JP5427961B2 - Desktop display system - Google Patents

Description

  The present invention relates to a desktop display system that displays an image in a space on a desktop using an optical element.

  Conventionally, various optical elements have been developed in order to realize a realistic three-dimensional aerial image. For example, in Patent Document 1, an image of an object, which is a projection object placed on one side of an element, is formed on a position that is a surface object on the opposite side of the element by using a reflection-type plane-symmetric imaging element. A spatial video display device is disclosed. The reflection-type plane-symmetric imaging element used in this spatial image display device has a plurality of holes that penetrate a predetermined base in the thickness direction, and is a unit optical system that is composed of two mirror surface elements orthogonal to the inner wall of each hole An element is formed, and when light is transmitted from one surface direction of the substrate to the other surface direction through the hole, the light is reflected once by each of the two mirror elements. The light emitted from the projection is reflected by one of the two mirror elements when passing through the unit optical element of the reflective surface-symmetric imaging element, and then reflected by the mirror surface to become reflected light. The light is reflected by the other of the two specular elements of the unit optical element, and the projection object is imaged at a position reflected on the virtual mirror.

  However, since the above-described optical element requires a very fine processing technique, a spatial image display device using such an optical element has a problem that manufacturing costs are high. In view of this, the present applicant has proposed a reflection-type plane-symmetric imaging element that does not require manufacturing costs in Patent Document 2.

  1 to 3 are diagrams showing a configuration of a reflection-type plane-symmetric imaging element (hereinafter referred to as a light reflecting optical element) proposed in Patent Document 2. FIG. FIG. 1 is an external view of a light reflecting optical element, FIG. 2 is an external view of a rectangular parallelepiped material constituting the light reflecting optical element, and FIG. 3 is an external view showing a combination of two mirror sheets forming the light reflecting optical element.

  As shown in FIGS. 1 and 3, the light reflecting optical element 2 includes two mirror sheets 21 and 22 each formed by closely contacting a large number of rod-shaped rectangular parallelepiped materials 20 in parallel.

  As shown in FIG. 2, the rectangular parallelepiped material 20 is a long member, and is represented by transparent acrylic whose one side of a rectangular cross section in the direction perpendicular to the longitudinal direction, that is, in the short direction, is several hundred μm to several cm. Made of plastic or glass rod. The length varies depending on the size of the projected image, but is about several tens mm to several m. Note that three of the four surfaces extending in the longitudinal direction are surfaces used for light transmission or reflection, and thus are in a smooth state. About 100 to 20000 rectangular parallelepiped materials 20 are used for each of the mirror sheets 21 and 22.

  As shown in FIG. 2, a light reflecting film 23 is formed on one surface of the rectangular parallelepiped material 20 extending in the longitudinal direction, thereby forming a light reflecting surface. The light reflecting film 23 is formed by vapor deposition or sputtering of aluminum or silver.

  With respect to such a plurality of rectangular parallelepiped members 20, a mirror sheet 21 is formed by bringing the opposite surface 24 opposite to the surface on which the light reflecting film 23 of one rectangular parallelepiped member 20 is formed into close contact with the light reflecting surface 23 of another rectangular parallelepiped member 20. , 22 are formed. As shown in FIG. 3, the mirror sheets 21 and 22 are bonded together in a state in which one of the rectangular parallelepiped materials 20 is rotated by 90 degrees so that the parallel directions of the rectangular parallelepiped materials 20 intersect, thereby forming the light reflecting optical element 2. Is done. A portion where each rectangular parallelepiped material 20 of the mirror sheet 21 and each rectangular parallelepiped material 20 of the mirror sheet 22 intersect constitutes a minute mirror unit (unit optical element), and the light reflecting surface 23 of the mirror sheet 21 of each minute mirror unit is the first. The light reflecting surface 23 of the mirror sheet 22 becomes the second light reflecting surface.

  In the spatial image display device using the light reflecting optical element 2, as shown in FIG. 4, the object 1 is disposed on one surface side of the light reflecting optical element 2, and the light reflecting optical element 2 includes the object 1 from the object 1. Light is incident obliquely. The observer's eyes E are positioned on the other surface side of the light reflecting optical element 2, and a real image 3, that is, a spatial image 3 is formed at a spatial position that is plane-symmetric with the object 1 with respect to the light reflecting optical element 2. Note that the lower end A and the upper end A ′, which are both ends of the light reflecting optical element 2 in FIG. 4, correspond to the opposing angles A and A ′ of the light reflecting optical element 2 in FIG. 1. More specifically, as shown in FIG. 5, the light from the object 1 is reflected on the light reflecting surface 23 (second light reflecting surface) of the mirror sheet 22 in the direction of the arrow Y1, and the reflected light is reflected in the direction of the arrow Y2. Since the light is reflected on the light reflecting surface 23 (first light reflecting surface) of the mirror sheet 21 and the reflected light travels toward the observer in the direction of the arrow Y3, each light reflecting surface 23 of the light reflecting optical element 2 has 1 each. It is designed to create a mirror image by reflecting twice, that is, twice.

JP 2008-158114 A International Publication No. WO2009 / 136578 Pamphlet

  In a spatial image display device using a light reflecting optical element as shown in Patent Document 1 or Patent Document 2, an object 1 (for example, an image displayed on a screen of a display device) and a surface of the light reflecting optical element 2 are used. Since the spatial image 3 is formed at a symmetric space position, the object 1 does not exist in the space on one surface side of the light reflecting optical element 2 where the spatial image 3 is formed. Using this feature, when the spatial video display device is used in a desktop environment and the space on which the spatial video 3 is formed is a desktop space, it is not necessary to arrange a display device on the desk. There is an advantage that it can be used widely.

  The present invention has been made in view of the above circumstances, and as an example of the problem, by using a light reflecting optical element that forms a real image at a plane-symmetrical position, even if the display device is not arranged on a desk, An object of the present invention is to provide a desktop display system capable of displaying an image in a space on a desktop.

  In order to achieve the above object, one aspect of the present invention is a desktop display system that displays an image in a space on a desk, and is disposed as a table top in parallel to an installation surface on which the desk is installed. A light transmissive top plate having a light transmission property, a display unit that is disposed in a space below the light transmissive top plate, displays a predetermined image, and is disposed near the light transmissive top plate, A planar plate-like light reflecting optical element that reflects light from the display unit toward the space on the desk above the light transmissive top plate, and the light reflecting optical element is arranged in the thickness direction. A first light reflecting surface and a second light reflecting surface orthogonal to the first light reflecting surface, and a plurality of unit optical elements composed of the first light reflecting surface and the second light reflecting surface. Light incident from the display unit arranged on one side Each of the first optical reflecting surface and the second reflecting surface in the unit optical element is reflected once each, emitted to the other side of the plate surface, transmitted through the light transmissive top plate, The desktop display system creates a mirror image for the predetermined image as a spatial image in the space on the desk.

It is an external view of a light reflection optical element. It is an external view of the rectangular parallelepiped material which comprises the light reflection optical element of FIG. It is a figure which shows the combination of two mirror sheets which form the light reflection optical element of FIG. It is the schematic of the optical system of the spatial image display apparatus using the light reflection optical element of FIG. It is a schematic diagram which shows a mode that light reflects twice in the light reflection optical element of FIG. 1 is a side view showing a schematic configuration of a desktop display system according to an embodiment of the present invention. 1 is an external perspective view of a light reflecting optical element according to an embodiment of the present invention. FIG. 3 is a top view, a side view, and a front view of a light reflecting optical element according to an embodiment of the present invention. It is a figure which shows the horizontal angle dependence of the light utilization efficiency of the light reflection optical element which concerns on embodiment of this invention. It is a figure which shows the horizontal angle dependence of the intensity | strength of the light which injected into the transmissive screen which concerns on embodiment of this invention. It is a figure which shows the mode of the spreading | diffusion of the perpendicular | vertical direction of the light which injected into the transmissive screen which concerns on embodiment of this invention. It is a figure which shows the inclination of the up-down direction of a transmission type screen and direct view type display in case the light of the direction of L1 looks brightest. It is a schematic diagram which shows the intensity ratio of the light which comprises the space | gap image in the case where there is no light-transmitting top plate, and the reflected light by the light reflection optical element 2 of external light. It is a schematic diagram which shows the intensity | strength ratio of the light which comprises the space image in the case where there exists a light-transmissive top plate, and the reflected light by the light reflection optical element of external light. It is an external appearance perspective view of the light reflection optical element which concerns on another embodiment of this invention. It is a top view of the modification of the light reflection optical element which concerns on another embodiment of this invention. It is a top view of the modification of the light reflection optical element which concerns on another embodiment of this invention. It is a figure which shows the horizontal angle dependence of the light utilization efficiency of the modification of the light reflection optical element which concerns on another embodiment of this invention. Horizontal angle dependence of light utilization efficiency when the transmission screen shown in FIG. 10 and the light reflection optical element shown in FIG. 18 are combined, and when the transmission screen shown in FIG. 10 and the light reflection optical element shown in FIG. 9 are combined. It is a figure which shows sex. It is a modification of the desktop display system which concerns on embodiment of this invention, Comprising: It is a figure which shows the operation | movement at the time of providing the mechanism which varies the elevation angle of a space image surface. It is a modification of the desktop display system which concerns on embodiment of this invention, Comprising: It is a figure which shows operation | movement at the time of making a light reflection optical element rotatable. It is a modification of the desktop display system which concerns on embodiment of this invention, Comprising: It is a figure which shows the advancing direction of the general light at the time of using the direct-view type display equipped with the peeping prevention film. It is a side view which shows schematic structure of the desktop display system which concerns on another embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 6 is a side view showing a schematic configuration of the desktop display system 10 according to the embodiment of the present invention. The desktop display system 10 is a desk in which the top 4 is light transmissive, and has a function of displaying the spatial image 3 in the space above the top 4. The desktop display system 10 includes, as characteristic components, a light-transmitting top 4 (hereinafter referred to as a light-transmitting top 4) that is installed horizontally with respect to the ground, and a light-transmitting top 4 The display unit 1 is arranged in a lower space of the display unit 1 and can display an image. The display unit 1 is disposed below the light-transmitting top plate 4 with a slight inclination with respect to the light-transmitting top plate 4 and displayed on the display unit 1. A light reflecting optical element 2 for displaying an image as a spatial image 3 in a space above the light-transmissive top plate 4. In the present embodiment, the desktop display system 10 will be described using the directions defined in FIG.

  The display unit 1 includes a short focus type projector 11, a flat mirror 12 that reflects light emitted from the projector 11, and a transmissive screen 13 that projects light reflected by the flat mirror 12. That is, the display unit 1 projects an image on the transmissive screen 13. In the present embodiment, the image is projected onto the transmissive screen 13, but the configuration of the display unit 1 is of course not limited to this. For example, a direct-viewing type liquid crystal display may be used as the display unit 1. In this case, the direct-viewing type liquid crystal display may be disposed at the position of the transmissive screen 13. Further, a reflective screen may be used instead of the transmissive screen 13 (the projector 11 is rearranged at a suitable position with respect to the reflective screen), and the light from the projector 11 is directly projected onto the screen. Good.

  The light reflecting optical element 2 is the light reflecting optical element 2 shown in FIGS. 1 to 5 and is formed in a flat plate shape. The mirror sheet 21 and the mirror sheet 22 constituting the light reflecting optical element 2 have the same shape, and the thickness of the mirror sheet 21 and the mirror sheet 22 (the length in the short direction of the light reflecting surface 23) is uniform. It has become.

  FIG. 7 is an external perspective view of the light reflecting optical element 2, and FIG. 8 is a top view, a side view, and a front view of the light reflecting optical element 2. FIG. 7 shows the shape of the light reflecting optical element 2 when cut along a plane parallel to the left-right direction and the front-rear direction of FIG. 1 (when cut along the dotted line P of FIG. 1). Here, the directions of AA ′ shown in FIGS. 1, 6, 7, and 8 are all the same direction. Moreover, S shown in FIG.6 and FIG.8 is a design line-of-sight direction, ie, a line-of-sight direction in which the observer can see the brightest spatial image 3. In the present embodiment, the design line-of-sight direction S is the AA ′ direction (from A to A ′ of the bonding surface L of the mirror sheets 21 and 22 (the surface F of the reflective optical element 2), that is, from the front to the back. Direction seen from the top) is a direction seen obliquely from above. Hereinafter, the mirror sheet 21 is also referred to as a first mirror sheet, the mirror sheet 22 is also referred to as a second mirror sheet, the light reflecting surface 23 of the mirror sheet 21 is a first light reflecting surface, and the light reflecting surface 23 of the mirror sheet 22 is second light reflecting. Also called a surface.

  In the present embodiment, the light beam emitted from the display unit 1 enters the light reflecting optical element 2 with an inclination of approximately 45 degrees (more precisely, the light L1 transmitted through the center of the transmissive screen 13 has an incident angle of 45). The display unit 1 and the light reflecting optical element 2 are arranged so that the light reflecting optical element 2 is incident on the light reflecting optical element 2 at a degree, and the light beam emitted from the display unit 1 is the first light reflecting surface of the light reflecting optical element 2. The light is reflected once by the second light reflecting surface and then emitted in a direction symmetrical to the incident direction with respect to the light reflecting optical element 2. As a result, the light emitted from the display unit 1 is imaged at a position symmetrical to the transmission screen 13 with respect to the light reflecting optical element 2, and this becomes a spatial image 3. That is, since the upside down image of the image projected on the transmissive screen 13 is displayed as a real image in the space on the desk, the observer views the information displayed on the display unit 1 by viewing the space image 3 as the real image. Can be read.

  The light reflecting optical element 2 has an optimum incident angle of light as described above. Light having an angle greatly deviating from the optimum incident angle does not become light that is reflected once on the first light reflection surface and the second light reflection surface even when incident on the light reflecting optical element 2, but becomes stray light. Therefore, it does not contribute to the image formation of the spatial image 3. In the case of the present embodiment, the light reflecting optical element 2 is formed so that the optimum light incident angle is 45 degrees with respect to the direction perpendicular to the surface F of the light reflecting optical element 2 (see FIG. 8). ).

  FIG. 9 is a diagram showing the light utilization efficiency of the light reflecting optical element 2 (= the amount of light emitted from the light reflecting optical element 2 / the amount of incident light incident on the light reflecting optical element 2 and also referred to as transmittance). More specifically, it is a graph showing the horizontal angle dependency of the ratio of the light reflected by the mirror sheets 21 and 22 once and transmitted through the light reflecting optical element 2. The horizontal angle in the light reflecting optical element 2 refers to the angle in the left-right direction when the line of sight is shifted from the design line-of-sight direction S to the left-right direction, and the vertical angle in the reflection optical element 2 is the line of sight in the design. An angle in the vertical direction when the line of sight is shifted from the direction S in the vertical direction.

  In the graph of FIG. 9, the incident angle of 0 degrees in the horizontal direction means the design line-of-sight direction S. Therefore, in FIG. 9, when the line of sight is shifted from the design line-of-sight direction S to the left and right, the transmittance decreases. It is shown that. Specifically, when the line of sight is shifted from the designed line-of-sight direction S by about ± 10 degrees in the left-right direction, the observer has a brightness of about 60% when viewing the spatial image 3 in the designed line-of-sight direction S. You will see spatial image 3.

  Here, the transmission screen 13 of the present embodiment is a screen having angle directivity, and has a function of narrowing light diffusion to a certain angle. This is because the light emitted from the projector 11 can be observed only on the extension of the optical path connecting the projection lens of the projector 11 and the projection position, and as described above, the light reflecting optical element 2 has an optimum light beam. This is because the incident angle exists, and the incident light greatly deviates from the optimum incident angle does not contribute to the image formation of the spatial image 3, so as to correspond to two contradictory conditions. In the present embodiment, specifically, a range of up to 15 degrees with respect to the incident direction of light is sufficient in order to diffuse light in a range where the entire spatial image 3 can be seen, while minimizing the occurrence of stray light. A transmissive screen 13 is used which can obtain diffuse light with high intensity and hardly emits diffused light in a range exceeding 30 degrees with respect to the incident direction of light.

  FIG. 10 is a diagram showing a diffusion distribution of light incident on the transmissive screen 13, and more specifically, a graph showing the horizontal angle dependency of the intensity of light incident on the transmissive screen 13. The horizontal angle in the transmissive screen 13 refers to the angle in the horizontal direction with respect to the incident direction of the light incident on the transmissive screen 13, and the vertical angle refers to the vertical direction relative to the incident direction of the light incident on the transmissive screen 13. The angle.

  FIG. 10 shows that the light intensity gradually decreases as the light incident on the transmission screen 13 diffuses in the left-right direction. Specifically, the diffused light diffused by about ± 15 degrees in the left-right direction from the incident direction of the light incident on the transmissive screen 13 becomes about half the brightness of the incident light in the incident direction.

  FIG. 11 shows how the light incident on the transmission screen 13 of the present embodiment is diffused in the vertical direction. As a result, as shown in FIG. 11, the light emitted from the transmissive screen 13 diffuses and travels at a suitable angle. On the other hand, when the light passes through the light reflecting optical element 2, this time, the image forming position has a suitable angle. Convergence progresses until. Note that FIG. 11 shows how light incident on the transmission screen 13 is diffused in the vertical direction, but the same applies to the diffusion in the horizontal direction.

  Further, as shown in FIG. 6, the light reflecting optical element 2 of the present embodiment is disposed with an inclination so that the front side is slightly lowered with respect to the light-transmissive top plate 4. This is because, as described above, in the light reflecting optical element 2, the optimum light incident angle in the vertical direction is 45 degrees, and the optimum human gaze direction is slightly lower than the horizontal (direction parallel to the ground). (Specifically, a direction 15 to 40 degrees below the horizontal). That is, when the light reflecting optical element 2 is horizontally arranged on the ground, the observer's line-of-sight angle is 45 degrees downward from the horizontal direction, which is further below the optimum line-of-sight direction. By tilting the front side of the element 2 slightly downward, the observer's line-of-sight angle is adjusted to be 15 to 40 degrees downward from the horizontal direction. As a result, the direction of the line of sight when observing the spatial image 3 and the direction of the line of sight other than when observing the spatial image 3 (for example, at the time of desktop work such as reading a book or signing) are closer and less Since the desktop work can be done by moving, physical fatigue can be reduced. That is, the desktop system 10 can provide an environment in which the observation of the spatial video 3 and the desktop work can be compatible.

  Further, in the present embodiment, as shown in FIG. 6, the light emitted from the projector 11 is designed to be projected with a slight inclination in the normal m direction of the transmission screen 13. This is because the optimum line-of-sight direction when the observer observes the spatial image 3 is matched with the direction in which the spatial image 3 can be observed brightest. That is, the light emitted from the transmissive screen 13 does not depend on the inclination angle of the screen surface of the transmissive screen 13 with respect to the surface F of the light reflecting optical element 2 (hereinafter, referred to as the vertical inclination). Therefore, the vertical inclination of the transmissive screen 13 can be adjusted to the optimum line-of-sight direction when the observer observes the spatial image 3.

  As shown in FIG. 12, when a direct-view display 14 such as a liquid crystal display is used as the display unit 1, the normal direction of the display surface is the brightest direction, so that the transmissive screen 13 shown in FIG. To make the direction L1 of the light emitted from the brightest direction, the display surface of the direct-view display 14 must be further tilted downward. Accordingly, in this case, since the spatial image 3A formed by the direct-view display 14 is inclined upward as compared with the spatial image 3, the optimal viewing direction when the observer observes the spatial image 3A, and the space The direction in which the image 3A can be observed brightest does not match. Therefore, from the viewpoint of matching the optimal line-of-sight direction when observing the observer's spatial image 3 with the direction in which the spatial image 3 can be observed brightest, the display unit 1 using the projector 11 and the transmissive screen 13 is provided. Is preferred.

  Since the light-transmissive top plate 4 is disposed in parallel to the installation surface on which the desk is installed, first, it has a function as a top plate of a normal desk. At the same time, since the light-transmissive top plate 4 is formed of a black glass plate or plastic resin having a high light absorption rate, the function of eliminating the influence of reflection of external light on the surface of the light-reflecting optical element 2 (hereinafter referred to as “light-transmitting top plate 4”) The external light exclusion function).

  The outside light exclusion function of the light-transmissive top plate 4 will be described with reference to FIGS. 13 and 14. FIG. 13 is a schematic diagram showing the intensity ratio of the reflected light OL2 of the light IL2 constituting the spatial image 3 and the external light OL1 reflected by the light reflecting optical element 2 in the absence of the light transmissive top plate 4, and FIG. FIG. 10 is a schematic diagram showing the intensity ratio of the reflected light OL2 of the light IL2 constituting the spatial image 3 and the external light OL1 reflected by the light reflecting optical element 2 when there is the nature ceiling plate 4; In addition, although the transmittance | permeability of the light-transmissive top plate 4 of this Embodiment is about 2%, the value of the transmittance | permeability is not limited to this.

  When the light-transmissive top plate 4 is not provided, as shown in FIG. 13, a part of the external light OL1 incident on the light reflecting optical element 2 is part of the surface of the light reflecting optical element 2 (the edge at the upper end of the light reflecting surface 23). Therefore, in addition to the light IL2 constituting the spatial image 3, the reflected light OL2 of the light reflecting optical element 2 of the external light OL1 also enters the observer's line of sight. For this reason, it becomes difficult for an observer to focus on the spatial image 3, and as a result, it becomes difficult to recognize the spatial image 3.

  On the other hand, when there is the light transmissive top plate 4, as shown in FIG. 14, the external light OL1 incident on the light transmissive top plate 4 is transmitted through the light transmissive top plate 4, and further, a light reflecting optical element. The external light OL2 that is reflected by the surface 2 and passes through the light-transmissive top plate 4 again and reaches the observer's line of sight is that (all of the light incident on the light-reflecting optical element 2 is reflected). ) 0.04% (= 2% × 2%) of the light OL1 incident on the light-transmissive top plate 4. On the other hand, the light IL2 constituting the spatial image 3 reaching the observer's line of sight through the reflective optical element 2 and the light transmissive top plate 4 is assumed to be (all of the light incident on the light reflective optical element 2 is transmitted). ), 2% of the light IL1 emitted from the transmissive screen 13. This is because the outside light OL1 does not become the outside light OL2 that reaches the observer's line of sight unless it passes through the light transmissive top plate 4 twice, but the light IL2 emitted from the transmissive screen 13 is light transmissive top. This is because if the light passes through the plate 4 once, the light IL2 constituting the spatial image 3 is obtained. As a result, when the light transmissive top plate 4 is employed, the contrast ratio between the light IL2 and the surface reflected light OL2 constituting the spatial image 3 is increased by about 50 times compared with the case where the spatial image 3 is not employed. The observer can easily recognize the spatial image 3. As described above, in the present embodiment, by setting the light transmissive top plate 4 and lowering the transmittance of the light transmissive top plate 4, the contrast of the light constituting the spatial image 3 with respect to the external light is improved. The presence of the spatial image 3 can be increased.

  In addition, since the light-transmissive top plate 4 is subjected to an AR (anti-reflection) grade surface treatment that reduces surface reflection, the external light OL1 is reflected by the light-transmissive top plate 4 itself. Is also suppressed. Furthermore, since the light-transmissive top plate 4 is also subjected to MR grade surface treatment with high scratch resistance, it is also suitable for desktop work.

  In the present embodiment, the entire portion of the alternate long and short dash line portion below the light-transmitting top plate 4 shown in FIG. This is a countermeasure against stray light, and the influence of undesirable light (for example, light other than light constituting the spatial image 3 such as external light) caused by causes other than normal reflection and refraction of light emitted from the display unit 1 is affected. This is to eliminate it. In this way, the outside of the optical path of the light beam emitted from the projector 11 of the display unit 1 is covered with the black frame 8, and consideration is given so that external light does not enter the display unit 1. The person can easily recognize the spatial image 3.

  The configuration of the light reflecting optical element 2 is not limited to the configuration shown in FIG. 7, but is an optical that forms an entity (projected object) as a real image at a plane symmetric with respect to the light reflecting optical element. Any configuration may be used as long as it is an element. For example, the configuration of the light reflecting optical element shown in Patent Document 1 may be used. FIG. 15 is an external perspective view of such a light reflecting optical element 5. More specifically, the light reflecting optical element 5 includes a plurality of holes 52 penetrating a predetermined base 51 in the thickness direction, and is a unit optical unit composed of two specular elements 54 a and 54 b orthogonal to the inner wall of each hole 52. The element 53 is formed, and when light is transmitted from one surface direction to the other surface direction of the base 51 through the hole, the light is reflected once by the two mirror surface elements 54a and 54b. Also good. Further, as disclosed in Japanese Patent Application Laid-Open No. 58-21702, two sets of imaging elements each having a double-sided reflection band arranged in parallel are combined so that the respective reflection bands are orthogonal to each other. It is good also as a light reflection optical element comprised so that it might become a grating | lattice.

  Further, when the light reflecting optical element 5 is used, the arrangement of the unit optical elements 53 may be devised in order to further widen the viewing angle with respect to the spatial image 3. FIGS. 16 and 17 are top views showing the appearances of light reflecting optical elements 5A and 5B, which are modifications of the light reflecting optical element 5, respectively. The light reflecting optical element 5A includes two unit optical elements 53 as one set, and each unit from the reference direction (specifically, the AA ′ direction shown in FIG. 6) in the surface of the light reflecting optical element 5A. The optical element 53 is formed by giving a rotational angle deviation of ± 10 degrees in the diagonal direction including the intersection of the specular elements 54a and 54b. As a result, in the light reflecting optical element 5A, the peak value of the maximum luminance of the spatial image 3 is lowered, but the maximum luminance of the spatial image 3 is secured in the P1 and P2 directions that are slightly shifted in the left and right directions from the AA ′ direction. The brightness of the spatial image 3 can be ensured with respect to the horizontal direction (the left-right direction in FIG. 6) of the light reflecting optical element 5A.

  FIG. 18 is a diagram showing the light utilization efficiency of the light reflecting optical element 5A. More specifically, the light reflecting optical element 5A is reflected once by the mirror elements 54a and 54b of the unit optical element 53 and then transmitted through the light reflecting optical element 5A. It is a graph which shows the horizontal angle dependence of the ratio of light. Compared with the horizontal angle dependency of the transmittance of the light reflecting optical element 2 shown in FIG. 9, the brightness when the spatial image 3 is viewed in the design viewing direction S is reduced, but the design viewing Brightness maximum points appear in the line-of-sight directions shifted ± 10 degrees in the left-right direction from the direction S, and the brightness of the spatial image 3 with respect to the horizontal direction (left-right direction in FIG. 6) relative to the light reflecting optical element 2. It can be seen that is secured.

  FIG. 19 is a graph showing the light utilization efficiency of the light reflecting optical element 5A when the transmissive screen 13 having the horizontal angle dependency of FIG. 10 and the light reflecting optical element 5A shown in FIG. 18 are combined. 10 is displayed in comparison with the light utilization efficiency of the light reflecting optical element 2 in the case where the transmissive screen 13 having the horizontal angle dependency of FIG. 10 and the light reflecting optical element 2 shown in FIG. 9 are combined. Here, the bidirectional element shown by the solid line in FIG. 19 shows the case where the light reflecting optical element 5A is used, and the unidirectional element shown by the dotted line shows the case where the light reflecting optical element 2 is used. FIG. 19 shows that when the light reflecting optical element 5A is used, a spatial image 3 having a substantially constant brightness can be obtained in the line-of-sight direction within ± 10 degrees from the design line-of-sight direction S in the left-right direction. Show.

  The light reflecting optical element 5B includes three unit optical elements 53 as one set, and from the reference direction (specifically, the AA ′ direction shown in FIG. 6) in the surface of the light reflecting optical element 5B. The unit optical element 53 is formed with a rotational angle deviation of 0 degrees and ± 30 degrees in the diagonal direction including the intersection of the mirror elements 54a and 54b. When the light reflecting optical element 5B is used, the brightness of the spatial image 3 can be secured further in the horizontal direction (left and right direction in FIG. 6) than when the light reflecting optical element 5A is used. In this way, when a plurality of unit optical elements 53 are set as one set and a rotation angle deviation is given to each unit optical element 53 from the reference direction, even if the line of sight is shifted from the reference direction to the left and right directions, Since the change in the brightness of the spatial image can be reduced, a wide viewing angle for viewing the spatial image 3 can be taken. That is, the light reflecting optical elements 5A and 5B are suitable for viewing a large spatial image 3 from a wide range.

  In the above embodiment, the plane of the spatial video 3 (hereinafter referred to as the spatial video plane) is formed so as to be optimal in the observer's line-of-sight direction, but the elevation angle of the spatial video plane is the observer. Therefore, a mechanism for changing the elevation angle of the spatial image plane may be provided. When such a mechanism is provided, an effect of further reducing the physical fatigue of the observer can be expected.

  FIG. 20 is a diagram illustrating the inclination of the spatial image 3 when the elevation angle of the spatial image plane is varied by varying the vertical tilt angle of the transmissive screen 13. As shown in FIG. 20, when the transmissive screen 13 is rotated in the clockwise A1 direction, the spatial image plane is rotated in the counterclockwise B1 direction. When 13 is rotated in the counterclockwise direction A2, the spatial image plane rotates in the clockwise B2 direction, so that the spatial image plane gradually falls down. In this manner, the elevation angle of the spatial image plane may be made variable in accordance with the viewer's preference.

  Furthermore, in the above-described embodiment, the installation position of the light reflecting optical element 2 is fixed, but the inclination angle of the surface F of the light reflecting optical element 2 with respect to the light transmitting top plate 4 (inclination angle in the vertical direction) is set. It may be variable. In other words, it has been described that the optimal human eye-gaze direction is slightly below the horizontal (specifically, 15 to 40 degrees below the horizontal). Since there are individual differences, it may be possible to adjust the line-of-sight direction optimal for each observer.

  FIG. 21 is a diagram showing the position of the spatial image plane when the vertical tilt angle of the light reflecting optical element 2 is varied. In this case, as shown in FIG. 21, when the light reflecting optical element 2 is rotated in the clockwise A1 direction, the spatial image plane is rotated in the clockwise C1 direction. When the light reflecting optical element 2 is rotated in the counterclockwise A2 direction, the spatial image plane rotates in the counterclockwise C2 direction. The position moves downward, and the downward line-of-sight direction has a gentle inclination.

  When the direct-view display 14 is used as the display unit 1, a peeping prevention film may be attached to the screen so that the light diffusion angle is narrowed. FIG. 22 is a diagram illustrating a schematic configuration and a light traveling direction when a direct-view display 14 equipped with a peep prevention film is used as the display unit 1. As described above, when the direct-view display 14 is used as the display unit 1, the stray light in the light reflecting optical element 2 is reduced by sticking the peeping prevention film to the display surface, and the spatial image 3 is imaged. More light may be contributed. In addition, as a more effective use of the peep prevention film, it is preferable to affix it to the light transmissive top plate 4. This is because stray light is generated in the light reflecting optical element 2 as described above, and it is preferable to control the light diffusion angle directly with respect to the light emitted from the light reflecting optical element 2. Further, when the peep prevention film is used for the light transmissive top plate 4, the configuration of the display unit 1 is not limited to the direct view type display 14.

  A sensor capable of detecting the observer's hand in the vicinity of the position where the spatial image 3 is displayed may be provided. FIG. 23 is a side view showing a schematic configuration of the desktop display system 30 when such a sensor 6 is provided. The sensor 6 is, for example, an infrared sensor provided immediately below the transmissive top plate 4 and detects the presence of an object in the vicinity region N of the spatial image 3. When the sensor 6 detects a predetermined object (for example, a hand when the observer performs an action of reaching for the spatial image 3), an image for controlling the image displayed on the display unit 1 A detection signal may be output to the control unit 7, and the video control unit 7 may control the content of the video in accordance with the detection signal. Thereby, it is possible to provide an interactive spatial image 3 according to the act of the observer.

  As described above, according to the above-described embodiment, it is possible to display an image in a space on a desktop without using a display device on a desk by using a light reflecting optical element that forms a real image at a plane-symmetric position. So you can get the effect of using the desk widely. In addition, since the spatial video 3 can be displayed in the line-of-sight direction optimal for the observer, desktop work can be performed comfortably.

  Therefore, the desktop system according to the above embodiment can be applied to various desks such as an OA desk, a conference table, a window reception desk, a guidance table in a station, a museum, and the like. In addition, since the spatial image itself is not accompanied by an entity (because the spatial image is displayed separately from the display unit that is the entity), it can also be used for evacuation guidance display and display in poor environments where contamination and theft are a concern. Is preferred. Furthermore, since the spatial image is visible only from a limited line-of-sight direction, it can also be applied to information display such as a device that needs to prevent peeping from the surroundings, such as a cash dispenser.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made to the embodiments of the present invention without departing from the gist of the present invention. Such modifications and changes can be made, and those accompanying such modifications and changes are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Display part 2, 5, 5A, 5B Light reflection optical element 3 Spatial image (real image)
6 Sensor 7 Video Control Unit 8 Frame 10, 30 Desktop Display System 11 Projector 12 Flat Mirror 13 Transmission Screen 14 Direct View Display 20 Rectangular Solid Material 21, 22 Mirror Sheet 23 Light Reflecting Surface

Claims (8)

A desktop display system for displaying images in a space on a desk,
As a desk top plate, a light transmissive top plate that is arranged in parallel to the installation surface on which the desk is installed and has light transmission,
A display unit disposed in a space below the light-transmissive top plate and displaying a predetermined image;
A flat plate-like light reflecting optical element that is disposed near the light-transmitting top plate and reflects light from the display unit toward the space on the desk above the light-transmitting top plate;
With
The light reflecting optical element is
A second light reflecting surface which is perpendicular to the first light reflecting surface and the first light reflecting surface in the thickness direction, a plurality comprises a configured unit optical element by the first light reflecting surface and the second light reflective surface The light incident from the display unit arranged on one side of the plate surface is reflected once on each of the first light reflection surface and the second light reflection surface in the predetermined unit optical element. Emanating to the other side of the plate surface, passing through the light transmissive top plate, creating a mirror image for the predetermined image as a spatial image in the space on the desk,
The plate surface of the light reflecting optical element is disposed to be inclined with respect to the light transmissive top plate ,
The light reflecting optical element is
Comprising a plurality of group optical elements configured by combining a plurality of predetermined unit optical elements;
Each of the plurality of unit optical elements constituting the group optical element is
A desktop display system regularly arranged in a direction rotated by a predetermined angle from a reference direction within the plate surface of the unit optical element .   2. The desktop display system according to claim 1, wherein the light transmissive top plate is formed of a glass plate or a resin plate having a characteristic of absorbing a part of incident light and transmitting a remaining part of the incident light.   The desktop display system according to claim 1, further comprising a variable mechanism that varies an inclination angle of the plate surface of the light reflecting optical element with respect to the light transmissive top plate. The desktop display system according to any one of claims 1 to 3 , wherein the display unit has a restriction on a radiation angle of light emitted from the display unit. A sensor unit that detects the presence of a predetermined object that has entered a region near the display position of the spatial image;
A video control unit for controlling video displayed on the display unit according to the detection content of the sensor unit;
The desktop display system according to any one of claims 1 to 4 , further comprising: 6. The desktop display according to claim 1 , further comprising a variable mechanism configured to vary a tilt of an image plane of the predetermined image displayed by the display unit with respect to the plate surface of the light reflecting optical element. system. The light transmissive top plate is
The desktop display system according to any one of claims 1 to 6 , wherein at least one of a scratch-resistant surface treatment and a surface reflection reduction treatment is performed. The desktop display system according to any one of claims 1 to 7 , further comprising a black frame body that covers an outside of an optical path of light emitted from the display unit in a lower space of the light transmissive top plate.

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