JP3452480B2 - Optical display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical display device for displaying image information and character information.

[0002]

2. Description of the Related Art In recent years, optical display devices for displaying image information and character information have been widely used in various fields. One example thereof is a lightning type optical display device which is widely used for traffic information display boards, destination information boards, advertising boards, etc., for example, JP-A-6-228921 and JP-A-7-129108. Japanese Laid-Open Patent Publication No. 7-140912
Japanese Patent Application Laid-Open No. 8-6513, Japanese Patent Application Laid-Open No. 8-158
No. 322 and Japanese Patent Application Laid-Open No. 8-160894,
Related techniques are disclosed. First, an optical road sign with a built-in fluorescent lamp, which is one of the most common examples of optical display devices, will be described below with reference to the drawings. However, in addition to this, various conventional configurations are known, such as one that incorporates an LED or EL element for self-luminous display and one that guides light from a light source by an optical fiber or a light guide plate.

FIG. 1A is a side view showing the structure of a conventional optical road sign, and FIG. 1B is a front view thereof. Specifically, 156 is a marker display plate, 157 is a ring type fluorescent tube, 158 is a marker body, and 159 is a marker column.

The sign display plate 156 is formed by printing a sign pattern on a semitransparent resin, and by illuminating this pattern from the inside of the sign with the light of the ring fluorescent tube 157, even at night. The sign is recognized. The sign main body 158 supports the ring type fluorescent tube 157 and the sign display plate 156, and is installed on the side wall of the road or the tunnel ceiling by being supported by the sign pillar 159.

However, the conventional configuration as described above has the following problems.

First, since the marking pattern is printed on a translucent resin or is composed of a color resin, most of the light emitted by the ring fluorescent tube 157 which is a light source is absorbed by this resin. Display is not bright enough.

Secondly, since the display unit including the marker display plate 156 and the fluorescent tube (light source) 157 is supported by the marker main body 158, the portion including the display unit is large and heavy. Furthermore, the support pillar 159 that supports it
Must also be robust, resulting in a larger and heavier overall construction.

Thirdly, because of its structure, it must be installed so as to largely protrude from the side wall of the road or the tunnel ceiling, which is the mounting surface, so that for some reason, a moving body such as a person, a car, or a transported object may be installed. If they come into contact with each other, the display device body may be damaged and the moving body may be damaged at the same time. Furthermore, in order to avoid such accidents, it is necessary to secure a large installation space, which is uneconomical.

The above-mentioned problems are not limited to the problems of the optical road signs with a built-in fluorescent lamp shown in FIG. 1A and FIG. 1B as conventional examples, but they are self-luminous structures such as LEDs, optical fibers and light guide plates. The same applies to the configuration in which the light from the light source is guided by. Further, the problem is not limited to the above-mentioned road signs, but is a problem common to all types of optical display devices that irradiate a pattern to be displayed with light from a light source.

Therefore, a configuration using a hologram is conceivable as a configuration capable of solving the above problems.

In the following, first, the principle of creating a hologram according to a general prior art and the principle of displaying (reproducing) image information using such a conventional hologram will be described.

FIG. 2A is a diagram schematically showing the principle of forming a general hologram.

That is, the object O is irradiated with the object illumination light IL emitted from the laser light source to form the object light OL having information about the shape of the object O and the hologram light plate H1. Further, at the same time, the reference light RL1 formed by separating the light emitted from the same laser light source as the object illumination light IL by a beam splitter or the like is used as a hologram dry plate H1.
It is incident at an angle to. As a result, interference fringes between the object light OL and the reference light RL1 are recorded on the hologram dry plate H1. Such interference fringes (having information on the subject O)
The hologram dry plate H1 on which is recorded is also referred to as "hologram plate H1" below.

FIG. 2B is a diagram schematically showing the reproduction principle of the hologram plate H1 formed by FIG. 2A.

That is, the reproduction illumination light RI1 which is the light from the same laser light source as that used when the hologram plate H1 is produced is propagated through the same path as the reference light RL1 (see FIG. 2A) and is applied to the hologram plate H1. To do. As a result, the light (reproduction light) R1 having the subject information recorded on the hologram plate H1 is reproduced, and the reproduced image I1 is observed at the position where the subject was initially placed.

[0016]

However, in the above method, since it is necessary to use a laser light source as a light source at the time of making and reproducing the hologram plate H1, the cost cannot be reduced and the handling is complicated. , And so on.

On the other hand, in the reflection hologram described below, it is possible to reproduce a hologram image using white light.

In producing the reflection hologram, first, as shown in FIG. 3A, a reproduction illumination light (from the direction opposite to the reproduction illumination light RI1 shown in FIG. 2B is formed on the hologram plate H1 produced by the method shown in FIG. 2A). Laser light) RI21 is irradiated. As a result, the reproduction light R21 traveling from the hologram plate H1 to the position where the subject was present is reproduced, and the real image (reproduction image) I21 of the subject is reproduced at the position where the subject was present.
Next, as shown in FIG. 3B, a new hologram dry plate H2 is placed at a position away from the reproduced image I21 of the subject by a distance z0, and the reference light beam is directed to the hologram dry plate H2 in the opposite direction to the hologram plate H1. The RL2 is obliquely incident. The reference light RL2 is formed by separating the light emitted from the same laser light source as the reproduction illumination light RI21 with a beam splitter or the like. Thereby, the interference fringes of the reproduction illumination light RI21 and the reference light RL2 are recorded on the hologram dry plate H2. The hologram dry plate H2 in which such interference fringes (having information on the subject) is recorded as a reflection hologram.
Will also be referred to as “reflection hologram plate H2” below.

FIG. 3C is a diagram schematically showing the reproduction principle of the reflection hologram plate H2 formed as described above.

That is, reproduction illumination light RI22 (white light from a point light source placed at a distance from the reflection hologram plate H2) propagating through the reflection hologram plate H2 in the direction opposite to the reference light RL2 of FIG. 3B. ), And irradiate. As a result, the reproduction light R22 having the subject information recorded on the reflective hologram plate H2 is reproduced, and the reproduced image I22 is formed at the position where the subject was initially placed.

Since the reflection type hologram has a high wavelength selectivity (color selectivity) in the diffraction characteristic (diffraction efficiency) of light, the image I22 is reproduced by the light in the vicinity of the wavelength of the laser light used for producing the hologram. To be done. As a result, it is possible to reproduce a color image by superimposing it. However, if the distance z0 indicating the position of the reflection hologram dry plate H2 and the display position of the reproduced image I22 is large, a clear reproduced image cannot be obtained.

Here, the reason why the reproduced image of the reflection type hologram is blurred will be further described with reference to FIGS. 3D and 3E.

Reconstruction illumination light RI for the reflection hologram
22 is white light. Therefore, wavelengths other than the wavelength λ0 of the laser light used when the hologram is created are also included in the reproduction illumination light RI22. As shown in the graph of the wavelength dependence of the diffraction efficiency in FIG. 3E, the reflection hologram has high wavelength selectivity, and the light having a wavelength greatly separated from the wavelength (center wavelength) λ0 of the laser light used when the hologram was created. Is hardly diffracted. Therefore, only the light having a wavelength in the vicinity of the central wavelength λ0 is diffracted and the image I22 is reproduced. However, at this time, actually, the light having a wavelength different from λ0, which is near the central wavelength λ0, as represented by λ1 and λ2 in FIGS. 3D and 3E, is also included in the reproduction light R22. A reproduced image by those lights is also formed at the same time and is superimposed on the original reproduced image by the light having the central wavelength λ0. Due to this influence, when the distance z0 to the position where the reproduced image I22 is formed is set to be large, the reproduced image I22 is blurred. That is, in the reflection hologram, a clear reproduced image I is obtained when the distance from the distance z0 set at the time of creation is increased.
22 cannot be seen. This is a very serious disadvantage in application to optical information devices such as road signs for the purpose of clearly transmitting desired information.

As described above, the conventional general hologram and the reflection type hologram to which the conventional hologram is applied are cost effective and accurate information for use as an optical display device such as a road sign. In terms of display and transmission,
Have a big problem.

On the other hand, as a hologram display method which is different from the one described above, there is a method known as a rainbow hologram.

In producing the rainbow hologram, first, the hologram plate H1 produced by the method shown in FIG. 2A is used.
Then, as shown in FIG. 4A, reproduction illumination light (laser light) RI31 is emitted from a direction opposite to the reproduction illumination light RI1 shown in FIG. 2B through a slit having a width Δ. As a result, the reproduction light R31 traveling from the hologram plate H1 to the position where the subject was present is reproduced, and the real image (reproduction image) I31 of the subject is reproduced at the position where the subject was present. Next, as shown in FIG. 4B, a new hologram dry plate H3 is placed at a position away from the reproduced image I31 of the subject by a distance z0, and the reference light RL3 from the same side as the hologram plate H1 with respect to this hologram dry plate H3. Incident at an angle. This reference light RL3 is
It is formed by separating the light emitted from the same laser light source as the reproduction illumination light RI31 with a beam splitter or the like. Thereby, the interference fringes of the reproduction illumination light RI31 and the reference light RL3 are
It is recorded on the hologram dry plate H3. The hologram dry plate in which such interference fringes (having information on the subject) is recorded as a transmission hologram by the rainbow hologram method is also referred to as “rainbow hologram plate H3” below.

FIG. 4C is a diagram schematically showing the reproduction principle of the rainbow hologram plate H3 formed as described above.

That is, the rainbow hologram plate H3
With the reproduction illumination light RI32 (white light from a point light source placed at a distance from the rainbow hologram plate H3) propagating in the direction opposite to the reference light RL3 in FIG. 4B. As a result, the reproduction light R32 having the subject information recorded on the rainbow hologram plate H3 is reproduced, and the reproduction light R32 heads to the position where the slit was placed at the time of creation,
The reproduced image I32 is formed at the position where the subject was initially placed.

In the rainbow hologram thus formed, a clear reproduced image is observed as compared with the reflection hologram. The reason for this will be described with reference to FIGS. 4D and 4E.

Since the reproduction illumination light RI32 for the rainbow hologram is white light, the reproduction illumination light RI32 also includes wavelengths other than the wavelength λ0 of the laser light used when the hologram was created. However, as shown in the graph of wavelength dependence of diffraction efficiency in FIG. 4E, a rainbow hologram, which is a transmission hologram, has low wavelength selectivity and diffracts light in a relatively wide wavelength range to emit reproduction light R32. The image I32 corresponding to light of different wavelengths is reproduced. However, since the slits are used when creating the rainbow hologram, the reproduced images with light of different wavelengths are at different positions (that is, spatially separated).
It is formed. For example, in FIGS. 4D and 4E, λ1 and λ2
A reproduced image with a wavelength different from the central wavelength λ0 is formed at the same time at a position different from the reproduced image with the light with the central wavelength λ0, and the original reproduced image with the light with the central wavelength λ0 is spatially formed. There is no overlap. For this reason,
In the rainbow hologram, the reproduced image I32 of different color is relatively clearly observed according to the change of the observation position.

A reproduced image I32 of a different color depending on the observation position
The fact that is observed is also the origin of the name of the rainbow hologram, and various applications that take this point as a merit have been proposed. However, on the other hand, from the viewpoint of reproducing a color image, such a change in color of the reproduced image I32 depending on the observation position has a demerit that a desired color image cannot be reproduced. For example, in the case of the above-mentioned road signs, the use of a predetermined color also constitutes a part of the information to be transmitted, and thus the features of the rainbow hologram as described above make the intended information clear. This is a very serious disadvantage in the application to an optical information device for the purpose of transmitting the information to the device.

The present invention has been made in consideration of the above-mentioned problems of the prior art, and the purpose thereof is to use a hologram technique based on a new method to occupy a small space and be bright and clear. It is an object of the present invention to provide a lightweight optical display device capable of reproducing and displaying image information.

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[0062]

Optical display device of the present invention According to an aspect of the image display apparatus, an imaging optical system, an optical display device comprising a holographic screen, and the image display device, at least The hologram screen has one point light source, and is configured to diffract and reflect light from the point light source to form a point image at a position different from the point light source. Is configured such that only a component along one direction of the image displayed on the image display device is focused on the hologram screen, and the display image of the image display device is reproduced on the virtual display surface. It is formed as an image.
With such a feature, the above-mentioned object is achieved.

The virtual display surface is the hologram screen.
And an observer of the reproduced image formed on the virtual display surface.
Placed between .

The hologram screen is the virtual table.
And a viewer of the reproduced image formed on the virtual display surface.
Placed between .

The image of the image displayed on the image display device is
One direction is a vertical direction, and the imaging optical system is a cylinder.
Cull lens and variable focus with power only in the lateral direction
And a point lens.

View of the reproduced image formed on the virtual display surface
It further has polarized glasses that are worn by the observer.
In the light glasses, the orientations of the respective polarizing plates are orthogonal to each other.

The optical display system of the present invention comprises the plurality of
Optical display devices are arranged side by side when viewed from the observer
Has been done.

Further , the optical display system of the present invention is
The depth of the image as seen by the observer
Are arranged in the direction.

The image display device is an LED, a CRT,
Select from molecular dispersion type liquid crystal panel or organic EL panel
And a polarization switching element.

The polarization switching element includes a ferroelectric liquid crystal panel. Moreover, further comprising, polarizing Me polarizing glasses for viewing a reproduced image formed on the virtual display plane
The glasses have the orientations of the respective polarizing plates orthogonal to each other.

[0071]

BEST MODE FOR CARRYING OUT THE INVENTION Prior to the description of specific embodiments of the present invention, first, the principle of the hologram proposed by the inventor of the present application for realizing the optical display device of the present invention will be described.

In producing a hologram according to the present invention, first, as shown in FIG. 5A, a hologram plate H1 produced by the conventional method shown in FIG. 2A is passed through a slit having a width Δ to obtain the reproduction illumination light RI1 shown in FIG. 2B. Irradiates reproduction illumination light (laser light) RI41 from the opposite direction. As a result, the reproduction light R41 traveling from the hologram plate H1 to the position where the subject was present is reproduced, and the real image (reproduction image) I41 of the subject is reproduced at the position where the subject was present. Next, as shown in FIG. 5B, the hologram dry plate H4 is placed at a position away from the reproduced image I41 of the subject by a distance z0, and the reference light RL4 is obliquely applied to the hologram dry plate H4 from the side opposite to the hologram plate H1. Incident on. This reference light RL4 is
The reproduction illumination light RI41 is formed by separating the light emitted from the same laser light source with a beam splitter or the like. Thereby, the interference fringes of the reproduction illumination light RI41 and the reference light RL4 are
It is recorded on the hologram dry plate H4. The hologram dry plate H4 in which such interference fringes (having information on the object) are recorded as a reflection hologram is also referred to as "hologram plate H4" below.

FIG. 5C is a diagram schematically showing the reproduction principle of the hologram plate H4 formed as described above.

That is, the hologram plate H4 is illuminated with reproduction illumination light (white light) RI42 propagating in the direction opposite to the reference light RL4 of FIG. 5B. As a result, the reproduction light R having the subject information recorded on the hologram plate H4 is obtained.
42 is reproduced, and the reproduced image I42 is formed at the position where the subject was initially placed toward the position where the slit was placed at the time of creation.

In the hologram of the present invention thus formed, a clear reproduced image I42 is observed as compared with the conventional reflection type hologram, and the color of the reproduced image depending on the observation position as in the conventional rainbow hologram. There is no problem of big change of. The reason for this will be described below.

Since the reproduction illumination light for the hologram of the present invention is white light, wavelengths other than the wavelength λ0 of the laser light used at the time of producing the hologram are also included in the reproduction illumination light. However, as shown in the graph of the wavelength dependence of the diffraction efficiency in FIG. 6A, the reflection hologram has a high wavelength selectivity, and a wavelength far apart from the wavelength (center wavelength) λ0 of the laser beam used when the hologram is formed is used. Light is hardly diffracted. Therefore, basically, only the light having a wavelength in the vicinity of the central wavelength λ0 is diffracted to become the reproduction light R42, and the image I42 by these lights is reproduced. At this time, actually, a reproduced image by light having a wavelength different from λ0, which is near the central wavelength λ0, as typified by λ1 and λ2 in FIGS. 6A and 6B, is simultaneously formed. In the invention, since the slit is used when the hologram is formed, the reproduced images by the light of different wavelengths are formed at different positions (that is, spatially separated).
For example, a reproduced image with a wavelength different from the central wavelength λ0, which is represented by λ1 and λ2 in FIGS. 6A and 6B, is simultaneously formed at a position different from the reproduced image with the light with the central wavelength λ0. It is not spatially superimposed on the original reproduced image by the light. Therefore, in the hologram of the present invention, although the color of the reproduced image I42 slightly changes depending on the observation position, the reproduced image I42 of each color is clearly observed.

Since the hologram of the present invention is a reflection type, it has high wavelength selectivity in diffraction efficiency, and light having a wavelength other than the vicinity of the central wavelength λ0 is not diffracted. For this reason, when the white light RI42A from the point light source arranged at a certain distance from the hologram plate H4 is used as the reproduction illumination light, the observation position changes significantly (that is, the observer moves greatly). The diffraction efficiency of the hologram with respect to the wavelength forming an image observable at the observation position becomes zero, and the reproduced image is not observed. In other words, when the hologram of the present invention is reproduced by the parallel light RI42A from the point light source, the visible range of the reproduced image I42 becomes extremely narrow.

However, as shown in FIG. 7A, when the reproduction illumination light RI42 incident on the hologram plate H4 is not a parallel light but a collection of light having a certain incident angle,
The reproduced image I42 by the reproduced light R42 having the most suitable wavelength according to each incident angle is separated and reproduced at positions spatially different from each other. Such an incident condition can be realized by using the linear light source LL instead of the point light source. That is, as shown in FIG. 7B,
If a linear light source LL such as a fluorescent lamp is used as the light source LL of the reproduction illumination light RI42 for the hologram of the present invention,
The incident angle of the reproduction illumination light RI42 with respect to the hologram plate H4 can intentionally have a certain angle range, and as a result, the visible range of the reproduction image I42 can be widened.

At this time, if the observation position for the hologram of the present invention changes, the color of the reproduced image I42 changes, as in the case of the conventional rainbow hologram. However, the ratio of such a color change of the reproduced image I42 is about several% of the color change in the rainbow hologram. For example,
When a hologram plate is formed with reference light having an incident angle of 45 degrees, a change in the observation position such that the color of the reproduced image in the rainbow hologram changes from blue to red causes a wavelength change of the order of 100 nm. On the other hand, in the hologram of the present invention, the wavelength change of the reproduced image I42 is about 6 nm with respect to the same change of the observation position, and the change of color is hardly recognized.

Even if the hologram structure of the present invention as described above is applied to a conventional rainbow hologram, the reproduced images of seven colors are overlapped with each other and only the whole is whitened. This is because the conventional rainbow hologram is a transmissive hologram, whereas the hologram of the present invention is a reflective hologram, and the diffraction efficiency is highly wavelength-dependent.

As described above, in the hologram forming principle of the present invention, the characteristic of “the diffraction efficiency has a high wavelength dependency and the visual recognition range of the reproduced image is narrow” which is considered to be a disadvantage in the conventional reflection hologram is regarded as an advantage. Then, the image reproduced by the laser light passing through the slit is printed as a reflection hologram to form a hologram plate. By obtaining a reproduced image using the hologram plate thus formed, it is possible to obtain a color reproduced image by superimposing the reproduced images with little blurring of the image even if the observation position is displaced and the wavelength selectivity is high. It is possible to obtain features that cannot be obtained by various conventional hologram construction principles, such as being possible.

Various embodiments of the optical display device of the present invention constructed by utilizing the hologram method of the present invention based on the above principle will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 8 shows a first embodiment of the present invention.
FIG. 9 is a side view showing the configuration of the optical display device in the embodiment of FIG. 5, and FIG. 9 is a plan view of the optical display device. In this embodiment, the optical display device of the present invention is used as a road sign in a tunnel.

In FIG. 8, 1 is the optical display device of the present embodiment, 2 is a hologram, 3 is a fluorescent lamp which is a linear light source,
Reference numeral 4 is a fluorescent lamp, and 5 is a shielding plate. Optical display device 1
Are arranged on the ceiling surface 7 of the tunnel 6.

Of the illumination light 8 emitted from the fluorescent lamp 3, one incident on the hologram 2 is diffracted by this to become a reproduction light 9 and a reproduction image 11 is formed on the virtual display surface 10. At this time, the reproduced image 11 viewed from the front is the tunnel 6
When viewed from a vehicle passing through the inside of the vehicle, the road sign indicating the speed limit looks as if it is hung at a position lower than the ceiling surface 7 of the tunnel 6. However, this is a display (reproduced image 11) on the virtual display surface 10, and in reality there is no object at that location. Therefore, a car accident or the like cannot occur at all.

The virtual display surface 10 is a plane or curved surface virtually provided in the space. The reflected light from the surface of the hologram 2 is directed toward the road surface (reflected light in this direction is shown in FIG. 8) or toward the ceiling surface 7 (reflected light in this direction is shown in FIG. 8). It can be deflected to the driver's eyes), so it does not come into direct contact with the driver's eyes. Rather, these reflected lights can be illumination lights that illuminate road surfaces and ceiling surfaces, respectively, and can be effectively used.

Further, since a part of the illumination light 8 from the fluorescent lamp 3 is blocked by the shielding plate 5, this also does not directly enter the eyes of the driver. The light of the illumination light 8 that directly goes to the road surface and the ceiling surface can also be illumination light that illuminates the road surface and the ceiling surface, respectively, and can be effectively utilized.

The light source section including the fluorescent lamp 3 and the fluorescent lamp 4 can be constructed by using a general lamp used at home or office, but it is waterproof to prevent water from entering when cleaning the tunnel. It is preferable to take measures. For example, the light source unit may be configured by embedding the fluorescent lamp 3 and the fluorescent lamp 4 in the ceiling surface 7 of the tunnel 6 and covering them with a transparent cover.

Next, the principle of forming the reproduced image 11 on the virtual display surface 10 by the hologram 2 will be described with reference to its manufacturing method.

First, a method for producing the hologram 2 will be briefly described with reference to FIG.

FIG. 10 is a perspective view showing an optical system for producing the hologram 2, in which 12 is a slit, 13 is a pattern mask of a road speed limit road sign which is an object, 14 is object light, 15 is an incident plane, and 16 is Reference beam 17 is a hologram dry plate. Normally, since the fabrication optical system is arranged on the optical plate, the optical system shown in FIG. 10 is placed horizontally by 90 degrees, but here, the optical display device is arranged during operation. The vertical arrangement is illustrated in accordance with FIG. Also,
Actually, a hologram is prepared by using a pattern mask having a plurality of different patterns corresponding to the three primary colors of color and appropriately switching the laser wavelength for exposure and the arrangement of the optical system. Therefore, a configuration having one pattern mask 13 will be described.

The method for producing the hologram 2 is as follows.

First, an argon laser beam having a wavelength of 514.5 nm which has become diffused light by passing through a frosted glass (not shown) is made incident on the slit 12, and the information passing through the slit mask 12 is read to read the information on the pattern mask 13. The object light 14 is formed. This configuration is for making the reproduced image appear to be raised, and the pattern mask 13 is installed so as to face up when viewed from the slit 12 side. The slit used has a width of about 1.5 m, for example.
m, the length is about 40 mm.

On the incident plane 15 uniquely defined as a plane perpendicular to the longitudinal direction of the slit 12, the reference light 16 which is the substantially parallel light emitted from the argon laser is incident. Here, in order to form a reflection hologram, the reference light 16 is incident from the back surface of the hologram dry plate 17 at an angle of 15 degrees. In addition, the reference light 16 is incident on the incident plane 1.
Although it is not always necessary to make the reference light 16 incident on the surface 5, the reference light 16 is drawn on the incident plane 15 as a more preferable form.

As described above, the object light 14 and the reference light 16 form interference fringes, and the interference fringes are recorded on the hologram dry plate 17. Generally, as a constituent material of the hologram dry plate 17, a silver salt, dichromated gelatin, a photopolymerization type photopolymer or the like is used. For example, a dry film type photopolymerizable photopolymer having a thickness of about 20 μm is attached to a glass substrate to form the hologram dry plate 17.

Next, with respect to the method for producing the hologram 2,
Further details will be described.

11A and 11B are a side view and a plan view, respectively, of the optical system for producing the hologram shown in FIG. In addition, 18 is a ground glass, 19 is a laser beam, 20
Is diffuse light.

As shown in FIG. 11A, the laser light 19 incident on the frosted glass 18 becomes diffused light 20 and enters the slit 12. The slit 12 viewed from the side has a narrow width and allows only a part of the diffused light 20 to pass through. Therefore,
When viewed from the side, the light that has passed through it looks like the divergent light emitted from a single point. This light reads the information on the pattern mask 13 and irradiates the hologram dry plate 17 as object light 14, which can be regarded as a projection of the pattern mask 13 on the hologram dry plate 17. The object light 14 including the information of the subject forms an interference fringe with the reference light 16 incident from the back surface of the hologram dry plate 17, and the interference fringe is recorded on the hologram dry plate 17.

At this time, since the "shadow" of the pattern mask 13 projected on the hologram dry plate 17 is enlarged,
In consideration of this projection magnification, the pattern mask 13 is manufactured by reducing it in one direction in advance. This magnification varies depending on the setting of the optical system, but is usually about 1.2 times to about 2 times.

More specifically, if the original height of the pattern mask 13 is Hm and the height of the image actually seen from the observation position OP is Hi, the magnification is the geometrical relation of FIG. Therefore, Hi = Hm (1-z0 / L ') / (1-z0 / L). Here, z0 is the distance from the hologram dry plate 17 to the image (pattern mask 13), L is the distance from the hologram dry plate 17 to the slit 12 during hologram production, and L'is the distance from the hologram dry plate 17 to the observation position OP. . As can be seen from the above, the magnification is 1 when L = L ', and when observing from the position where the slit 12 was placed, the scaling action does not occur. on the other hand,
When the distance L ′ changes, that is, when the slit 12 is moved from the position where it was placed and is observed from a wide range, the scaling action occurs.

This relationship is expressed by the normalized observation distance (L '/ L)
And the normalized image height (Hi / Hm) as L / z
FIG. 13 shows 0 as a parameter. From this, to reduce the change in magnification when observing from a wider range, L
The value of / z0 should be large. Preferably L / z0
When it is set to 10 or more, the magnification can be suppressed to 1.1 or less (that is, 10% or less shape change) even when observed from a wide range.

More preferably, if the value of L / z0 can be selected to be substantially infinite, the change in magnification can be theoretically eliminated. Returning to the definition and thinking back, L / z0
Choosing the value of is substantially infinite corresponds to the fact that the straight line drawn from the slit 12 to the hologram 17 has no inclination except for the case of z0 = 0. Therefore,
As shown in FIG. 14, the slit 12 and the frosted glass 18 may be replaced by a one-dimensional diffuser 1001 having no light diffusion effect in the height direction of the hologram 17 and having a light diffusion effect only in the width direction of the hologram 17. . As such a diffuser 1001, a structure using a diffraction grating, a holographically manufactured structure, or the like,
There are several examples of configurations, and for example, a lenticular lens sheet having a configuration in which cylindrical lenses are arranged may be used.

Here again, the slit 12 and the ground glass 1
The description will be continued by returning to the method for producing a hologram using 8 and 8.

As shown in the plan view of FIG. 11B, the width of the slit 12 when viewed from above is wide, and the diffused light 20 emitted from the frosted glass 18 is allowed to pass through a wide range. Figure 1
In 1B, the diffused light passing through the central portion of the slit 12 is shown by a solid line, and the diffused light passing through both ends of the slit 12 is shown by a broken line. The diffused light indicated by the solid line represents the information when the pattern mask 13 is viewed from the front side.
Both of the diffused lights, which are projected on 7, and which are indicated by broken lines, project information on the hologram dry plate 17 when the pattern mask 13 is seen slightly obliquely from the end of the slit 12. The object light 14 including these pieces of information forms interference fringes with the reference light 16 incident from the back surface of the hologram dry plate 17, and the interference fringes are recorded on the hologram dry plate 17. this is,
This is a principle of forming a reproduced image of the pattern mask 13 viewed from different angles toward both eyes of the observer when reproducing the hologram later.

Although the side view and the plan view have been described separately for the sake of clarity, it goes without saying that the recording of the above interference fringes proceeds simultaneously in the actual hologram manufacturing process.

Next, the hologram reproducing principle of the present invention will be described.

Generally, the illumination light used for reproducing the hologram is a conjugate light of the reference light. In the hologram manufacturing process of the present invention, since the reference light is parallel light as described above, the illumination light may be parallel light. However, since laser light is used during hologram production, parallel light can be easily formed, but it is difficult to form parallel light from a white light source such as a halogen lamp generally used for hologram reproduction. Realistically, select a light source with a small light emitting part, limit the aperture to this, and arrange the light source that can be regarded as this rough point light source at a sufficient distance from the hologram, and emit it with the substantially parallel light. The hologram is reproduced by illuminating with divergent light that can be considered. The hologram 2 in the present embodiment can also be used to temporarily reproduce an image by such a method.

15A and 15B are a side view and a plan view showing the principle of reproducing the hologram 2. 21 is a halogen lamp, 22 is an opening, 23 is illumination light, 24 is reproduction light,
25 is an observer, and 26 is a reproduced image of the slit 12.

The light emitted from the halogen lamp 21 has an opening 22.
Illumination light 23 that can be regarded as substantially parallel light is formed. The reproduction light 24 formed by diffracting the illumination light 23 by the hologram 2 forms the reproduction image 11 near the virtual display surface 10, that is, the position where the pattern mask 13 was placed at the time of hologram production, and the observer observes it. At 25, the reproduced image 11 appears to rise from the hologram surface.

As a result of the observation, the viewing angle in the horizontal direction at which the reproduced image 11 can be observed is about 8 degrees, which means that even if the automobile changes lanes (ie, moves about 6 m to the left and right) on an actual road. This means that the display by the optical display device 1 of the present invention can be recognized when viewed from a position 50 to 100 m away. However, the viewing angle in the vertical direction is as small as about 1 degree, which means that it is not always possible to sufficiently secure a section or time in which a sign can be recognized by a vehicle traveling at high speed.

The reproduced image 11 looks brightest when the observer is present at the position where the reproduced image 26 of the slit 12 is formed, that is, at the position where the slit 12 was placed at the time of hologram production. The entire reproduced image 11 can be seen in the vicinity. However, when it is closer to the hologram 2 than this position, or when it is far from the hologram 2, only part of the image is visible.

From the above observation results, although reproduction images can be obtained by reproduction using a point light source, it is extremely difficult to construct a practical road sign for tunnels.

Therefore, the inventor of the present application further continued to study the positional relationship between the light source and the hologram, the interaction between the illumination light and the hologram, and observed the reproduced image in more detail. As a result, the above problem was solved. The inventors have come to find an unprecedented practical advantage that is extremely important in solving and configuring the optical display device 1 of the present invention.

16A and 16B show two characteristic shapes of the opening 22 used in the process of observing the reproduced image.

As a result of the observation, when the width of the opening 22 is expanded horizontally as shown in FIG. 16A, the reproduced image of the hologram 2 is blurred, but even if the length of the opening 22 is extended vertically as shown in FIG. 16B, The reproduced image of hologram 2 was not blurred. Moreover, it was confirmed that as the length of the opening 22 was extended, the visible range in the vertical direction expanded, and the color of the reproduced image did not change in the visible range. That is, the observer always sees an image of the same color without blurring within the viewing range in the vertical direction. This is a remarkable effect due to the hologram 2 being a reflection type.

Further, when the opening 22 which is long in the vertical direction is used, even when the observer is closer to the hologram 2 or farther from the hologram 2 than the position where the reproduced image 26 of the slit 12 is formed, the reproduced image is obtained. The whole can be observed. In other words, even if the position from the image is changed in the depth direction, the observer can see the entire image of the same color without blur without a part thereof being lost.

The expression "color does not change" is used here, but strictly speaking, the reproduction wavelength changes. However, as will be described later, by appropriately selecting the parameters of the hologram, it is possible to suppress the wavelength change that cannot be seen by human eyes.

The above observation results mean that the combination of the hologram 2 according to the present invention and the vertically long opening 22 can solve all the above-mentioned problems and form a practical tunnel road sign. ing.

In the first embodiment of the present invention, as shown in FIG. 8, the straight tube fluorescent lamp 3 is used as the light source. Even when reproduced by the straight tube fluorescent lamp 3, a bright reproduced image with no blur and no color change is obtained. Also, hologram 2
Even if you observe the image from above and below, you can always see the reproduced image without blur. When the fluorescent lamp 3 is brought a little closer to the hologram 2 under a predetermined condition, the vertical viewing angle is ±.
It can reach up to 5 degrees, which suggests that the distance and the time during which a sign can be recognized by a car running at high speed can be sufficiently large. Further, even if the distance from the hologram 2 is changed, the reproduced image is not lost, and the reproduced image can be seen sufficiently in front of the optical display device 1.

In the hologram manufacturing process, the reference light 16 is incident on the incident plane 15, but the invention is not limited to this. Further, in the image reproduction, the fluorescent lamp is arranged on the incident plane 15, but the invention is not limited to this. According to the present invention, there is a margin in the incident direction of the reference light and the arrangement and direction of the linear light source.

Further, in the method of producing a hologram using the one-dimensional diffuser 1001, the plane of incidence can be defined as a plane orthogonal to the direction in which diffused light spreads. The reference light is basically incident on the incident plane, but the invention is not limited to this.
Further, in image reproduction, the basic configuration is to arrange the fluorescent lamp on the incident plane, but the invention is not limited to this.

(Second Embodiment) In the first embodiment,
Although the fluorescent lamp 3 which is a linear light source is arranged horizontally, the installation condition of the fluorescent lamp 3 does not matter as long as it is basically placed on the incident plane 15 or in the vicinity thereof.

FIG. 17A is a perspective view showing the reproducing optical system of the optical display device of the present invention, and either horizontal or vertical arrangement shown is possible, and
Installation at any angle in between is possible. However, the viewing angle range in the vertical direction changes depending on the installation direction.

FIGS. 17B and 17C are comparison diagrams of the viewing angle range when the fluorescent lamps 27 having the same length are horizontally arranged and vertically arranged.

In the case of the horizontal arrangement of FIG. 17B, the illumination light 28 emitted from the right end of the fluorescent lamp 27 is diffracted by the hologram 2 to form a reproduced image 29, which is reproduced by the observer 3.
Recognized by 0. On the other hand, the illumination light 31 emitted from the left end of the fluorescent lamp 27 is diffracted by the hologram 2 to form a reproduced image 32, which is recognized by an observer 33. The angle formed by the position of the observer 30 and the position of the observer 33 with respect to the hologram 2 is the visible angle range in the horizontal arrangement.

Further, in the case of the vertical arrangement of FIG. 17C, the illumination light 34 emitted from the lower end of the fluorescent lamp 27 shown by the solid line is diffracted by the hologram 2 to form a reproduced image 35, which is observed by the observer. Recognized by 36. On the other hand, the illumination light 37 emitted from the upper end of the fluorescent lamp 27 is diffracted by the hologram 2 to form a reproduced image 38.
Are recognized by the observer 39. The angle formed by the position of the observer 36 and the position of the observer 39 with respect to the hologram 2 is the visible angle range in the vertical arrangement.

By comparing the case of the horizontal arrangement and the case of the vertical arrangement, it can be seen that the viewing angle can be wider in the vertical arrangement. From a different point of view, it is possible to use a shorter fluorescent lamp by adopting a configuration close to the vertical arrangement. Strictly speaking, it is more preferable to arrange the fluorescent lamp vertically in the optical path of the reproduction illumination light.

FIG. 18 is a side view showing the configuration of the optical display device according to the second embodiment of the present invention. Also in this embodiment, the optical display device of the present invention is used as a road sign in a tunnel.

In FIG. 18, 40 is the optical display device of the present embodiment, 41 is a fluorescent lamp which is a linear light source, 42 is a fluorescent lamp, and 43 is a reflector. The optical display device 40 is
It is arranged on the ceiling surface 7 of the tunnel 6.

The direct light emitted from the fluorescent lamp 41 and the indirect light once reflected by the reflection plate 43 are combined to form the illumination light 44. Due to the effect of the reflection plate 43, a brighter display is possible. Of the illumination light 44, that incident on the hologram 2 is diffracted by this to become the reproduction light 45, and the reproduction image 11 is formed on the virtual display surface 10. At this time, when viewed from the car passing through the inside of the tunnel 6, the reconstructed image 11 seen from the front is hung at a position where the road sign indicating the speed limit is lowered as if separated from the ceiling surface 7 of the tunnel 6. It will look as if it were. However, this is a display on the virtual display surface 10 (reproduced image 11).
And, in reality, there is no object in that place.
Therefore, a car accident or the like cannot occur at all.

The virtual display surface 10 is a plane or a curved surface virtually provided in the space. The reflected light from the surface of the hologram 2 is directed toward the road surface (the reflected light in this direction is shown in FIG. 18) or the ceiling surface 7
Since it can be deflected in the direction toward (the reflected light in this direction is not shown in FIG. 18), it does not directly enter the eyes of the driver. Rather, these reflected lights can be illumination lights that illuminate road surfaces and ceiling surfaces, respectively, and can be effectively used.

Further, since a part of the illumination light 44 from the fluorescent lamp 41 is blocked by the fluorescent lamp fixture 42 and the reflector 43, this also does not directly enter the eyes of the driver. Illumination light 4
The light that directly goes to the road surface or the ceiling surface among the four can also be illumination light that illuminates the road surface and the ceiling surface, respectively, and can be effectively used.

The light source section including the fluorescent lamp 41 and the fluorescent lamp 42 can be constructed by using a general lamp used at home or office, but it is waterproof to prevent water from entering when cleaning the tunnel. It is preferable to take measures. For example,
The light source unit may be configured by covering the fluorescent lamp 41 and the fluorescent lamp fixture 42 with a transparent cover.

(Third Embodiment) By utilizing the above-mentioned characteristic that the viewing angle range depends on the length of the fluorescent lamp and the arrangement direction thereof, the viewing range can be intentionally limited. For example, as shown in FIG.
It is possible to realize a configuration in which it is visible from m before and disappears at 50 m before by appropriately setting the length and arrangement direction of the fluorescent lamp.

It should be noted that this structure can be implemented in the optical display device of the present invention in any of the embodiments described in this specification.

(Fourth Embodiment) FIG. 20 shows a fluorescent lamp 46.
FIG. 6 is a plan view of the optical display device of the present invention when the installation position of is away from the incident plane 15.

Although there is a slight change in color and a decrease in the horizontal viewing angle range, the reproduced image 48 can be recognized well even in such a case. However, at this time, as shown in FIG. 20, the observer 49 must observe from the position where the fluorescent lamp 46 has moved in the direction opposite to the moving direction from the incident plane 15. This is because the illumination light 47 is obliquely incident on the hologram 2, so that the reproduced image 48 is also incident on the incident plane 15.
This is because the image is formed at a position away from. When it is difficult to install the fluorescent lamp 46 on the incident plane 15 due to restrictions such as the installation location of the optical display device, it is preferable to positively utilize the above arrangement for displaying. Of course, it goes without saying that it is possible to intentionally create a hologram in consideration of such a reproduction arrangement.

Note that this configuration can be implemented in the optical display device of the present invention in any of the embodiments described in this specification.

(Fifth Embodiment) Up to this point, only the process for one pattern mask and the reproduction of the hologram produced thereby have been described. This is sufficient in the case of monochromatic display, but in the case of color display, holograms are produced using different pattern masks corresponding to the colors to be displayed, and these are laminated to realize color display.

FIG. 21A shows three exposure pattern masks corresponding to the three primary colors of color. By using these pattern masks as a subject, holograms of R, G, and B single colors are produced, respectively. FIG. 21B shows a reproduced image when three produced holograms are stacked. In addition, FIG. 21C shows a state in which the manufactured hologram is stacked on one substrate.

The useful characteristic of the hologram described in the embodiment of the present invention, that is, the characteristic that the color of the reproduced image does not change in the visible range even if the vertical aperture limit width is widened, is To establish. Therefore, the color of the color reproduction image of the stacked holograms does not change in the visible range (strictly speaking, the reproduction wavelength slightly changes,
It is not recognized by the human eye as a large color change). The change of the reproduction wavelength at the center position of the reproduction image is shown in FIG.
Wavelength shift ratio (ΔλR / Δ for incident angle θ of reference light)
As shown by λT), it depends on the incident angle θ of the reference light set when the hologram of each color is produced. That is, as the incident angle θ of the reference light increases, the color change also increases. However, taking the case where the incident angle of the reference light is 30 degrees as an example, the color change (wavelength change) in the range of the visual angle of ± 2 degrees required for the sign is about 4 nm, which is almost the same as human eyes. It is not a color change that can be detected by. Therefore, the reproduced image is recognized as a single color when the angle of incidence θ of the reference light is 45 ° or less, which is normally used.

The wavelength shift ratio (ΔλR
/ ΔλT) indicates the ratio of the wavelength shift amount ΔλR in the configuration of the present invention, which is a reflection hologram, to the wavelength shift amount ΔλT in the transmission type configuration such as the conventional rainbow hologram.

Strictly speaking, a color distribution also exists in the reproduced image, and if the incident angle θ of the reference light increases, the color distribution also increases. This relationship is shown in FIG. 23 as the relationship between the reference light angle and the reproduction wavelength width. Where H
Indicates the height of the hologram. From FIG. 23, by selecting a large value for the parameter L / H, the color distribution can be reduced to an unrecognizable level in the range of the reference light angle of 45 degrees or less that is normally used.

Further, the color distribution in the reproduced image also changes depending on the observation position. That is, the farther the observation position is, the larger the color change becomes. This relationship is shown in FIG. 24 as the relationship between the normalized observation position and the reproduction wavelength width. Therefore, by appropriately selecting the parameters L / H, the color distribution can be reduced to an unrecognizable level.

More preferably, if the value of L / H can be selected to be substantially infinite, the change in magnification can be theoretically eliminated. Returning to the definition, considering that the value of L / H is substantially infinite corresponds to that the straight line drawn from the slit to the hologram has no inclination. Therefore, the slit and the frosted glass may be replaced with a one-dimensional diffuser that has no light diffusion effect in the hologram height direction and has a light diffusion effect only in the hologram width direction. For such a diffuser,
There are a number of structural examples such as a structure using a diffraction grating and a holographically manufactured structure. For example, a lenticular lens sheet having a structure in which cylindrical lenses are arranged may be used.

The structure of the exposure optical system in such a case is as described with reference to FIG.

The configuration of the present embodiment described above can be implemented in the optical display device of the present invention in any of the embodiments described in this specification.

(Sixth Embodiment) As shown in FIGS. 25A to 25C, the hologram 2 of the present invention can be laminated on a flexible substrate that can be bent, rolled, or folded. Is.

In the manufacturing process of the hologram 2 described above, a hologram dry plate was formed by sticking a dry film type photopolymer to a glass substrate. After the process, the photopolymer on which the hologram image was recorded was a glass substrate. It can be peeled off and replaced with another substrate. The hologram 2 of the present invention, which is attached to another flexible substrate such as a plastic film, paper, cloth, or the like, is not limited to this, and can be bent, rolled, or folded as shown in FIGS. 25A to 25C. be able to. By doing so, the display device can be compactly stored when not needed and can be easily carried.

At this time, it is not necessary to carry the light source. Because it's very easy to find where fluorescent lights are used, whether it's a typical home, office, train station,
A reproduced image can be easily obtained only by expanding the hologram in the vicinity of a fluorescent lamp used in a train, an elevator, or the like. Therefore, the hologram of the present invention can be effectively used as an advertisement, a guide display, a signboard, and various other applications. As for the installation method, it suffices to attach it to the wall surface using a common means such as a push pin or a tape. It is possible to take the form described above.
In the present invention, a fluorescent lamp that can be said to be the most popular light source,
This is because the reproduced image of the hologram can be displayed.

It is also possible to form a file or book form by stacking a plurality of holograms. In this case, the reproduced image can be viewed like turning pages one by one under a fluorescent lamp, and can be effectively used as a product catalog, picture book, map, etc., or for various other purposes. Is.

Further, by recording an image on a flexible substrate having a loop shape as shown in FIG. 25D and moving the image with a roll, continuous images can be reproduced. Further, it may take a winding type form as shown in FIG. 25E.

The structure of this embodiment in which the hologram is laminated on the flexible substrate described above can be implemented in the optical display device of the present invention in any of the embodiments described in this specification. .

(Seventh Embodiment) Lasers generally used as exposure lasers are argon lasers or krypton lasers, respectively, 488 nm and 514.5 n.
m and 647.1 nm are the main oscillation wavelengths. If exposure is performed at these three wavelengths, color reproduction display at those wavelengths is possible, but for example, human eyes have the highest luminosity 55.
Generally, the following process is required when reproducing and displaying a color other than the oscillation wavelength of the laser, such as when displaying a green color at 0 nm or when displaying a yellow color near 570 nm.

When silver salt is used as the hologram material, the sample is dipped in an appropriate solution after exposure with an argon laser of 514.5 nm to widen the interval of the hologram periodic structure and shift the reproduction wavelength to 550 nm or 570 nm. . Further, in the case of a dry film type photopolymer, a sample similarly exposed with an argon laser of 514.5 nm is irradiated with UV light over the entire surface, and then a color tuning film is laminated on the sample and subjected to heat treatment. By moving the substance that swells the color tuning film to the photopolymer side, the interval of the periodic structure is widened, and the reproduction wavelength is shifted to 550 nm or 570 nm. In any case, such a method requires an additional process after laser exposure, which is not preferable from the viewpoint of improving production efficiency.

On the other hand, in the hologram of the optical display device of the present invention, by setting the reference light and the object light to be incident on the hologram plate at an appropriate angle during laser exposure, additional holograms after that are added. It is possible to shift the reproduction color without going through the process.

FIG. 26 is a side view of a hologram production optical system for reproducing and displaying in a color other than the laser oscillation wavelength. Unlike the optical system shown in FIG. 15A, the hologram dry plate 50 is arranged at an angle of θobj with respect to the optical axis of the object light. Further, the pattern mask 51, which is the subject, is also inclined and arranged at an angle of θobj. The pattern mask 51 is made smaller than the pattern mask 13 in one direction.
Strictly speaking, the reduction ratio is not uniform, and the reduction ratio is continuously changed depending on the position of the pattern mask 51. On the other hand, the reference light 52 is configured to enter from the back surface of the hologram dry plate 50 at an angle of θref.

When exposure is performed using a laser beam having a wavelength λ = 514.5 nm using such a manufacturing optical system, the object light angle θobj is −25.3 ° and the reference light angle θref is 4 °.
By setting the angle to 2.1 °, a bright green reproduced image with a wavelength λE = 550 nm can be observed in front of the hologram dry plate during reproduction. At this time, the incident angle of the illumination light having a wavelength of 550 nm is 15 °.

Similarly, when exposure is performed with laser light having a wavelength λ = 514.5 nm, the object light angle θobj is -33.
By setting 1 ° and the reference light angle θref to 51.2 °,
At the time of reproduction, the wavelength λE = 570 is displayed in front of the hologram plate.
A bright yellow reproduced image of nm can be observed. At this time, the incident angle of the illumination light having a wavelength of 570 nm is also 15 °.

The above angle can be obtained from the relational expression of θRE = sin ⁻¹ [nsin {(θO + θR) / 2 + π−φ}] θOE = sin ⁻¹ [nsin {(θO + θR) / 2 + φ}]. Where θRE and θOE
Are incident angles of illumination light and reproduction light at wavelengths to be displayed. π is the circular constant, and n is the average refractive index of the hologram material. Here, calculation was performed with n = 1.52. Further, θR, θO, and φ are respectively θO = sin ⁻¹ (sin θobj / n) θR = sin ⁻¹ (sin θref / n) −π φ = sin ⁻¹ [λsin {(θO−θR) / 2} / λE] is a parameter.

In this way, by using the hologram produced so as to show a desired reproduction wavelength, an arbitrary intermediate color can be displayed by combining with a light source having a continuous light emission distribution, for example, a white fluorescent lamp. . Also, RG
By combining with a light source having three emission peaks corresponding to B3 colors, for example, a three-wavelength type fluorescent lamp, a bright reproduced image with high light utilization efficiency can be displayed.

The configurations of the embodiments described above can be implemented in the optical display device of the present invention in any of the embodiments described in this specification.

(Eighth Embodiment) As already described in the description of the fifth embodiment of the present invention, when the observer's visual field is moved in the vertical direction, the reproduction wavelength slightly changes. . Assuming that the object light is incident from the front when the hologram is produced, the degree of this color change depends on the incident angle θ of the reference light that has been set, and the larger θ, the larger the color change.
For example, when θ exceeds 45 degrees, a reproduction wavelength change of 6 nm or more occurs in the center of the reproduction image within a range of a visual angle of ± 2 degrees required for a sign, and even in a place where a hue change is large, it may be visible to human eyes. It is recognized that the color changes slightly. In addition, the color distribution inside the image becomes remarkable.

The method of optimally selecting the parameter L / H to produce the hologram in order to suppress this has already been described in the description of the fifth embodiment, but the hologram of the optical display device of the present invention is described. Then, there is a hologram setting angle that can minimize color change after fabrication.
The set angle is approximately 1/2 of the angle formed by the illumination light and the object light.
Which is, strictly speaking, an angle satisfying the relational expression of θac = sin ⁻¹ [nsin {(θO + θR + π) / 2}].

For example, the exposure wavelength is 514.5 nm,
When the incident angle of the reference light θref = 45 ° and the incident angle of the object light is 0 °, θac = 21.4 ° from the above formula. At this time, within the range of the visual angle of ± 2 degrees required for the mark, there is only a reproduction wavelength change of about 0.2 nm, and no color change is recognized. Further, the color distribution inside the reproduced image can be suppressed to be extremely small. At this time, since the reproduction wavelength is slightly shifted to the long wavelength side, it is preferable to set the manufacturing optical system in consideration of this.

FIG. 27A shows the hologram installation angle θac.
FIG. 27B shows a normal installation situation for the purpose of comparison.

As shown in FIG. 27A, when the installation angle of the hologram 53 is made as close as possible to θac, the optical path of the illumination light 54 and the optical path of the reproduction light 55 come close to each other. Therefore, in reality, it is preferable to install the hologram so that the installation angle is as close as possible to θac and the illumination light 54 is not blocked by the observer 56 who is going to see the reproduced image. Alternatively, as described in the fourth embodiment, the illumination linear light source (not shown) is slightly moved to the left and right, and the illumination light 54
It is more preferable not to overlap the observer 56 with the observer 56.

The configuration of this embodiment described above can be implemented in the optical display device of the present invention in any of the embodiments described in this specification.

(Ninth Embodiment) If the size of the hologram is increased, the size of the virtual display surface and the reproduced image can be increased. However, the exposure area that is usually realized in the hologram production optical system is about φ300 mm to φ400 mm, and the size of the reproduced image is limited to this size. It is not impossible to achieve a large exposure area beyond this, but (1) it is difficult and expensive to manufacture optical parts such as lenses and mirrors. (2) Due to the extremely widening of the laser beam Light intensity decreases (3) Exposure time increases with (2) above. (4) Exposure conditions become unstable due to (3) above (fluctuation of air, vibration, stability of laser, etc.). The adverse effect of will increase with probability). In order to avoid these difficult problems, in the optical display device of the present invention, a small element hologram that can be produced under more stable conditions is prepared, and by combining the element holograms just like pasting tiles, Form large size holograms.

FIG. 28 shows an example of forming a 1 m square hologram. Here, a 25 cm square element hologram 16
The 1 m square is realized by arranging the sheets in a 4 × 4 matrix. Each element hologram is produced by dividing a pattern mask of about 1 m square, which is a subject, into four equal parts vertically and horizontally and using the divided element mask.
In the exposure of 25 cm size, the above difficult problems do not occur.

The configuration of the present embodiment described above can be implemented in the optical display device of the present invention in any of the embodiments described in this specification.

(Tenth Embodiment) A feature of the optical display device of the present invention which is not found in the conventional device is that the optical display device whose basic structure has been shown as each embodiment is newly added. One display unit is provided, and by arranging a plurality of the display units on the arrangement surface, the reproduced images from the units can be combined and displayed on the virtual display surface. For example, when the display units are arranged side by side from the observer's side, the display width can be widened to the left and right by combining the reproduced images on the virtual display surface.

29A and 29B show the display unit 5.
7A and 7B are a front view and a side view of an example of an optical display device that is configured by arranging three right and left.

The hologram reproduction image 59 reproduced by the fluorescent lamp 58 is different for each display unit, and the characters "A", "B" and "C" are reproduced and displayed one by one on each display unit. It is configured. As shown in the figure, when the display units are arranged close to each other on the left and right, the characters are arranged side by side and can be recognized as one word.

A shielding plate 60 is arranged between the units,
It is desirable to prevent the fluorescent lamps in each unit from reproducing holograms in other units.

(Eleventh Embodiment) If the displayed information is a character string as shown in FIG. 29A, the information is transmitted to the observer without any problem even if there is a slight gap between the characters. However, when the displayed information is a figure, it is not preferable that there is a gap in it, and in some cases the gap itself is recognized as one piece of information, and as a result, it is different from the information that should be originally transmitted. It may be perceived by the observer. In the case of the configuration of the tenth embodiment,
Even if the hologram of each display unit is placed in close contact with each other, when the fluorescent lamp is placed at the basic position, the reproduced image from each hologram is reproduced at a distant position on the virtual display surface, and the above-mentioned problem occurs. Occur.

In order to solve such a problem, this embodiment uses the method described in the fourth embodiment of the present invention. That is, by positively utilizing the shift of the image forming position of the reproduced image due to the offset arrangement of the fluorescent lamps, a large combined reproduced image without the joint of the images is formed.

FIG. 30A and FIG. 30B are views showing an example of an optical display device in which three display units are arranged on the left and right to display one large pattern, and a reproduced image which is divided and a synthesized image which is seamlessly synthesized, respectively. A reproduced image is shown.

Each display unit is configured to display an individual reproduced image as shown in FIG. 30A. When the respective units are arranged side by side and the fluorescent lamp 62 of the display unit 61 on the left side indicated by the broken line is moved to the left, the reproduced image 63 moves to the right and the reproduced image of the display unit 64 placed in the center. It will be displayed side by side in 65 without a gap. Similarly, when the fluorescent lamp 67 of the display unit 66 on the right side is moved to the right, the reproduced image 68 moves to the left side so that the reproduced image 65 of the display unit 64 placed in the center is displayed side by side without any gap. Become.

As described above, according to the present invention, reproduced images can be joined together without a gap, which makes it possible to display a large pattern.

(Twelfth Embodiment) The configuration of the present invention in which the characteristics of the optical display device are sufficiently exhibited is such that a plurality of display units are arranged in the depth direction of the reproduced image viewed from the observer and the holograms from the respective holograms are arranged. In this configuration, the reproduced image is combined on the virtual display surface.

FIG. 31A is a side view showing the structure of the optical display device according to the twelfth embodiment of the present invention. In this embodiment, the optical display device of the present invention is used as a road sign in a tunnel. Specifically, 69 is the optical display device of the present embodiment, 70 to 72 are display units, 73 to 75 are holograms, and 76 to 78 are fluorescent lamps which are linear light sources. The display units 70 to 72 are
They are arranged side by side on the ceiling surface 80 of the tunnel 79.

Optical display device 6 constructed as described above
The operation of No. 9 will be described below.

First, the holograms 73, 74 and 75 are
The original image pattern 81 of the road sign indicating the speed limit as shown in FIG. 31B is divided and recorded by the method as described in the first embodiment of the present invention. That is, FIG.
As shown in FIG. 1C, the hologram 73 has an original pattern 8
Element pattern 82 of the lower about 1/3 obtained by dividing 1
Is recorded, and the hologram 74 has about 1/3 of the central portion.
The element pattern 83 of is recorded, and the hologram 75
An element pattern 84 of about 1/3 of the upper part is recorded in the. In each hologram production optical system, each hologram is produced by disposing the pattern mask of the element pattern and the hologram dry plate at different distances.

As shown in FIG. 31A, the reproduced image 85 of the hologram 73 by the fluorescent lamp 76 is formed in the vicinity of the virtual display surface 86. Similarly, the reproduced image 87 of the hologram 74 by the fluorescent lamp 77 is displayed on the virtual display surface 8.
8 and the reproduced image 89 of the hologram 75 by the fluorescent lamp 78 is formed in the vicinity of the virtual display surface 90. At this time,
Since the reproduced images 85, 87, 89 viewed from the front are combined as one image as shown in FIG. 31D, when viewed from a car passing through the inside of the tunnel 79, a road sign indicating the speed limit is displayed. It looks as if it is suspended from the ceiling surface 80 of the tunnel 79. However, this is a display on the virtual display surface, and since no object actually exists on the display surface, a car accident or the like cannot occur at all.

The advantage of this structure is that the height of the display units can be reduced by a ratio of approximately 1 / N, where N is the number of display units to be arranged. Thus, the optical display device having an extremely flat structure can reduce the cross-sectional area of tunnel excavation, which has a great effect of reducing the construction cost.

(Thirteenth Embodiment) FIG. 32 is a perspective view of an optical display device according to this embodiment. This is an example configured to display the position of the emergency telephone in the tunnel, where 91 is a fluorescent lamp, 92 is a hologram unit, and 93 is an emergency telephone.

This hologram unit 92 has a structure as shown in FIG. Specifically, 94 is the first
A hologram, 95 is a second hologram, 96 is a display plate, the first hologram 94 is on the first surface 97 side of the hologram unit 92, the second hologram 95 is on the second surface 98 side of the hologram unit 92, Each is configured to form a reproduced image. The first hologram 94 is provided on the first surface 99 of the display plate 96 on which the first hologram 94 is arranged.
The same information as the display information reproduced by the display plate 96 on which the second hologram 95 is arranged.
The same information as the display information reproduced by the second hologram 95 is written on the second surface 100 of the.

As shown in FIG. 32, the hologram unit 92 having such a structure is arranged below the fluorescent lamp 91 which is a linear light source. In order to explain this operation, referring to the side view of FIG. 34, a reproduced image 103 of the first hologram 94 is formed by the illumination light 102 emitted from the region 101 of the fluorescent lamp 91. In this example, the characters "emergency phone" are displayed. On the other hand, the area 10 of the fluorescent lamp 91
By the illumination light 105 emitted from the second hologram 9
A reproduced image 106 of No. 5 is formed, and similarly, the characters "emergency telephone" are displayed. Therefore, it is possible to clearly indicate the position of the emergency telephone 93 to the persons on both sides of this optical display device. Further, in this example, character information of "emergency telephone" is written on both sides of the display plate 96, and the display on the opposite side can be confirmed through the transparent hologram surface. Therefore, for example, even in an emergency where the fluorescent lamp 91 does not light up, the position of the emergency telephone 93 can be confirmed with a flashlight or the like.

Although the example in which the same information is displayed is described here, it goes without saying that different information can be displayed on both sides by recording different information in each hologram.

(Fourteenth Embodiment) FIG. 35 is a perspective view of an optical display device according to the present embodiment. 107 is a fluorescent lamp, 108 is a first hologram unit, and 109 is a second hologram unit. .

The hologram units 108 and 109
Have a structure as shown in FIG. That is, 110 is the first hologram, 111 is the first display plate, 112 is the second hologram, and 113 is the second display plate. The first and second hologram units 108 and 109 thus configured are arranged near both ends of the fluorescent lamp 107, which is a linear light source, as shown in FIG.

The operation of the optical display device according to the present embodiment will be described with reference to the plan view of FIG.

The reproduced image 115 of the first hologram 110 is formed by the illumination light 114 emitted from the fluorescent lamp 107. On the other hand, the reproduced image 117 of the second hologram 112 is formed by the illumination light 116 emitted from the fluorescent lamp 107. Therefore, the same or different information can be displayed to persons on both sides of this optical display device.

The same information as the reproduced image 115 of the first hologram 110 is written on the first display plate 111, and the reproduced image 117 of the second hologram 112 is written on the other second display plate 113. The same information is written, and these can be confirmed from the opposite side through the transparent hologram surface. Therefore, for example, even in an emergency where the fluorescent lamp 107 does not light up, the information can be confirmed with a flashlight or the like.

[0196] Here, the configuration has been described in which the display plate is provided for an emergency display, and the holograms are arranged one on each side of the display plate. However, in other applications, the display plate having the above function is unnecessary. In this case, the hologram unit can be replaced with one hologram. This hologram is a reflection hologram recorded by double exposure from the front side and the back side, and the same or different reproduced images can be observed from both sides.

(Fifteenth Embodiment) In the above thirteenth and fourteenth embodiments, an example of an optical display device for reproducing a plurality of holograms from one linear light source is shown. The holograms need not be placed on the same placement surface as in the above example.

FIG. 38 is a plan view of the optical display device according to the present embodiment in which one hologram is arranged on the side wall and the other hologram is arranged on the ceiling.

Reference numeral 118 is a fluorescent lamp, 119 is a first hologram, and 120 is a second hologram. The illumination light 121 emitted from the fluorescent lamp 118 is the reproduced image 1 of the first hologram 119.
22 and the illumination light 123 forms the second hologram 120.
To form a reproduced image 124. Such a reproducing operation can be realized because the hologram of the present invention can be reproduced by a fluorescent lamp.

The structure of the optical display device for simultaneously reproducing a plurality of holograms as described above is not limited to this form, and the light emitted from the linear light source in all directions can be skillfully used as the illumination light. In addition to this, various configurations are possible.

In the first embodiment, the reference beam 16 is made incident on the incident plane 15 in the hologram manufacturing process. However, the present invention is not limited to this, and it is effective not to take this structure. become. For example, when the object light is made incident on the incident plane and the reference light is made incident on a plane different from the incident plane to form a hologram, in the arrangement of the fluorescent lamp and the hologram shown in FIG. The reproduced image can be seen from the front of the hologram with respect to the illumination light coming from one side. Further, since the reflected light of the illumination light and the direction in which the reproduced image is obtained are different, a display that is easy to see is realized.

(Sixteenth Embodiment) The method for producing a hologram in the present invention is not limited to the method described in the first embodiment. For example, it is possible to reproduce an image once recorded as a transmission hologram and record it as a reflection hologram.

39A and 39B are a side view and a plan view, respectively, of the hologram manufacturing optical system in this embodiment.

As shown in FIG. 39A, the laser light 126 incident on the frosted glass 125 becomes diffused light 127 and enters the slit 128. The slit 128 seen from the side has a narrow width and allows only a part of the diffused light 127 to pass through. Therefore, the light passing through it looks like a divergent light emitted from one point when viewed from the side. This light reads the information on the pattern mask 129 and irradiates the hologram dry plate 130 as object light 131, which can be regarded as a projection of the pattern mask 129 on the hologram dry plate 130. The object light 131 containing the information of the subject forms an interference fringe on the hologram dry plate 130 with the reference light 132 incident from the same side, and the interference fringe is recorded on the hologram dry plate 130.

At this time, since the “shadow” of the pattern mask 129 projected on the hologram dry plate 130 is enlarged, the pattern mask 12 is taken into consideration in consideration of this projection magnification in advance.
9 is manufactured by reducing in one direction. This magnification varies depending on the setting of the optical system, but is usually about 1.2 times to about 2 times.

On the other hand, as shown in the plan view of FIG. 39B, the slit 128 seen from above has a wide width and allows the diffused light 127 emitted from the frosted glass 125 to pass over a wide range. In FIG. 39B, the diffused light passing through the central portion of the slit 128 is shown by a solid line, and the diffused light passing through both ends of the slit 128 is shown by a broken line. The diffused light indicated by the solid line projects the information when the pattern mask 129 is viewed from the front onto the hologram dry plate 130, and the two diffused lights indicated by the broken lines respectively slightly pass through the pattern mask 129 from the end of the slit 128. Information when viewed obliquely is projected on the hologram dry plate 130. Object light 1 containing these information
31 forms interference fringes with the reference light 132 which is incident on the hologram dry plate 130 from the same side.
This interference fringe is recorded at 30. This is the principle of forming a reproduced image of the pattern mask 129 viewed from different angles toward both eyes of the observer when reproducing the hologram later.

Although the side view and the plan view have been described separately for the sake of clarity, it goes without saying that the recording of the above interference fringes proceeds simultaneously in the actual hologram manufacturing process.

FIG. 40 shows an optical system for obtaining a reflection hologram from the master hologram using the hologram produced by the above process as a master hologram. Illumination light 1 incident on the master hologram 133
34 is equal to the reference light 132 used when producing this master hologram. The reproduction light 135 is formed from the master hologram 133 by the illumination light 134, and this becomes the object light and enters the hologram dry plate 136, and by forming an interference fringe with the reference light 137 entering from the back side, the reflection light 135 is reflected. A type hologram is formed.

As described above, in this embodiment, the transmission hologram is once produced, and the reflection hologram is produced using this as a master hologram. This method has the advantages that the configuration of the optical system for producing the reflection hologram becomes easy and that the distance between the reproduction display surface and the hologram can be readjusted. That is, the reconstructed image 138 is formed at the position where the pattern mask 129 was placed when the master hologram was produced, but the distance between the master hologram 133 and the reconstructed image 138 was d1, whereas the reflection hologram 136 was formed. The distance between the image and the reproduced image 138 is d2. Thereby, the flying height of the reproduced image from the hologram surface can be enlarged or reduced.

(Seventeenth Embodiment) FIG. 41 shows a hologram manufacturing optical system in the seventeenth embodiment. This is also a process in which a transmissive hologram is once produced and a reflective hologram is formed by using this as a master hologram.

In FIG. 41, the object light 141 obtained by illuminating the object 139, which is a three-dimensional object, with the illumination light 140 interferes with the reference light 143 incident on the hologram dry plate 142 from the same side. To form. This is recorded as a transmission hologram on the hologram dry plate 142 and becomes the master hologram 144.

In FIG. 42, the master hologram 144
When the illumination light 145, which is a conjugate wave of the reference light 143, is incident on, a reproduced image of the subject 139 is obtained. here,
The slit 146 is arranged close to the master hologram 144, and the light emitted through the slit is used as the object light 147. The reference light 1 is incident from the back side of the hologram dry plate 148.
Interference fringes are formed between the hologram 49 and the hologram 49, and this is recorded on the hologram dry plate 148 as a reflection hologram. In addition, 15
0 is a reproduced image of the subject 139.

By taking such a method, even for a three-dimensional object or an object distant from the hologram surface,
A reproduced image without blur can be obtained.

(Eighteenth Embodiment) FIG. 43 shows an optical system for producing a hologram in the eighteenth embodiment. This is also a process in which a transmissive hologram is once produced and a reflective hologram is formed by using this as a master hologram.

The optical system of FIG. 43 differs from the optical system of FIG. 42 in that the slit 146 is replaced by a negative cylindrical lens 151 and an aperture 152. By the function of the cylindrical lens 151, the position where the reproduced light 153 forms an image in the vertical direction in the figure can be matched on the hologram dry plate 154, and thus, for a three-dimensional object or an object distant from the hologram surface. Therefore, a sharp reproduced image can be obtained. In addition, 155 is
It is a reproduced image of the subject 139.

In FIG. 43, the cylindrical lens 151 having negative power is used, assuming that the reproduced image 155 is formed between the master hologram and the hologram dry plate. However, in FIG. 43, the reproduced image 155 is used. Is formed on the left side of the hologram dry plate 154, a cylindrical lens having a positive power is used.

(Nineteenth Embodiment) FIG. 44 is a side view showing the structure of an optical display device according to a nineteenth embodiment of the present invention. In this embodiment, the optical display device of the present invention is used as a road sign in a tunnel.

In FIG. 44, 201 is the optical display device of this embodiment, 202 is a hologram screen, and 203.
Is a cylindrical lens, and 204 is an LED display device. The optical display device 201 is arranged on the ceiling surface 206 of the tunnel 205. As illustrated, the width direction (perpendicular to the drawing) of the tunnel 205 is the x direction, the longitudinal direction is the y direction, and the vertical direction is the z direction.

The image displayed on the LED display device 204 is projected on the hologram screen 202 by the cylindrical lens 203, and the image diffracted and reflected by the hologram screen 202 is reproduced and imaged on the virtual display surface 208. It At this time, when the image 209 is seen from the car passing through the inside of the tunnel 205, the sign is
It looks as if it were suspended from the ceiling surface 206 of the tunnel 205 and lowered. However, this is a display on the virtual display surface 208, and there is practically no object on the display surface 208, and a contact accident with a vehicle or the like cannot occur at all.

The virtual display surface 208 is a plane or curved surface virtually provided in the space. The reflected light reflected by the surface of the hologram screen 202 is deflected in the direction toward the road surface or the direction toward the ceiling surface 206 and does not directly enter the eyes of the driver. These deflected reflected lights are useful as illumination lights for illuminating road surfaces and ceiling surfaces, respectively.

The reason why the optical display device of this embodiment has the above-mentioned functions will be described below.

In FIG. 44, the image displayed on the LED display device 204 is formed on the hologram screen 202 by the cylindrical lens 203. L
The image displayed on the ED display device 204 is inverted vertically and horizontally, and the generatrix of the cylindrical lens 203 is placed parallel to the x direction. At this time, each component is arranged so that only the z component of the image is focused on the hologram screen 202. In other words, by the action of the cylindrical lens 203,
The respective constituent elements are arranged so that the lines and the contours extending in the x direction, for example, included in the image become clearest on the hologram screen 202. As a result, when a normal projection screen is placed at the position of the hologram screen 202, only the lines and contours extending in the x direction are clear and the lines and contours extending in the z direction are blurred, as shown in FIG. 45. The image will be reflected. Note that FIG. 45 is a diagram schematically illustrating how a circular and square image is formed by the cylindrical lens 203 and a normal projection screen is placed at the position of the hologram screen 202.

Next, the function of the hologram screen 202 will be described.

46A and 46B are a plan view and a side view of a structure in which only the hologram screen 202 and the LED display device 204 are taken out from the optical display device 201. If the cylindrical lens 203 is not provided, the hologram screen 202 will be displayed at the point A of the LED display device 204.
Has a function of forming an image on the point B on the virtual display surface 208.

The hologram screen 202 having the above-mentioned function can be manufactured by the exposure optical system shown in FIG. 47, for example. That is, the laser beam 211 condensed by the lens 210 is the pinhole 21 placed at the position of the point A.
After passing through 2, the light becomes divergent light, and is incident on the hologram dry plate 213 which will later become the hologram screen 202 from the right side in the figure. On the other hand, the laser beam 2 that converges toward the point B
14 is incident on the hologram dry plate 213 from the left side in the figure, that is, the side opposite to the laser beam 211. By recording the interference pattern of these two laser beams on the hologram dry plate 213, the hologram screen 202 having the above-described function is configured.

The cylindrical lens 203 is arranged in the optical path, and as shown in FIG. 45, the z component of the image (that is, x component).
When an image in which only the lines and contours extending in the direction are clear and the x component of the image (that is, the lines and contours extending in the z direction) is blurred is projected, the hologram screen 202 exhibits the following functions.

48A and 48B are a plan view and a side view showing how a light ray travels through each element of the optical display device 201.

First, regarding the x component of the image, FIG.
As shown in FIG. 7, since it is not affected by the cylindrical lens 203, it can be considered that the image of the point A displayed on the LED display device 204 is directly projected on the hologram screen 202. Therefore, as in the case where the light emitted from the point A is imaged at the point B in FIG.
Due to the action of the hologram screen 202, only the x component (that is, the line or contour extending in the z direction) is sharply imaged on the virtual display surface 208.

On the other hand, the z component of the image is the clearest on the hologram screen 202 due to the action of the cylindrical lens 203 as described above. This is illustrated in FIG. 48B. As shown in FIG.
The image of the point A displayed on 04 is formed on the point C on the hologram screen 202. Point C is point A
The light that has emitted and once spread in the z direction is transmitted through the cylindrical lens 203, and then is converged at a convergence angle with only the z component. Therefore, after being diffracted and reflected by the hologram screen 202, it becomes divergent light having a slight divergence angle in the z direction and is projected on the virtual display surface 208.

Strictly speaking, each light beam included in this divergent light has a slightly different wavelength component. In other words, the light emission distribution of the display device has a width of several tens of nm, is dispersed by the hologram screen 202, and is diffracted and reflected at different angles for each wavelength.

In the above, the L component is divided into the x component and the z component.
It has been described how the image displayed on the ED display device 204 is projected and imaged on the virtual display surface 208. As a result, the observer 215
What it looks like to the eye is described next.

FIGS. 49A and 49B are a plan view and a side view in which the light rays after the hologram screen 202 are taken out from FIGS. 48A and 48B, respectively, and show the pupil of the observer 215 seen from a position away from the virtual display surface 208. The paths of the rays to reach are shown.

As shown in FIG. 49A, the same light rays as when light is emitted from point B on the virtual display surface 208 are incident on the left and right eyes of the observer 215. This means that the x component of the image appears as a sharp line or outline on the virtual display surface 208. It should be noted that the viewer 215 can see the above image within the range indicated by the two broken lines.

On the other hand, as shown in FIG.
The same light rays as those emitted from one point C of the hologram screen 202 are incident on both eyes of No. 5. This means that the z component of the image is the hologram screen 20.
It shows that it is visible as a sharp line or outline on 2. It should be noted that the viewer 215 can see the above image within the range indicated by the two broken lines.

When the x component and the z component look different from each other as described above, it seems difficult for the human eye to recognize as one image, but it is not so.

Generally, since the human eyes have a binocular parallax in the horizontal direction, a stereoscopic effect and a sense of depth are recognized. here,
The binocular parallax means that the positions where the images of the objects are projected are different in the visual fields of the right eye and the left eye when one object is viewed, or the difference between the positions. For example, assuming that a long straight line extending vertically is viewed by both eyes for the sake of simplicity, both the right and left eyes can recognize it as a long straight line extending vertically. At the same time, because the position where the image is projected is different for each eye due to binocular parallax, it is possible to empirically determine how far apart the long straight line is in the horizontal direction.

On the other hand, in the vertical direction, since the human eyes are at the same height, the binocular parallax as described above does not occur, and as a result, it is difficult to obtain a stereoscopic effect and a sense of depth. For example, assuming that a long straight line extending horizontally is viewed by both eyes for the sake of simplicity, both the right and left eyes can be recognized as long straight lines extending horizontally. However, since the position where the image is projected is the same for both eyes, no parallax occurs. Therefore, it cannot be clearly determined how far apart the long straight line is in the vertical direction. For example, when trying to jump to catch a high horizontal bar, if you can not grasp the distance to the horizontal bar that appears as a straight line extending to the left and right against the sky as a background, you may hesitate to jump for a moment, Corresponds to the case.

It is important that the binocular parallax in the horizontal direction is the most dominant factor that gives a stereoscopic effect and a sense of depth. Based on this, the appearance of each of the x component and the z component of the above-described optical display device of the present invention will be considered.

FIG. 49A shows the fact that the left and right eyes of the observer 215 can see the sharp lines and contours of the x component of the image on the virtual display surface 208. In the metaphor above, this corresponds to the appearance of a long straight line extending vertically. Therefore, since the left and right eyes of the observer 215 have binocular parallax, it is recognized that the image is located exactly on the virtual display surface 208.

On the other hand, FIG. 49B shows that the observer 21
It is the fact that sharp lines and contours of the z component of the image are visible on the holographic screen 202 in the left and right eyes of 5, respectively. In the metaphor above, this corresponds to the appearance of a long straight line extending horizontally. Therefore, the binocular parallax does not occur in the left and right eyes of the observer 215, and the position of the image cannot be clearly determined.

Therefore, the sharp line or outline of the x component is
Since it is a main factor that gives the binocular parallax and is a dominant factor in recognizing the position, as a result, it looks as if an image floats at the position of the virtual display surface 208 to the eyes of the observer. It will be.

Although omitted in the above description, the hologram screen 202, the cylindrical lens 203,
The relative installation angle of the LED display device 204 is intentionally inclined. This is because the matrix screen pixel array, which is normally formed on the LED display device 204 at equal intervals in the vertical and horizontal directions, can be clearly displayed without distortion.
This is to form an image on top of. This is a technique called front rising used when photographing buildings. That is, when a normal camera is pointed at a building such as a tall building and photographed in a form of looking up, the originally rectangular shape of the building becomes a trapezoidal shape as shown in FIG. To be done. The front rising method is used to correct the distortion of such a shape and to take a photograph in which the entire subject is in focus.

The procedure of the front rising method is shown in FIG.
~ Shown in Figure 51D. Here, 216 is the film surface, 21
7 is a taking lens.

That is, first, the camera is turned from the normal arrangement (FIG. 51A) toward the subject (FIG. 51B), and then only the film surface 216 is tilted in the direction parallel to the subject (FIG. 51).
C). At this time, the above-mentioned distortion of the subject is corrected.
Next, the taking lens 217 is tilted in a direction parallel to the subject (FIG. 51D). At this time, the entire subject is in focus. The name of front rising is
As a result of the above procedure, the taking lens 217 comes to be in a state of being lifted with respect to the film surface 216.

FIG. 52 is a hologram screen 2 of the optical display device 201 of the present embodiment described so far.
02, cylindrical lens 203, LED display device 2
It is the figure which took out only 04 and rotated it counterclockwise.
Considering the LED display device 204 as a subject, the cylindrical lens 203 as a photographing lens, and the hologram screen 202 as a film surface, the optical display device 20 of the present embodiment.
It can be seen that No. 1 has the same configuration as the above front rising.

The above is the arrangement configuration of the optical display device 201 when it is assumed that the LED display device 204 has a matrix of pixel arrays formed at equal intervals in the vertical and horizontal directions. If a display device having a pixel array that corrects the trapezoidal distortion as shown in FIG. 2 can be used, these arrangements are different.

FIG. 53 shows an arrangement configuration when a display device 218 having a trapezoidal pixel array which is vertically inverted from the beginning so as to correct the trapezoidal distortion is used.

The surfaces on which the hologram screen 202, the cylindrical lens 203, and the display device 218 are placed (indicated by straight lines in the figure) are arranged so that their respective extension lines intersect at one point. This is a condition well known in the photographic art, which is called Scheimpflug condition. When this condition is satisfied, the entire image displayed on the display device 218 is clearly projected on the hologram screen 202.

According to the present invention, although the light flux in the z direction is slightly changed in color, the color change in the light flux taken into the pupil is small and it appears as a single color. When the method of manufacturing the hologram screen 202 was described above, only the method using a monochromatic laser was described, but if multiple exposures using red, blue, and green lasers are performed using the same method, a color image can be displayed. Become.

Further, although the cylindrical lens 203 is used in this embodiment, the present invention is not limited to this.
As described above, the z component of the image is converted into the hologram screen 2
Other configurations can be used as long as they can clearly project and form an image on 02. For example, an anamorphic optical system having different vertical and horizontal focal lengths, or a combination of an ordinary projection lens and a cylindrical lens can be used. In particular, x
By using a lens or mirror whose focal length in the direction can be changed, the position in the depth direction where the image is observed can be easily changed. For example, as shown in FIGS. 54A and 54B, the variable focus lens 30 having power only in the x direction
When 1 is arranged, the position of the virtual display surface 208 on which an image is formed is moved back and forth without changing the position of the LED display device 204. A variable focus mirror may be used instead of the variable focus lens 301, and the optical path may be bent.

In the present embodiment, the LED display device is used as the image display device, but the present invention is not limited to this, and any device capable of displaying a bright image may be used. For example, it is conceivable to use an image display device including a display element selected from an LED, a CRT, a polymer dispersed liquid crystal panel, or an organic EL panel, and a polarization switching element. As the polarization switching element, a structure including a ferroelectric liquid crystal panel can be used.

As described above, according to the optical display device of the present invention, the image displayed on the LED display device 204 is reproduced and imaged on the virtual display surface 208, which is a virtual display. It is a display on the surface 208, and no object actually exists on the display surface 208. Therefore, a car accident or the like cannot occur at all. Further, since the height of the entire device can be set low, it is possible to provide a display device that can effectively use a narrow space.

The application of the optical display device of the present invention as a road sign in a tunnel has been mainly described here, but the present invention is not limited to this. The optical display device having the same configuration as that described in the present embodiment can be easily used as a projection display.
Taking advantage of the characteristic that an image floats in front of the screen surface, various application forms in fields such as games and amusement can be considered.

Further, in FIG. 47, when the hologram screen 202 is manufactured, the laser beam 214 which converges toward the point B is made incident on the hologram dry plate 213 from the left side in the figure, which is as shown in FIG. 55. The laser beam 219 which is divergent light emitted from the point E on the left side of the hologram dry plate 213 may be replaced. The hologram screen 220 manufactured in this manner is arranged as shown in FIG. Since the constituent elements other than the hologram screen 220 are not changed at all, as in the above description, the LE
The image displayed on the D display device 204 is projected and imaged by the cylindrical lens 203, and the lines and contours included in the image extending in the x direction, for example, are arranged so as to be the clearest on the hologram screen 220. It

On the other hand, since the x component of the image is not affected by the cylindrical lens 203, it can be considered that the image displayed on the LED display device 204 is directly projected on the hologram screen 220. Therefore, by the action of the hologram screen 220, only the x component (that is, the line or the contour extending in the z direction) is newly formed at the position where the point image E which is the virtual image on the left side of the hologram screen 220 is newly formed. A sharp image is formed on 221. For the observer,
Virtual display surface 2 on the other side of the hologram screen 220
Since a clear image of the x component can be seen above 21, the image is perceived as floating in this place, as in the previous description.

Although such an optical display device can be applied as a road sign as in the above description, a more suitable application field is a so-called head-up display. In the best known application,
It is placed on the dashboard of an automobile and displays traffic information, speed information, navigation information, etc. necessary for driving near the upper part of the hood behind the windshield. FIG. 57 shows an example of the arrangement configuration for this purpose. In this case, as the display device 204, in addition to the LED display device, CR
T, a liquid crystal display device, a fluorescent display tube, an organic EL, etc. can be used. The hologram screen 220 is produced by causing divergent light to interfere with each other, as in the case of producing the hologram screen 220 described above. The hologram screen 220 may be installed on the windshield. Also,
The projection optical system may also be a cylindrical lens, an anamorphic optical system, or a combination of an ordinary projection lens and a cylindrical lens, as described above.

(Twentieth Embodiment) According to the present invention, a two-dimensional image can be projected at a position away from the screen. By applying this principle, it is possible to construct a display device that shows a three-dimensional image. The details will be described below.

When a person looks at one three-dimensional object, the images of the object appearing in the right eye and the left eye are slightly different from each other. Based on this slight difference called binocular parallax, a person recognizes the three-dimensional structure and depth of the object.
Utilizing this principle, the display device alternately displays the right-eye image and the left-eye image, and the respective images are shown to the right eye and the left eye independently to recognize a three-dimensional image. Many display devices have been proposed.

Generally, when a user views a three-dimensional image, he or she tends to feel tired, and in some cases, he or she may feel uncomfortable, similar to car sickness. These physiological phenomena are
Although it cannot be generally stated because of individual differences, it has been pointed out as a problem of the three-dimensional image so far, and research and development for solving this problem are under way.

By applying the above-mentioned three-dimensional image display principle to the display device of the present invention, a new three-dimensional image display device which solves the above problems can be constructed.
The configuration is schematically shown in FIG. Specifically, 42
0 is a hologram screen, 402 is a spatial light modulator,
Reference numeral 403 is a projection optical system. A three-dimensional image 406 is observed by an observer 415 wearing the polarizing glasses 404.

Here, the spatial modulation element 402 may be any image display device that can switch the polarization direction of the displayed image, and can switch the direction of linear polarization or the direction of rotation of circular polarization. Things can be used. As such a spatial modulation element 402,
Those already operating at 120 Hz or higher are generally available, and three-dimensional image display by binocular parallax is possible by switching images at a speed that cannot be recognized by human eyes. Further, by using such an element as a polarization switching element, a non-polarized display device such as a CRT or an organic E
By combining with L, polymer dispersion type liquid crystal element, etc.,
The spatial modulation element 402 can be configured.

As the projection optical system 403, as described above, a cylindrical lens can be used as the simplest structure. However, the present invention is not limited to this, as long as the z component of the image is clearly projected and imaged on the hologram screen 420 as described above. For example, an anamorphic optical system having different vertical and horizontal focal lengths, or a combination of an ordinary projection lens and a cylindrical lens may be used. Further, as described above, when a lens or a mirror whose focal length in the x direction can be changed is used, the position in the depth direction where the image is observed can be easily changed. For example, as shown in FIGS. 54A and 54B, when a varifocal lens having power only in the x direction is arranged, the position of the virtual display surface on which an image is formed is changed forward and backward without changing the position of the LED display device. To do. A variable focus mirror may be used instead of the variable focus lens, and the optical path may be bent.

The polarizing glasses 404 are such that the orientations of the polarizing plates are orthogonal to each other, and by mounting them,
Images that are switched by the spatial light modulator 402 can be independently recognized by the right eye and the left eye.

The feature of the three-dimensional display device according to the present invention is that the screen surface can be separated from the position where the image is observed, and the distance between them can be changed. This is the point that can solve the above-mentioned problems such as feeling tired. That is, since the image is not fixed on the screen surface, the eye focus is adjusted to the actual image, not the screen. Furthermore, since the position of the image can be changed, the focus of the eye and the vergence angle can be adjusted to the place where the actual image is visible, and a natural three-dimensional display is possible.

(Twenty-first Embodiment) As described above, the feature of the optical display device of the present invention which is not found in the conventional device is the optical structure whose basic configuration is shown in each embodiment. The display device is newly changed to one display unit,
By arranging a plurality of these on the arrangement surface, the reproduced image from each unit can be combined and displayed on the virtual display surface.

59A and 59B show the display unit 2
23 is a side view and a front view of an example of an optical display device in which three 23 are arranged side by side. FIG.

The image 22 formed on the virtual display surface 224.
5 is different for each display unit, and in the illustrated example, "A", "B", and "C" are used for each display unit.
Each character of is played and displayed one by one. As shown in the figure, when the display units are arranged close to each other on the left and right, the characters can be recognized side by side and recognized as one word.

Alternatively, as shown in FIG. 60, one large pattern is converted into three patterns 270, 271, and 27.
It is also possible to display the image by dividing it into two and synthesize them on the virtual display surface.

As described above, when the display units are arranged side by side from the observer's side, the display width can be widened to the left and right by combining the reproduced images on the virtual display surface.

Further, in the constitution in which the characteristics of the optical display device of the present invention are sufficiently exhibited, a plurality of display units are arranged in the depth direction of the image viewed by the observer, and the images from the respective display units are displayed on the virtual display surface. It is the composition synthesized above.

FIG. 61 is a side view showing the structure of an optical display device 226 in which a plurality of display units are arranged in the depth direction of the image. In this embodiment, the optical display device 226 of the present invention is used as a road sign in a tunnel. Specifically, in FIG. 61, 226 is an optical display device of this embodiment, 227 to 229 are display units, and each display unit 227 to 229 is a tunnel 230.
Are arranged side by side on the ceiling surface 231.

The hologram screen of each of the display units 227 to 229 is manufactured by the manufacturing optical system shown in FIGS. 62A to 62C. Each of these optical systems is basically the same as the optical system described in FIG. However, they are different in that the laser beam incident as convergent light is condensed.

FIG. 62A shows an optical system for producing a hologram screen used in the display unit 227. The laser beam 232 is incident so as to converge on the point F. FIG. 62B shows an optical system for producing a hologram screen used in the display unit 228, and the laser beam 233 is incident so as to converge on the point G. FIG. 62C shows an optical system for producing a hologram screen used in the display unit 229, and the laser beam 234 is incident so as to converge on the point H.

As shown in FIG. 61, the display unit 22
The image 235 of No. 7 is formed in the vicinity of the virtual display surface 236. Similarly, the image 237 of the display unit 228 is formed near the virtual display surface 238, and the image 239 of the display unit 229 is formed near the virtual display surface 240.

On each of the display units 227, 228, 229, the element patterns 242, 243, 244 as shown in FIG. 63B are displayed in which the original image pattern 241 of the road sign indicating the speed limit shown in FIG. 63A is divided. ing.
That is, the original image pattern 241 is displayed on the display unit 227.
Element pattern 242 of the lower approximately 1/3 obtained by dividing
Is displayed as an image 235. Similarly, in the display unit 228, the element pattern 243 in the central portion of about 1/3 is provided.
Is displayed as an image 237, and the display unit 229 displays
About one-third of the upper element pattern 244 is displayed as an image 239.

At this time, the reproduced images 235, 2 viewed from the front.
Since the images 37 and 239 are combined as one image as shown in FIG. 63C, when viewed from a vehicle passing through the inside of the tunnel 230, the road sign indicating the speed limit indicates as if the ceiling surface 231 of the tunnel 230. It looks as if it is hung from. However, this is a display on the virtual display surface, and since no object actually exists on the display surface, a car accident or the like cannot occur at all.

An advantage of this structure is that the height of the display units can be reduced by a ratio of 1 / N, where N is the number of display units to be arranged. With such an extremely flat optical display device, the cross-sectional area of tunnel excavation can be reduced, and the effect of reducing the construction cost is great.

As described above, in the optical display device using the hologram according to the present invention, the industrial value of the fact that an inexpensive and long-life light source called a fluorescent lamp can be used for the first time is extremely high. .

However, the light source for making the best use of the features of the optical display device of the present invention is not limited to the fluorescent lamp, and may be an elongated linear light source. As the linear light source, in addition to the combination of the lamp and the vertically long opening already mentioned, in addition to the straight tube fluorescent lamp, one-dimensional array of small light bulbs, one-dimensional array of semiconductor lasers and LEDs, and linear light emitting section Organic E formed on
L, or light in which a light source is guided by using a light guide means such as an optical fiber to form a linear light emitting portion, or the like can be easily used. In addition to this, various selections are possible. For example, a pseudo linear light source can be formed by combining a point light source with a cylindrical mirror or a polygon mirror. It is also preferable to reduce the size by using an eccentric mirror. Alternatively, a linear light source can be formed by a light beam linearly condensed by a mirror or a lens. According to this structure, a virtual high-luminance linear light source can be formed at a position close to the hologram. Alternatively, even if a long and thin bright line is displayed in the vertical direction on a two-dimensional display device such as a CRT, it can function as a linear light source. If the display position of the bright line is sequentially moved, the reproduction position moves correspondingly, so that it is possible to produce the effect that the reproduced image appears to move. In addition to this, the same effect can be obtained by using a movable linear light source.

Regarding the light emission characteristics of the light source, a light source having a continuous light emission distribution or a light source having independent light emission peaks of the three primary colors may be used. Alternatively, the linear light source may be configured by combining independent light emitting sources of the three primary colors. By doing so, the light source can be turned on and off for each color, and extremely effective display such as displaying or not displaying a reproduced image of a specific color is possible.

In FIG. 8, when the hologram 2 is turned upside down 180 ° about the axis orthogonal to the paper surface, the virtual display surface on which the reproduced image is formed or the other side of the hologram 2, that is, the ceiling surface 7 in FIG. Hologram 2 to move to the back of
A reproduced image is formed on the other side. The optical display device of the present invention can also display such a reproduced image. However, since the reproduced image obtained in this case is turned upside down, when displaying the reproduced image in such an arrangement, it is necessary to previously set the pattern mask to the front side when viewed from the hologram plate side when manufacturing the hologram 2. There is.

If the reference light is formed by superimposing a plurality of beams in the direction orthogonal to the longitudinal direction of the slit, the visible range can be widened without using a linear light source during reproduction. In this case, the illumination light source may be a point light source. However, the place where the reproduced image is observed is essentially discrete,
When the viewpoint is moved vertically, the position where the reproduced image is visible and the position where it is difficult to see appear alternately. The state changes depending on the degree of overlap of the plurality of beams used in producing the hologram.
When the plurality of beams are arranged close to each other, the reproduced image is observed without interruption even if the viewpoint is moved. The configuration of this reference light is not limited to the case where the object light is formed by the combination of the slit and the scattered light, and when the cylindrical lens is combined with this, when the reproduced image of the transmission hologram is used as the object light, or in one direction. It is also effective when object light is formed by diffused diffused light.

By arranging a primary diffuser such as a lenticular lens sheet so as to be close to the hologram dry plate and exposing the hologram, it is possible to widen the visible range without using a linear light source during reproduction.
In this case, the illumination light source may be a point light source. However, the position where the reproduced image is observed is essentially discrete, and when the viewpoint is moved in the vertical direction, the position where the reproduced image can be seen and the position where it is difficult to see appear alternately. The state changes depending on the specifications of the lenticular lens sheet, and by selecting a lenticular lens sheet having a fine pitch, the reproduced image can be observed without interruption even if the viewpoint is moved.

The reproduction display surface is not limited to one plane and may be composed of a plurality of planes or curved surfaces. Also, as already described in some of the above embodiments, a three-dimensional object may be used as the subject. However, in the case of using a three-dimensional object as a subject, FIG. 10 and FIG.
In the hologram production optical system shown in A and FIG. 11B, the reflected light from the subject generated by irradiating the three-dimensional subject with laser light passes through the slit placed between the subject and the hologram plate. In addition, it is necessary to rearrange the optical system. In this case as well, the light passing through the slit becomes the object light, but the laser light and the object light do not align on the optical axis.

Also, the hologram 2 can be easily duplicated. For example, the hologram 2 and the unexposed hologram dry plate are more preferably brought into close contact with each other via a refractive index matching liquid,
Information recorded on the hologram 2 can be transferred and duplicated on the hologram dry plate by making the laser beam incident from the hologram dry plate side at an appropriate angle.

In each of the above embodiments, an optical road sign,
Although the application of the present invention has been described mainly with respect to the application example to the road information display board, the application is not limited to this application, and general character information, advertisements and the like may be displayed. Similarly, the installation place is not limited to the inside of the tunnel, but the effect is great even if it is installed in a building, an elevator, an underground mall, a station or the like. Alternatively, the non-diffracted light that has not been diffracted by the hologram may be used for ambient illumination.

Further, the installation position is not limited to the ceiling, and it is effective if it is installed on the wall surface, the floor surface, or the like. For example, if a hologram is installed on the floor of the passage and the reproduction is performed by the fluorescent lamp for illumination that is already provided on the ceiling, and an arrow indicating the position of the reproduced image is displayed as the reproduced image,
It functions as a guide sign. In particular, if the reproduced image is displayed so as to be raised by several tens of centimeters from the floor surface, it becomes easy to see. Alternatively, the display obtained in this way is
Since it is a display that catches the eye of the person, it can be used as a means for stopping the foot of a passing person.

(Twenty-second Embodiment) An optical display device using a hologram according to the principle of the present invention presents a certain space to an observer by displaying an arrow or a position index as a reproduced image. You can In the present embodiment, as an application example of this feature, a system that visualizes a position where a contactless card is passed and presents it to the user will be described.

Taking a railway station as an example, the currently installed automatic ticket gate system is mainly of the type that magnetically reads the information recorded on the commuter pass. However, in the future, replacement of the information of the commuter pass carried by the user with contactless reading by radio waves or other methods is being considered. This is to improve the efficiency of the ticket gate by allowing the user to pass through the ticket gate while holding the commuter ticket, which is a contactless card, instead of the current method of inserting the ticket into the machine. We aim to achieve a smoother flow of people.

The point to be considered here is that the user can use the commuter pass within a predetermined communication area (for example, an area for wirelessly reading signals) set in a space away from the card reader. The point is whether or not it can be passed. If this is not successful and you have to repeat reading many times, the flow of people at the ticket gate will be delayed.

The problem of effective passage of the card to this communication area is a problem peculiar to the contactless card system. This is because with the conventional reader, the user simply inserts the card into the insertion slot, and the machine automatically positions the card for reading. Therefore, the user is not burdened with a device for reading well.
On the other hand, in the contactless card system, the communication area is spatially spread out, so it is necessary to bring the card into the optimal communication area first, and the card is placed in the communication area only for the time required to read information. Continued presentation becomes an indispensable condition, and all such work will be entrusted to the user.

Under such circumstances, in order to read the card securely without burdening the user,
Visualizing the position (area) where the non-contact card should pass is considered to be an effective means. According to the optical display device of the present invention, an index such as an arrow can be displayed as a hologram reproduction image of a clear color image in a communication area located at a position distant from the card reader, and the position where the card should be held is determined. It can be surely presented to the passing user.

[0293] Further, since the user who normally passes through the ticket gate is in a hurry, the original function cannot be fulfilled by the display in which the communication area can be seen only when the user passes the ticket gate. This is because it takes a lot of load to move the card to the optimum position when the display is seen. Therefore, in order to surely inform the user of the position of the communication area, it is desirable that the display is such that the position of the communication area can be roughly grasped when the user approaches the ticket gate. The optical display device of the present invention also works effectively for this.

That is, as described in connection with the third embodiment, for example, in the optical display device of the present invention, the visual recognition area of the display can be expanded in the front and back by the arrangement of the light source. By using this function, it is possible to create a situation where the user can see something even when the user is still away from the ticket gate. Therefore, the user can start the preparation for presenting the card by using the visible portion as a guide. In addition, as the user approaches the ticket gate, the display portion gradually becomes more visible, and the user can be sure where to place the commuter pass. When actually passing through the ticket gate, the card can be passed while being held at an appropriate height and position, so that reliable information reading can be performed.

[0295] The above "situation where something is visible" means what kind of display is provided as long as it is eye-catching to the person, such as the presentation position blinking as the user walks or the color changes. But it's okay. For this purpose, it is possible to effectively utilize the characteristic of the present invention that a hologram produced by a plurality of reference lights is seen or disappeared depending on the viewing position.
Alternatively, it can be realized by configuring the optical information device while avoiding the arrangement in which the color change is small.

[0296] It is desirable that the visual recognition range be set wide in the front, and at the same time, the visual range can be seen even if the user looks back a little when passing the presentation position. This is also
As described in connection with the third embodiment, the visual recognition area of the display can be limited by the arrangement of the light sources.

Since the height of the user varies from person to person, it is desirable that the user can see clearly even when the viewing height changes. This can be realized by increasing the degree of diffusion of the diffuser used when producing the hologram and lengthening the slit, or by increasing the width and the degree of diffusion of the one-dimensional diffuser.

In Japanese Patent Application Laid-Open No. 9-6935 relating to a wireless card processing device, a hologram projection device displays a hatched pattern in a range approximately equal to the communication area.
There is a description that a three-dimensional image is projected. However, in order to actually realize such a function, it is essential to use the method proposed by the present invention.

Although the contactless card system is taken as an example in the above, the optical display device of the present invention can be combined with other information communication devices such as a POS system. In this case, in the constructed optical display system, the optical display device three-dimensionally displays the communication area of the information communication device. Preferably, the display area of the optical display device and the communication area of the information communication device are matched with each other. The information communication device may be configured to perform information communication (reception or transmission) in one direction, or may be configured to perform interactive communication (transmission / reception) in two directions.

[0300]

According to the present invention, since the hologram reproduced image is displayed by the above-mentioned structure, the hologram reproduced image having no substance can be displayed on the substanceless surface virtually provided in the space. it can. In addition, since the display device itself is arranged in a flat area extremely close to the wall surface of the installation location, the protruding portion is small, and the display apparatus becomes huge, the installation area (occupied area) increases, or Problems with conventional display devices such as contact accidents are eliminated.

Further, according to the present invention, it is possible to perform a display using a fluorescent lamp as a reproduction light source, and the reproduction light source can be used anytime and anywhere. Therefore, by manufacturing only the hologram on a lightweight and flexible substrate. Thus, it is possible to easily realize a portable display device.

Further, by applying this principle, a novel display such as a head-up display or a three-dimensional display device for observing an image away from the screen surface is realized.

For example, if the optical display device of the present invention is used in a contactless card system, the spatially wide communication area can be clearly presented to the user, and the original function of the contactless card system can be obtained. Can be exhibited more reliably and effectively.

[Brief description of drawings]

FIG. 1A is a side view showing a configuration of a conventional optical road sign.

FIG. 1B is a front view showing a configuration of a conventional optical road sign.

FIG. 2A is a diagram schematically showing a general conventional hologram creation principle.

FIG. 2B is a diagram schematically showing the reproduction principle of the hologram formed by FIG. 2A.

FIG. 3A is a diagram schematically showing the principle of creating a conventional reflection hologram.

FIG. 3B is a diagram schematically showing the principle of creating a conventional reflection hologram.

FIG. 3C is a diagram schematically showing the reproduction principle of the reflection hologram formed in FIGS. 3A and 3B.

FIG. 3D is a schematic diagram for explaining the reason why a reproduced image of a reflection hologram is blurred.

FIG. 3E is a diagram schematically showing the wavelength dependence of diffraction efficiency in a reflection hologram.

FIG. 4A is a diagram schematically showing the principle of creating a conventional rainbow hologram.

FIG. 4B is a diagram schematically showing the principle of creating a conventional rainbow hologram.

FIG. 4C is a diagram schematically showing the reproduction principle of the rainbow hologram formed in FIGS. 4A and 4B.

FIG. 4D is a schematic diagram for explaining the reason that a reproduced image of a rainbow hologram has less blur.

FIG. 4E is a diagram schematically illustrating wavelength dependence of diffraction efficiency in a rainbow hologram.

FIG. 5A is a diagram schematically showing the principle of producing a reflection hologram according to the present invention.

FIG. 5B is a diagram schematically showing the principle of producing a reflection hologram according to the present invention.

FIG. 5C is a diagram schematically showing the reproduction principle of the reflection hologram of the present invention formed in FIGS. 5A and 5B.

FIG. 6A is a schematic diagram for explaining the reason that the reproduced image of the reflection hologram of the present invention has less blur.

FIG. 6B is a diagram schematically illustrating wavelength dependence of diffraction efficiency in the reflection hologram of the present invention.

FIG. 7A is a diagram schematically showing how the reflection hologram of the present invention formed in FIGS. 5A and 5B is reproduced using a linear light source.

FIG. 7B is a diagram schematically showing how the reflective hologram of the present invention formed in FIGS. 5A and 5B is reproduced using a linear light source.

FIG. 8 is a side view showing the configuration of the optical display device according to the first embodiment of the present invention.

9 is a plan view of the optical display device of FIG.

FIG. 10 is a perspective view showing an optical system for producing a hologram in the present invention.

FIG. 11A is a side view of an optical system for producing the hologram shown in FIG.

11B is a plan view of the optical system for producing the hologram shown in FIG.

FIG. 12 is a diagram schematically showing a geometrical relationship between a hologram height and an observation position.

FIG. 13 is a graph showing the relationship between the size of a reproduced image and the observation position.

FIG. 14 is a diagram schematically showing a configuration of an exposure optical system using a one-dimensional diffuser.

FIG. 15A is a side view showing the principle of reproducing a hologram according to the present invention.

FIG. 15B is a plan view showing the principle of reproducing a hologram according to the present invention.

FIG. 16A is a diagram showing a shape of an aperture that can be used for observing a reproduced image according to the present invention.

FIG. 16B is a diagram showing a shape of an aperture that can be used for observing a reproduced image according to the present invention.

FIG. 17A is a perspective view showing a reproducing optical system of the optical display device of the present invention.

FIG. 17B is a diagram showing a viewing angle range when fluorescent lights of the same length are horizontally arranged.

FIG. 17C is a diagram showing a viewing angle range when fluorescent lights of the same length are vertically arranged.

FIG. 18 is a side view showing the configuration of the optical display device according to the second embodiment of the present invention.

FIG. 19 is a diagram schematically showing that the viewing distance can be limited.

FIG. 20 is a plan view of the optical display device of the present invention when the installation position of the linear light source (fluorescent lamp) is away from the incident plane (offset arrangement).

FIG. 21A is a diagram showing three exposure pattern masks corresponding to the three primary colors of color.

FIG. 21B is a diagram showing a reproduced image when the produced holograms of three primary colors are overlapped.

FIG. 21C is a diagram showing a state in which the manufactured holograms are stacked on one substrate.

FIG. 22 is a graph showing the relationship between the color change at the center of the reproduced image and the reference light angle.

FIG. 23 is a graph showing a relationship between a color distribution in a reproduced image and a reference light angle.

FIG. 24 is a graph showing a relationship between a color distribution in a reproduced image and an observation position.

FIG. 25A is a diagram showing an example in which a hologram is formed on a flexible substrate.

FIG. 25B is a diagram showing an example in which a hologram is formed on a flexible substrate.

FIG. 25C is a diagram showing an example in which a hologram is formed on a flexible substrate.

FIG. 25D is a diagram showing an example in which a hologram is formed on a flexible substrate.

FIG. 25E is a diagram showing an example in which a hologram is formed on a flexible substrate.

FIG. 26 is a side view of an optical system for producing a hologram for reproduction display in a color other than the laser oscillation wavelength.

FIG. 27A is a diagram showing an installation state of holograms in which a color change is small within a visible range.

FIG. 27B is a diagram showing a normal hologram reproduction state.

FIG. 28 is a conceptual diagram showing that a large display is performed by combining element holograms.

FIG. 29A is a front view of an example of an optical display device including three display units arranged side by side.

FIG. 29B is a side view of an example of an optical display device in which three display units are arranged side by side.

FIG. 30A is a diagram showing an example of an optical display device in which three display units are arranged on the left and right to display one large pattern, and shows a divided reproduced image.

FIG. 30B is a diagram showing one example of an optical display device in which three display units are arranged on the left and right to display one large pattern, and a reproduced image seamlessly combined is shown.

FIG. 31A is a side view showing the configuration of the optical display device according to the twelfth embodiment of the present invention.

FIG. 31B is a diagram showing a pattern displayed by the optical display device of FIG. 31A.

FIG. 31C is a diagram showing element patterns recorded in each display unit in the optical display device of FIG. 31A.

31D is a diagram showing a reproduced image displayed by the optical display device of FIG. 31A.

FIG. 32 is a perspective view of an optical display device according to a thirteenth embodiment of the present invention.

33 is a configuration diagram of a hologram unit included in the optical display device of FIG. 32.

34 is a diagram showing the principle of operation of the optical display device of FIG. 32.

FIG. 35 is a perspective view of an optical display device according to a fourteenth embodiment of the present invention.

36 is a configuration diagram of a hologram unit included in the optical display device of FIG. 35.

37 is a diagram showing the principle of operation of the optical display device of FIG. 35.

FIG. 38 is a configuration diagram of an optical display device according to a fifteenth embodiment of the present invention.

FIG. 39A is a side view of an optical system for producing a transmission hologram according to a sixteenth embodiment of the present invention.

FIG. 39B is a plan view of a transmission hologram producing optical system according to a sixteenth embodiment of the present invention;

FIG. 40 is a side view of an optical system for producing a reflection hologram in the sixteenth embodiment of the present invention.

FIG. 41 is a side view of an optical system for producing a transmission hologram according to a seventeenth embodiment of the present invention.

FIG. 42 is a side view of a reflection hologram producing optical system in the seventeenth embodiment of the present invention.

FIG. 43 is a side view of an optical system for producing a reflection hologram in the eighteenth embodiment of the present invention.

FIG. 44 is a side view of the optical display device in the nineteenth embodiment of the present invention.

45 is a diagram schematically showing an image projected and imaged on a hologram screen in the optical display device of FIG. 44.

46A is a plan view schematically showing the functional principle of the hologram screen in the optical display device of FIG. 44. FIG.

46B is a side view schematically showing the functional principle of the hologram screen in the optical display device of FIG. 44. FIG.

47 is a diagram schematically showing a manufacturing optical system of a hologram screen in the optical display device of FIG. 44.

48A is a plan view schematically showing how a light ray travels in the optical display device of FIG. 44. FIG.

48B is a side view schematically showing how a light beam travels in the optical display device of FIG. 44. FIG.

49A is a plan view schematically showing how a light beam travels from a hologram screen to an observer in the optical display device of FIG. 44. FIG.

49B is a side view schematically showing how a light beam travels from a hologram screen to an observer in the optical display device of FIG. 44.

[Fig. 50] Fig. 50 is a diagram schematically illustrating distortion of a captured image when a tall building is captured by a normal camera.

FIG. 51A is a diagram schematically showing the procedure of a front rising photography technique.

FIG. 51B is a diagram schematically showing the procedure of a front rising photography technique.

FIG. 51C is a diagram schematically showing the procedure of a front rising photography technique.

FIG. 51D is a diagram schematically showing the procedure of a front rising photography technique.

52 is a diagram schematically showing that the arrangement of the optical display device of FIG. 44 satisfies the conditions of the front rising photography technique.

[Fig. 53] Fig. 53 is a configuration diagram based on Shine-Plug conditions, which is a photography technique.

FIG. 54A is a plan view schematically showing how a light beam travels in an optical display device configured using a variable focus lens.

FIG. 54B is a side view schematically showing how a light beam travels in an optical display device configured using a variable focus lens.

FIG. 55 is a diagram schematically showing a hologram screen manufacturing optical system in an optical display device in which an image is formed on the other side of the hologram screen.

FIG. 56 is a diagram schematically showing a configuration of an optical display device in which an image is formed on the other side of the hologram screen.

57 is a diagram schematically showing a configuration when the optical display device of FIG. 56 is applied to a head-up display.

FIG. 58 is a diagram schematically showing the structure of the three-dimensional display device in the twentieth embodiment of the present invention.

FIG. 59A is a side view of an example of an optical display device in which three display units are arranged on the left and right to display one large pattern.

FIG. 59B is a front view of an example of an optical display device in which three display units are arranged on the left and right to display one large pattern.

FIG. 60 is a front view of another example of the optical display device in which three display units are arranged on the left and right to display one large pattern.

FIG. 61 is a side view showing the configuration of an optical display device in which a plurality of display units are arranged in the depth direction of an image to display one large pattern.

FIG. 62A is a diagram showing an optical system for producing a hologram screen of each display unit included in the optical display device of FIG. 61;

FIG. 62B is a diagram showing an optical system for producing a hologram screen of each display unit included in the optical display device of FIG. 61;

FIG. 62C is a diagram showing a holographic screen manufacturing optical system of each display unit included in the optical display device of FIG. 61;

63A is a diagram showing a pattern displayed by the optical display device of FIG. 61. FIG.

63B is a diagram showing element patterns recorded in each display unit in the optical display device of FIG. 61. FIG.

63C is a diagram showing a reproduced image displayed by the optical display device of FIG. 61. FIG.

[Explanation of symbols]

1 Optical display device 2 hologram 3 fluorescent lights 4 fluorescent light fixtures 5 Shield 6 tunnels 7 ceiling surface 8 illumination light 9 Playback light 10 Virtual display surface 11 Reproduced image 12 slits 13 pattern masks 14 Object light 15 plane of incidence 16 Reference light 17 Hologram Dry Plate 18 frosted glass 19 laser light 20 diffused light 21 Halogen lamp 22 opening 23 Illumination light 24 Playback light 25 Observer 26 Reconstructed image of slit 27 Fluorescent lamp 28, 31, 34, 37, 44, 47 Illumination light 29, 32, 35, 38, 48 Reconstructed image 30, 33, 36, 39, 49 Observer 40 Optical display device 41 Fluorescent lamp 42 Fluorescent lamp 43 Reflector 44 Illumination light 45 Playback light 46 Fluorescent lamp 50 hologram dry plate 51 pattern mask 52 Reference light 53 hologram 54 Illumination light 55 Playback light 56 Observer 57 display unit 58 fluorescent light 59 Reproduced image 60 Shield 61, 64, 66 display unit 62, 67 Fluorescent lamp 63, 65, 68 reconstructed image 69 Optical display device 70, 71, 72 display unit 73, 74, 75 hologram 76, 77, 78 Fluorescent lamp 79 tunnel 80 ceiling 81 original pattern 82, 83, 84 element patterns 85, 87, 89 reconstructed image 86, 88, 90 Virtual display surface 91 fluorescent light 92 Hologram unit 93 Emergency telephone 94 First hologram 95 Second hologram 96 display board 97 First surface of hologram unit 98 Second surface of hologram unit 99 Display board 1st surface 100 Second side of display panel 101, 104 area 102, 105 Illumination light 103,106 Reconstructed image 107 fluorescent light 108, 109 hologram unit 110 First hologram 111 First display plate 112 Second hologram 113 Second display board 114,116 Illumination light 115,117 Reproduced image 118 fluorescent light 119 First hologram 120 Second hologram 121,123 Illumination light 122,124 Reproduced image 125 frosted glass 126 laser light 127 diffused light 128 slits 129 pattern mask 130 hologram dry plate 131 Object light 132 reference light 133 Master hologram 134 Illumination light 135 Playback light 136 hologram dry plate 137 Reference light 138 Reproduced image 139 subject 140 illumination light 141 Object light 142 hologram dry plate 143 reference light 144 Master hologram 145 Illumination light 146 slits 147 object light 148 hologram dry plate 149 reference light Reproduced image of 150 subjects 151 Cylindrical lens 152 Aperture 153 Playback light 154 hologram dry plate 155 Reconstructed image of subject 156 sign display board 157 Ring type fluorescent tube 158 sign body 159 Sign post 201 Optical display device 202 hologram screen 203 Cylindrical lens 204 LED display device 205 tunnel 206 ceiling 208 Virtual display surface 209 statue 210 lens 211 laser beam 212 pinhole 213 hologram dry plate 214 laser beam 215 Observer 216 Film side 217 Shooting lens 218 display device 219 laser beam 220 hologram screen 221 Virtual display surface 223 display unit 224 Virtual display surface 225 statue 226 Optical Display Device 227, 228, 229 Display unit 230 tunnel 231 Ceiling surface 232, 233, 234 laser beam 235, 237, 239 images 236, 238, 240 Virtual display surface 241 original pattern 242,243,244 element pattern 270, 271, 272 patterns 301 Variable focus lens 402 Spatial modulator 403 Projection optical system 404 polarized glasses 406 3D image 415 Observer 420 hologram screen 1001 one-dimensional diffuser

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Zenrou Hayashi, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-174572 (JP, A) JP-A-7 -104646 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03H 1/00 G02B 5/32

Claims (10)

(57) [Claims] 1. An optical display device comprising an image display device, an imaging optical system, and a hologram screen, wherein the image display device has at least one point light source, and the hologram screen comprises: The diffracted light from the point light source is diffracted and reflected to form a point image at a position different from the point light source, and the image forming optical system is a part of the image displayed on the image display device. only component along the direction, is configured so as to focus on the hologram screen, the display image of the image display device and a reproduction image on the virtual display plane
An optical display device formed as described above. 2. The optical display device according to claim 1 , wherein the virtual display surface is arranged between the hologram screen and an observer of a reproduced image formed on the virtual display surface. 3. The optical display device according to claim 1 , wherein the hologram screen is arranged between the virtual display surface and an observer of a reproduced image formed on the virtual display surface. The unidirectional wherein image displayed on the image display device is a vertical direction, the imaging optical system has a cylindrical lens, a variable focus lens having a power only in the horizontal direction, wherein Item 2. The optical display device according to item 1 . 5. The polarizing glasses further include polarizing glasses attached to an observer of a reproduced image formed on the virtual display surface, and the polarizing glasses have the orientations of the respective polarizing plates orthogonal to each other. The optical display device according to claim 1 . 6. An optical display system in which a plurality of optical display devices according to claim 1 are arranged side by side when viewed from an observer. 7. A plurality of optical display devices according to claim 1 are arranged in a depth direction of an image viewed from an observer,
Optical display system. 8. The image display device comprises an LED, a CRT,
The optical display device according to claim 1 , comprising a display element selected from a polymer dispersed liquid crystal panel or an organic EL panel, and a polarization switching element. 9. The optical display device according to claim 8 , wherein the polarization switching element includes a ferroelectric liquid crystal panel. 10. further comprising a polarized glasses for observing a reproduced image formed on the virtual display plane, Me polarization is
Roots is the orientation of the polarizing plates are perpendicular to each other, claim
8. The optical display device according to item 8 .