JPWO2013118698A1 - 3D image projector - Google Patents

Abstract

A three-dimensional image projection apparatus that reduces a lack of a three-dimensional image of an object is provided. SOLUTION: First reflection means configured to reflect light from a virtual point light source placed at its first focus as parallel light, and configured to focus the parallel light to its second focus. Second reflecting means, and the first and second reflecting means are arranged so that the focal point of one reflecting means coincides with the center point of the other reflecting means, and the first reflecting means is at least partially A three-dimensional image of an object disposed inside the first and second reflecting means through the semi-transmissive region. Projecting outside of one reflecting means. [Selection] Figure 1

Description

  The present invention relates to a stereoscopic image projection apparatus, and more particularly to a stereoscopic image projection apparatus capable of projecting an image of an object placed inside the apparatus to the outside of the apparatus.

  Conventionally, as an object image can be projected three-dimensionally, two opposing reflecting mirrors having curved surfaces are matched with a clam type, and the object placed inside at the opening of the upper reflecting mirror Is known (see, for example, Patent Document 1). In such an apparatus, light from an object is reflected by the upper reflecting mirror, then reflected by the lower reflecting mirror, and passes through an opening provided in the upper reflecting mirror to form an image on the opening. Is. According to this apparatus, the observer can appreciate a three-dimensional image of the object projected on the opening, and is mainly used as a toy or a decoration.

US Pat. No. 3,647,284

  The apparatus described in Patent Document 1 passes an opening provided in the upper reflecting mirror and forms an image on the opening. Therefore, depending on the angle (elevation angle) of the observer's viewpoint, Some or all of them may be missing, and the observable elevation range is limited. Further, when the viewpoint moves in the elevation angle direction, the continuity of the image is not maintained, and it is easily understood that the image is not the object itself.

  In such an apparatus, an opening is usually provided near the center of the upper reflecting mirror, and it is necessary to place the object near the center of the lower reflecting mirror. If the object is placed at a position off the center of the lower reflecting mirror, the light for combining the real images will be reflected in the region that is not the opening, and the image could not be projected. As described above, in the conventional apparatus, the placement position of the object is restricted near the center of the lower reflecting mirror. Furthermore, in the case of an object larger than the diameter of the opening, the entire image cannot be projected, and a part thereof may be lost.

  In addition, when the opening is looked into from above, the object body can be visually recognized. Furthermore, the object may be exposed to the outside air, moisture, ultraviolet rays, or the like through the opening, and the object may be deteriorated or damaged. Further, since the object can be touched and taken out easily, there is a risk of theft if it is a valuable item.

  Further, in the conventional apparatus, the object is merely placed near the center of the lower reflecting mirror and is not fixed. Therefore, it is necessary to keep the apparatus horizontal so that it does not roll. For this reason, this apparatus is not suitable for the use installed diagonally or on a wall. Furthermore, since the object is simply placed on the lower reflecting mirror surface in a stationary state, it is not suitable for the purpose of dynamically projecting the object. In order to appreciate the entire circumference of the object image, the observer needs to move around the device.

  An object of the present invention is to provide a three-dimensional image projection apparatus that can solve at least a part of the problems described above.

  In order to solve the above-described problem, a stereoscopic image projection apparatus according to the present invention is parallel to first reflecting means configured to reflect light from a virtual point light source placed at its first focal point as parallel light. Second reflecting means configured to focus the light on its second focal point, the first and second reflecting means such that the focal point of one reflecting means coincides with the center point of the other reflecting means. The first reflecting means has a semi-transmissive region that reflects at least a part of the light and transmits the other part, and is disposed inside the first and second reflecting means. A three-dimensional image of the object is projected outside the first reflecting means through the semi-transmissive region.

  In the stereoscopic image projection apparatus, the first and second reflecting means are preferably parabolic mirrors having a predetermined focal length. The semi-transmissive region is preferably formed by a half mirror.

  The stereoscopic image projection apparatus further includes an illuminating unit capable of irradiating the first polarized wave, and the semi-transmissive region of the first reflecting unit reflects the first polarized wave and is the second polarized light orthogonal to the first polarized wave. Preferably, the second reflecting means has a quarter wave plate layer on the inner surface side of the reflecting layer.

  In the stereoscopic image projection apparatus, it is preferable that the first and second reflecting means are configured by a holographic optical element having the same optical characteristics as a parabolic mirror. Preferably, the first and second reflecting means are each formed in a flat plate shape. Further, each of the first and second reflecting means has side surfaces that become wider toward the other reflecting means, and the maximum lateral width of the first and second reflecting means is the focal length of the first and second reflecting means. Shorter than that.

  Furthermore, in the stereoscopic image projection apparatus, it is preferable that the semi-transmissive region is formed in a part of a circle or a polygon including the center point of the first reflecting means. The semi-transmissive region may be formed on the entire first reflecting means.

  The stereoscopic image projection apparatus preferably includes mounting means for mounting the object. It is preferable that the above-mentioned placing means is removably attached to the opening of the second reflecting means and has a process of reflecting light on the inner surface. It is preferable to provide a driving means for driving the object. It is preferable that the housing including the first and second reflecting means can be sealed.

  According to the present invention, the reflecting means on the upper side of the stereoscopic image projector has no physical opening and forms an image outside the semi-transmissive region provided in the first reflecting means. Even if it moves (in the elevation direction), the image is less chipped, the continuity of the image can be maintained as compared with the conventional case, and the internal object becomes difficult to see. Furthermore, since the object is not exposed to the outside air, moisture, ultraviolet rays, etc. through the opening, it is possible to suppress the deterioration and damage of the object, and since the first reflecting means has no opening, Since it cannot be directly touched or taken out, the safety of the object can be improved. In addition, the semi-transmissive region can be configured with an appropriate size, arrangement, and shape, and the degree of freedom in designing the size, arrangement, shape, and the like of the device is increased. Other effects will be described in the mode for carrying out the invention.

1 is a schematic configuration diagram of a stereoscopic image projection apparatus according to a first embodiment of the present invention. (A), (B), and (C) are examples of the structure of a semi-transmissive region. Schematic configuration diagram of a stereoscopic image projection apparatus according to a second embodiment of the present invention. Schematic configuration diagram of a stereoscopic image projector according to a third embodiment of the present invention. (A), (B), and (C) are examples of the shape of a housing. Schematic configuration diagram of a stereoscopic image projector according to a fourth embodiment of the present invention. An example of the curved shape of a parabolic mirror An example of the overall structure of the enclosure

[Outline of the present invention]
The present invention can project a real image of an object stored inside the housing to the outside of the housing without providing a physical opening at the projection position, and can allow a viewer to appreciate a stereoscopic image. A stereoscopic image projection apparatus. The stereoscopic image projection apparatus of the present invention includes at least a first reflecting means 1 having a semi-transmissive region 2 and a second reflecting means 4 (see FIGS. 1, 3, 4, 6, and 8). Hereinafter, the direction in which the other reflecting means is located is referred to as the inside, and the opposite direction is referred to as the outside.

  The first reflecting means 1 is configured to reflect the light 15 from the virtual point light source placed at its first focal point F1 as parallel light 16, and at least part of the first reflecting means 1 A semi-transmissive region 2 formed so as to reflect a part and transmit the other part is formed. The second reflecting means 4 is configured to focus the parallel light from the first reflecting means on its second focus F2.

  Each of the reflecting means 1 and 4 may be constituted by, for example, a parabolic mirror (see the first and second embodiments), or holographic optics having an action (optical characteristics) equivalent to that of the parabolic mirror. You may comprise by the element (HOE: Holographic Optical Element) (refer 3rd and 4th embodiment). In addition, any one of the reflecting means can be constituted by a parabolic mirror, and the other reflecting means can be constituted by a holographic optical element.

Here, the parabolic mirror used in the present invention means that a parabola represented by the equation y = x ² / 4f (focal point: F (0, f)) is rotated around its axis of symmetry (in this case, the y axis). It is a reflecting mirror (refer FIG. 7) containing the paraboloid shape formed with the curved surface made to. The distance between the parabola vertex O (0,0) and the focal point F (0, f) on the axis of symmetry is the focal length f of the parabola. However, as the first and second reflecting means of the present invention, it is preferable that all of them have a paraboloid shape, but it is sufficient that at least a part thereof has a paraboloid shape. For example, the center of the second reflecting means may be a plane in order to facilitate the mounting of the object or ensure stability, or the paraboloid to correct the aberration with reference to the parabola shown by the above equation. It may be a curved surface whose shape is slightly changed. When a virtual point light source is placed at a focal point F that defines the paraboloid in the parabolic mirror, the parabolic mirror has an action of reflecting light from the point light source to make parallel light. In other words, the parabolic mirror has an action of reflecting and collimating the parallel light toward the focal point F when parallel light with respect to the symmetry axis is incident.

  In addition, the holographic optical element is an optical element that utilizes the optical characteristics (angle selectivity, diffraction efficiency, wavelength selectivity, etc.) of the hologram, and by appropriately setting the diffraction efficiency and angle selectivity in each hologram. An optical element in which the reflection direction of light rays, the transmittance, and the like that are different for each position can be configured. The holographic optical element used as the first reflecting means corresponds to the focal point F1 of the first reflecting means 1 (the focal point F1 of the parabolic mirror 1), similarly to the first parabolic mirror 1 (see FIG. 1). The light 15 spreading from the virtual point light source placed on () can be reflected into the parallel light 16. Further, the holographic optical element used as the second reflecting means 4 is similar to the second parabolic mirror 4 (see FIG. 1), and the parallel light 16 is converted into the focal point F2 (parabolic mirror) of the second reflecting means 4. 4) (corresponding to a focal point F2 of 4). For example, the holographic optical element uses a thin Lippmann (reflective) hologram that forms a hologram by interfering with light from a point light source located at the inner focal position and parallel light from the outside. can do. The holographic optical element can be designed relatively freely in shape and size as compared to a parabolic mirror, and can have various shapes such as a flat plate shape, curved surface shape, half barrel shape, and truncated cone shape. Can do.

  The semi-transmissive region 2 has a function of reflecting a part of light and transmitting the other part, and is constituted by, for example, a half mirror, a polarizing element that passes only a specific polarized wave, or a holographic optical element. can do. Here, the half mirror which forms the semi-transmissive region of the present invention is not limited to the one having the same transmittance and reflectance (50%: 50%), and the material and thickness of the reflective layer, and the insertion of the absorption layer In which the transmittance and the reflectance are appropriately set. The holographic optical element can appropriately set the transmittance by setting the diffraction efficiency, and can be processed into both a planar shape and a curved surface shape. The semi-transmissive region 2 of the present invention may be provided at least in part of the first reflecting means, and the entire first reflecting means may be the semi-transmissive region 2. Moreover, when providing the translucent area | region 2 of this invention in a part of 1st reflection means, the range, arrangement | positioning, shape, quantity, etc. can be set arbitrarily. The ratio between the transmittance and the reflectance of the semi-transmissive region 2 is influenced by the type and light amount of the light source to be used, the brightness outside the apparatus, etc., but the transmittance may be in the range of 5% to 95%. preferable.

  In the present invention, it is preferable to form the casing by combining the first reflecting means 1, the second reflecting means 4, and the casing member 7 as necessary. It is preferable that the housing does not have a physical opening in the combined state so that the object 20 can be stored therein and the object 20 cannot be visually recognized and taken out from the outside. Moreover, it is more preferable that the container be a sealed container that can block outside air, moisture, ultraviolet rays, moisture, and the like. The housing member 7 may be configured to connect the periphery of the first reflecting means 1 and the periphery of the second reflecting means 4, and the first reflecting means 1 and the second reflecting means 4 are arranged in a predetermined arrangement. Can be fixed.

  Furthermore, the three-dimensional image projector of the present invention may appropriately include a mounting unit 8 for mounting the object 20, a driving unit 9 for driving the object 20, an illumination unit 10 for irradiating light inside the housing, and the like. .

  The placing means 8 fixes the object 20 to the first reflecting means and the second reflecting means 4, and is configured to be attachable to the inner surface of the second reflecting means 4 by screws, fitting means, or the like. However, more preferably, it is preferably configured to be detachably attached to an opening provided in a part of the second reflecting means 4 by a screw or a fitting means. When the mounting means 8 is attached to the opening of the second reflecting means 4, the mounting means 8 in the attached state is reflected on the inner surface of the mounting means 8 so as to be reflected integrally with the second reflecting means 4. It is preferable to provide a reflective layer, and it is more preferable that the reflective layer has an optical characteristic that focuses parallel light to the second focal point F2.

  Moreover, when using a magnet for the mounting means 8, the target object which has magnetism can also be hold | maintained non-contactingly with the magnetic force from the mounting means set | placed outside the housing. In this case, it is possible to hold using the attractive force of the magnet, or to float using the repulsive force. Furthermore, the mounting means can be made to be a magnetic body and can be held inside the housing by a magnetic force from an external magnetic body. In these cases, the second reflecting means may not be provided with an opening for attaching the placing means.

  The drive means 9 includes a drive unit that drives the object 20, such as a rotary motor, an actuator, a blower fan, a fluid blowing nozzle, and a screw, and a power source that supplies power to the drive unit, such as a power source and a battery. It has. The drive means 9 may be configured to provide a drive unit inside the object 20, provide a power source outside the housing, and drive the object by power supplied from the outside, or hold the object. A driving unit may be provided in the mounting means to be fixed, and a power source may be provided outside the mounting means or other casing to drive the object. In the latter case, the object may be operated by driving the mounting means itself that holds and fixes the object, or the object may be operated while the mounting means is fixed. Since the moving object 20 can be projected by the driving means, an impressive and effective image can be given to the observer.

  The illuminating means 10 illuminates the interior of the housing and supplies light to the object 20, a lighting window for taking natural light into the interior of the housing, a light source for irradiating light from the outside of the housing through a semi-transmissive region, and the housing It can be configured by white light, a light source that generates a specific wavelength or a specific polarized wave, and the like installed therein. When a lighting window is provided in the housing as an illuminating device, a transparent region such as an opening or glass may be provided in a part of the first reflecting device 1, the second reflecting device 4, or the housing member 7, but it affects the projection. In order to avoid this, it is preferable to provide the housing member 7. When the light source is installed inside the housing, the light source may be attached to the inside of the first reflecting means 1, the second reflecting means 4, or the housing member 7, but the housing member 7 does not affect the projection. It is preferable to provide in. Moreover, when installing a light source inside a housing | casing, it may be comprised integrally with a mounting means or a drive means, and the light source which illuminates a target object from the downward direction may be sufficient. In this case, the power supply cable may be connected to the object main body via a mounting means or the like, and the object having transparency may be configured to emit light.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following examples.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram of a stereoscopic image projection apparatus according to a first embodiment of the present invention. The present embodiment is an example in which parabolic mirrors are employed as the first reflecting means and the second reflecting means. The first reflecting means 1 (hereinafter also referred to as a parabolic mirror 1) has a vertex O1 that is an intersection with the symmetry axis of the paraboloid and a focal point F1 of the paraboloid. Similarly, the second reflecting means 4 (hereinafter also referred to as a parabolic mirror 4) has a vertex O2 that is an intersection with the axis of symmetry of the paraboloid and a focal point F2 of the paraboloid.

  When a virtual point light source is placed at its own focal point F1, the parabolic mirror 1 can reflect the light 15 from the point light source to form parallel light 16 parallel to the symmetry axis L. The parabolic mirror 4 can reflect the parallel light 16 from the parabolic mirror 1 to form a focused light 17 toward the focal point F2 of itself.

  The focal length of the parabolic mirror 1 (distance from the vertex O1 to the focal point F1) is preferably equal to the focal length of the parabolic mirror 4 (distance from the vertex O2 to the focal point F2). When each parabolic mirror is arranged so that the focal point of one parabolic mirror coincides with the apex of the other parabolic mirror, the symmetry axes L of the parabolic mirrors coincide with each other as shown in the figure. The length of the axis L is the focal length of each parabolic mirror. Since the focal length and the sum of the heights of the parabolic mirrors may not coincide with each other, a housing member 7 is provided in a gap between the parabolic mirrors, so that the parabolic mirror and the housing You may comprise the housing which consists of the member 7. FIG.

  The first reflecting means 1 is formed with a semi-transmissive region 2 that reflects a part of light and transmits another part of light. This semi-transmissive region 2 preferably includes the center of the first reflecting means 1 or the focal point of the second reflecting means 4. Since the light 17 reflected by the second reflecting means 4 reaches the outside of the housing through the semi-transmissive region 2, according to the stereoscopic image projector, the image of the object 20 placed in the vicinity of the focal point F1. 30 can be projected in the vicinity of the focal point F2.

  The semi-transmissive region 2 can be configured by a half mirror. However, the present invention is not limited to this, and a polarizing element (a light source using a specific polarized wave is necessary separately), a holographic optical element, and the like can be used. The semi-transmissive region 2 also preferably has an action (optical characteristic) equivalent to that of a parabolic mirror. When a half mirror is employed, a semi-transmissive layer may be vapor deposited instead of the reflective layer in the member of the reflecting means, so that it can be formed at low cost. However, direct light from the internal object may also be transmitted, and the observer may be able to directly view the object placed inside. The range, arrangement, shape, and quantity of the semi-transmissive region 2 can be set as appropriate.

  FIG. 2 shows an example of the formation range of the semi-transmissive region 2. FIG. 2A shows an example in which a circular semi-transmissive region 2a is provided in the vicinity of the center point O1 (the apex of the paraboloid) of the first reflecting means 1. FIG. 2B is an example in which a semi-transmissive region 2 b is provided on the entire surface of the first reflecting means 1. FIG. 2C is an example in which a plurality of semi-transmissive areas having an arbitrary shape are provided without including the center point O1 of the first reflecting means 1, and a rectangular semi-transmissive area 2c and a circular semi-transmissive area are provided. The region 2d is disposed at a position of 90 degrees with respect to the center point O1.

  In the example of FIG. 2A, in the first parabolic mirror 1, instead of the conventional opening, a circular semi-transmissive region 2a is formed by a half mirror, so that the observer is inside the housing as compared with the conventional case. There is little risk of directly observing the object. In addition, you may comprise not only a circle but a rectangular semi-transmissive area | region. In the example of FIG. 2B, since the semi-transmissive region 2b is provided on the entire surface of the first parabolic mirror 1, the image 30 of the object can be projected on any position on the housing. That is, conventionally, an opening is provided near the center of the upper reflecting mirror, and it has been necessary to place the object near the center of the lower reflecting mirror. In the present embodiment, however, the first The entire surface of the parabolic mirror 1 is a semi-transmissive region 2b, and the object 20 can be placed at an appropriate position on the second parabolic mirror 4. However, there is a possibility that the internal object body can be visually recognized from any viewpoint. In the example of FIG. 2C, the first parabolic mirror 1 is provided with a rectangular semi-transmissive region 2 c and a circular semi-transmissive region 2 d that do not include the center point O <b> 1, and corresponding positions of the parabolic mirror 4. It is possible to simultaneously project images of a plurality of objects placed on the. In this case, if a plurality of semi-transmissive regions are formed symmetrically with respect to the center point O1, image formation may be insufficient due to light interference. On the other hand, it may be formed asymmetrically. In FIGS. 2A to 2C, rectangular and circular semi-transmissive regions are configured, but the present invention is not limited to this. The semi-transmissive region may be a polygon, an ellipse, or a combination of various figures.

  Returning to the description of FIG. 1, the three-dimensional image projector according to the present embodiment is not only a case main body constituted by the first parabolic mirror 1 and the second parabolic mirror 4 (and the member 7 for the case), but also a target. A mounting means 8 for mounting the object 20, a driving means 9 for driving the object 20 via the mounting means 8, an illuminating means 10 for illuminating the inside of the housing, a support member 11 for supporting the housing body, and the like. May be.

  The mounting means 8 may be attached to the second reflecting means with an opening, or may be configured to be removable. It is preferable that the mounting means 8 is subjected to surface processing and, when attached, is integrated with the second reflecting means so as not to prevent light reflection inside the housing. As a result, it is possible to reduce chipping of the projected image. As shown in FIG. 2C, when a plurality of semi-transmissive regions are provided, a plurality of mounting means 8 may be provided at corresponding positions.

  For the mounting means 8, a holding base, a shaft, a knob (including a magnet) or the like that can fix or semi-fix the object 20 can be used. Moreover, you may use the bowl in which a target object can roll, the container in which the liquid is stored or enclosed. A rotary motor, an actuator, a blower fan, a fluid spray nozzle, a screw, or the like can be used for the drive unit of the drive unit 9. The object may be operated by driving the mounting means itself that holds and fixes the object, or the object may be operated while the mounting means is fixed. Further, a drive unit may be provided in the object body, and the object may be driven by electric power supplied from outside the housing.

  The movement of the object is not particularly limited. For example, rotational movement, vertical movement, forward / backward / left / right movement, rocking movement, partial movement (for example, movement of a doll waving), vibration (for example, Ripples of waves), floating (using electromagnetic force, compressed air jets, etc.), swimming (for example, a model swimming underwater), and the like. In addition, in FIG. 1, although the mounting means 8 and the drive means 9 are described separately, both may be integral structures.

  The illuminating means 10 is a light source to which electric power is supplied via a side portion (a member 7 for the casing) in the casing and illuminates the inside of the casing. However, the present invention is not limited to this, and it may be a simple daylighting window or an electric lamp that irradiates light through a semi-transmissive region. Further, it may be a light source configured integrally with the placing means or the driving means and illuminating the object from below. Further, the power supply cable may be connected to the object main body via a placing means or the like so that the transmissive object itself emits light.

  As described above, according to the present embodiment, the first reflecting means 1 is provided with the semi-transmissive region 2 that transmits a part of the light from the inside. A real image 30 of the object 20 stored inside can be projected outside the housing.

  Since the semi-transmissive region that transmits the light 17 for forming the image of the object in the first reflecting means can be configured with an appropriate size, arrangement, and shape, the observation direction of the observer (the elevation angle θ direction) ) Changes, the image lacks and the image continuity can be maintained. In addition, since the semi-transmissive region can be appropriately arranged, restrictions on the arrangement and shape of the object can be reduced.

  Furthermore, since there is no physical opening on the upper surface (first reflecting means) of the housing, it is difficult for the observer to see the object body directly. The observer appreciates the stereoscopic image 30 that emerges outside the housing of the stereoscopic image projection device, without being aware of the internal object, as compared with the conventional projection device having the opening of the reflecting means. Can do.

  Since the object can be held by appropriate mounting means, the housing apparatus of the stereoscopic image projection apparatus can be installed in any orientation (posture). In addition, when the driving means is provided, it is possible to project a dynamic object, so that an impressive and effective advertisement that attracts the viewer's attention can be expected.

  If the housing of the 3D image projection device is sealed, the objects stored inside (for example, precious metals, souvenirs, important materials, cultural assets, etc.) will be affected (deteriorated or damaged) by the external environment. , Submersion, theft, etc.). Further, since the reflecting means is constituted by a parabolic parabolic mirror, the structure of the projection apparatus is simple and can be realized at low cost.

[Embodiment 2]
FIG. 3 is a schematic configuration diagram of a stereoscopic image projection apparatus according to the second embodiment of the present invention. This embodiment is an example in which the semi-transmissive region 2 of the first reflecting means 1 is configured by a polarizing element. The stereoscopic image projection apparatus further includes an illuminating unit 10 that irradiates a specific polarized wave, and forms a semi-transmissive region 2 by a polarizing element on the entire surface of the first reflecting unit 1. Two layers of the quarter-wave plate 6 and the reflective layer 5 are formed in this order from the inside toward the outside. In the present embodiment, the polarizing element as the semi-transmissive region is provided on the entire surface of the first reflecting means 1, but the present invention is not limited to this. A part of the first reflecting means 1 may be constituted by a polarizing element, and the remainder may be constituted by a reflective layer. Hereinafter, description of the same configuration as that of the first embodiment will be omitted.

  For example, a wire grid can be used as the polarizing element. The wire grid has a function of reflecting a first polarized wave (for example, P wave) parallel to the wire and transmitting a second polarized wave (for example, S wave) perpendicular to the wire, and functions as a polarizing filter. It is. Further, since the wire grid can be bent, it can be used for a curved surface shape.

  The illumination unit 10 generates a first polarized wave (for example, a P wave) by allowing light from the light source to pass through a polarization filter (not shown). In FIG. 2, the illumination unit 10 is disposed inside the driving unit 9, and light of the first polarized wave (P wave) is supplied from the center point O <b> 2 of the second reflecting unit 4 through the mounting unit 8 into the housing. Since the light of the first polarized wave (P wave) is parallel to the wire grid, it is reflected by the first reflecting means 1 to become parallel light 16. When the parallel light 16 passes through the quarter-wave plate 6, the linearly polarized P wave becomes circularly polarized light, is reflected by the reflective layer 5, and passes through the quarter-wave plate 6 again, the circularly polarized light is The second polarized wave (S wave) is linearly polarized light orthogonal to the first polarized wave. Since the second polarized wave 17 is perpendicular to the wire grid, it passes through the wire grid and forms an image at the focal point F2. As shown in FIG. 1, the illumination means 10 can be provided on the side of the enclosure via the enclosure member 7 or via the first or second reflection means if it can irradiate a specific polarized wave. It is good also as a structure to provide.

  Therefore, according to the present embodiment, the semi-transmission region on the first reflecting means side is constituted by the wire grid, and the wave plate is constituted on the second reflecting means side, so that only the light reflected by the second reflecting means is encased. It can be passed to the upper part, and it is possible to make it difficult for the observer to visually recognize the object inside the housing. However, since the light reflected by the second reflecting means may be reflected by the object and travel upward, the object inside the housing may be visible from the observer. However, the degree to which the object can be visually recognized is sufficiently small as compared with a projector having a conventional opening.

[Embodiment 3]
FIG. 4 is a schematic configuration diagram of a stereoscopic image projection apparatus according to the third embodiment of the present invention. In the present embodiment, as the first reflecting means and the second reflecting means, a Lippmann method (reflective type) formed by interfering light from a point light source arranged at an inner focal position and parallel light from the outside. This is an example of employing a holographic optical element having a thin hologram.

  In the present embodiment, the first reflecting means 1 is configured in a flat plate shape, but the focal point F1 of the first reflecting means 1 (the focal point of the parabolic mirror 1) is similar to the parabolic mirror 1 (see FIG. 1). The light 15 spreading from the virtual point light source placed on (corresponding to F1) can be reflected into the parallel light 16. Further, the second reflecting means 4 is also formed in a flat plate shape, but like the parabolic mirror 4 (see FIG. 1), the parallel light 16 is converted into the focal point F2 of the second reflecting means 4 (of the parabolic mirror 4). Can be reflected toward the focal point F2. Therefore, the light 15 spreading from the virtual point light source placed at the focal point F1 of the first reflecting unit 1 (corresponding to the focal point F1 of the parabolic mirror 1) is reflected by the first reflecting unit 1 to become parallel light 16. Next, the light is reflected by the second reflecting means 4 and the reflected light 17 is imaged at the focal point F2 of the second reflecting means 4 (corresponding to the focal point F2 of the parabolic mirror 4).

  Further, since the reflection means constituted by the holographic optical element can appropriately set the transmittance by utilizing the optical characteristic of the diffraction efficiency, the holographic optical element of the first reflection means 1 has an appropriate size. A semi-transmissive region having a shape can be formed. In other words, if the diffraction efficiency is 40%, 40% of the light applied to the holographic optical element is diffracted and reflected, and the remaining 60% is transmitted without being diffracted. A semi-transmissive region can be formed. If the entire surface of the first reflecting means is made transmissive, the object can be placed outside the housing through the semi-transmissive region formed on the entire surface, regardless of the position of the second reflecting means. Since an image can be projected, it is preferable.

  FIG. 5 is an example of the shape of the housing part of the three-dimensional image projector of the present embodiment, and is a top view of the housing viewed from above. The holographic optical element can be designed relatively freely in shape and size as compared to a parabolic mirror, and FIG. 5A shows an example in which each reflecting means 1a is formed of a rectangular flat plate. The box is a rectangular parallelepiped. FIG. 5B is an example in which each reflecting means 1b is formed of an elliptical flat plate, and the casing is a right elliptical cylinder. FIG. 5C is an example in which the first reflecting means is constituted by a circular flat plate, and the second reflecting means 4c is constituted by a circular flat plate larger than the circular shape, and the casing is a truncated cone. 4 and 5, the reflecting means is formed in a flat plate shape, but is not limited thereto, and may be formed in a curved surface shape.

  As described above, according to the present embodiment, the diffraction efficiency of the holographic optical element can be set as appropriate, so that a desired transmittance can be realized, and a semi-transmissive region can be set as appropriate. Further, since the reflecting means can be configured in a flat plate shape by the holographic optical element, the thickness (height) of the housing is higher than that in the first or second embodiment in which the parabolic parabolic mirrors are superimposed. ) Can be made thinner, saving space. Since the second reflecting means is a flat plate, there are few restrictions on the arrangement and driving of the object. Furthermore, compared to a parabolic parabolic mirror, a support base is not required and stable installation is possible.

  The holographic optical element can be easily mass-produced by producing a master holographic optical element, and the accuracy of the curved surface is not required unlike a parabolic mirror. Is easy to manufacture. In addition, the shape and size of the holographic optical element can be designed relatively freely as compared with a parabolic mirror, and thus the appearance can be designed freely according to the form of use.

[Embodiment 4]
FIG. 6 is a schematic configuration diagram of a stereoscopic image projection apparatus according to the fourth embodiment of the present invention. In the present embodiment, the first and second reflecting means formed by the holographic optical element are formed in a vertically long shape, and the occupied area is narrowed. Each of the first and second reflecting means has a side surface that becomes wider toward the other reflecting means. FIG. 6 shows an example in which a barrel-shaped housing having a curved side surface is employed and the side surface is swollen. However, the shape is not limited to a barrel shape, and an oval shape (a shape in which the semi-transmission region of the first reflecting means is formed by a curved surface), a shape that combines a truncated cone shape, a polygonal truncated pyramid shape, and the like can be appropriately designed. . The first and second reflecting means are preferably designed so that the maximum width is shorter than the focal length f in order to reduce the occupation area of the housing.

  Also in the stereoscopic image projection apparatus of FIG. 6, the light 15 spreading from the virtual point light source placed at the center point O2 (corresponding to the apex of the parabolic mirror 4 of FIG. 1) of the second reflecting means 4 is the first reflection. The light is reflected by the means 1 and travels downward as parallel light 16 and then reflected by the second reflecting means 4, and the reflected light 17 is imaged at the focal point F <b> 2 of the second reflecting means 4. In the figure, for the sake of explanation, the first reflecting means 1 and the second reflecting means 4 are shown as separate members, but the first and first reflecting means 1 are controlled by controlling the diffraction direction in one holographic optical element. The same function as the two-reflection means may be realized by a single holographic optical element.

  The semi-transmissive region 2 may be constituted by a half mirror or a holographic optical element. In FIG. 6, the first reflecting means 1 and the semi-transmissive region 2 are separately shown as separate bodies, but this is merely an example, and the upper surface and side surfaces of the housing are formed by an integral holographic optical element. May be. Moreover, in FIG. 6, although the upper part of a housing is shown as a flat plate, it is not limited to this. For example, the housing may be configured like an egg shape. Moreover, you may provide the illumination 10 suitably. In FIG. 6, illumination means for illuminating from above to below is provided at the boundary between the first reflecting means 1 and the semi-transmissive region 2.

  According to the present embodiment, the maximum horizontal width (typically, the central width between the upper and lower sides) of the first and second reflecting means is designed to be shorter than the focal length f, thereby saving space. be able to. Thus, in the case of a vertically long casing shape, a large number of casings can be arranged side by side, which is advantageous for applications such as exhibitions.

[Example]
Hereinafter, an embodiment of a structure of a casing using a parabolic mirror for the stereoscopic image projector of the present invention will be described.

FIG. 7 is an example of a parabola that defines the curved surface shape of the parabolic mirrors 1 and 4 used in the housing. In this example, a parabola y = x ² / 4f with a focal length f of 197 mm was used. In such a parabola, at a height of 10.3 mm from the apex (0, 0), the distance (radius) from the symmetry axis (y-axis) in the x-axis direction is 90 mm, and at a height of 21.4 mm, The radius is 130 mm, the radius is 180 mm at a height of 41.1 mm, and the radius is 215 mm at a height of 58.7 mm.

  When such a parabola is rotated around the axis of symmetry, a paraboloid having a distance of 197 mm from the vertex (0, 0) to the focal point is formed.

  FIG. 8 shows an example in which the housing is configured by a parabolic mirror having such a parabolic curved surface shape. Both the parabolic mirrors 1 and 4 have a diameter of 430 mm, a height of 64.7 mm, and a parabolic mirror thickness of 6 mm. When the apex of one parabolic mirror is arranged so as to coincide with the other focal point, the height of the housing is 200.2 mm, and the gap between the side edges of each parabolic mirror is 74.1 mm. The parabolic mirror 1 is provided with a semi-transmissive region 2 formed by a circular half mirror having a diameter of 100 mm with the vertex O1 as the center. When such a casing was used, a three-dimensional image of the object placed in the vicinity of the focal point F1 could be projected on the vicinity of the focal point F2 on the upper surface of the casing.

  As described above, according to the present invention, since a real image of an object is projected through a semi-transmissive region without having a physical opening, even if the observer's viewpoint moves, the image is missing. There are few, and it can make it difficult to visually recognize an object main part. In addition, since the range, arrangement, and shape of the semi-transmissive region can be set as appropriate, the object can be projected even if the object is placed at a position somewhat away from the focal point F1 with less restrictions on the placement position. it can. In addition, since the object can be driven, effective advertising that attracts the viewer's interest is possible.

DESCRIPTION OF SYMBOLS 1 1st reflection means 2 Translucent area | region 4 2nd reflection means 8 Mounting means 9 Driving means 10 Illumination means 20 Object 30 Image F1 1st focus F2 2nd focus O1 The vertex (center point) of the parabolic mirror 1
O2 Apex (center point) of parabolic mirror 2

Claims (13)

A first reflecting means configured to reflect light from a virtual point light source placed at its first focus as parallel light; and a first reflecting means configured to focus the parallel light onto its second focus. Two reflection means,
The first and second reflecting means are arranged so that the focal point of one reflecting means coincides with the center point of the other reflecting means,
The first reflecting means has a semi-transmissive region that reflects at least part of the light and transmits the other part.
A three-dimensional image projecting apparatus for projecting a three-dimensional image of an object arranged inside the first and second reflecting means to the outside of the first reflecting means through the semi-transmissive region.   The stereoscopic image projection apparatus according to claim 1, wherein the first and second reflecting means are parabolic mirrors having a predetermined focal length.   The stereoscopic image projection apparatus according to claim 1, wherein the semi-transmissive region is formed by a half mirror. An illumination unit capable of irradiating the first polarized wave;
The semi-transmissive region of the first reflecting means is constituted by a wire grid that reflects the first polarized wave and transmits the second polarized wave orthogonal to the first polarized wave,
3. The stereoscopic image projection apparatus according to claim 1, wherein the second reflection unit includes a quarter-wave plate layer on the inner surface side of the reflection layer. 4.   The three-dimensional image projector according to claim 1, wherein the first and second reflecting means are configured by a holographic optical element having the same optical characteristics as a parabolic mirror.   The three-dimensional image projector according to claim 5, wherein the first and second reflecting means are each formed in a flat plate shape.   Each of the first and second reflecting means has side surfaces that become wider toward the other reflecting means, and the maximum lateral width of the first and second reflecting means is larger than the focal length of the first and second reflecting means. The three-dimensional image projector according to claim 5, wherein the three-dimensional image projector is short.   The three-dimensional image projector according to claim 1, wherein the semi-transmissive region is formed in a part of a circle or a polygon including a center point of the first reflecting means.   The three-dimensional image projector according to claim 1, wherein the semi-transmissive region is formed on the entire first reflecting unit.   The three-dimensional image projector according to any one of claims 1 to 9, further comprising mounting means for mounting the object.   The three-dimensional image projector according to claim 10, wherein the placing unit is detachably attached to the opening of the second reflecting unit and has a process of reflecting light on the inner surface.   The stereoscopic image projection apparatus according to claim 1, further comprising a driving unit that drives the object.   The three-dimensional image projector according to any one of claims 1 to 12, wherein a casing including the first and second reflecting means is sealable.

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