JP4894046B2 - Color electronic holographic display device - Google Patents

Description

  The present invention relates to a color electronic holography display device that displays a color electronic holographic image by removing unnecessary light generated from a hologram pattern.

  Conventionally, as a method of displaying a color electronic holographic image, for example, there is a method disclosed in Patent Document 1. The method disclosed in Patent Document 1 irradiates a hologram display device on which hologram patterns corresponding to respective colors are displayed with red, green, and blue three-color light sources, and optically outputs the obtained three-color hologram light. And a color holography device that displays a color electronic holographic image.

  In addition, this Patent Document 1 discloses that a semiconductor laser is used as a light source in order to reduce the size of a color holography device, and compensates for a color shift of a color electronic holography image due to a temperature change of the semiconductor laser. A laser temperature control method is also disclosed.

Here, the color holography apparatus disclosed in Patent Document 1 will be described with reference to FIG.
As shown in FIG. 15, the color holography apparatus 100 is irradiated with laser diodes (red LD, green LD, blue LD) 101, 102, and 103 of red, green, and blue constituting the semiconductor laser, and from these laser diodes. A beam expanding lens 111, 112, 113 that expands the beam diameter of the laser beam and a liquid crystal element (LCD), and the expanded light from the three-color hologram pattern of red, green, and blue (red monochromatic light, Beam synthesis that combines LCD (hologram display devices) 121, 122, and 123 that display green monochromatic light and blue monochromatic light) and three color monochromatic lights displayed on these, and outputs a color electronic holographic image And an optical system 130.

The beam combining optical system 130 has a configuration in which half mirrors orthogonal to each other are arranged on a square diagonal line, and reflects light incident from the left and right downward and transmits light incident from above downward. Monochromatic light of each color can be synthesized and a color electronic holographic image can be output.
The color holography apparatus 100 further includes a hologram memory 124 that stores a hologram pattern in advance and outputs the hologram pattern to the hologram display devices 121, 122, and 123.

  In the color holography apparatus 100, conjugate light generated from the hologram pattern and zero-order light (light that does not bend in the lens system) irradiated on the hologram display device are also output at the same time. Therefore, it becomes unnecessary light that overlaps the object light that forms the image of the subject, making it difficult for the viewer to see the color electronic holographic image.

  For example, when the hologram display device is a liquid crystal element, the interval P of the liquid crystal element is about 10 times larger than the wavelength of light λ, and the incident direction of light (incident light) expanded by a beam expansion lens or the like and the hologram pattern The angle θ formed with the diffracted light that is diffracted and becomes object light is given by sin θ = λ / 2P, and becomes very small. As a result, incident light that overlaps the subject light enters the eyes of the viewer, and a color electronic holographic image is hardly seen.

  In addition, the hologram pattern is obtained by converting both the amplitude and phase of the object light described by complex numbers into shades of interference fringe patterns and recording only absolute values. When displaying, conjugate light that diffracts in the direction opposite to the diffraction direction of the object light is generated. Since the diffraction angle of this conjugate light is also small, it is superimposed on the object light, becomes unnecessary light, and the quality of the color electronic holographic image is significantly deteriorated.

  Then, when displaying a color electronic holographic image, as a conventional technique for removing unnecessary light (unnecessary light removing optical system), the light incident on the convex lens is Fourier-transformed, and the energy of the light is converted into the focal position. There is one that utilizes the fact that it has a function of converging (see Non-Patent Document 1, for example). This unnecessary light removing optical system will be described with reference to FIG.

  As shown in FIG. 16, in the unnecessary light removing optical system 140, a lens (convex lens) 141 and a lens (convex lens) 143 having a focal length f are arranged 2f apart to block unnecessary light at both focal length positions. A light shielding plate 142 that transmits only the necessary object light is disposed. A display device 120 for displaying a hologram pattern is separately provided outside the unnecessary light removing optical system 140.

  In the unnecessary light removing optical system 140, a hologram pattern is required so that the conjugate light and the object light converge at different positions. This hologram pattern is above the horizontal (the side without the light shielding plate 142) for each point of the subject in FIG. 16 in the reference light (laser light from the semiconductor laser) scattered and reflected in all directions from each point of the subject. It consists only of light scattered in space. Such removal of unnecessary light by the unnecessary light removal optical system 140 is called a single sideband method. Note that the hologram pattern described here can be obtained only by computer simulation. In an analog hologram that actually irradiates a subject with laser light and records the reflected light on a film, the hologram pattern is horizontally measured for each point of the subject. Since it is impossible to stop the light scattered below, this is not feasible.

  Here, how to obtain the hologram pattern by computer simulation will be described. First, in the computer simulation, a coherent laser beam R having the same direction and phase is assumed, and when this laser beam R hits a point (u, v, w) on the subject, it is scattered and the subject light A (u, v, w), the subject light A (u, v, w) at a point (x, y, z) away from the subject by a distance z in the z-axis direction is obtained using the following formula (1). .

  A (x, y, z) = A (u, v, w) exp (−j2πd / λ) / d (1)

  In this equation (1), j = imaginary unit, π = circularity, λ = wavelength of light, and d is obtained by using the following equation (2).

d = {(z−w) ² + (x−u) ² + (y−v) ² } ^1/2 Equation (2)

  Note that at the point (x, y, z) separated from the subject by the distance z in the z-axis direction, all the subject light (scattered light) from each point (u, v, w) on the subject has reached. Therefore, the sum of all the object lights that have arrived is the object light O (x, y, z) at a point (x, y, z) that is separated from the object by a distance z in the z-axis direction. . However, since the single sideband method is used here, only the light scattered in the upper half from the subject (v <y: the coordinate y in the vertical direction of the point separated from the subject by the distance z in the z-axis direction is the subject's (Only light scattered in a portion larger than the coordinate v in the vertical direction) is added using the following formula (3).

O (x, y, z) = Σu _{, v <y, w} A (x, y, z) (3)

  The object light O obtained in this way (hereinafter, light emitted from each point of the subject is referred to as “subject light”, and light in which the subject light overlaps on the hologram surface is distinguished as “object light”. ) Is generally an amplitude | O (x, y, z) | and a phase φ (x, y, z), and can be expressed by the following equation (4).

O (x, y, z) = | O (x, y, z) | exp {−jφ (x, y, z)}
... Formula (4)

  The hologram pattern is obtained by recording the amplitude and phase of this light as an interference fringe pattern. For this reason, when the laser beam R described above is used as the reference beam and superimposed on the beam O, the light at the point (x, y, z) away from the subject by the distance z in the z-axis direction becomes O + R. If a hologram pattern recording material such as a film is placed on the hologram pattern recording material, the square I of the absolute value of O + R is recorded as an interference fringe pattern on the hologram pattern recording material. This I is expressed by the following formula (5).

I = | R + O | ² = (R + O) (R ^* + O ^* ) = RR ^* + OO ^* + (RO ^* + OR ^* )
= | R | ² + | O | ² +2 | R || O | cos (φ) (5)

In this formula (5), R ^* is a complex conjugate term of R, and O ^* is conjugate light that is a complex conjugate term of O. In the mathematical formula (5), the third term includes the amplitude | O | of the original subject light and the phase φ, and therefore only the third term | O | cos (φ) is calculated in the computer simulation. The hologram pattern.

When the reproduction light when the original reference light (laser light) R is irradiated onto the hologram pattern is P, the reproduction light P is expressed by the following formula (6).
P = R | O | cos (φ) = R | O | {exp (−jφ) + exp (jφ)} / 2
... Formula (6)

In this equation (6), the reproduction light P includes the original object light O = | O | exp (−jφ) of the subject and the conjugate light O ^* = | O | exp (jφ) of the object light O. It is a thing.

  When the hologram pattern thus obtained is displayed on the display device 120 shown in FIG. 16 and irradiated with reference light, the reproduction light including the original object light and conjugate light is diffracted and emitted. The object light is diffracted upward in the figure and is the same as the light emitted from the original subject, and the conjugate light is a complex conjugate component of the reproduced light. Therefore, the object light is diffracted in the downward direction indicated by the dotted line in FIG. Then, a conjugate image is formed at a mirror image position with respect to the display device 120.

  These object light and conjugate light are converged when passing through the convex lens 141, but the object light passes only in the region above the optical axis of the convex lens 141 in the vicinity of the focal length f. On the other hand, the conjugate light passes only in the lower region in the figure from the optical axis of the convex lens 141. For this reason, if a light shielding plate is arranged in this region, conjugate light will be blocked.

  Since the reference light applied to the display device 120 converges on the focal length f on the optical axis of the convex lens 141, it can be blocked by installing the light shielding plate slightly higher than the optical axis. As a result, a part of the object light is blocked and the viewing zone is slightly reduced, but the reproduced image formed by the reproduced light is not lost. Further, the object light converged in this way is returned to the original object light (light scattered from the subject and scattered in the upper half) by passing through the convex lens 143.

  In general, the focal lengths of the first convex lens (convex lens 141) and the second convex lens (convex lens 143) are f and g, the distance between the convex lenses is 2f, and the distance D in front of the first lens is from the optical axis. If a point on the subject at a distance A is formed at a position at a distance Z behind the second convex lens and a position at a distance B from the optical axis, the distance Z is expressed by the following equation (7). Thus, the distance B is expressed by Equation (8).

Z = fg (2f−D) / {g (D−f) + f (2f−D)} (7)
B = Afg / {g (D−f) + f (2f−D)} (8)

Here, when g = f, Z = 2f−D and B = A. That is, the reproduced image that has passed through the unnecessary light removing optical system 140 is only shifted in position by 4f in the optical axis direction, and the size and shape are unchanged.
Japanese Patent Laid-Open No. 9-68917 NHK R & D, No. 93, pp. 14-19, 2005. 9 (FIG. 3)

  However, a color holography device that displays a color electronic holographic image by combining the conventional unnecessary light removal optical system 140 with hologram light of each color of red, green, and blue (red monochromatic light, green monochromatic light, and blue monochromatic light). The following problems (1) to (3) occur when applying to the above.

  (1) Since the focal length of the lens used in the conventional unnecessary light removal optical system 140 differs depending on the color of light passing through the lens medium, the focal length also differs. It is necessary to insert the hologram light of each blue color individually, and the color holography device cannot be reduced in size.

  (2) When the common unnecessary light removing optical system 140 is inserted into the synthesized light obtained by synthesizing the hologram lights of the respective colors, as shown in FIG. 17, for each light color (red monochromatic light, green monochromatic light, Since the convergence position of the light is different from that of blue monochromatic light), one light shielding plate can handle only one color, and reference light and conjugate light of other colors leak.

  (3) Since the distance between the lenses is not twice the focal length for each color of light, the position and size of the output color electronic holographic image are the position of the original image recorded in the hologram pattern and This is different from the size, and color misregistration of the color electronic holographic image occurs and the shape is distorted.

  Therefore, in the present invention, a color electronic holographic image in which the reference light and the conjugate light of each of the three colors of light are not leaked and no color shift or distortion is generated while solving the above-described problems and downsizing the apparatus. An object of the present invention is to provide a color electronic holographic display device capable of displaying.

  In order to solve the above-described problem, the color electronic holographic display device according to claim 1 is an object in which the range of light diffusion from each point of the subject is limited to half for each of red, green, and blue colors. A color electronic holographic display device that displays a color electronic holographic image of the subject using a hologram pattern that is a pattern of interference fringes between light and colored light that is the light of each color, the light source and the display device And a color unnecessary light removing unit having a first optical system, a light shielding plate, and a second optical system.

  According to such a configuration, the color electronic holographic display device generates color light of three colors of red, green, and blue by the light source of the color hologram light generating means, and the display device is provided on the optical path of the light from the light source Thus, a hologram pattern corresponding to each color light is displayed. The color electronic holography display device emits light generated by irradiating light from the light source onto the hologram pattern displayed on the display device of the color hologram light generation means by the first optical system of the color unnecessary light removal means. The first optical system is focused on the image-side focal plane of the first optical system so as to correspond to the range of light diffusion limitation from each point of the subject when the hologram pattern is generated by the light shielding plate. The light in a predetermined region, which is half of the light emitted from the first optical system with the optical axis as a boundary, is blocked, and the light is emitted from the first optical system by the second optical system installed at the subsequent stage of the light shielding plate The light that is not blocked by the light shielding plate is condensed to form a color electronic holographic image.

  Here, in the color electronic holography display device, the first optical system has a first condensing lens that condenses light generated by irradiating light from the light source onto the hologram pattern displayed on the display device. Then, the hologram pattern displayed on the display device has a focal plane of the first condenser lens resulting from a difference in color of the other condenser light with respect to the position of the focal plane of the first condenser lens in the color light of one color. Therefore, the convergence position of the first condenser lens is the same for all three colors of light, and all the reference light and conjugate light for all colors are received by one light-shielding plate. Can be blocked.

  The color electronic holography display device according to claim 2 is the color electronic holography display device according to claim 1, wherein the second optical system is not blocked by the light shielding plate among the light emitted from the first optical system. It has a concave mirror that collects light, and a mirror that is installed on the optical path of light from the concave mirror and that changes the emission direction of the light.

  According to such a configuration, the color electronic holographic display device reflects only the object light from which the reference light and the conjugate light have been removed from the light generated by the color hologram light generating means, and reflects the half mirror to the concave mirror of the second optical system. Output via. As a result, the color electronic holography display device can display a color electronic holographic image with no color shift.

  The color electronic holography display device according to claim 3 is the color electronic holography display device according to claim 1, wherein the second optical system is not blocked by the light shielding plate among the light emitted from the first optical system. A second condensing lens that condenses light, and the hologram pattern is formed by the second condensing lens for the color light of another color with the color light of one color as a reference. The electronic holographic image is a pattern in which a shift in position and size caused by a color difference is further corrected.

  According to such a configuration, the color electronic holographic display device is a hologram pattern in which the correction of the position and size deviation of the color electronic holographic image formed by the second condenser lens caused by different colors is performed. Is used. As a result, the color electronic holography display device can display a color electronic holographic image with no color shift.

  5. The color electronic holographic display device according to claim 4, wherein the object light in which the range of light diffusion from each point of the subject is limited to half for each color of red, green and blue, and each of the colors A color electronic holographic display device that displays a color electronic holographic image of the subject using a hologram pattern that is a pattern of interference fringes with colored light that is light of the color light generating means having a light source and a display device And a color unnecessary light removing unit having a first optical system, a light shielding plate, and a second optical system.

  According to such a configuration, the color electronic holographic display device generates color light of three colors of red, green, and blue by the light source of the color hologram light generating means, and the display device is provided on the optical path of the light from the light source Thus, a hologram pattern corresponding to each color light is displayed. The color electronic holography display device emits light generated by irradiating light from the light source onto the hologram pattern displayed on the display device of the color hologram light generation means by the first optical system of the color unnecessary light removal means. The first optical system is focused on the image-side focal plane of the first optical system so as to correspond to the range of light diffusion limitation from each point of the subject when the hologram pattern is generated by the light shielding plate. The light in a predetermined region, which is half of the light emitted from the first optical system with the optical axis as a boundary, is blocked, and the light is emitted from the first optical system by the second optical system installed at the subsequent stage of the light shielding plate The light that is not blocked by the light shielding plate is condensed to form a color electronic holographic image.

  Here, in the color electronic holography display device, the first optical system is installed on the optical path of the light from the display device, and the half mirror that changes the emission direction of the light and the optical path of the light from the half mirror And a first concave mirror that collects the light. In the first concave mirror, since the focal length shift due to the difference in color does not occur, the convergence position by the first concave mirror coincides with the light of all three colors, and the color electronic holography display device has one light shielding plate. Thus, the reference light and conjugate light of all colors can be blocked.

  The color electronic holographic display device according to claim 5 is the color electronic holographic display device according to claim 4, wherein the second optical system is installed on an optical path of light from the first concave mirror, and the light And a second concave mirror that is installed on an optical path from the half mirror and collects the light.

  According to such a configuration, the color electronic holographic display device reflects only the object light from which the reference light and the conjugate light have been removed from the light generated by the color hologram light generating means, by the second mirror of the second optical system. Condensed by a concave mirror and output. As a result, the color electronic holography display device can display a color electronic holographic image with no color shift.

  The color electronic holography display device according to claim 6 is the color electronic holography display device according to claim 4, wherein the second optical system is installed on an optical path of light from the first concave mirror, A second concave mirror that collects light that is not blocked by the light-shielding plate out of light emitted from one optical system, and an optical path for the light from the second concave mirror that changes the emission direction of the light. And a reflecting mirror.

  According to such a configuration, the color electronic holographic display device condenses only the object light from which the reference light and the conjugate light have been removed from the light generated by the color hologram light generating means, with the second concave mirror of the second optical system. Reflected by the total reflection mirror and output. As a result, the color electronic holography display device can display a color electronic holographic image with no color shift.

  The color electronic holographic display device according to claim 7 is the color electronic holographic display device according to claim 4 or 5, wherein the second optical system blocks the light out of the light emitted from the first optical system. A second condensing lens that condenses the light that is not blocked by the plate, and the hologram pattern is formed by the second condensing lens with respect to the color light of another color on the basis of the color light of one color The color electronic holographic image is a pattern in which a shift in position and size due to a color difference is further corrected.

  According to such a configuration, the color electronic holographic display device is a hologram pattern in which the correction of the position and size deviation of the color electronic holographic image formed by the second condenser lens caused by different colors is performed. Is used. As a result, the color electronic holography display device can display a color electronic holographic image with no color shift.

According to the first to seventh aspects of the present invention, the reference light and the conjugate light of each of the three color lights are not leaked while the apparatus is downsized, and no color shift or distortion occurs, that is, unnecessary light is removed. Thus, it is possible to display a color electronic holographic image that is easy to see.
In addition, according to the inventions of claims 4 to 6, color electrons that are easy to see by removing unnecessary light by using a conventional hologram pattern as it is by using concave mirrors that reflect colored light in the first and second optical systems. A holographic image can be displayed.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a block diagram of a color electronic holographic display system (color electronic holographic display device). As shown in FIG. 1, the color electronic holographic display system S includes a color hologram light generating device (color hologram light generating means) 10 and a color unnecessary light removing optical system (color unnecessary light removing means) 20. Yes.

  When displaying a color electronic holographic image, the color electronic holographic display system S removes unnecessary light (conjugate light, reference light) included in the color electronic holographic image through a color unnecessary light removing optical system. Are displayed.

  The color hologram light generator 10 irradiates a hologram display device on which hologram patterns corresponding to the respective colors are displayed with red, green, and blue three-color light sources, and optically synthesizes the obtained three-color hologram light. A color electronic holographic image is displayed. The color hologram light generator 10 may have a conventional configuration, and details will be described later.

The color unnecessary light removing optical system 20 is for removing unnecessary light from the three-color hologram light generated by the color hologram light generator 10.
Hereinafter, six embodiments in which the elements constituting the color hologram light generating apparatus 10 and the color unnecessary light removing optical system 20 are variously changed and combined will be described in detail.

(Color hologram light generator 1)
First, the details of the color hologram light generator 10 will be described with reference to FIG. As shown in FIG. 2, the color hologram light generator 10 includes a red LD 11, a green LD 12, and a blue LD 13 that are three-color light sources of red, green, and blue, and light of each of the three colors (red light, green light, A beam expanding lens 14, a beam expanding lens 15 and a beam expanding lens 16, a beam combining optical system 17 for combining red light, green light and blue light, an LCD 18 which is a hologram display device, and the LCD 18 And a hologram memory 19 for storing hologram patterns (R, G, B hologram patterns) corresponding to red, green, and blue, respectively. In these configurations, the beam magnifying lens 14, the beam magnifying lens 15, the beam magnifying lens 16, and the beam combining optical system 17 correspond to the light shaping optical system.

  Since the color hologram light generating apparatus 10 includes only one LCD 18 as a hologram display device, first, hologram patterns corresponding to red, green, and blue are time-divided from the hologram memory 19, respectively. Multiplexed and output sequentially and displayed on the LCD 18. In accordance with this, any one of the red LD 11, the green LD 12 and the blue LD 13 is turned ON, and the light emitted from any one of the beam magnifying lens 14, the beam magnifying lens 15 and the beam magnifying lens 16 is sent to the same optical path by the beam combining optical system 17. It is irradiated after passing through.

(Colorless light removal optical system 1)
Next, details of the color unnecessary light removing optical system 20 will be described with reference to FIG. As shown in FIG. 3, the color unnecessary light removing optical system 20 includes a first optical system (convex lens 21), a light shielding plate 22, and a second optical system (half mirror 23 and concave mirror 24).

The LCD 18 is a hologram display device in the color hologram light generator 10 shown in FIG.
The first optical system (convex lens 21; first condensing lens) is composed of a convex lens installed on the optical axis from the LCD 18, receives light from the LCD 18 (here, blue subject light), and receives this light. The object light contained therein and other unnecessary light are condensed (converged) at spatially different positions.

The light shielding plate 22 is disposed at a position away from the convex lens 21 by a predetermined distance (focal length), and shields unnecessary light as will be described later.
The half mirror (mirror) 23 and the concave mirror 24 are installed at a position further away from the light shielding plate 22 by a predetermined distance, and are for returning the condensed object light to the original object light. The concave mirror 24 is installed on the optical axis of the first optical system 21, and the half mirror 23 is installed on the optical path from the concave mirror 24.

  Since the first optical system is the convex lens 21, the received object light and unnecessary light pass through the convex lens. These object light and unnecessary light pass through the convex lens (pass through the lens medium constituting the convex lens), and thereby the focal length of the lens due to the difference in wavelength that is the color difference between the object light and unnecessary light. Are different, and the condensing position is different.

  For this reason, in the color unnecessary light removing optical system 20, for example, when the light shielding plate 22 is arranged in accordance with the focal length f of red light, the focal length g of green light or blue light is shorter than f. Unnecessary light cannot be accurately blocked by the light shielding plate 22 disposed at the position of the distance f.

  Therefore, the color unnecessary light removing optical system 20 assumes a virtual lens (focal length h) for correcting the focal length between the subject and the convex lens 21, and the focal length h of the virtual lens and the green light or blue light. When the combined focal length with the focal length g is f, the following formula (9) is established.

1 / f = 1 / g + 1 / h
h = fg / (g−f) (9)

  In this equation (9), since g <f, h <0, and it is understood that a concave lens having a focal length h may be assumed as the virtual lens. This virtual lens is assumed to be placed between the subject and the LCD 18 when creating a hologram pattern. If the hologram pattern is obtained from the object light and the reference light passing through the virtual lens, the composite focal length is corrected to f. Is reflected in the hologram pattern, and there is no need to insert a virtual lens during reproduction.

  When obtaining the hologram pattern, the light passing through the lens having the focal length h is obtained by multiplying the input light O (x, y, z) by the following formula (10).

exp {j2π (x ² + y ² ) / 2h} Expression (10)

  In this equation (10), (x, y, z) represents a coordinate value with the center of the lens as the origin, and j represents an imaginary unit. Further, in this formula (10), since h <0, it indicates that the phase is delayed as the distance from the center of the lens increases (x, y> 0), and the light passing through the lens is diffused. In addition, the hologram pattern obtained from the reference light and object light after passing through the correction lens is the same as the hologram pattern before passing through the correction lens when the hologram surface is at the center of the virtual lens. ) May not be used, but the position of the hologram surface is limited. At the time of reproduction, it is necessary to irradiate the hologram pattern with the light that has passed the reference light through the correction lens. This shaping of the reference light can be realized by adjusting the distance between the beam magnifying lenses as described below.

  Further, in the color unnecessary light removing optical system 20, the interval between the beam magnifying lens 15 or the beam magnifying lens 16 (see FIG. 2) of the color holographic light generator 10 for the green or blue reference light that irradiates the hologram pattern during reproduction is set. If the distance between the beam magnifying lenses is adjusted and the distance is too narrow, the light is condensed behind the light shielding plate. If it is too wide, the light is condensed in front, so that the reference light is focused on one point on the light shielding plate. Is adjusted, the focal length of the first optical system is corrected to f. In this way, the light is condensed at one point at the position f of the light shielding plate 22. As a result, the color unnecessary light removing optical system 20 can obtain the same reference light as when the hologram pattern was obtained, and all red, green and blue subject light reproduced from the LCD 18 is separated from the conjugate light at the position of the light shielding plate 22. Thus, unnecessary light can be removed by the single light shielding plate 22.

  However, in the color unnecessary light removing optical system 20, if the second optical system (the half mirror 23 and the concave mirror 24) is configured with a convex lens as in the prior art, the change in focal length due to the wavelength of light again with this convex lens. As described in the background art, the depth and size of the output video are distorted.

  Therefore, in the color unnecessary light removing optical system 20, the half mirror 23 and the concave mirror 24 are used as the second optical system. In this second optical system, the concave mirror 24 plays a role of condensing light, and the half mirror 23 changes the direction of the collected light.

  In the concave mirror 24, light from the convex lens 21 (light from which unnecessary light has been removed by the light shielding plate 22) does not pass through the lens medium like a convex lens, and is a mirror surface that is the surface of the concave mirror 24 that forms a paraboloid. Since it is reflected, the focal length f does not change depending on the wavelength of light. However, since the light reflected by the concave mirror 24 returns to the incident direction and cannot be viewed from the outside, the color unnecessary light removal optical system 20 changes the emission direction by the half mirror 23 so that it can be viewed from the outside. ing.

  As a result, the color unnecessary light removing optical system 20 is equivalent to installing a lens having a focal length f 2 f away from all colors of light (red light, green light, blue light), and Unnecessary light can be removed without changing the depth or size (without distortion).

(Colorless light removal optical system 2)
Next, another configuration of the unnecessary color light removing optical system 20 (part 2; the unnecessary color light removing optical system 20A) will be described with reference to FIG. 4 (see FIG. 3 as appropriate). In the color unnecessary light removing optical system 20 described with reference to FIG. 3, the half mirror 23 is used to change the direction of the light (reproduced light) collected and reflected by the concave mirror 24. For this reason, since this light passes through the half mirror 23 twice at the time of entering and exiting the concave mirror, the intensity of the light becomes ¼ dark.

  Therefore, as shown in FIG. 4, the color unnecessary light removing optical system 20 </ b> A includes a total reflection mirror 25 instead of the half mirror 23. The total reflection mirror (mirror) 25 is installed on the optical path from the concave mirror 24. In this unnecessary color light removing optical system 20A, the same components as those in the unnecessary color light removing optical system 20 shown in FIG.

  In this embodiment, the position of the LCD 18 is set so that the distance between the blue subject and the convex lens 21 is in the vicinity of the focal length f, so that the light passing through the convex lens 21 becomes thick parallel light, and the total reflection mirror is The concave mirror 24 is reached. The light reflected by the concave mirror 24 becomes condensed light and is condensed near the total reflection mirror, so that the light can be extracted to the outside with a small mirror.

  In the color unnecessary light removing optical system 20A, a part of the light is blocked by the total reflection mirror, so that the image becomes slightly dark, but a part of the image is not lost. Since the area of the total reflection mirror can be made sufficiently small, a brighter image than that of the half mirror can be obtained, and a decrease in the amount of light can be suppressed.

(Color unnecessary light removal optical system 3)
Next, another configuration of the unnecessary color light removing optical system 20 (No. 3; the unnecessary color light removing optical system 20B) will be described with reference to FIG. 5 (see FIGS. 3 and 4 as appropriate). In the unnecessary color light removing optical system 20 and the unnecessary color light removing optical system 20A, since the first optical system is a convex lens, it is necessary to correct the change in focal length with respect to the wavelength of the light of the convex lens by processing the hologram pattern.

  When the color unnecessary light removing optical system 20 and the color unnecessary light removing optical system 20A are applied to a moving image (moving image holography) instead of a static color electronic holographic image, the processing time for processing the hologram pattern becomes long. Therefore, it becomes difficult to apply to moving image holography with a high frame rate. Therefore, as shown in FIG. 5, in the color unnecessary light removing optical system 20B, both the first optical system and the second optical system are configured using a half mirror and a concave mirror. That is, in the color unnecessary light removing optical system 20B, the half mirror 26 and the concave mirror (first concave mirror) 27 are employed as the first optical system, and the half mirror 23 and the concave mirror (second concave mirror) are employed as the second optical system. 24 is adopted.

  The half mirror 26 of the first optical system is installed on the optical path of the LCD 18, and the concave mirror 27 is installed on the optical path from the half mirror 26. The half mirror 23 of the second optical system is installed on the optical axis of the concave mirror 27, and the concave mirror 24 is installed on the optical path from the half mirror 23.

  With this configuration, in the color unnecessary light removing optical system 20B, since the focal length is not changed by the first optical system and the second optical system, it is not necessary to correct the hologram pattern, and the hologram pattern can be quickly performed without increasing the processing time. And can be applied to a high frame rate moving image holography.

(Colorless light removal optical system 4)
Further, another configuration of the color unnecessary light removing optical system 20 (No. 4; color unnecessary light removing optical system 20C) will be described with reference to FIG. 6 (see FIGS. 3 to 5 as appropriate). Although the color unnecessary light removal optical system 20B shown in FIG. 5 can be applied to high-frame-rate moving image holography, the second optical system employs the half mirror 23. Therefore, the color unnecessary light removal optical system 20 is used. In the same manner as described above, there is a problem that the intensity of the light passing through the half mirror 23 is reduced to ¼ when passing through the half mirror 23 at the time of entering and exiting the concave mirror. Therefore, in the color unnecessary light removing optical system 20C, the half mirror 23 of the second optical system is configured to be a total reflection mirror 25.

  The half mirror 26 constituting the first optical system is installed on the optical path of the LCD 18, and the concave mirror 27 is installed on the optical path from the half mirror 26. The concave mirror 24 of the second optical system is installed on the optical axis of the concave mirror 27, and the total reflection mirror 25 is installed on the optical path from the concave mirror 24. The LCD 18 is installed such that the subject comes to a position away from the concave mirror 27 by the focal length f.

  With this configuration, in the color unnecessary light removal optical system 20C, the light that has passed through the focal length f hits the concave mirror 24 as a thick parallel light, as in the color unnecessary light removal optical system 20A. The light hits the total reflection mirror 25 again. However, since the light is condensed in a sufficiently narrow range at that time, the total reflection mirror 25 may be small, and the light blocked by this is a part, and most of the light is totally reflected. Since it passes around 25 and reaches the concave mirror 24, a decrease in the amount of light can be suppressed.

  Incidentally, it can be assumed that the half mirror 26 employed as the first optical system is replaced with a total reflection mirror. However, when the half mirror 26 is replaced with a total reflection mirror, the total reflection mirror is changed from the concave mirror 27 to the concave mirror. It must be arranged at a position separated by a focal length f of 27, and since the color hologram light generator 10 is installed at this position, it is difficult to replace it.

(Color hologram light generator 2)
In these third and fourth embodiments, the color hologram light generator 10 does not have to be configured as shown in FIG. 2, and may be configured as shown in FIG. As shown in FIG. 7, the color hologram light generation apparatus 10A includes a power switch (switch) 30, a light source 31, a beam magnifying lens 32, an LCD 18, and a hologram memory 19A. Note that the same components as those of the color hologram light generator 10 shown in FIG.

  The power switch 30 switches the connection with a power source (not shown), and outputs from the red, green, and blue light emitting elements (FIG. 7, R, G, B) provided in the light source 31 to the beam expanding lens 32 ( Color to be emitted).

  The light source 31 is composed of a single semiconductor laser (hereinafter also referred to as RGBLD 31) in which red, green, and blue light emitting elements are brought close to each other, and sequentially generates red, green, and blue light by time division multiplexing. The light source 31 is not limited to this, and white light generated by a light emitter composed of a single semiconductor laser or the like is passed through a rotating disk in which red, green, and blue color filters are arranged, thereby allowing red light to pass through. A configuration in which green-blue light is sequentially extracted may be used.

  The beam magnifying lens 32 is not provided for each of the red, green, and blue light, but is provided in common for the red, green, and blue light, and the red, green, and blue light generated by the light source 31. Are sequentially enlarged and output to the LCD 18. The beam magnifying lens 32 is configured by combining lenses of different materials, and is formed so as to cancel the change in the focal length of red, green and blue. This is because if the beam magnifying lens 23 is made of a single lens material, the focal length changes due to red, green, and blue, and the red, green, and blue light does not become an accurate parallel beam.

  The hologram memory 19A stores a hologram pattern in which the focal length is not corrected for another color on the basis of one color.

  In this color hologram light generating apparatus 10A, after the light switched to red, green and blue passes through the beam magnifying lens 32, the hologram pattern for red, green and blue is displayed in synchronization with the color of the light source. Is done. The color hologram light generation apparatus 10A can sequentially output red, green, and blue hologram lights from the LCD 18 and display a color electronic holographic image without optically synthesizing these holographic lights.

  By configuring the color hologram light generating apparatus 10A in this way, only one light source and one hologram display device are required, so that the entire apparatus can be further downsized.

(Colorless light removal optical system 5)
Furthermore, another configuration of the color unnecessary light removal optical system 20 (No. 5; color unnecessary light removal optical system 20D) will be described with reference to FIG. 8 (see FIGS. 3 to 6 as appropriate). In the color unnecessary light removing optical system 20D shown in FIG. 8, both the first optical system and the second optical system are constituted by convex lenses. That is, the color unnecessary light removing optical system 20D employs the convex lens 21 as the first optical system and the convex lens (second condensing lens) 28 as the second optical system.

  As a result, in the color unnecessary light removing optical system 20D, the amount of light is not reduced by the half mirror, but the focal length changes depending on the wavelength of the light by both convex lenses. Therefore, it is necessary to use a hologram pattern corresponding to this. is there. That is, this hologram pattern is obtained by correcting a change in focal length between the convex lens 21 of the first optical system and the convex lens 28 of the second optical system.

  The hologram pattern in which the change in the focal length is corrected twice is obtained by performing the correction due to the change in the focal length of the convex lens 21 and the correction due to the change in the focal length of the convex lens 28. The correction due to the change in the focal length of the first optical system (convex lens 21) is omitted because it has been described in the color unnecessary light removing optical system 20, and here the focus of the second optical system (convex lens 28) is omitted. The correction by the change in distance will be described.

  The case where the focal length of the convex lens 28 of the second optical system is different from that of the first optical system (focal length f and focal length g) has been described in the background art and will be omitted. Here, after the convex lens 28 of the second optical system, the position of the image formed at the positions of Z and B shown in the above formulas (7) and (8) is the position 2f− with reference color light (for example, red). When the subject position D ′ when correcting the hologram pattern so as to be D and the distance A from the optical axis is obtained, the following equation (11) is established.

2f−D = Z = fg (2f−D ′) / {g (D′−f) + f (2f−D ′)}
... Formula (11)

From this equation (11), the position D ′ of the subject is as shown in the following equation (12).
D ′ = f {4f (g−f) + D (2f−g)} / {f (3g−2f) + D (f−g)}
... Formula (12)

In this case, it is only necessary that the distance B from the optical axis of the output image composed of the hologram light is the same as A, so the following formula (13) is obtained.
A = B = A′fg / {g (D′−f) + f (2f−D ′)} (13)

From this equation (13), the distance A ′ from the optical axis of the subject is expressed by the following equation (14).
A ′ = A {g (D′−f) + f (2f−D ′)} / fg (14)

  Thus, in the hologram pattern in which the change in the focal length is corrected twice, the position of each point of the subject is first corrected (u, v, w) from the position D ′ of the subject and the distance from the optical axis of the subject. After obtaining from A ′, the light (subject light) emitted from the corrected subject and the reference light may be obtained through a virtual lens having a focal length h.

  In the color unnecessary light removing optical system 20D, red, green, and blue light obtained by irradiating the reference light shaped according to red, green, and blue to the hologram pattern that has been corrected for the change in focal length twice. Is condensed at the position of the focal length f by the convex lens 21 of the first optical system. Subsequently, in the unnecessary color light removing optical system 20D, the unnecessary light is blocked by the light shielding plate 22 that removes unnecessary light in common with the red, green, and blue light, and the light that has passed through the convex lens 28 of the second optical system. Will form images of the same size (color electronic holographic images) at the same positions.

  As a result, according to the color unnecessary light removing optical system 20D, by using the hologram pattern in which the change in focal length is corrected twice, the apparatus is made compact by the first optical system and the second optical system configured by convex lenses. In addition, it is possible to display a bright color electronic holographic image without reducing the amount of light. In the color unnecessary light removing optical system 20D, the first optical system may be configured by the concave mirror (first concave mirror) 27 and the half mirror 26 (see FIGS. 5 and 6) instead of the convex lens 21. The hologram pattern used at this time is not corrected by the change in the focal length of the convex lens 21 but is only corrected by the change in the focal length of the convex lens 28.

  Up to this point, the color hologram light generators 10, 10A (No. 1, No. 2) and the color unnecessary light removing optical systems 20, 20A, 20B, 20C, 20D (No. 1 to No. 5) have been described in the order of improvement. The correspondence relationship with the claims will be described, and the operation of the color electronic holography display system (color electronic holography display device) including these will be described with reference to the flowcharts shown in FIGS.

  The color hologram light generators 10 and 10A shown in FIG. 2 or 7 and the color unnecessary light removing optical systems 20 and 20A shown in FIG. 3 or 4 correspond to the color electronic holographic display device described in claim 2. The operations of the color hologram light generating device 10 shown in FIG. 2 and the color unnecessary light removing optical system 20 shown in FIG. 3 correspond to the flowchart shown in FIG. 9 (the operation of the color electronic holography display device 1). is doing. Further, the operations of the color hologram light generating device 10 shown in FIG. 2 and the color unnecessary light removing optical system 20A shown in FIG. 4 correspond to the flowchart shown in FIG. 10 (the operation of the color electronic holography display device 2). ing.

  Moreover, the color hologram light generators 10 and 10A shown in FIG. 2 or FIG. 7 and the color unnecessary light removing optical system 20B shown in FIG. 5 correspond to the color electronic holography display device described in claim 5. The operations of the color hologram light generating device 10 shown in FIG. 2 and the color unnecessary light removing optical system 20B shown in FIG. 5 correspond to the flowchart shown in FIG. 11 (the operation of the color electronic holography display device 3). . The color hologram light generators 10 and 10A shown in FIG. 2 or FIG. 7 and the color unnecessary light removing optical system 20C shown in FIG. 6 correspond to the color electronic holography display device described in claim 6. The operations of the color hologram light generating apparatus 10 shown in FIG. 6 and the color unnecessary light removing optical system 20C shown in FIG. 6 correspond to the flowchart shown in FIG. 12 (the operation of the color electronic holography display apparatus 4). Further, the operations of the color hologram light generating device 10A shown in FIG. 7 and the color unnecessary light removing optical systems 20B and 20C shown in FIG. 5 or 6 are shown in the flowchart shown in FIG. 14 (the operation of the color electronic holography display device) 6).

  The color hologram light generators 10 and 10A shown in FIG. 2 or 7 and the color unnecessary light removing optical system 20D shown in FIG. 8 correspond to the color electronic holography display device described in claim 3. The operations of the color hologram light generating apparatus 10 shown in FIG. 6 and the unnecessary color light removing optical system 20D shown in FIG. 8 correspond to the flowchart shown in FIG. 13 (the operation of the color electronic holography display apparatus 5).

(Operation of color electronic holographic display device 1)
Next, the operation of the color electronic holography display system S (operation 1 of the color electronic holography display device) will be described with reference to the flowchart shown in FIG. 9 (see FIGS. 2 and 3 as appropriate). Here, red, green, and blue are sent in a time division manner, but blue subject light will be described as an example.
First, the color hologram light generation device 10 of the color electronic holography display system S displays a hologram pattern with the corrected focal length on the LCD 18, and displays a color electronic holographic image by synthesizing the hologram light (step S1). ).

  Subsequently, the color unnecessary light removing optical system 20 of the color electronic holography display system S collects light by the convex lens 21 of the first optical system (step S2), and removes unnecessary light by the light shielding plate 22. Then, the unnecessary color light removing optical system 20 passes the light from which unnecessary light has been removed through the half mirror 23 of the second optical system, and converts it into diffused light constituting the original color electronic holographic image by the concave mirror 24. 23 (step S3).

(Operation of color electronic holography display device 2)
Next, the operation of the color electronic holography display system S (operation 2 of the color electronic holography display device) will be described with reference to the flowchart shown in FIG. 10 (see FIGS. 2 and 4 as appropriate).
First, the color holographic light generation device 10 of the color electronic holography display system S displays a hologram pattern with a corrected focal length on the LCD 18 and displays a color electronic holographic image by synthesizing the holographic light (step S11). ).

  Subsequently, the color unnecessary light removing optical system 20A of the color electronic holography display system S collects light with the convex lens 21 of the first optical system and removes unnecessary light with the light shielding plate 22 (step S12). At this time, the light passing through the convex lens 21 becomes parallel light, and reaches the concave mirror 24 through the total reflection mirror. Therefore, a bright image can be obtained as compared with a configuration using a half mirror. Then, the unnecessary color light removing optical system 20A collects the light from which the unnecessary light has been removed by the concave mirror 24 of the second optical system, reflects it by the total reflection mirror 25, and outputs it (step S13). The light that has passed through the condensing point becomes diffused light that constitutes the original color electronic holographic image.

(Operation of color electronic holographic display device 3)
Next, the operation of the color electronic holography display system S (operation 3 of the color electronic holography display device) will be described with reference to the flowchart shown in FIG. 11 (see FIGS. 2 and 5 as appropriate).
First, the color hologram light generation device 10 of the color electronic holography display system S displays a hologram pattern on which the focal length is not corrected on the LCD 18 and combines the hologram light to generate a color electronic holographic image (reproduced light). Displayed (step S21).

  Subsequently, the unnecessary color light removing optical system 20B of the color electronic holography display system S reflects the reproduction light by the half mirror 26 of the first optical system, condenses it by the concave mirror 27, passes the half mirror 26, and passes through the light shielding plate. In step S22, unnecessary light is removed. Then, the unnecessary color light removing optical system 20B reflects the light from which unnecessary light has been removed by the half mirror 23 of the second optical system, and converts it into diffused light that constitutes the original color electronic holographic image by the concave mirror 24. Output through the mirror 23 (step S23).

(Operation of color electronic holographic display device 4)
Next, the operation of the color electronic holography display system S (operation 4 of the color electronic holography display device) will be described with reference to the flowchart shown in FIG. 12 (see FIGS. 2 and 6 as appropriate).
First, the color hologram light generation device 10 of the color electronic holography display system S displays a hologram pattern on which the focal length is not corrected on the LCD 18 and combines the hologram light to generate a color electronic holographic image (reproduced light). Displayed (step S31).

  Subsequently, the color unnecessary light removing optical system 20C of the color electronic holography display system S reflects the reproduction light by the half mirror 26 of the first optical system, makes it parallel light by the concave mirror 27, passes the half light 26, and passes through the light shielding plate. In step S32, unnecessary light is removed. Then, the unnecessary color light removing optical system 20C collects the light from which the unnecessary light has been removed by the concave mirror 24 of the second optical system, reflects it by the total reflection mirror 25, and outputs it (step S33). The light that has passed through the condensing point becomes diffused light that constitutes the original color electronic holographic image.

(Operation of color electronic holography display device 5)
Next, operation of the color electronic holography display system S (operation 5 of the color electronic holography display device) will be described with reference to the flowchart shown in FIG. 13 (see FIGS. 2 and 8 as appropriate). Here, the operations of the first optical system and the second optical system are collectively described as one step.
First, the color hologram light generation device 10 of the color electronic holography display system S irradiates laser light using three LDs of red LD11, green LD12, and blue LD13, and corrects the position and size of the hologram pattern (focal length). Is displayed on the LCD 18 and the hologram light is synthesized to display a color electronic holographic image (reproduction light) (step S41).

  Subsequently, the unnecessary color light removing optical system 20D of the color electronic holography display system S allows the reproduction light to pass through the convex lens 21 of the first optical system, removes unnecessary light by the light shielding plate 22, and the convex lens 28 of the second optical system. (Step S42).

(Operation of color electronic holographic display device 6)
Next, operation of the color electronic holography display system S (operation 6 of the color electronic holography display device) will be described with reference to the flowchart shown in FIG. 14 (refer to FIGS. 5, 6, and 7 as appropriate). Here, the operations of the first optical system and the second optical system are collectively described as one step.
First, the color hologram light generation apparatus 10A of the color electronic holography display system S irradiates laser light using one LD of RGBLD 31, and corrects the position and size of the hologram pattern (corrected the change in focal length once). A hologram pattern) is displayed on the LCD 18 and the hologram light is synthesized to display a color electronic holographic image (reproduction light) (step S51).

  Subsequently, the color unnecessary light removing optical system 20D of the color electronic holography display system S reflects the reproduction light by the concave mirror 27 constituting the first optical system, removes unnecessary light by the light shielding plate 22, and removes the second optical system. It outputs via the concave mirror 24 which comprises (step S52).

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, the semiconductor laser is used as the light source (red LD11, green LD12, blue LD13, RGBLD31), but a gas laser may be used. When an image hologram in which the subject position and the hologram surface are close to each other is used as the hologram pattern, the light source may not have a very high degree of phase matching of light such as a light emitting diode, a white lamp, or natural light.
Furthermore, although the transmissive liquid crystal element is used for the LCD 18 which is a hologram display device, a reflective display device may be used.

  Further, although the half mirror is used for the beam combining optical system 17 of the color hologram light generating apparatus 10, a prism may be combined to realize the same function. Further, instead of the convex lenses 21 and 28, a condensing lens combining a convex lens and a concave lens, a refractive index distribution lens using a glass cylinder whose refractive index changes concentrically, and a hologram pattern obtained from Equation (10) A hologram lens that collects light may be used.

  In the color unnecessary light removing optical systems 20, 20A, and 20D, the change in focal length is corrected with reference to red light, but green or blue light may be used as a reference. In this case, a part or all of the virtual lens assumed when the hologram pattern is obtained becomes a convex lens, but it can be obtained in the same manner.

1 is a schematic view of a color electronic holography display system (color electronic holography display device) according to an embodiment of the present invention. It is the schematic of a color hologram light generator (the 1). It is the schematic of a color unnecessary light removal optical system (the 1). It is the schematic of a color unnecessary light removal optical system (the 2). It is the schematic of a color unnecessary light removal optical system (the 3). It is the schematic of a color unnecessary light removal optical system (the 4). It is the schematic of a color hologram light generator (the 2). It is the schematic of a color unnecessary light removal optical system (the 5). It is the flowchart which showed the operation | movement (the 1) of a color electronic holography display system (color electronic holography display apparatus). It is the flowchart which showed the operation | movement (the 2) of a color electronic holography display system (color electronic holography display apparatus). It is the flowchart which showed the operation | movement (the 3) of a color electronic holography display system (color electronic holography display apparatus). It is the flowchart which showed the operation | movement (the 4) of a color electronic holography display system (color electronic holography display apparatus). It is the flowchart which showed the operation | movement (the 5) of a color electronic holography display system (color electronic holography display apparatus). It is the flowchart which showed the operation | movement (the 6) of a color electronic holography display system (color electronic holography display apparatus). It is the schematic of the conventional color holography apparatus. It is the schematic of the conventional unnecessary light removal optical system. It is the schematic for demonstrating the problem of the conventional unnecessary light removal optical system.

Explanation of symbols

10, 10A Color hologram light generator 11 Red LD (Red light source)
12 Green LD (Green light source)
13 Blue LD (Blue light source)
14, 15, 16, 32 Beam expansion lens 17 Beam synthesis optical system 18 LCD (hologram display device)
19, 19A Hologram memory 20, 20A, 20B, 20C, 20D Color unnecessary light removing optical system 21 Convex lens (first optical system)
22 light shielding plate 23 half mirror (first optical system)
26 Half mirror (second optical system)
24 Concave mirror (second optical system)
27 Concave mirror (first optical system)
25 Total reflection mirror (second optical system)
28 Convex lens (second optical system)
30 Power switch (switch)
31 Light source

Claims (7)

This is a pattern of interference fringes between object light in which the range of light diffusion from each point of the subject is limited to half for each color of red, green, and blue and colored light that is the light of each color. A color electronic holography display device that displays a color electronic holographic image of the subject using a hologram pattern,
A light source that generates the colored light of three colors of red, green, and blue;
A display device provided on an optical path of light from the light source and displaying the hologram pattern corresponding to each of the color lights;
A color hologram light generating means having
A first optical system that condenses light generated by irradiating light from the light source onto the hologram pattern displayed on the display device of the color hologram light generating means;
Corresponding to the limitation range of light diffusion from each point of the subject at the time of generating the hologram pattern, the optical axis of the first optical system is used as a boundary on the image side focal plane of the first optical system. A light-shielding plate arranged so as to be able to block light in a predetermined region that is half of the light emitted from the first optical system;
A second optical system that is installed at a subsequent stage of the light shielding plate and collects light that is not blocked by the light shielding plate among the light emitted from the first optical system to form a color electron holographic image;
A means for removing unnecessary color light,
With
The first optical system has a first condensing lens that condenses light generated by irradiating light from the light source onto the hologram pattern displayed on the display device,
The hologram pattern has a focal plane position of the first condenser lens caused by a color difference of the other colored light with respect to a focal plane position of the first condenser lens in the color light of one color. A color electronic holographic display device characterized in that the pattern is a pattern in which the deviation is corrected.   The second optical system is installed on a concave mirror that collects light that is not blocked by the light shielding plate among the light emitted from the first optical system, and the light emission direction of the light from the concave mirror. The color electronic holographic display device according to claim 1, further comprising a mirror to be changed. The second optical system has a second condenser lens that condenses light that is not blocked by the light shielding plate among light emitted from the first optical system,
Position and size of the color electronic holographic image formed by the second condensing lens with respect to the color light of the other color with respect to the color light of one color as a reference. The color electronic holographic display device according to claim 1, wherein the shift is a pattern in which the deviation is further corrected. This is a pattern of interference fringes between object light in which the range of light diffusion from each point of the subject is limited to half for each color of red, green, and blue and colored light that is the light of each color. A color electronic holography display device that displays a color electronic holographic image of the subject using a hologram pattern,
A light source that generates the colored light of three colors of red, green, and blue;
A display device provided on an optical path of light from the light source and displaying the hologram pattern corresponding to each of the color lights;
A color hologram light generating means having
A first optical system that condenses light generated by irradiating light from the light source onto the hologram pattern displayed on the display device of the color hologram light generating means;
Corresponding to the limitation range of light diffusion from each point of the subject at the time of generating the hologram pattern, the optical axis of the first optical system is used as a boundary on the image side focal plane of the first optical system. A light-shielding plate arranged so as to be able to block light in a predetermined region that is half of the light emitted from the first optical system;
A second optical system that is installed at a subsequent stage of the light-shielding plate, collects light that is not blocked by the light-shielding plate among the light emitted from the first optical system, and forms the color electronic holographic image;
A means for removing unnecessary color light,
With
The first optical system is installed on the optical path of the light from the display device, is installed on the optical path of the light from the half mirror that changes the emission direction of the light, and collects the light. A color electronic holographic display device comprising: a first concave mirror.   The second optical system is installed on the optical path of the light from the first concave mirror, and is installed on the optical path from the half mirror that changes the emission direction of the light, and collects the light. The color electronic holographic display device according to claim 4, further comprising a second concave mirror.   A second concave mirror that is installed on an optical path of light from the first concave mirror and collects light that is not blocked by the light shielding plate out of the light emitted from the first optical system; The color electronic holographic display device according to claim 4, further comprising a total reflection mirror that is installed on an optical path of light from the second concave mirror and changes an emission direction of the light. The second optical system has a second condenser lens that condenses light that is not blocked by the light shielding plate among light emitted from the first optical system,
Position and size of the color electronic holographic image formed by the second condensing lens with respect to the color light of the other color with respect to the color light of one color as a reference. 6. The color electronic holographic display device according to claim 4, wherein the shift is a pattern in which the deviation is further corrected.

Images