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

Abstract

To provide an information display system capable of displaying video with excellent visibility to a user, and a prism body, a prism device and a reflection type display device for realizing the information display system.SOLUTION: A prism body 1 is arranged over a plurality of locations on a projection surface onto which light is projected from a light source, and can individually direct and emit light from the light source in a predetermined direction. The prism body comprises an incident / emission surface 10 that is curved and protrudes toward the light source, and a reflective surface 11 that is curved and recessed on the side of the incident / emission surface 10, where both of a cross-sectional shape along a first direction X orthogonal to a tangential direction of the incident / emission surface 10 and a cross-sectional shape along a second direction Y orthogonal to the first direction X are formed into a convex meniscus lens shape.SELECTED DRAWING: Figure 1

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 Art

[0002] Conventionally, as an information display system that displays information such as accident occurrence situations and weather information on the road to a user as characters, images, etc., information display means that reflects video light projected from a projector on a screen to display a video is known (see, for example, Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional information display means, since the reflected light diffuses on the screen surface, there is room for improvement in the visibility of characters, images, etc. viewed by the user. Further, in the above conventional information display means, since the direction of the reflected light depends on the shape of the screen, the degree of freedom in the light distribution design of the reflected light is low, and for this reason, there is a difficulty in improving the visibility of characters, images, etc.

[0005] Therefore, in the application of Japanese Patent Application No. 2021-129967, the inventor proposed an information display system capable of displaying a video with excellent visibility to a user, as well as a prism body, a prism device, and a reflective display device for realizing the same.

[0006] In the above application, as shown in FIG. 18, the prism body 9 includes an incident / output surface 90 and a reflection surface 91 facing the incident / output surface 90, and the cross-sectional shape along one direction (C1 direction) orthogonal to the tangential direction of the incident / output surface 90 is formed in a convex meniscus lens shape. Due to the characteristic shape of the prism body 9, it is possible to efficiently emit light in a predetermined one direction, for example, toward the user. Specifically, by swinging the prism body 9 in the direction along the curvature of the reflection surface 91 (or the incident / output surface 90), regardless of the incident angle of the incident light with respect to the prism body 9, light can be emitted from the prism body 9 toward the user.

[0007] The above-described prism body 9 is used by being arranged at a plurality of locations on a projection surface (for example, the screen of a reflection type display device) onto which light is projected from a light source. By adjusting the posture of each prism body 9 arranged on the projection surface, regardless of the incident angle of the incident light with respect to each prism body 9, light can be emitted from each prism body 9 toward the user. That is, by using each prism body 9 arranged on the projection surface, light with excellent visibility can be emitted from the projection surface to the user.

[0008] Incidentally, while the cross-sectional shape of the above-described prism body 9 along one direction (C1 direction) orthogonal to the tangential direction of the incident / output surface 90 is a convex meniscus lens shape, the cross-sectional shape along the other direction (C2 direction) orthogonal to the above one direction is a rectangular shape. For this reason, in the C1 direction, as shown in FIG. 19A, the intensity of the emitted light of the prism body 9 forms a gentle mountain having one peak over the entire area, and the peak of the emitted light of the prism body 9 is clear. On the other hand, in the C2 direction, as shown in FIG. 19B, the inventor has obtained the finding that a plurality of peaks are formed in the intensity of the emitted light of the prism body 9, and local unevenness occurs in the emitted light of the prism body 9.

[0009] Therefore, as a result of intensive research based on the obtained findings, the inventor has found that reducing the local unevenness of the illuminance as seen in the above-described prism body 9 makes the emitted light clearer, and as a result, the visibility of the emitted light is improved, and the present invention has been completed.

[0010] That is, an object of the present invention is to provide an information display system capable of displaying an image excellent in visibility for a user, and a prism body, a prism device, and a reflection type display device for realizing the same.

Means for Solving the Problems

[0011] In order to achieve the above object, the prism body described in the present application is arranged at a plurality of positions on a projection surface on which light is projected from a light source, can be and includes an incident / output surface and a reflection surface. The incident / output surface protrudes with a curved surface on the light source side so that the light reflected by the reflection surface is condensed and the diffusion of the emitted light is suppressed. The reflection surface is recessed with a curved surface on the incident / output surface side so that the focusing of the emitted light from the incident / output surface is suppressed. The prism body is capable of individually emitting the light from the light source in a predetermined one direction. The cross-sectional shape along a first direction orthogonal to the tangential direction of the incident / output surface and the cross-sectional shape along a second direction orthogonal to the first direction are both convex meniscus lens shapes. The reflection surface is defined with a reflection region that is defined at the central portion of the reflection surface and reflects incident light and is set to a size that can ensure the brightness required for the emitted light, and a non-reflection region that is defined outside the reflection region and does not reflect the incident light.

[0012] Further, the prism body may be formed in a rectangular shape in plan view.

[0014] The prism device described in the present application is characterized by including the prism body and a swing shaft portion that swingably supports the prism body behind the reflection surface.

[0015] In addition, the reflective display device described in the present application is a reflective display device that reflects image light projected from an image source on a screen to display an image. On the screen, a plurality of the prism bodies or the prism devices are arranged in a matrix to form an image reflection portion, and the postures of the individual prism bodies or prism devices are adjusted so that the directions of the respective emitted lights emitted from the individual prism bodies or prism devices in the image reflection portion are the same direction. and the screen surface of the screen is curved toward the projection side of the video light, and the left and right end portions in the left and right direction have a greater curvature than the central portion in the left and right direction It is characterized by this.

[0016] In addition, in the reflective display device, the screen may be provided with a disturbance light shielding portion for shielding disturbance light.

[0018] In addition, the information display system described in the present application is characterized by including the reflective display device and a projector that projects image light onto the reflective display device.

[0019] In addition, in the information display system, the projector is capable of emitting the image light in three primary colors of RGB, and projects the image light so that one prism body or prism device of the image reflection portion reflects one color component toward the screen. The reflective display device may display an image composed of the three primary colors respectively reflected by the individual prism bodies or prism devices.

Effects of the Invention

[0020] According to the present invention, it is possible to display an image with excellent visibility for the user.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 2E

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19A

Figure 19B

Mode for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same components among the embodiments described below, and redundant descriptions of these components are omitted.

[0023] - Prism body - First, the prism body 1 will be described.

[0024] (Embodiment of Prism Body) FIG. 1 is a perspective view showing an embodiment of the prism body 1. FIG. 2A is a plan view of the prism body 1. FIG. 2B is an end view of the prism body 1 taken along the line A1 - A1 in FIG. 2A. FIG. 2C is an end view of the prism body 1 taken along the line A2 - A2 in FIG. 2A. FIG. 2D is an end view of the prism body 1 taken along the line B1 - B1 in FIG. 2A. FIG. 2E is an end view of the prism body 1 taken along the line B2 - B2 in FIG. 2A. FIG. 3A is a graph showing the relative intensity of the emitted light of the prism body 1 in the first direction X. FIG. 3B is a graph showing the relative intensity of the emitted light of the prism body 1 in the second direction Y. FIG. 4 is a schematic side view showing the prism body 1 arranged on the projection surface P. In FIG. 4, the solid - line straight arrow indicates the direction of the incident light, and the dashed - line arrow indicates the direction of the emitted light.

[0025] The prism body 1 has an incident - exit surface 10 that protrudes with a curved surface on the light - source side, and a reflecting surface 11 that recesses with a curved surface on the incident - exit surface 10 side (see FIG. 1). Hereinafter, the "incident light" refers to the light incident on the incident - exit surface 10, and the "emitted light" refers to the light emitted from the incident - exit surface 10.

[0026] The prism body 1 is capable of emitting light in a predetermined single direction. That is, as follows. Note that the "single direction" not only means that the directions of the respective light rays of the light coincide with each other, but also includes the case where the directions of the respective light rays of the light are generally in the same direction. First, since the input / output surface 10 protrudes with a curved surface on the light source side, the light reflected by the reflecting surface 11 is condensed and the diffusion of the emitted light is suppressed. Further, since the reflecting surface 11 is recessed with a curved surface on the input / output surface 10 side, the focusing of the light emitted from the input / output surface 10 is suppressed. Furthermore, by swinging the prism body 1 in the direction along the curvature of the reflecting surface 11 or the input / output surface 10 to adjust the posture of the prism body 1, the direction of the emitted light can be changed. Here, the "posture" refers to the orientation in space, that is, the rotation angle in the three-dimensional space. As a specific example of the swinging direction of the prism body 1, it includes around a swinging axis along a first direction X orthogonal to the tangential direction of the input / output surface 10, around a swinging axis along a second direction Y orthogonal to the first direction X, or around a swinging axis along a direction (not shown) intersecting both the first direction X and the second direction Y. Summarizing the above, depending on the shapes of the input / output surface 10 and the reflecting surface 11, the emitted light can be emitted in a single direction, and by swinging the prism body 1 in the direction along the curvature of the reflecting surface 11 or the input / output surface 10, the emitted light can be emitted in a predetermined direction.

[0027] The cross-sectional shape of the prism body 1 described above has the following characteristics. That is, in the prism body 1, the cross-sectional shape along the first direction X orthogonal to the tangential direction of the input / output surface 10 and the cross-sectional shape along the second direction Y orthogonal to the first direction X are both convex meniscus lens shapes.

[0028] Specifically, as shown in FIGS. 2A to 2C, the cross-sectional shape S of the cross-section A1-A1 along the first direction X at the central portion of the prism body 1 A1 and the cross-sectional shape S of the cross-section A2-A2 along the first direction X at one end portion of the prism body 1 A2 are both convex meniscus lens shapes. The cross-sectional shape along the first direction X at the other end portion of the prism body 1 is the cross-sectional shape SA2 is equivalent to

[0029] Similarly, as shown in FIGS. 2A, 2D, and 2E, the cross-sectional shape S of the cross-section B1-B1 along the second direction Y at the central portion of the prism body 1 B1 and the cross-sectional shape S of the cross-section B2-B2 along the second direction Y at one end portion of the prism body 1 B2 are both convex meniscus lens-shaped. The cross-sectional shape along the second direction Y at the other end portion of the prism body 1 is equivalent to the cross-sectional shape S B2 is equivalent to

[0030] Due to the above cross-sectional shape of the prism body 1, as shown in FIG. 3A, the intensity of the light emitted from the prism body 1 in the first direction X forms a gentle mountain having one peak over the entire area. Similarly, as shown in FIG. 3B, the intensity of the light emitted from the prism body 1 in the second direction Y also forms a gentle mountain having one peak over the entire area. As a result, in both the first direction X and the second direction Y, the peak of the light emitted from the prism body 1 becomes clear, so that the light emitted from the prism body 1 becomes distinct, and thus the visibility of the emitted light can be improved.

[0031] The above prism body 1 is used by being arranged over a plurality of locations on the projection surface P onto which light is projected from a light source (see FIG. 4). By swinging the individual prism bodies 1 (1a to 1c) arranged on the projection surface P to adjust the postures of the individual prism bodies 1 (1a to 1c), regardless of the incident angle of the incident light with respect to the individual prism bodies 1 (1a to 1c), light can be emitted from the prism bodies 1 (1a to 1c) in a predetermined single direction, for example, toward the user. Since the light emitted from the individual prism bodies 1 (1a to 1c) toward the user reaches the user's eyes efficiently, it can be said that the light has a light distribution that is easy for the user to visually recognize. Here, "light distribution" refers to the distribution of luminous intensity. In this way, since the prism bodies 1 (1a to 1c) are arranged over a plurality of locations on the projection surface P and the postures of the individual prism bodies 1 (1a to 1c) are adjusted, light can be emitted with a light distribution that is easy for the user to visually recognize, and thus light having excellent visibility can be emitted to the user.

[0032] Conventionally, when prism bodies are arranged at multiple locations on such a projection surface P and light is to be emitted in a predetermined single direction using these prism bodies, it is necessary to change the shape of each prism body according to its installation position. As a result, there have been problems such as increased manufacturing costs and complicated assembly. Furthermore, since it is necessary to use prism bodies of different shapes according to the installation location and shape of the projection surface P, there has been a problem of low freedom in light distribution design. In the present invention, as described above, since the prism body 1 is swung with a specific shape, the prism body 1 can efficiently direct light in a predetermined single direction regardless of the incident angle of the incident light, wherever it is arranged on the projection surface P. That is, since the same-shaped prism bodies 1 can be arranged at multiple locations on the projection surface P and light can be emitted in a predetermined single direction using these prism bodies 1, the shapes of the prism bodies can be standardized. As a result, manufacturing costs can be suppressed and assembly becomes easier. Furthermore, according to the installation location and shape of the projection surface P, each prism body 1 can be swung to adjust its posture so that the direction of the emitted light becomes a predetermined single direction. Therefore, light can be emitted with a light distribution that is easy for the user to visually recognize regardless of the installation location and shape of the projection surface P, and the freedom in light distribution design is improved.

[0033] In the present embodiment, the prism body 1 is formed in a rectangular shape in plan view (see FIG. 2A). As a result, a plurality of prism bodies 1 can be spread on the projection surface P without wasteful gaps.

[0034] By the way, in conventional information display means that reflects light projected from a projector or the like on a screen to display an image, since the screen reflects light over the entire area of the reflecting surface, in the emitted light of such a screen, colors with low brightness, particularly black, become excessively bright, resulting in low contrast of the displayed image and poor visibility.

[0035] Therefore, in the present embodiment, the reflecting surface 11 is defined with a reflection region 12 that reflects incident light and a non-reflection region 13 that does not reflect incident light (see FIG. 1). The reflection region 12 is defined in the central portion of the reflecting surface 11, and the non-reflection region 13 is defined outside the reflection region 12. As an example, among the regions of the reflecting surface 11 formed from a reflecting member such as a mirror material, a light absorbing material is applied to the regions other than the central portion of the reflecting surface 11, or an antireflection film is laminated, whereby the reflection region 12 and the non-reflection region 13 are defined. The size of the reflection region 12 is set to a size that can ensure the brightness required for the emitted light. Among the incident light, the light that hits the reflection region 12 is reflected by the reflection region 12 and emitted from the input / output surface 10 as the emitted light, while the light that hits the non-reflection region 13 is absorbed by the non-reflection region 13.

[0036] In this way, since not only the reflection region 12 but also the non-reflection region 13 is defined on the reflecting surface 11, it is possible to prevent a color with a low brightness, particularly black, from becoming excessively bright as compared with the case where the entire region of the reflecting surface 11 reflects light. Thereby, the visibility of the emitted light can be improved.

[0037] Note that, in order to make the surface of the input / output surface 10 look dark when the incident light is not irradiated, a translucent film or the like may be attached to the surface of the input / output surface 10.

[0038] Further, the surface of the prism body 1 may be subjected to an antifouling treatment.

[0039] Further, the projection surface P is not limited to a flat surface and may be curved, for example.

[0040] - Prism device - Next, a prism device 2 including the prism body 1 will be described.

[0041] (Embodiment of the prism device) FIG. 5 is a schematic perspective view showing an embodiment of the prism device 2.

[0042] The prism device 2 is a device in which the prism body 1 is made into a device so that the direction of the emitted light can be adjusted according to the optical axis direction of the incident light, and includes the prism body 1 and the swing shaft portion 20 (see Fig. 5). In Fig. 5, the illustration of the drive unit 8 is omitted.

[0043] The swing shaft portion 20 supports the prism body 1 so as to be swingable around a swing axis along the first direction X behind the reflecting surface 11. In the present embodiment, the swing shaft portion 20 is rotatably penetrated through a mounting hole (not shown) formed on the outer surface on the back side of the concave surface of the reflecting surface 11, and is rotationally driven by the drive unit 8 or manually. By providing such a swing shaft portion 20 on the prism body 1, the attitude of the prism body 1 can be easily adjusted to adjust the direction of the emitted light.

[0044] Note that the swing shaft portion 20 may support the prism body 1 so as to be swingable around a swing axis along the second direction Y behind the reflecting surface 11, or may support the prism body 1 so as to be swingable around a swing axis along a direction (not shown) intersecting both the first direction X and the second direction Y.

[0045] -Reflective display device- Subsequently, a reflective display device 3 using the prism body 1 or the prism device 2 will be described.

[0046] (Embodiment of the reflective display device) Fig. 6 is a schematic front view showing an embodiment of the reflective display device 3. Fig. 7 is a schematic cross-sectional view showing a part of the longitudinal section of the reflective display device 3. Fig. 8 is a schematic cross-sectional view showing the cross-section of the screen 30. Fig. 9 is a schematic cross-sectional view showing a part of the longitudinal section of a modified example of the screen 30. Fig. 10 is a schematic cross-sectional view showing the cross-section of another modified example of the screen 30. In Figs. 7 and 9, the solid straight arrows indicate the direction of the incident light, and the broken-line arrows indicate the direction of the emitted light.

[0047] The reflective display device 3 reflects the video light projected from the video source to display a video, and includes a screen 30 for reflecting the video light (see FIG. 6). Here, the "video light" refers to the light modulated based on the video signal, and the "video" includes still images and moving images. In the present embodiment, the video source is installed below the left side when viewed from the front of the reflective display device 3, and the prism device 2 is arranged such that the swing shaft portion 20 extends along the lateral direction of the screen 30.

[0048] On the screen 30, a large number of prism devices 2 are arranged in a matrix to form an image reflection portion 31 for reflecting the video light (see FIG. 6). Here, the "matrix shape" is not limited to being arranged in a checkerboard pattern in the row direction and the column direction, but also includes those arranged according to an arbitrary system or pattern in the entire region of the screen 30. The video is configured by the emitted light from each of the individual prism devices 2 in the image reflection portion 31.

[0049] The postures of the individual prism devices 2 are adjusted so that the directions of the respective emitted lights emitted from the individual prism devices 2 in the image reflection portion 31 are the same direction (see FIG. 7). Specifically, the swing shaft portions 20 of the individual prism devices 2 are respectively rotationally driven, and the prism bodies 1 of the individual prism devices 2 are swung in the swing direction R, so that the video light is emitted from the image reflection portion 31 toward the user. In other words, the postures of the individual prism devices 2 are adjusted so that the video light is emitted from the image reflection portion 31 with a light distribution that is easy for the user to visually recognize.

[0050] Also, in the present embodiment, since the swing shaft portion 20 is arranged along the lateral direction of the screen 30, the prism device 2 is swung around the swing axis along the lateral direction of the screen 30. For this reason, the light distribution of the video light emitted from the image reflection portion 31, particularly the light distribution of the video light in the vertical direction of the screen 30, is restricted.

[0051] In such a reflective display device 3, the image light projected from the image source is reflected by the image reflection part 31 composed of a large number of prism devices 2, and is emitted from the image reflection part 31 with a light distribution that is easy for the user to visually recognize. Thereby, an image with excellent visibility can be displayed to the user. Note that the same effect can also be achieved when the image reflection part 31 is composed of a large number of prism bodies 1 instead of the large number of prism devices 2.

[0052] In the present embodiment, a plurality of ventilation holes 33 that allow the passage of wind are formed in the screen 30 (see FIG. 6). By such a plurality of ventilation holes 33, for example, when the reflective display device 3 is installed in an outdoor open environment such as on a road, the wind resistance to the reflective display device 3 can be reduced.

[0053] Also, in the present embodiment, a disturbance light shielding part 32 for shielding disturbance light is provided on the screen 30 (see FIG. 7). Here, "disturbance light" refers to other optical signals and light other than the image source, and includes, for example, sunlight, illumination light, etc. The disturbance light shielding part 32 extends from the screen 30 in a roof-like shape between the individual prism devices 2 in the image reflection part 31. By providing such a disturbance light shielding part 32, it is possible to suppress a decrease in the contrast of the image light emitted from the image reflection part 31 due to the disturbance light.

[0054] Also, in the present embodiment, the left and right end portions of the screen 30 surface are curved toward the projection side of the image light (see FIG. 8). Due to such a shape of the screen 30, the light distribution of the image light emitted from the image reflection part 31, particularly the light distribution of the image light in the left and right directions of the screen 30, is narrowed, so that the visibility of the image viewed by the user can be improved.

[0055] Also, in the present embodiment, the surface of the screen 30 is subjected to antifouling treatment.

[0056] Incidentally, the prism device 2 may be arranged such that the swing axis portion 20 extends along the vertical direction of the screen 30. In this case, since the prism device 2 swings around the swing axis along the vertical direction of the screen 30, the light distribution of the video light emitted from the image reflection portion 31, particularly the light distribution of the video light in the left - right direction of the screen 30, is restricted. Also, in this case, as shown in FIG. 9, by curving the upper end portion of the screen 30 surface toward the projection side of the video light, the light distribution of the video light emitted from the image reflection portion 31, particularly the light distribution of the video light in the vertical direction of the screen 30, can be restricted, and the visibility of the video viewed by the user can be improved.

[0057] Also, as an auxiliary means for adjusting the directions of the respective emitted lights emitted from the individual prism devices 2 in the image reflection portion 31 to the same direction, as shown in FIG. 10, the screen 30 may be formed to have a plurality of wedge - shaped protrusions 35.

[0058] -Configuration of the Information Display System- Furthermore, an information display system 4(A,B) including the above - mentioned reflective display device 3 will be described. For convenience of explanation, in the first and second embodiments of the information display system 4(A,B), they are respectively denoted as information display system 4A and information display system 4B, but their functions are the same.

[0059] (First Embodiment of the Information Display System) FIG. 11 is a schematic plan view showing an information display system 4A which is a first embodiment of the information display system 4. FIG. 12 is a block diagram showing a schematic configuration of the information display system 4A. FIG. 13 is a schematic front view showing an example of an arrangement pattern of the prism device 2 in the image reflection unit 31 of the reflective display device 3. FIG. 14 is a schematic side view showing a state in which sunlight is reflected by the reflective display device 3. FIG. 15 is a schematic side view showing a modified example of the information display system 4A. FIG. 16 is a schematic plan view showing another modified example of the information display system 4A. In FIGS. 11, 14, 15 and 16, solid arrows indicate the direction of video light projected from the projector 5, and broken arrows indicate the direction of light emitted by the image reflection unit 31 of the reflective display device 3 reflecting the video light. Further, in FIG. 14, the dashed-dotted line indicates the direction of sunlight, and the double-dashed-dotted line indicates the direction of light emitted by the image reflection unit 31 of the reflective display device 3 reflecting the sunlight.

[0060] The information display system 4A is configured to display information for a user as video, and includes a reflective display device 3, a projector 5 that projects video light onto the reflective display device 3, and a control unit 6 that controls the projector 5 (see FIGS. 11 and 12). In the present embodiment, the information display system 4A is configured to display, as video, accident occurrence situations, weather information, etc. on the road toward the driver D. Here, the "road" refers to a road on which a vehicle can travel, and includes general roads, highways, inside tunnels, etc.

[0061] In the present embodiment, the reflective display device 3 is suspended at a predetermined height position from the ground of the road. Further, in the present embodiment, the image reflection unit 31 of the reflective display device 3 is composed of a plurality of prism devices 2 (see FIG. 13). The attitude of each prism device 2 is adjusted according to the optical axis direction of the video light projected from the projector 5 so that the direction of the emitted light emitted from each prism device 2 in the image reflection unit 31 is toward the driver D. In other words, the attitude of each prism device 2 is adjusted so that light is emitted from the image reflection unit 31 with a light distribution that is easy for the driver D to visually recognize.

[0062] The projector 5 includes 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. 12). The projection optical unit 53 is, for example, a projection lens group. Note that the light source 51 may be composed of an LD (Laser Diode), an LED (Light Emitting Diode), or the like.

[0063] The projector 5 is installed on the left side of the road, that is, on the side of the road where vehicles pass.

[0064] The control unit 6 includes 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 that is an interface with various devices, and a display unit 63 composed of a liquid crystal display or the like that indicates the processing state of the processing unit 60, etc. (see FIG. 12). The processing unit 60, the storage unit 61, the I / F unit 62, and the display unit 63 are interconnected by bus lines (not shown).

[0065] The 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, whereby the control program 64 is executed. Note that the control program 64 is not limited to this, and may be read from a recording medium such as an HDD, or may be downloaded from a network such as a LAN (Local Area Network).

[0066] The I / F unit 62 is communicably connected to the projector 5 and an external device such as a PC that supplies video data, and the type of communication is not limited, and includes wired, wireless, indirect connection, direct connection, etc.

[0067] The information display system 4A as described above displays information for the user as characters, images, etc. as follows. First, the processing unit 60 of the control unit 6 transmits the video data input to the I / F unit 62 to the projector 5 from the I / F unit 62 as a video signal. 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 the modulated video light toward the reflective display device 3. The reflective display device 3 reflects this video light by the image reflection unit 31 and emits it in the direction of the driver D, and is configured to display an image toward the driver D.

[0068] In such an information display system 4A, the video light projected from the projector 5 is reflected by the image reflection unit 31 of the reflective display device 3 and is emitted from the image reflection unit 31 with a light distribution that is easy for the driver D to visually recognize. Thereby, an image with excellent visibility can be displayed for the driver D.

[0069] Also, in the information display system 4A as described above, as shown in FIG. 14, the video light projected from the projector 5 is reflected by the image reflection unit 31 of the reflective display device 3 and is emitted from the image reflection unit 31 toward the driver D. On the other hand, sunlight having an incident angle different from that of the video light is reflected by the image reflection unit 31 of the reflective display device 3 and is emitted from the image reflection unit 31 in a direction necessarily different from the direction of the emitted light by the video light. For this reason, a situation where sunlight, particularly the setting sun incident from the west or light with a small sunlight angle, is reflected to the driver D side and adversely affects the visibility of the image viewed by the driver D is avoided.

[0070] Also, in the information display system 4A as described above, the image light projected from the projector 5 is reflected by the image reflection unit 31 of the reflective display device 3 and emitted from the image reflection unit 31 toward the driver D. As a result, the image light can reach the eyes of the driver D efficiently. Therefore, even without using a high-brightness projector, an image with excellent visibility can be displayed for the driver D. For this reason, an increase in the size of the housing of the projector is avoided, and the cost of the information display system 4A can be suppressed.

[0071] Furthermore, in the information display system 4A as described above, compared with the case where a road display board having a weight of about 1 to 3 tons and equipped with a conventional LED dot matrix or the like is suspended on the road, the weight of the equipment suspended on the road can be reduced.

[0072] In addition to the configuration of the information display system 4A described above, in the present embodiment, the projector 5 is capable of emitting image light in the three primary colors of RGB, and projects the image light so that one prism body 1 or prism device 2 of the image reflection unit 31 reflects one color component toward the screen 30 of the reflective display device 3. Specifically, the processing unit 60 of the control unit 6 converts the video data input to the I / F unit 62 into a video signal in an arrangement pattern of the three primary colors (for example, 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 reflection unit 31 of the reflective display device 3 based on the control program 64. Also, the processing unit 60 may convert the video data into a video signal so that one prism body 1 or prism device 2 of the image reflection unit 31 of the reflective display device 3 reflects one pixel of the projector 5. Subsequently, the processing unit 60 transmits the converted video signal to the projector 5. The projector 5 projects the image light based on the converted video signal toward the reflective display device 3.

[0073] The reflective display device 3 is configured to display an image composed of the three primary colors respectively reflected by the individual prism bodies 1 or prism devices 2. For example, as shown in FIG. 13, when the arrangement pattern of the prism devices 2 in the image reflection portion 31 of the reflective display device 3 is in a triangular lattice shape and a video signal converted into a triangular mosaic arrangement pattern is projected onto the reflective display device 3, an image reflection portion group 31a composed of three adjacent prism devices 2a to 2c constitutes one pixel group in the three primary colors, and an image reflection portion group 31b composed of the prism devices 2b and 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 individual prism bodies 1 or prism devices 2 reflects one color component, the color development of each emitted light emitted therefrom becomes vivid, so that the visibility of the image viewed from the driver D can be improved.

[0074] In view of the nature that the above information display system 4A displays information such as traffic safety and disasters, the projector 5 may be configured to issue an alarm, for example, not only in case of a failure but also to notify the lamp replacement deadline.

[0075] Also, the image reflection portion 31 of the reflective display device 3 may be composed of a large number of prism bodies 1.

[0076] Also, the control unit 6 may be configured integrally with the projector 5.

[0077] Also, video data may be stored in advance in the storage unit 61 of the control unit 6.

[0078] Further, not limited to the above, for example, the projector 5 can emit image light in four primary colors of RGBY, and projects one prism body 1 or prism device 2 of the image reflection part 31 toward the screen 30 of the reflection type display device 3 so as to reflect one color component. The image displayed by the reflection type display device 3 may be composed of the four primary colors respectively reflected by the individual prism bodies 1 or prism devices 2. Further, in the above embodiment, the individual prism bodies 1 or prism devices 2 are configured to reflect one color component of RGB. However, the configuration is not limited to such a configuration in which the individual prism bodies 1 or prism devices 2 reflect one color component. For example, when the resolution of the projector 5 is high, the individual prism bodies 1 or prism devices 2 may be configured to directly reflect light including a plurality of color components projected from the projector 5.

[0079] Further, the information display system 4A may include sensors such as an illuminance sensor that measures the illuminance around the reflection type display device 3, and may be configured to adjust the brightness of the image light of the projector 5 according to the signals of these sensors.

[0080] (Modification example of information display system) In addition to the above embodiments, for example, as shown in a modification example of FIG. 15, the reflection type display device 3 may be suspended in a state of being fixed to a frame 34 at a predetermined height position from the ground of the road, and a short-focus projector 5 may be installed at the lower part of the frame 34 of the reflection type display device 3 so as to project from below the reflection type display device 3.

[0081] Further, as shown in another modification example of FIG. 16, the reflection type display device 3 may be installed on the side of the road on the passing side of the road facing the road side, and the projector 5 may also be installed diagonally in front of the reflection type display device 3 on the side of the road on the passing side of the road. In the second modification example, the posture 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 emitted light emitted from each prism body 1 or prism device 2 in the image reflection part 31 of the reflection type display device 3 intersects the traveling direction of the driver D.

[0082] (Second Embodiment of Information Display System) Hereinafter, only the differences from the first embodiment will be described for the second embodiment of the information display system 4. FIG. 17 is a block diagram showing a schematic configuration of an information display system 4B which is the second embodiment of the information display system 4.

[0083] 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. 17).

[0084] The image reflection unit 31 of the reflective display device 3 is composed of a large number of prism devices 2.

[0085] A drive unit 8 that rotationally drives the swing axis portion 20 of each prism device 2 in the image reflection unit 31 of the reflective display device 3 is connected to the I / F unit 62 of the control unit 6 via a controller 7 (see FIG. 17).

[0086] Based on the signal input to the I / F unit 62, the processing unit 60 of the control unit 6 causes the drive unit 8 to be rotationally driven by the controller 7 via the I / F unit 62. Thereby, the posture of each prism device 2 in the image reflection unit 31 of the reflective display device 3 can be adjusted by remote control.

[0087] As described above, an example of applying the present invention to road information display means has been described. However, the present invention is not limited to the display of road information on roads, beside roads, on the inner walls or ceilings of tunnels. Of course, it is not limited to the display of road information only. For example, the fields of use are not limited, such as departure and arrival guidance display boards at airports and stations, and information display boards installed on the outer wall surfaces of buildings. Also, the places of use are not limited to indoors and outdoors.

[0088] The above-described embodiments and examples are illustrative in all respects and are not to be construed as a basis for limiting interpretation. Therefore, the technical scope of the present invention is not construed only by the above-described embodiments and examples, but is defined based on the description in the claims. Also, all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0089] 1 Prism body 10 Input / output surface 11 Reflecting surface 12 Reflection region 13 Non-reflection region 2 Prism device 20 Oscillation axis portion 3 Reflective display device 31 Image reflection portion 4(A,B) Information display system 5 Projector 6 Control unit First direction X Second direction Y

Claims

1. It can be arranged at a plurality of locations on a projection surface onto which light is projected from a light source, comprising an incident / output surface and a reflection surface, the incident / output surface protrudes with a curved surface drawn toward the light source side so that the light reflected by the reflection surface is condensed and the diffusion of the emitted light is suppressed, the reflection surface is recessed with a curved surface drawn toward the incident / output surface side so that the focusing of the emitted light from the incident / output surface is suppressed, a prism body capable of individually emitting the light from the light source in a predetermined one direction, the cross-sectional shape along a first direction orthogonal to the tangential direction of the incident / output surface and the cross-sectional shape along a second direction orthogonal to the first direction are both convex meniscus lens-shaped, on the reflection surface, there is defined a reflection region that is defined at the central portion of the reflection surface and reflects incident light and is set to a size capable of ensuring the brightness required for the emitted light, and a non-reflection region that is defined outside the reflection region and does not reflect the incident light, and the prism body is characterized in that these are defined.

2. A prism body according to claim 1, characterized in that it is formed in a rectangular shape in plan view.

3. A prism body according to claim 1 or claim 2, and a swing shaft portion that swingably supports the prism body behind the reflection surface, and a prism device provided therewith.

4. A reflective display device that reflects video light projected from a video source on a screen to display a video, on the screen, a plurality of the prism bodies according to claim 1 or 2, or the prism devices according to claim 3 are arranged in a matrix to form an image reflection portion, and the postures of the individual prism bodies or prism devices are adjusted so that the directions of the respective emitted lights emitted from the individual prism bodies or prism devices in the image reflection portion are the same direction, the screen surface of the screen is curved toward the projection side of the video light, and the left and right end portions in the left and right direction have a greater curvature than the central portion in the left and right direction, and the reflective display device is characterized in that.

5. A reflective display device according to claim 4, characterized in that the screen is provided with an ambient light shielding portion that shields ambient light.

6. A reflective display device according to claim 4 or 5, and a projector that projects video light onto the reflective display device, and an information display system provided therewith.

7. An information display system according to claim 6, The projector is capable of emitting the video light in the three primary colors of RGB, and projects one prism body or prism device of the image reflection unit toward the screen so as to reflect one color component. The reflective display device is an information display system characterized by displaying an image composed of the three primary colors respectively reflected by the individual prism bodies or prism devices.

Images