5, and the dashed line arrow indicates the direction of the light reflected by the image reflecting section 31 of the reflective display device 3 and emitted. In FIG. 12, the dashed line indicates the direction of the sunlight, and the dashed line indicates the direction of the light reflected by the image reflecting section 31 of the reflective display device 3 and emitted.

[0053] The information display system 4A displays information to the user as an image, and includes a reflective display device 3, a projector 5 that projects image light onto the reflective display device 3, and a control unit 6 that controls the projector 5 (see Figs. 9 and 10). In this embodiment, the information display system 4A displays accident occurrence status on the road, weather information, etc., as an image toward the driver D. Here, "road" refers to a road on which a vehicle can travel, and includes general roads, expressways, inside tunnels, etc.

[0054] In this embodiment, the reflective display device 3 is suspended at a predetermined height from the ground of the road. Also, in this embodiment, the image reflecting section 31 of the reflective display device 3 is composed of a number of prism devices 2 (see FIG. 11). The attitude of each prism device 2 is adjusted according to the optical axis direction of the image light projected from the projector 5 so that the direction of the light emitted from each prism device 2 in the image reflecting section 31 is toward the driver D. In other words, the attitude of each prism device 2 is adjusted so that the light is emitted from the image reflecting section 31 with a light distribution that is easily visible to the driver D.

[0055] The projector 5 has a video signal receiving unit 50 that receives a video signal from the control unit 6, a light source 51 such as a lamp, a light modulation unit 52 that modulates the output light of the light source 51 based on the video signal received by the video signal receiving unit 50, and a projection optical unit 53 that projects the video light modulated by the light modulation unit 52 (see FIG. 10). The projection optical unit 53 is, for example, a group of projection lenses. The light source 51 may be composed of an LD (Laser Diode), an LED (Light Emitting Diode), or the like.

[0056] Projector 5 is installed on the left side of the road, that is, on the traffic side of the road.

[0057] The control unit 6 has a processing unit 60 such as a CPU (Central Processing Unit), a storage unit 61 including a non-volatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory), an I / F unit 62 which is an interface with various devices, and a display unit 63 consisting of a liquid crystal display or the like which shows the processing state of the processing unit 60 (see FIG. 10). The processing unit 60, the storage unit 61, the I / F unit 62, and the display unit 63 are mutually connected by a bus line (not shown).

[0058] A control program 64 is stored in the storage unit 61. Under the control of the processing unit 60, the control program 64 stored in the ROM is read out and loaded onto the RAM, thereby executing the control program 64. Note that the control program is not limited to this, and may be read from a recording medium such as a HDD, or downloaded from a network such as a LAN (Local Area Network).

[0059] The I / F unit 62 is communicatively connected to external devices such as the projector 5 and a PC that supplies video data, and the type of communication is not limited and may include wired, wireless, indirect connection, direct connection, etc.

[0060] The information display system 4A as described above displays information for the user as characters, images, and the like as follows. First, the processing unit 60 of the control unit 6 transmits video data input to the I / F unit 62 as a video signal from the I / F unit 62 to the projector 5. The video signal receiving unit 50 of the projector 5 receives this video signal. The light modulation unit 52 of the projector 5 modulates the output light of the light source 51 based on this video signal, and the projection optical unit 53 projects this modulated video light towards the reflective display device 3. The reflective display device 3 reflects this video light at the image reflecting unit 31 and emits it in the direction of the driver D, thereby displaying an image towards the driver D.

[0061] In such an information display system 4A, the image light projected from the projector 5 is reflected by the image reflecting section 31 of the reflective display device 3, and is emitted from the image reflecting section 31 with a light distribution that is easily visible to the driver D. This makes it possible to display an image with excellent visibility to the driver D.

[0062] 12, in the information display system 4A as described above, the image light projected from the projector 5 is reflected by the image reflecting section 31 of the reflective display device 3 and emitted from the image reflecting section 31 toward the driver D, while sunlight having an incident angle different from that of the image light is reflected by the image reflecting section 31 of the reflective display device 3 and is inevitably emitted from the image reflecting section 31 in a direction different from that of the emitted light of the image light. This avoids a situation in which sunlight, particularly the setting sun incident from the west or light with a small sunshine angle, is reflected toward the driver D and adversely affects the visibility of the image seen by the driver D.

[0063] In addition, in the above-described information display system 4A, the image light projected from the projector 5 is reflected by the image reflecting section 31 of the reflective display device 3 and emitted from the image reflecting section 31 toward the driver D, so that the image light efficiently reaches the eyes of the driver D, and therefore an image with excellent visibility can be displayed to the driver D without using a high-illuminance projector. This avoids an increase in the size of the projector housing, and reduces the cost of the information display system 4A.

[0064] Furthermore, in the above-described information display system 4A, the weight of the equipment suspended above the road can be reduced compared to the case where a road sign board equipped with a conventional LED dot matrix or the like and weighing approximately 1 to 3 tons is suspended above the road.

[0065] In addition to the above-mentioned configuration of the information display system 4A, in this embodiment, the projector 5 is capable of emitting image light in the three primary colors of RGB, and projects the image light toward the screen 30 of the reflective display device 3 so that one prism body 1 or prism device 2 of the image reflecting section 31 reflects one color component. Specifically, the processing section 60 of the control section 6 converts the image data input to the I / F section 62 based on the control program 64 into an image signal of an arrangement pattern of the three primary colors (e.g., a mosaic arrangement, a diagonal mosaic arrangement, a triangular mosaic arrangement, etc.) according to the arrangement pattern of the prism body 1 or prism device 2 of the image reflecting section 31 of the reflective display device 3. The processing section 60 may also convert the image data into an image signal so that one prism body 1 or prism device 2 of the image reflecting section 31 of the reflective display device 3 reflects one pixel of the projector 5. The processing section 60 then transmits the converted image signal to the projector 5. The projector 5 projects the image light based on the converted image signal toward the reflective display device 3.

[0066] The reflection type display device 3 is configured to display an image composed of the three primary colors reflected by each of the prism bodies 1 or prism devices 2. For example, as shown in FIG. 11, when the arrangement pattern of the prism devices 2 of the image reflecting section 31 of the reflection type display device 3 is a triangular lattice and an image signal converted into a triangular mosaic arrangement pattern is projected onto the reflection type display device 3, an image reflecting section group 31a consisting of three mutually adjacent prism devices 2a to 2c constitutes one pixel group in the three primary colors, and an image reflecting section group 31b consisting of the prism devices 2b, 2c and the prism device 2d adjacent thereto constitutes the next pixel group in the three primary colors. With such a configuration in which each of the prism bodies 1 or prism devices 2 reflects one color component, the color of each light emitted from them becomes vivid, thereby improving the visibility of the image viewed by the driver D.

[0067] In consideration of the nature of the information display system 4A described above, which displays information on traffic safety, disasters, and the like, the projector 5 may be configured to issue an alarm, for example, in the event of a malfunction or to notify the user when the lamp needs replacing.

[0068] Furthermore, the image reflecting section 31 of the reflective display device 3 may be composed of a number of prism bodies 1 .

[0069] Moreover, the control unit 6 may be configured integrally with the projector 5.

[0070] Furthermore, the storage unit 61 of the control unit 6 may store video data in advance.

[0071] Furthermore, without being limited to the above, for example, the projector 5 may be capable of emitting image light in the four primary colors of RGBY, and may project the image light toward the screen 30 of the reflective display device 3 so that one prism body 1 or prism device 2 of the image reflecting section 31 reflects one color component, and the image displayed by the reflective display device 3 may be composed of the four primary colors reflected by each of the prism bodies 1 or prism devices 2. Furthermore, in the above embodiment, each of the prism bodies 1 or prism devices 2 reflects one color component of RGB, but the configuration is not limited to such that each of the prism bodies 1 or prism devices 2 reflects one color component, and for example, when the resolution of the projector 5 is high, each of the prism bodies 1 or prism devices 2 may reflect light including multiple color components projected from the projector 5 as it is.

[0072] In addition, the information display system 4A may be configured to include sensors such as an illuminance sensor that measures the illuminance around the reflective display device 3, and to adjust the brightness of the image light of the projector 5 in response to signals from these sensors.

[0073] (Modification of information display system) In addition to the above embodiments, for example, as in the first modified example shown in Figure 13, the reflective display device 3 may be suspended at a predetermined height from the ground of the road and fixed to a frame 34, and a short-focus projector 5 may be installed below the frame 34 of the reflective display device 3 so as to project onto the reflective display device 3 from below.

[0074] 14, the reflective display device 3 may be installed on the side of the road facing the road, and the projector 5 may be installed diagonally in front of the reflective display device 3 on the side of the road facing the road. In the second modification, the attitude of each prism body 1 or prism device 2 is adjusted according to the angle of the image light projected from the projector 5 so that the direction of the light emitted from each prism body 1 or prism device 2 in the image reflecting section 31 of the reflective display device 3 intersects with the traveling direction of the driver D.

[0075] (Second embodiment of information display system) Hereinafter, the second embodiment of the information display system 4 will be described only in terms of the differences from the first embodiment. FIG. 15 is a block diagram showing a schematic configuration of an information display system 4B which is a second embodiment of the information display system 4. As shown in FIG.

[0076] The information display system 4B includes a projector 5, a reflective display device 3, and a control unit 6 that controls the projector 5 and the reflective display device 3 (see FIG. 15).

[0077] The image reflecting section 31 of the reflective display device 3 is composed of a number of prism devices 2.

[0078] The I / F section 62 of the control section 6 is connected via a controller 7 to a drive section 8 that rotates the oscillation shaft section 20 of each prism device 2 in the image reflector 31 of the reflective display device 3 (see FIG. 15).

[0079] The processing unit 60 of the control unit 6 causes the controller 7 to rotate the driving unit 8 via the I / F unit 62 based on a signal input to the I / F unit 62. This allows the attitude of each of the prism devices 2 in the image reflecting unit 31 of the reflective display device 3 to be adjusted by remote control.

[0080] The above describes an example of applying the present invention to a road information display means, but the present invention is not limited to displaying road information on roads, roadsides, or the inner walls or ceilings of tunnels, and the field of use is not limited to displaying road information, and can be used in other applications such as arrival and departure information display boards at airports and stations, and information display boards installed on the outer walls of buildings, and the place of use is not limited to indoors or outdoors.

[0081] The above-mentioned embodiments and examples are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-mentioned embodiments and examples, but is defined based on the claims. In addition, all modifications within the meaning and scope of the claims are included. [Explanation of symbols]

[0082] 1 Prism body 10. Input / Output Surface 11 Reflective surface 12 Reflection area 13 Non-reflective area 2 Prism device 20 Swing shaft 3 Reflective display device 31 Image reflection section 4(A,B) Information display system 5. Projector 6. Control Unit

Claims

1. A prism body is arranged in a plurality of locations on a projection surface onto which light is projected from a single light source, and is capable of emitting the light individually in a predetermined direction, a light input / output surface and a reflecting surface facing the light input / output surface; The cross-sectional shape is formed into a convex meniscus lens shape, the convex surface side of the lens serves as the light input / output surface, and the concave surface side of the lens serves as the reflecting surface, A prism body, wherein the reflecting surface is defined by a reflecting area that reflects incident light and a non-reflecting area that does not reflect the incident light.

2. A prism body arranged at multiple points on a projection surface onto which light is projected from a single light source, capable of emitting the light individually in a predetermined direction, the prism body having an entrance / exit surface and a reflecting surface opposing the entrance / exit surface, the prism body having a cross-sectional shape formed into a convex meniscus lens shape, the convex surface side of the prism body being the entrance / exit surface and the concave surface side being the reflecting surface; a pivot shaft portion supporting the prism body behind the reflecting surface so that the prism body can pivot in a direction along the curvature of the reflecting surface.

3. A reflective display device that displays an image by reflecting image light projected from an image source onto a screen, A reflective display device characterized in that an image reflecting section is formed on the screen by arranging a large number of the prism bodies described in claim 1 or the prism devices described in claim 2 in a matrix form, and the attitudes of the individual prism bodies or prism devices in the image reflecting section are adjusted so that the directions of the respective exit lights emitted from the individual prism bodies or prism devices in the image reflecting section are the same.

4. A reflective display device according to claim 3, The reflective display device is characterized in that the screen is provided with a disturbance light shielding portion for shielding disturbance light.

5. A reflective display device according to claim 3 or claim 4, A reflective display device, characterized in that at least one side edge of the screen surface is curved toward the projection side of the image light.

6. A reflective display device according to any one of claims 3 to 5, a projector that projects image light onto the reflective display device.

7. The information display system according to claim 6, the projector is capable of emitting the image light in the three primary colors of RGB, and projects the image light toward the screen so that one prism body or prism device of the image reflecting unit reflects one color component; The information display system is characterized in that the reflective display device displays an image constituted by the three primary colors reflected by each of the prism bodies or prism devices.

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