JPH08286595A - Formation of holographic stereoscopic hard copy and forming device therefor - Google Patents

Abstract

PURPOSE: To miniaturize an optical system and to obtain a holographic stereoscopic hard copy which extremely withstands to vibration. CONSTITUTION: A reflection type hologram 3 and a photosensitive material 4 are superposed on each other and the light transmitted through a space modulation element like a liquid crystal panel 5 is condensed by a lens 6 and exposure is executed from the surface of the photosensitive material 4. The light transmitted through the photosensitive material 4 by such exposure is reproduced by the element hologram on the reflection type hologram 3. The hologram of a volume type having the object light condensed by the lens 6 and the beam- shaped light reproduced by the reflection type hologram 3 as reference light is recorded on the photosensitive material 4 by forming the beam-shaped light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a holographic three-dimensional hard copy using a hologram.

[0002]

2. Description of the Related Art Today, three-dimensional image processing technology is widely used. For example, in the medical field, X-ray CT (Com
puted Tomography), MRI (Magnetic Resonannce Imagi
ng) etc. to collect three-dimensional information of the human body and use it for diagnosis and surgery planning. In addition, a three-dimensional CAD system is used for construction, product design, and the like.

At present, photographs such as two-dimensional tomographic images and projected images are used as the hard copy output from these three-dimensional image processing systems. However, as a more efficient and easy-to-understand item, there is a demand for a hard copy that expresses a three-dimensional object with a planar object.

A holographic stereogram (hereinafter, referred to as HS) is the most excellent as a hard copy capable of stereoscopically displaying a three-dimensional object processed and generated by a computer. This HS synthesizes a plane image of an object viewed from various angles into one hologram, and is suitable for three-dimensional recording and display of a fictitious object.

However, the hard copy of a three-dimensional object
Up to now, no HS method satisfying the above condition has been reported. Therefore, in the conventional method, the vertical parallax cannot be recorded, and the reproduced image is distorted depending on the observation position. Moreover, the hologram cannot be automatically recorded by the method of combining in two steps.

On the other hand, as a method of automatically synthesizing, a multiplex hologram, an Alcove Hologram and the like have been proposed, but these are not only capable of recording parallax information in the vertical direction, but also a cylindrical type, It is a semi-cylindrical type,
Since a playback device is required for observation, a general
Not suitable for copying.

Therefore, recently, for example, "Japanese Patent Laid-Open No. 3-2"
A method according to Japanese Laid-Open Patent Publication No. 49686 has been proposed by the present applicant. That is, as shown in the optical system of FIG. The light is displayed on the spatial modulation element, and the transmitted light is condensed as an object light (a converging spherical wave) on the hologram surface (hologram dry plate) 14 through the lens 12, and the light is condensed in the opposite direction on the condensing portion (same point) 16. The reference light (plane wave) is incident from the above, and the interference fringe pattern with the reference light is recorded as a dot-shaped element hologram on the hologram surface 14. Then, the hologram film is moved little by little in the vertical and horizontal directions and sequentially. It is a method of creating a holographic three-dimensional hard copy by performing exposure and exposing a dot-like hologram element over the entire surface of the hologram.

The holographic three-dimensional hard copy produced by this method is a flat type and can be combined in one step, and since parallax information in the vertical direction is also recorded, a three-dimensional image can be accurately recorded and displayed. it can. Further, according to this method, since dot-shaped hologram elements are sequentially recorded on the surface of the base material, it is possible to perform recording in a manner similar to that of a conventional dot printer. Therefore, it is optimal for realizing a 3-D printer as a hard copy machine for three-dimensional data.

That is, a three-dimensional hard copy can be created by one optical system, and a holographic three-dimensional hard copy can be automatically created. However, in an optical system for realizing such a method, it is necessary to branch one light into an object light and a reference light once and then focus these lights again at one point. Therefore, there is a problem that not only the optical system becomes large, but also the distance after the light is branched is long, which makes it weak against vibration.

[0010]

As described above, in the conventional method for producing a holographic three-dimensional hard copy, there is a problem that not only the optical system becomes large but also it is susceptible to vibration. SUMMARY OF THE INVENTION It is an object of the present invention to provide a holographic three-dimensional hard copy capable of miniaturizing an optical system and extremely resistant to vibration, and a method and apparatus for producing the same.

[0011]

In order to achieve the above object, first, in the invention corresponding to claim 1, a plurality of dot-shaped element holograms are formed on the surface of a base material to display a three-dimensional image. In the method of creating a hard copy, the step of creating an original image corresponding to the coordinate position of the photosensitive material,
An optical means for reproducing a plane wave by injecting a spherical wave and a photosensitive material are combined, an original image is displayed at a desired display position, and an optical system is used to display the coordinate position of the photosensitive material. Spherical waves that have passed through the original image and are collected are incident on the photosensitive material, and the plane wave reproduced by the optical means and transmitted through the photosensitive material is caused to interfere with the spherical wave. It comprises a step of forming element holograms, a step of sequentially moving the coordinate position of the photosensitive material to display and a step of forming element holograms to form a plurality of dot-shaped element holograms on the photosensitive material.

Further, in the invention according to claim 2, a plurality of dot-shaped element holograms are formed on the surface of the substrate to form 3
In a device for making a hard copy for displaying a three-dimensional image, optical means for reproducing a spherical wave into a plane wave, moving means for moving the photosensitive material to a desired position, and corresponding to each point of the photosensitive material from three-dimensional image data An original image creating means for obtaining an original image pattern to be displayed, a display means for displaying the original image pattern,
An optical system for forming a dot-shaped element hologram corresponding to the original image pattern displayed on the display means on the photosensitive material, a developing means for developing the photosensitive material on which the element hologram is formed, a moving means, an original image forming means, and a developing device. Control means for controlling the means to create a holographic stereoscopic hard copy.

Here, it is preferable to use a reflection hologram as an optical means for reproducing the spherical wave into a plane wave. A liquid crystal panel is preferably used as the display means.

[0014]

Therefore, in the method and apparatus for producing the holographic three-dimensional hard copy of the invention corresponding to claims 1 and 2, the optical means for reproducing a spherical wave into a plane wave and the photosensitive material are superposed, When light transmitted through a spatial modulation element such as a liquid crystal panel is condensed and exposed from the surface of the photosensitive material, the light transmitted through the photosensitive material is reproduced by optical means to reproduce beam light. . As a result, a volume hologram using the condensed object light and the beam-like light reproduced by the optical means as the reference light is recorded on the photosensitive material.

That is, in such an optical system, since it is not necessary to split the light for the reference light, the optical system can be downsized and is extremely resistant to vibration. Furthermore, by using a reflection hologram as an optical means for reproducing a spherical wave into a plane wave, the optical means and the photosensitive material can be brought into close contact with each other, so that the distance after branching the light becomes almost zero, Not only is it less affected by vibration, but also the cost is lower.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of the present invention will be described with reference to FIGS. The present invention uses a reproduction light from a reflection hologram as a reference light by combining a light-sensitive material and an optical means (for example, a reflection hologram), thereby eliminating the need to split the laser light. The system can be miniaturized and a device extremely resistant to vibration is realized.

In this case, the hologram used for the reflection type hologram is formed by an optical system as shown in FIG. 2, for example. That is, the interference fringes of the spherical wave reference light focused by the lens 1 and the beam-shaped object light are recorded on the photosensitive material 2 as a volume hologram.

Further, as shown in FIG. 3, when such reflection hologram 3 is illuminated with spherical wave illumination light,
The beam-shaped reproduction light is reproduced at the same angle as the object light. Then, as shown in FIG. 1, such a reflection hologram 3 and the photosensitive material 4 are overlapped with each other, and the light transmitted through the spatial modulation element such as the liquid crystal panel 5 is condensed by the lens 6, and the surface of the photosensitive material 4 is covered. By performing the exposure from, the light transmitted through the photosensitive material 4 is reproduced by the element hologram on the reflection hologram 3, and the beam-like light is reproduced. This allows
A volume hologram is recorded on the photosensitive material 4 using the object light focused by the lens 6 and the beam-like light reproduced by the reflection hologram 3 as reference light.

That is, in such an optical system, since it is not necessary to split the beam-like light for the reference light, the optical system can be downsized and can be extremely resistant to vibration.

An embodiment of the present invention based on the above principle will be described below in detail with reference to the drawings. First, an original image corresponding to the coordinate position of the photosensitive material is created.

In this case, the method for creating the original image is as shown in FIG.
And it is created by the method as shown in FIG. That is, as shown in FIG. 4, the original pattern displayed on the liquid crystal panel 10 is created by perspective projection conversion. The center point of the projection is a point on the hologram surface 14 that exposes the pattern 10, and the range of light rays to be calculated is determined by the aperture and focal length of the lens 12 in the optical system shown in FIG. What is different from the general computer graphics method is that the center point of projection and the viewpoint are different, and therefore the hidden surface removal process is performed with the right side facing in FIG. This is to calculate the direction and intensity of the light ray that passes through a certain point on the hologram surface 14 among the reflected light rays from the object.

In HS recording, light rays are condensed in the same direction as in the original pattern calculation and recorded as a Lippmann hologram. The hologram film is moved in the vertical and horizontal directions and is exposed so as to fill the entire surface of the hologram 14 as shown in FIG.

On the other hand, when the HS recorded in this way is reproduced, as shown in FIG. 5, the light rays from each point on the hologram surface 14 are correctly reproduced, and a stereoscopic image can be observed. In other words, the hologram 14 is used as a window to correctly record and reproduce the directions and intensities of all the rays that pass through the window. Therefore, this method can reproduce a stereoscopic image without any distortion.

Next, as shown in FIG. 2, the optical system is used to capture an image of the reflection hologram 3 of spherical wave and plane wave which is an optical means. Next, a three-dimensional image is photographed using an optical system (one-step Lippmann HS stereo image forming system) as shown in FIG.

That is, as shown in FIG.
The laser beam from the neon laser 20 becomes parallel light through the lens 24, illuminates the liquid crystal panel 10, and is modulated by the liquid crystal panel 10. This modulated light is reflected by the lens 26, the slit 28, the lens 30, and the mirror 32.
Is guided to a spherical lens 34 having a large power, and is focused on the photosensitive material (hologram dry plate) 14 as object light by this lens 34.

Of this object light, the plane wave which is the reference light transmitted through the photosensitive material 14 and reproduced by the reflection hologram 3 superposed on the photosensitive material 14 is condensed on the photosensitive material 14. By interfering with the spherical wave that is the object light, a dot-shaped element hologram corresponding to the original image is formed.

Here, the lens 26, the pinhole 28 and the lens 30 constitute a spatial filtering system for removing the matrix structure of the liquid crystal panel 10. On the other hand, the photosensitive material 14 is fixed to the XY pulse stage 36 in a state of being superposed on the reflection hologram 3.
It can be moved vertically and horizontally. Then, the liquid crystal panel 10
Is changed and the XY pulse stage 36 is moved to form a dot-shaped element hologram on the entire surface of the photosensitive material 14. The entire system is controlled by a personal computer.

As for the focal point distance of the lens 34 for condensing the object light, it is preferable to use a lens having the same focal length as the lens for condensing the reference light of the reflection hologram 3.
As the photosensitive material 14, for example, a silver salt sensitive material is preferably used.

The HS according to the present invention has the following features. (A) A parallax in the horizontal and vertical directions can be added, and a stereoscopic image can be displayed accurately.

(B) If a Lippmann type hologram is used, it is basically possible to realize a real color. (C) It can be synthesized by a small device without using a special optical component such as a cylindrical lens.

(D) When creating a large hologram,
It is only necessary to use the exact same optical system and increase the number of exposure points. (E) Since the light beam is condensed and used, the power of the light source can be effectively used, and high stability of the optical system is not required.

(F) Since it can be synthesized in one step, it can be used in an automatic system. Next, with reference to FIGS. 7 and 8, an embodiment of a holographic three-dimensional hard copy producing apparatus (printer) according to the present invention will be described.

By using the HS of the present invention, it is possible to realize a practical holographic printer which outputs a hard copy of a fictitious three-dimensional object. FIG. 7 shows the system. This printer is used in an image like a three-dimensional version of a video printer. The operator can obtain a three-dimensional hard copy of the three-dimensional object by observing the three-dimensional object from various angles on the monitor and setting the output direction.

In step A of FIG. 8, three-dimensional image data is input to the host computer 40. Next, in step B, the photosensitive material 14 and the reflection hologram 3 superposed thereon are moved by the film moving controller 46 to set the photosensitive material 14 and the reflection hologram 3 at desired positions.

Next, in step C, the graphic processor 42 calculates the original image pattern for exposing each point of the hologram from the original three-dimensional data,
It is stored in the frame memory 44.

Next, in step D, the liquid crystal panel 1
The original pattern is displayed at 0. In step E, the shutter of the optical system 48 is opened to expose the liquid crystal panel 10. The laser light extracted from the laser device 20 is modulated by the original image pattern of the liquid crystal panel 10 and condensed on the photosensitive material 14 as object light.

Of this object light, the plane wave which is the reference light transmitted through the photosensitive material 14 and reproduced by the reflection hologram 3 superposed on the photosensitive material 14 is condensed on the photosensitive material 14. By interfering with the spherical wave which is the object light, one dot-shaped element hologram corresponding to the original image is formed.

Next, in step F, the photosensitive material 14 and the reflection hologram 3 are sequentially moved by the film moving controller 46, and the whole surface of the photosensitive material 14 is exposed through step G so as to be exposed.

Then, in step H, the photosensitive material 14 on which the element holograms are formed is developed by the developing machine 50, and the holograms (holographic three-dimensional halves) are processed.
The copy is automatically created.

The graphic processor 42, the film moving controller 46, and the developing machine 50 are C
It is controlled by the PU. Such a holographic
By using a three-dimensional printer system, a three-dimensional hard copy can be created completely automatically, and the hologram can be widely used as a hard copy of a three-dimensional object.

As described above, in the present embodiment, the reflection hologram 3 and the photosensitive material 14 are overlapped with each other to form the liquid crystal panel 10.
By condensing the light transmitted through the spatial modulation element as described above by the lens 34 and exposing from the surface of the photosensitive material 4,
The light transmitted through the photosensitive material 4 is reproduced by the element hologram on the reflection hologram 3, and the beam-shaped light is reproduced. As a result, a volume hologram is recorded on the photosensitive material 4 using the object light condensed by the lens 34 and the beam-shaped light reproduced by the reflection hologram 3 as reference light.

Therefore, in the optical system, it is not necessary to branch the beam-like light for the reference light as in the conventional case described above, so that the optical system can be downsized and is extremely strong against vibration. It becomes possible to do.

Further, according to the method for producing the holographic solid copy of this embodiment, a stereoscopic hard copy can be automatically created by one optical system, and the automatic copy of the hard copy can be made. The system can be realized.

Furthermore, since the reflection hologram 3 is used as an optical means for reproducing a spherical wave into a plane wave, the reflection hologram 3 and the photosensitive material 14 can be brought into close contact with each other.
The distance after splitting the light becomes as close to zero as possible, so that it is not affected by vibration and the cost is low.

The present invention is not limited to the above embodiment, but can be implemented in the same manner as described below. (A) In the above embodiment, the case where a reflection hologram is used as an optical means for reproducing a spherical wave into a plane wave has been described, but the invention is not limited to this, and as an optical means for reproducing a spherical wave into a plane wave, for example, as shown in FIG. 9, a spherical mirror (concave mirror) 7 is used, or as shown in FIG.
A spherical mirror (convex mirror) 8 may be used, or a lens 9a and a mirror 9b may be combined as shown in FIG.

(B) In the above embodiment, the case where the liquid crystal panel 10 is used as the spatial light modulating element used for modulating the laser light by the original pattern has been described. , The number of pixels is 256 ×
A spatial modulation element capable of expressing 8-bit gradation at 256 or more and capable of displaying an image with low noise even in coherent light illumination is preferable.

(C) In the above embodiment, the case where the silver salt sensitive material is used as the photosensitive material 14 has been described, but the present invention is not limited to this, and a polymeric photosensitive material is used for recording a high quality Lippmann hologram. You can also

[0048]

As described above, according to the invention corresponding to claim 1, first, a hard copy for displaying a three-dimensional image is formed by forming a plurality of dot-shaped element holograms on the surface of a base material. In the method, the step of creating an original image corresponding to the coordinate position of the light-sensitive material, the step of combining the light-sensitive material with an optical means for reproducing a plane wave by injecting a spherical wave, and the original image at a desired display position. The step of displaying and using the optical system at the coordinate position of the photosensitive material, the spherical wave which is transmitted and condensed through the displayed original image is incident on the photosensitive material, and transmitted through the photosensitive material and reproduced by the optical means. By forming the dot-shaped element hologram corresponding to the original image by causing the generated plane wave to interfere with the spherical wave, and sequentially moving and displaying the coordinate position of the photosensitive material The step of forming a plurality of dot-shaped element holograms on the photosensitive material by repeating the step of forming a program makes it possible to miniaturize the optical system and, at the same time, it is a holographic stereoscopic three-dimensional type that is extremely resistant to vibration. A method for creating a copy can be provided.

According to the inventions corresponding to claims 2 to 4, in a device for forming a hard copy displaying a three-dimensional image by forming a plurality of dot-shaped element holograms on the surface of a substrate, Optical means for reproducing spherical waves into plane waves, moving means for moving the photosensitive material to a desired position,
An original image creating means for obtaining an original image pattern corresponding to each point of the photosensitive material from the three-dimensional image data, a display means for displaying the original image pattern, and a dot-shaped element hologram corresponding to the original image pattern displayed on the display means. An optical system for forming a hologram, a developing means for developing the photosensitive material on which the element hologram is formed, a moving means, an original image creating means, and a controlling means for controlling the developing means to create a holographic stereoscopic hard copy. As a result, it is possible to provide a device for making a holographic three-dimensional hard copy, which is capable of downsizing the optical system and is extremely resistant to vibration.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of a principle of creating a holographic three-dimensional hard copy of the present invention.

FIG. 2 is a diagram for explaining a method of producing a reflection hologram applied to the present invention.

FIG. 3 is a diagram for explaining the reproduction principle of the reflection hologram of FIG.

FIG. 4 is a diagram for explaining a method of creating an original image pattern used in the present invention.

FIG. 5 is a diagram for explaining a hologram reproducing method of the present invention.

FIG. 6 is a diagram showing a detailed optical system for Lippman HS synthesis according to the present invention.

FIG. 7 is a diagram showing a configuration of a holographic printer system of the present invention.

8 is a flowchart of the holographic printer system of FIG.

FIG. 9 is a diagram for explaining another embodiment of the principle of creating a holographic solid hard copy of the present invention.

FIG. 10: Holographic stereoscopic hard copy of the present invention
For explaining another embodiment of the creation principle of FIG.

FIG. 11: Holographic stereoscopic hard copy of the present invention
For explaining another embodiment of the creation principle of FIG.

FIG. 12 is a diagram showing an optical system of a one-step Lippmann HS.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lens, 2 ... Photosensitive material, 3 ... Reflective hologram, 4 ... Photosensitive material, 5 ... Liquid crystal panel, 6 ... Lens, 10 ... Liquid crystal panel, 12, 24, 26, 30, 34 ... Lens, 14 ... Photosensitive material (Hologram dry plate), 16 ... Focusing unit, 20 ... Laser, 22 ... Beam splitter, 28 ... Pinhole, 32 ... Mirror, 36 ... XY stage, 40 ... Host computer, 42 ... Graphic processor, 44 ... Frame memory, 46 ... Film moving controller, 48 ... Optical system, 50 ... Developing machine.

Claims (4)

[Claims] 1. A method of forming a hard copy displaying a three-dimensional image by forming a plurality of dot-shaped element holograms on a surface of a substrate, and creating an original image corresponding to a coordinate position of a photosensitive material, Optical means for reproducing a plane wave by entering a spherical wave, a step of combining the photosensitive material, a step of displaying the original image at a desired display position, using an optical system at the coordinate position of the photosensitive material By making a spherical wave collected by passing through the displayed original image incident on the photosensitive material and causing a plane wave reproduced by the optical means to pass through the photosensitive material and interfere with the spherical wave, Forming a dot-shaped element hologram corresponding to the original image, sequentially moving the coordinate position of the photosensitive material to form the display step and element hologram Holographic stereoscopic hard copy creation method characterized in that it consists of the steps of forming a plurality of element holograms dot-shaped repeated steps to the photosensitive material that. 2. An apparatus for forming a hard copy for displaying a three-dimensional image by forming a plurality of dot-shaped element holograms on the surface of a base material, an optical means for reproducing a spherical wave into a plane wave, and a photosensitive material. Moving means for moving to a desired position, original image creating means for obtaining an original image pattern corresponding to each point of the photosensitive material from three-dimensional image data, display means for displaying the original image pattern, and display means for displaying the original image pattern. An optical system for forming a dot-shaped element hologram corresponding to an original image pattern on the photosensitive material, a developing means for developing the photosensitive material on which the element hologram is formed, the moving means, the original image creating means, and the developing means. Control means for controlling the holographic stereoscopic hard copy to create a holographic stereoscopic hard copy. Of creating apparatus. 3. A holographic three-dimensional hard copy apparatus according to claim 2, wherein a reflection hologram is used as an optical means for reproducing the spherical wave into a plane wave. 4. The holographic three-dimensional hard copy producing apparatus according to claim 2, wherein a liquid crystal panel is used as the display means.