JP2002123162A - Holographic stereogram making method and holographic stereogram making device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably assure the visual area in a non-parallax direction. SOLUTION: Object light is diffused into a recording medium 10 for holograms by an optical recording part 54 constituted by integrally laminating, in a curved state, a lenticular lens 60 as a diffusion lens for imparting a diffusion angle of a prescribed direction to a holographic stereogram and a prism plate 61 formed by paralleling a plurality of prisms capable of diffusing incident light only in the specific direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for producing a holographic stereogram, and more particularly, to a method and an apparatus for producing a holographic stereogram for controlling a viewing zone in a non-parallax direction.

[0002]

2. Description of the Related Art Among holographic stereograms for recording a three-dimensional image, a holographic stereogram recorded on a colorless and transparent photopolymer can be superimposed on a base pattern because of its transparency. It has been conventionally used for cards, forgery and alteration prevention seals, and the like.

In order to record the holographic stereogram as described above, a conventional holographic stereogram producing apparatus has a basic configuration as shown in FIG. Here, FIG. 9A shows a state in which the entire optical system of the exposure processing unit 100 of the conventional holographic stereogram producing apparatus is viewed from above, and FIG.
FIG. 9 shows a state where the object light portion of the optical system 0 is viewed from the lateral direction.
It is shown in (B).

[0004] As shown in FIG.
0 is a laser light source 10 for emitting laser light of a predetermined wavelength.
Exposure shutter 102 and half mirror 103 arranged on the optical axis of laser light L1 from laser light source 101
And

The exposure shutter 102 is closed when not exposing the hologram recording medium, and is opened when exposing the hologram recording medium. The half mirror 103 is for separating the laser light L2 passing through the exposure shutter 102 into reference light and object light, and the light L3 reflected by the half mirror 103 becomes reference light, Light L4 transmitted through 103 becomes object light.

[0006] On the optical axis of the light L3 reflected by the half mirror 103, a cylindrical lens 110, a collimator lens 111 for converting the reference light into parallel light, and a collimator lens 111 as an optical system for reference light. A total reflection mirror 112 that reflects the parallel light is arranged in this order.

[0007] The light reflected by the half mirror 103 is first diverged by the cylindrical lens 110, and then converted by the collimator lens 111 into parallel light. Thereafter, the light is reflected by the total reflection mirror 112 and enters the hologram recording medium 10.

On the other hand, the light L transmitted through the half mirror 103
As shown in FIGS. 9A and 9B, on the optical axis of No. 3, a total reflection mirror 104 that reflects the transmitted light from the half mirror 103 and a convex lens are provided as an optical system for the object light. Spatial filter 10 combined with pinhole
5 and a collimator lens 10 for making the object light parallel
6, a display device 107 for displaying an image to be recorded, and a cylindrical lens 108 for converging object light on the hologram recording medium 120 are arranged in this order.

The light L3 transmitted through the half mirror 103 is
After being reflected by the total reflection mirror 104, it is made into diffused light from a point light source by a spatial filter 105,
Next, the light is made parallel by the collimator lens 106,
After that, the light enters the display device 107. Here, the light transmitted through the display device 107 is modulated according to the image displayed on the display device 107, and then modulated by the cylindrical lens 108.
Incident on.

Here, the image displayed on the display device 107 is, although not shown, an image from an object photographed from a plurality of different viewpoints in one direction by, for example, simultaneous photographing with a multi-view camera or continuous photographing with a mobile camera. Image data or CAD (Computer Aided Design) or CG (Compu
This is image data of a disparity image sequence including a plurality of images including disparity information using the technique of ter Graphics.

Light transmitted through the display device 107 is converged in the lateral direction by a cylindrical lens 108, and the converged light is incident on the hologram recording medium 120 as object light. That is, in the exposure processing unit 100, the display device 1
The projection light from 07 enters the hologram recording medium 120 as rectangular object light.

The reference light and the object light are such that the reference light is incident on one main surface of the hologram recording medium 120 and the object light is incident on the other main surface of the hologram recording medium 120. I have. As a result, the reference light and the object light interfere with each other on the hologram recording medium 120, and interference fringes generated by the interference are generated.
Recorded above as the change in refractive index.

The exposure processing unit 100 includes a print head unit 1 for intermittently sending a hologram recording medium 120 under the control of a control computer (not shown).
13 is provided. The exposure processing unit 100 sends a control signal from the control computer to the hologram recording medium 120 set in a predetermined state in the print head unit 113 every time one image is recorded as one element hologram. Based on this, the hologram recording medium 120 is intermittently sent out for one element hologram. As a result, images displayed on the display device 107 are sequentially and sequentially recorded in the horizontal direction on the hologram recording medium 120 as element holograms.

In the print head unit 113, when the exposure shutter 22 is released for a predetermined time, the exposure image displayed on the display device 107 is exposed to the hologram recording medium 120. As shown in FIG. 10, a conventional print head unit includes a cylindrical lens 11.
4, or by using a holographic optical element or the like, the object light is uniformly diffused in all primary directions in the hologram recording medium 120 with X, Y, and Z standing.

At this time, of the laser light L2 emitted from the laser light source 101 and transmitted through the exposure shutter 102, the light L3 reflected by the half mirror 103 enters the hologram recording medium 120 as reference light. Further, the light L4 transmitted through the half mirror 103 becomes projection light for projecting an image displayed on the display device, and the projection light enters the hologram recording medium 120 as object light.
As a result, the exposure image displayed on the display device 107 is recorded on the hologram recording medium 120 as a rectangular element hologram.

When the recording of one image on the hologram recording medium 120 is completed, the hologram recording medium 120 is sent by the print head unit 113 by one element hologram.

The images to be displayed on the display device 107 are sequentially sent in the order of the parallax image sequence, and the above operation is repeated, whereby the exposure image based on the image data is sequentially recorded on the hologram recording medium 120 as a rectangular element hologram. Is done.

Generally, in a holographic recording medium having transparency, the recorded holographic stereogram must be visually recognized when viewed from a predetermined angle, and the underlying pattern must be transmitted when viewed from another angle. Conventionally, for example, a hologram recording layer is formed on a substrate surface that has been subjected to a surface treatment such as a relief structure or an embossing treatment in order to provide a viewing angle characteristic having a viewing zone in the non-parallax direction. Have been. The holographic stereogram recorded and produced on such a hologram recording medium has a position where the holographic stereogram can be visually recognized by selectively reflecting incident light incident on the surface due to a difference in surface structure. And an invisible position.

[0019]

However, when an attempt is made to secure a viewing zone in the non-parallax direction due to the difference in the surface structure as described above, the manufacturing process is complicated in the process of processing the surface structure of the hologram recording medium. However, there are problems such as an increase in manufacturing costs and manufacturing costs.

In addition, when the hologram recording medium as described above is attached to a display unit of a portable telephone or the like, it becomes difficult to visually recognize information displayed on the display unit by a holographic stereogram. There are cases.

Therefore, the present invention has been proposed in view of such a conventional situation. In particular, when recording a holographic stereogram on a transparent holographic recording medium, the present invention is applied to a surface structure. It is an object of the present invention to provide a holographic stereogram producing apparatus and a holographic stereogram producing method capable of stably securing a viewing zone in a non-parallax direction and controlling the viewing zone without making any changes.

[0022]

In order to achieve the above-mentioned object, a holographic stereogram producing method according to the present invention records a refractive index modulation generated by interference between object light and reference light on a recording medium. A holographic stereogram producing method for producing a holographic stereogram having parallax in one direction, wherein the object light is directed to a recording medium in a specific direction so as to secure a viewing zone in a non-parallax direction different from one direction. When the light is diffused and incident, the viewing area in the non-parallax direction is controlled.

Here, the diffusion of the object light is performed by a lenticular lens and a plurality of prisms, and when the object light is diffused and made incident on the recording medium, a substantially central portion of the recording medium is excluded. It can be diffused only to the peripheral part.

Further, in order to achieve the above-mentioned object, the holographic stereogram producing apparatus according to the present invention records a refractive index modulation generated by interference between object light and reference light on a recording medium, and records the data in one direction. A holographic stereogram producing apparatus for producing a holographic stereogram having parallax, in which object light is diffused in a specific direction with respect to a recording medium so as to secure a viewing zone in a non-parallax direction different from one direction. It is characterized by having a diffusing means for making it incident.

Here, the diffusing means includes a lenticular lens and a plurality of prisms, and the recording medium is colorless and transparent.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings.

A holographic stereogram producing apparatus according to the present invention diffuses an object beam at a specific angle with respect to a recording medium for recording a holographic stereogram, thereby forming an object on a recording surface of the recording medium. By generating a position where light and reference light interfere with each other and a position where light and reference light do not interfere with each other, it is possible to produce a holographic stereogram that secures and controls a viewing zone in a non-parallax direction.

In the embodiment of the present invention, the configuration of the holographic stereogram producing apparatus will be described first, and then the details of the optical recording unit which is a feature of the holographic stereogram producing apparatus according to the present invention will be described.

As shown in FIG. 1, a holographic stereogram producing apparatus 1 shown as one configuration example of an embodiment of the present invention includes an image data processing unit 11 for processing image data to be recorded, and an entire system. A control unit 12 having a control computer 13 for performing control and an exposure processing unit 14 having an optical system for producing a holographic stereogram are provided, and a holographic stereogram recording medium (hereinafter referred to as a hologram recording medium). .)
This is a device for recording a holographic stereogram with respect to 10.

The image data processing unit 11 includes an image processing computer 16 and a storage device 17, and generates image data D1 from the parallax image sequence photographing device 2 for generating a plurality of images having one-way parallax information. Data D from an image data generating computer 3 for generating a parallax image sequence
2 is read as image data D3 of a parallax image sequence. The details of the optical system of the exposure processing unit 14 will be described later together with the description of FIG.

Further, the image data processing section 11 stores the holographic stereogram in the storage device 17.
, And sequentially reads out image data for each image, and sends out the read image data D5 to the control computer 13.

The parallax image sequence photographing apparatus 2 converts, as image data D1, a subject photographed from a plurality of different viewpoints in one direction by, for example, simultaneous photographing with a multi-view camera or continuous photographing with a mobile camera. To supply.

The image data generating computer 3 has a CA
D (Computer Aided Design) and CG (Computer Graphi
The image data D2 of the parallax image sequence including a plurality of images including the parallax information is created by using the method of cs), and the image data D2 is supplied to the image data processing unit 11.

The image processing computer 16 in the image data processing section 11 performs predetermined image processing for holographic stereograms, for example, viewpoint conversion processing, keystone distortion correction processing, and the like on the parallax image sequence D3. After performing the image processing described above, the image data D4 is recorded in the storage device 17 such as a memory device or a hard disk.

The control computer 13 includes the exposure processing unit 1
4 to sequentially record images based on the image data D5 supplied from the image data processing unit 11 on the hologram recording medium 10 set in the exposure processing unit 14 as rectangular element holograms.

At this time, the control computer 13 controls a shutter, a display device, a printer head unit, and the like, which will be described later, provided in the exposure processing unit 14, as described later. That is, the control computer 13 sends a control signal S1 to the shutter to control the opening and closing of the shutter, supplies image data D5 to the display device to display an image based on the image data D5, and controls the printer head unit. Signal S
2 to control the operation of feeding the hologram recording medium 10 in the printer head.

Here, a specific example of the hologram recording medium 10 will be described with reference to FIG. The hologram recording medium 10 includes a base material 4 as a skeleton structure of the hologram recording medium 10, a hologram recording layer 5 on which image data is recorded as a holographic stereogram,
A hologram recording layer 5 made of a photopolymer layer is formed on a base material 4 made of a colorless and transparent resin film or the like; A protective layer 6 made of a transparent resin film or the like is formed.

For the hologram recording layer 5, a so-called photopolymerizable photopolymer suitable for recording interference fringes generated by interference between reference light and object light as a change in refractive index is used as a film. The film-formed photopolymerizable photopolymer has a property that the refractive index of the material changes when irradiated with light.

In the initial state, the photopolymerizable photopolymer is 10 to 4 as shown in FIGS. 3 (A) and 3 (B).
When irradiated with light LA having a power of about 00 mJ / cm ² ,
The monomer M in the exposed portion is polymerized according to the power of the irradiated light LA. As a result, refractive index modulation occurs because the concentration of the monomer M varies from place to place. After this,
As shown in FIG. 3C, when the entire surface is irradiated with ultraviolet light LB having a power of about 1000 mJ / cm ² , the polymerization of the monomer M is completed, the refractive index modulation degree is increased, and the refractive index modulation is fixed. I do.

The configuration of the optical system of the exposure processing unit 14 for recording a holographic stereogram on the hologram recording medium 10 as described above will be described in detail with reference to the drawings.

FIG. 4A shows the entire optical system in the exposure processing section 14 as viewed from above, and shows the object light portion of the optical system in the exposure processing section 14 viewed from the lateral direction. It is shown in FIG. The optical system is shown in FIG.
The structure does not have to be the structure shown in (A) or (B), and if it has a structure capable of producing a holographic stereogram, for example, the incident direction of the reference light, the number of lenses,
The type, combination, and the like can be appropriately changed.

As shown in FIG. 4A, the exposure processing unit 14
Is a laser light source 21 for emitting laser light of a predetermined wavelength.
, An exposure shutter 22 arranged on the optical axis of the laser light L1 from the laser light source 21, and a half mirror 23.

The exposure shutter 22 is closed when the hologram recording medium 10 is not exposed, and is opened when the hologram recording medium 10 is exposed. The half mirror 23 separates the laser light L2 that has passed through the exposure shutter 22 into reference light and object light. The laser light L2 is reflected by the half mirror 23 to become reference light L4, and passes through the half mirror 23 to become object light L3.

The exposure processing section 14 further includes a light L reflected by the half mirror 23 as an optical system for a reference light.
On the optical axis of No. 4, a cylindrical lens 30, a collimator lens 31 for converting the reference light into parallel light, and a total reflection mirror 32 for reflecting the light converted into parallel light by the collimator lens 31 are provided.

Light L reflected by half mirror 23
4 is first made divergent light by the cylindrical lens 30 and then made parallel light by the collimator lens 31. After being reflected by the total reflection mirror 32, the parallel light enters the hologram recording medium 10 as reference light.

As shown in FIGS. 4A and 4B, the exposure processing unit 14 serves as an object light optical system on the optical axis of the light L3 transmitted through the half mirror 23, as shown in FIGS. A total reflection mirror 24 for reflecting the transmitted light from the mirror 23,
A spatial filter 25 combining a convex lens and a pinhole, a collimator lens 26 for collimating object light, and a display device 27 for displaying an image to be recorded
And a cylindrical lens 28 for condensing object light on the hologram recording medium 10.

The light L3 transmitted through the half mirror 23 is reflected by the total reflection mirror 24, and then is made into a diffused light from a point light source by the spatial filter 25.
The light is collimated by the collimator lens 26, and then
The light enters the display device 27. Here, the light transmitted through the display device 27 is modulated according to the image displayed on the display device 27, and then enters the cylindrical lens 29.

The light transmitted through the display device 27 is converged in the lateral direction by the cylindrical lens 29, and the converged light is incident on the hologram recording medium 10 as object light. That is, in the exposure processing unit 14, the projection light from the display device 27 is converted into a rectangular object light as the hologram recording medium 1
Incident at 0.

It is essential that the reference light is incident on one main surface of the hologram recording medium 10 and that the object light is incident on the other main surface of the hologram recording medium 10. Therefore, the exposure processing unit 14 controls the hologram recording medium 10
The reference light is incident on one main surface of the hologram at a predetermined incident angle, and the object light is incident on the other main surface of the hologram recording medium 10 such that the optical axis is substantially perpendicular to the hologram recording medium 10. Is made to be an optical structure for making the incident light. As a result, the reference light and the object light are shifted from the hologram recording medium 1.
The interference fringes that occur on 0 are recorded on the hologram recording medium 10 as a change in the refractive index.

Under the control of the control computer 13, the exposure processing section 14 controls the print head section 33 for recording a parallax image sequence on the hologram recording medium 10 while intermittently feeding the hologram recording medium 10. Have. The exposure processing unit 14 controls the hologram recording medium 10 set in a predetermined positional relationship with the print head unit 33 every time one image is recorded as one element hologram by the control computer 13. Based on the signal, the hologram recording medium 10 is intermittently sent out by one element hologram. Thus, an image based on the image data processed by the image data processing unit 11 is sequentially and sequentially recorded in one direction on the hologram recording medium 10 as an element hologram.

The holographic stereogram producing apparatus 1 according to the present invention is characterized by an optical recording section in the print head section 33 described above. Hereinafter, the print head unit 33 will be described in detail.

The configuration of the print head section 33 and its peripheral portion will be described in detail with reference to FIG. The print head unit 33 includes a film cartridge 51
, A first intermittent feeding roller 52, a second intermittent feeding roller 53, an optical recording unit 54, and a pinch roller 55, and a fixing operation is performed at a position close to the print head unit 33. Lamp 56 for heating, a heat roller 57, and a pair of discharge feed rollers 58A and 58A.
8B and a cutter 59 are provided.

The print head unit 33 rotatably supports the first intermittent feed roller 52 in the film cartridge 51 loaded at a predetermined position with a predetermined torque, and pulls out the film cartridge 51 from the film cartridge 51. The hologram recording medium 10 is held between the first intermittent feeding roller 52 and the second intermittent feeding roller 53 and the pinch roller 55. Thereby, the hologram recording medium 10 is moved between the first intermittent feeding roller 52 and the second
The recording surface is held so as to be substantially perpendicular to the object light.

The first first intermittent feed roller 52 and the second
The intermittent feed roller 53 is urged in a direction away from each other by a torsion coil spring (not shown). As a result, a predetermined tension is applied to the hologram recording medium 10 that is placed between the first intermittent feeding roller and the second intermittent feeding roller 53. As a result, the position of the hologram recording medium 10 is stabilized, and vibration is suppressed. Note that such tension may be applied by a pinch roller method, a sprocket method, or the like.

The first intermittent feed roller 52 and the second intermittent feed roller 53 can be freely rotated in the direction indicated by arrow c in FIG. 5 by a stepping motor (not shown). This stepping motor is controlled based on a control signal supplied from the control computer 13.
Each time the exposure for one image is completed, the first intermittent feeding roller 52 and the second intermittent feeding roller 53 are rotated to feed the hologram recording medium 10 by one element hologram.

The ultraviolet lamp 56 is connected to the hologram recording medium 1 sent by the second intermittent feeding roller 53.
0 is irradiated with ultraviolet light L3, and the polymerization of the monomer M forming the hologram recording layer 5 in the hologram recording medium 10 is completed by the ultraviolet light emitted from the ultraviolet lamp 56.

The heat roller 57 has a heating means such as a heater inside, and maintains a temperature required for the fixing operation of the hologram recording medium 10. Hologram recording medium 10
Is heated to a predetermined temperature by the heat roller 57, the refractive index modulation degree of the hologram recording layer 5 is increased, and the recorded image of the hologram recording layer 5 is fixed.

The discharge feed rollers 58A and 58B provided at the subsequent stage of the heat roller 57 are synchronized with the second intermittent feed roller 53 by a drive mechanism (not shown) driven based on a control signal from the control computer 13. Rotate. Thereby, the hologram recording medium 10 is
A second intermittent feed roller 53 and a discharge feed roller 58;
The protective layer 6 is securely held in close contact with the peripheral side surface of the heat roller 57 without loosening between A and 58B.

Although not shown, the drive mechanism of the cutter 59 operates based on a control signal supplied from the control computer 13. After the respective images based on the respective image data of the parallax image sequence are recorded on the hologram recording medium 10, the cutter 59 discharges all the area portions of the hologram recording medium 10 where the images are recorded to the outside of the cutter 59. It operates at the point of time when the recorded area is separated from other parts. As a result, the portion of the hologram recording medium 10 where each image data of the parallax image sequence is recorded is discharged to the outside as one holographic stereogram.

Next, the structure of the optical recording section 54 in the print head section 33 will be described in detail.

The optical recording section 54 is a diffusion plate for diffusing object light, and is formed by bonding a lenticular lens 60 and a prism plate 61 together in a curved state, and forms a first intermittent feed. Between the first roller 52 and the second intermittent feeding roller 53 in correspondence with the incident position of the object light. The optical recording unit 54 is movably held by a not-shown optical recording unit driving mechanism in a direction indicated by an arrow b, that is, in a direction to approach or separate from the hologram recording medium 10.

The lenticular lens 60 is a diffusion lens for giving a holographic stereogram a diffusion angle in a predetermined direction. That is, the lenticular lens 60 diffuses the incident object light in one specific direction. In the present embodiment, the lenticular lens 60 is a lens that diffuses perpendicularly to the sending direction of the hologram recording medium 10.

The prism plate 61 is formed by arranging a plurality of prisms capable of diffusing incident light only in a specific direction. Therefore, the prism plate 61 further restricts the diffusion angle of the object light diffused by the lenticular lens 60.

FIGS. 6 and 7 show how the prism plate 61 further restricts and diffuses the object light from the lenticular lens 60. FIG.

For example, when the optical recording unit 54 is formed by using a prism plate 61 that does not diffuse incident light in a direction substantially perpendicular to the main surface of the prism plate 61, as shown in FIG. The object light transmitted and diffused through 60 is diffused by the prism plate 61 in the directions of substantially P ₁ and Q _1, but is not diffused in the direction of approximately O ₁ . In this case, on the recording surface of the hologram recording medium 10,
Since approximately O ₁ direction, i.e. the interference between the reference beam and the object beam in a direction substantially perpendicular to the recording surface of the hologram recording medium 10 does not occur, it does not occur refractive index change on the hologram recording medium 10.

Therefore, by using such a prism plate 61 for the optical recording section 54, a holographic stereogram that is invisible from a substantially vertical direction and visible from a peripheral portion can be produced. .

Further, for example, the incident light is
In the case where the optical recording unit 54 is configured using a prism plate 61 that diffuses only in a certain specific direction with respect to the main surface of No. 1, as shown in FIG. 7, the light is transmitted through the lenticular lens 60 and diffused. object beam is diffused only in a substantially Q ₂ direction by the prism plate 61, it is not diffused to approximately P ₂ and substantially O ₂ direction. In this case, on the recording surface of the hologram recording medium 10, the interference between the object light and the reference light does not occur in the directions substantially P ₂ and O ₂ , so that the recording medium 1
There is no change in the refractive index above zero.

Therefore, when such a prism plate 61 is used for the optical recording section 54, a holographic stereogram that can be viewed only from a predetermined angle with respect to the substantially vertical direction can be produced.

The operation of the holographic stereogram producing apparatus 1 when a three-dimensional image is recorded on the hologram recording medium 10 using the above-described print head unit 33 will be described.

First, when the hologram recording medium 10 is loaded between the first first intermittent feeding roller 52 and the second intermittent feeding roller 53, the control computer 13 causes the print head unit 33 to operate. Send a control signal to the optical recording unit driving mechanism, drive the optical recording unit driving mechanism,
The optical recording unit 54 is pressed against the hologram recording medium 10 at a predetermined pressure.

Subsequently, the control computer 13 sends out the image data D5 to the display device 27 of the exposure processing section 14, and
The display device 27 displays an exposure image based on the image data D5.
To be displayed. At this time, the control computer 13
A control signal S1 is sent to the exposure shutter 32, and the exposure shutter 32 is released for a predetermined time to display an exposure image on the display device 27.

At this time, the light is emitted from the laser light source 21 and
Of the laser light that has passed through the exposure shutter 32, the light L4 reflected by the half mirror 23 enters the hologram recording medium 10 as reference light. The light L3 transmitted through the half mirror 23 becomes projection light for projecting an image displayed on the display device 27, and the projection light enters the hologram recording medium 10 as object light.

At this time, in the hologram recording layer 5 of the hologram recording medium 10, there is a difference in the power of the irradiated light due to the interference between the object light and the reference light. In the hologram recording layer 5, the exposed portion of the monomer M is polymerized in accordance with the power of the irradiation light. When the concentration of the monomer M changes depending on the location, the hologram recording medium 10
The refractive index modulation occurs on the recording surface. Thereafter, when the entire surface of the hologram recording medium 10 is irradiated with ultraviolet rays, the monomer M
Is completed, the degree of refractive index modulation is enhanced, and the refractive index modulation is fixed. Thus, the display device 2
The exposure image displayed in 7 is recorded on the hologram recording medium 10 as a rectangular element hologram.

After the recording of one image on the hologram recording medium 10 is completed, the control computer 13 sends a control signal S2 to the print head unit 33 to send out the hologram recording medium 10 by one element hologram. .

Next, the control computer 13 sequentially changes the exposure images to be displayed on the display device 27 in the order of the parallax image sequence, and repeats the above-described operation, whereby the exposure based on the image data processed by the image data processing unit 11 is performed. Images are sequentially recorded on the hologram recording medium 10 as elementary holograms.

Therefore, as described in detail above, the holographic stereogram producing apparatus 1 includes the prism plate 61 immediately before the hologram recording medium 10 so that the diffusion of the object light is restricted in a specific direction, Even without changing the surface structure of the recording medium 10, it is possible to produce a holographic stereogram in which a viewing zone is secured only in a specific direction. In other words, it is possible to produce a controlled holographic stereogram while ensuring a sufficient viewing zone in the non-parallax direction.

By changing the diffusion direction of the prism plate 61, it becomes possible to produce a holographic stereogram capable of securing a viewing zone in a parallax direction and a non-parallax direction at a desired position.

Here, the above-mentioned lenticular lens 6
0 indicates that the holographic stereogram to be produced has a vertical viewing angle if the diffusion direction is the vertical direction, that is, the major axis direction of the element hologram to be produced; The holographic stereogram will have a lateral viewing angle. By determining the diffusion direction of the prism plate 61 in accordance with the diffusion direction of the lenticular lens 60, it is possible to set the viewing angle in either the vertical direction or the horizontal direction.

In order to prevent the reference light transmitted through the hologram recording medium 10 from being reflected by the lenticular lens 60 and entering the hologram recording medium 10 again, the prism plate 61 and the hologram recording medium 10
(Not shown), a louver film having a fine grid-like lattice may be provided between them.

The optical recording unit 54 may use a holographic optical element instead of the lenticular lens 60.

FIG. 8 shows an application example of the holographic stereogram produced as described above. The holographic stereogram 71 shown in FIG. 8 is formed by forming a hologram recording layer and a colorless and transparent protective layer on a base made of a colorless and transparent resin film. 9 is a holographic stereogram produced by a holographic stereogram producing apparatus including an optical recording section 54 having a prism plate 61 that does not diffuse in a direction substantially perpendicular to the holographic stereogram.

It is assumed that such a holographic stereogram 71 is used by attaching it to a display unit 72 of a portable telephone 70 or the like. Since the holographic stereogram 71 is formed as a colorless and transparent film, when viewed from a direction substantially perpendicular to the main surface of the display unit 72 of the holographic stereogram 71,
The display screen of the display unit 72 can be viewed, and when the main surface of the display unit 72 of the holographic stereogram 71 is viewed from a specific direction, a recorded three-dimensional image can be viewed.

FIG. 8A shows a portable telephone 70 in which a holographic stereogram 71 is attached to the display section 72 when viewed from a direction substantially perpendicular to the main surface of the display section 72. When the display unit 72 is viewed from a direction substantially perpendicular to the main surface of the display unit 72, the holographic stereogram 7
The three-dimensional image recorded as 1 is not visually recognized, and the display unit 7
2 can be visually recognized.

On the other hand, when the holographic stereogram 71 is attached to the display unit 72 so that the longitudinal direction of the portable telephone 70 coincides with the non-parallax direction, the display unit 7
FIG. 8B shows a state in which the display unit 72 is viewed from below or above the main surface of No. 2. At this time, the three-dimensional image recorded as the holographic stereogram 71 is visually recognized, and the display content of the display unit 72 cannot be visually recognized.

The case where the holographic stereogram 71 is attached to the display unit 72 so that the lateral direction of the portable telephone 70 coincides with the non-parallax direction will be described.
FIG. 8C shows a state in which the display unit 72 is viewed from the side with respect to the main surface of No. 2. At this time, as in the previous case, the three-dimensional image recorded as the holographic stereogram 71 is visually recognized, and the display content of the display unit 72 cannot be visually recognized.

Therefore, when the holographic stereogram 71 described above is attached to a display unit of a portable telephone or the like, the holographic stereogram 71 is displayed on the display unit 72 from a position shifted from the main surface of the display unit 72 by a predetermined angle. Since the contents to be displayed cannot be visually recognized, the confidentiality of the information displayed on the display unit is improved.

The holographic stereogram 7
1 is not to control the visual field by changing the surface shape, but to control and secure the visual field in the non-parallax direction because the prism plate 61 limits the interference between the object light and the reference light at the stage of fabrication. it can.

The present invention is not limited to only the above-described embodiments, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

[0089]

As described in detail above, the method for producing a holographic stereogram according to the present invention records the refractive index modulation generated by the interference between the object light and the reference light on a recording medium, and performs one-way parallax. A method for producing a holographic stereogram having a holographic stereogram, wherein object light is diffused into a recording medium in a specific direction so as to secure a viewing zone in a non-parallax direction different from one direction and is incident. At this time, the viewing zone in the non-parallax direction is controlled.

Here, the object light is characterized by being diffused by a lenticular lens and a plurality of prisms. When the object light is diffused and incident on the recording medium, the object light is diffused. It is characterized in that it is diffused only to a peripheral part except a substantially central part.

Therefore, the holographic stereogram producing method according to the present invention restricts the diffusion of the object light in a specific direction, so that the viewing zone in the non-parallax direction can be secured without changing the surface structure of the recording medium. Along with
It is possible to produce holographic stereograms with a controlled viewing zone. Further, by changing the diffusion direction of the diffusion unit, it is possible to secure a viewing zone in the non-parallax direction at a desired position.

When the holographic stereogram produced by the above-described holographic stereogram producing method is attached to a display unit of a portable telephone or the like, the confidentiality of information displayed on the display unit is improved. Further, the holographic stereogram can sufficiently secure a viewing area in the non-parallax direction without changing the surface structure.

Further, according to the holographic stereogram producing apparatus according to the present invention, simplification of the production process and reduction of the production cost can be expected.

Further, the holographic stereogram producing apparatus according to the present invention produces a holographic stereogram having one-way parallax by recording a refractive index modulation generated by interference between object light and reference light on a recording medium. A holographic stereogram producing apparatus, comprising: a diffusing unit that diffuses object light in a specific direction into a recording medium so as to ensure a viewing zone in a non-parallax direction different from one direction.

Here, the diffusing means is composed of a lenticular lens and a plurality of prisms.
It is characterized by being colorless and transparent.

Therefore, the holographic stereogram producing apparatus restricts the diffusion of object light in a specific direction, so that the holographic stereogram in which the viewing area in the non-parallax direction is ensured without changing the surface structure of the recording medium. It is possible to make grams.

By changing the diffusion direction of the diffusion means, it is possible to secure a viewing zone in a parallax direction and a non-parallax direction at a desired position.

When the holographic stereogram produced by the above-described holographic stereogram producing apparatus is attached to a display unit of a portable telephone or the like, the confidentiality of information displayed on the display unit is improved. Further, the holographic stereogram can clarify the viewing zone in the parallax direction and the viewing zone in the non-parallax direction without changing the surface structure.

Further, according to the holographic stereogram producing apparatus according to the present invention, simplification of the production process and reduction of the production cost can be expected.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of a holographic stereogram producing apparatus shown as one configuration example of an embodiment of the present invention.

FIG. 2 is a sectional view of a main part showing a configuration of a hologram recording medium.

FIGS. 3A to 3C are explanatory diagrams illustrating a photosensitive process of a photopolymerizable photopolymer.

FIG. 4A is a top view of an optical system in an exposure control unit of a holographic stereogram producing apparatus according to an embodiment of the present invention, as viewed from above, and FIG. FIG. 3 is a side view of the device viewed from the lateral direction.

FIG. 5 is a configuration diagram showing a configuration of a print head unit and a peripheral portion of the holographic stereogram producing apparatus shown as an embodiment of the present invention.

FIG. 6 is a schematic diagram schematically showing a state in which object light transmitted through a lenticular lens and diffused by an optical recording unit is diffused by a prism plate;

FIG. 7 is a schematic diagram schematically showing a state in which object light transmitted and diffused through a lenticular lens is diffused by a prism plate in an optical recording unit.

FIG. 8A is a front view of a portable telephone having a holographic stereogram attached to a display portion, which is viewed from a direction substantially perpendicular to a main surface of the display portion, and FIG. 8B is a front view of the display portion. FIG. 4 is an isometric view showing the main surface of the display unit from below a substantially predetermined angle, and FIG.

9A is a top view of the optical system in the exposure control unit of the conventional holographic stereogram producing apparatus as viewed from above, and FIG. 9B is a view of the optics in the exposure control unit as viewed from the lateral direction. It is a side view.

FIG. 10 is a schematic diagram schematically showing a state in which an optical recording unit of a conventional holographic stereogram producing apparatus diffuses object light.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 holographic stereogram, 2 parallax image sequence photographing device, 3 image data generation computer, 4 base material, 5 hologram recording layer, 6 protective layer, 10 hologram recording medium, 11 image data processing unit, 12 control unit, 13 Control computer, 14 exposure processing unit, 1
6. Computer for Image Processing, 17 Storage Device, 21
Laser light source, 22 exposure shutter, 23 half mirror, 24 total reflection mirror, 25 spatial filter,
26 collimator lens, 27 display device, 28 cylindrical lens, 30 cylindrical lens, 31 collimator lens, 32 total reflection mirror, 33 print head unit, 51 film cartridge, 52 first intermittent feed roller, 53 second intermittent feed Roller, 5
4 Optical recording section, 55 pinch roller, 56 ultraviolet lamp, 57 heat roller, 58A, 58B discharge feed roller, 59 cutter, 60 lenticular lens, 61 prism plate, 70 portable telephone, 71 holographic stereogram, 72 display Department

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H049 CA05 CA08 CA22 CA28 2H059 AB04 AC04 2K008 AA13 BB04 BB06 BB08 DD12 EE04 FF08 HH01 HH07 HH18 HH20 HH23 HH25 HH26

Claims (6)

[Claims] 1. A holographic stereogram producing method for recording a refractive index modulation caused by interference between object light and reference light on a recording medium to produce a holographic stereogram having one-way parallax, When diffusing the object light into the recording medium in a specific direction and entering the object light so as to secure a viewing zone in a non-parallax direction different from one direction, the viewing zone in the non-parallax direction is controlled. Holographic stereogram production method. 2. The holographic stereogram producing method according to claim 1, wherein the diffusion of the object light is performed by a lenticular lens and a plurality of prisms. 3. The method according to claim 1, wherein when the object light is diffused and made incident on the recording medium, the object light is diffused only to a peripheral portion excluding a substantially central portion of the recording medium.
The method for producing a holographic stereogram described. 4. A holographic stereogram producing apparatus for producing a holographic stereogram having one-way parallax by recording a refractive index modulation generated by interference between object light and reference light on a recording medium, A holographic stereogram producing apparatus, comprising: a diffusing unit that diffuses the object light into the recording medium in a specific direction and causes the object light to enter a non-parallax direction different from one direction. 5. The holographic stereogram producing apparatus according to claim 4, wherein said diffusing means comprises a lenticular lens and a plurality of prisms. 6. The holographic stereogram producing apparatus according to claim 4, wherein said recording medium is colorless and transparent.