JP2000253347A - Optical recording medium and reproducing device for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record and reproduce a continuous picture (animation) through the use of CGHs by providing a recording area for recording a still picture equivalent to each frame outputted as a continuous picture at the time of reading continuously in the order of reading information. SOLUTION: In order to reproduce animation through the use of the CGHs, illumination light is illuminated to plural transmitting or reflecting type CGHs and diffracted light beams (still picture) generated from the CGHs are projected on a screen or an image pickup element by feeding frames like movies to reproduce the pictures as if they are animation through the use of the after image effect of eyes. Namely, the transmitting type CGHs (recording areas) 11 plurally collected by each content of the frames are arranged in a line in the order of frames in a card-like optical recording medium 10, which is moved by frame feeding or continuously in parallel with the line of the CGHs 11. Or else, the medium 10 is fixed and a monochromatic light emitting part 21 and a screen 22 are moved in parallel with the line of the CGHs 11 to display the reproduced picture of the CGHs 11 on the screen 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for generating a continuous image hologram, an optical recording medium on which the hologram is recorded, and a reproducing apparatus suitable for the method.

[0002]

2. Description of the Related Art CGH (Computer generated hologra)
m) is a diffraction grating designed using computer hologram technology (see Oplus E, 96, December issue, p. 83), and uses a computer to calculate the diffracted light arrangement information corresponding to the diffraction angle of the desired diffraction grating. By performing Fourier inverse transform, a phase distribution corresponding to the interference fringes of the diffraction grating is calculated, and a step-like step corresponding to the phase distribution is created on the substrate by applying a semiconductor manufacturing technology, and the step-like step is formed. Is transferred to an optical recording medium. The applicant of the present invention has disclosed an optical recording medium having this CGH and a method of manufacturing the same in Japanese Patent Application Laid-Open No. Hei 10-143929. As a reproducing apparatus for this optical recording medium, an image recorded on a CGH is detected as a hologram image, and a two-dimensional image thereof is captured, as filed by the present applicant in Japanese Patent Application No. 10-58824. Thus, an optical recording medium reproducing device capable of reading out an information signal has been proposed.

FIG. 13 is a cross-sectional view of the transmission phase type CGH 1. In the figure, the incident light incident from above is diffracted by the transmission phase type CGH1, and the transmitted diffracted light is output to the lower side in the figure. The material of the transmission phase type CGH 1 is a transparent light-transmitting resin 2, and a step-like step corresponding to the phase difference is provided in order to generate a phase difference in the incident light and cause a light diffraction phenomenon. This example is a ternary phase-type CGH. In the ternary, one cycle (2π) of the wavelength of incident light is divided into three, the phase difference for one value is ２π, and the step is 0π (phase change). 3) including the portion where the is not performed). In the case of the simplest phase-type CGH, it is binary, and since one cycle is divided into two, the phase difference for one value is π, and the number of steps is two, including 0π. Furthermore, even in the case of four or more values, a multi-level CGH can be manufactured by equally dividing one cycle (2π) of the wavelength and assigning it to each stage. The diffraction efficiency increases as the number of values increases, but the manufacturing process becomes complicated.

FIG. 14 is a sectional view of the reflection phase type CGH 3. As shown in FIG. In the figure, the incident light incident from below is a reflection phase type CGH3.
, And the reflected diffraction light is output to the lower side in the figure. The reflection phase type CGH 3 protects the metal reflection film 4 by providing a metal reflection film 4 such as aluminum on a stepped step surface and coating a resin protection film 5 thereon to reflect incident light. ing. Note that the step-like stepped surface is provided at a position corresponding to the phase difference just like the transmission phase type CGH1.

[0005] The CGH designed in this manner is provided on a card medium or the like by the manufacturing method presented in Japanese Patent Application Laid-Open No. 10-143929. Then, the information of the optical recording medium 40 provided with the CGH (transmission phase type CGH1) is read by, for example, an optical recording medium reproducing device as shown in FIG. In the figure, the monochromatic light output from the monochromatic light source (monochromatic light emitting section) 21 is the C light of the optical recording medium 40.
By projecting the diffracted light radiated on the GH 1 and transmitted and diffracted onto the screen 22, the image recorded on the CGH 1 can be viewed as a CGH reproduction pattern.

[0006]

The above-described conventional optical recording medium and optical recording medium reproducing apparatus described above are premised on recording and reproducing a two-dimensional still image on the optical recording medium. Therefore, there is a problem that a moving image cannot be recorded and reproduced.

It is therefore an object of the present invention to provide an optical recording medium on which a moving image is recorded and a reproducing apparatus for reproducing a moving image from the optical recording medium.

[0008]

SUMMARY OF THE INVENTION As means for attaining the above object, the following optical recording medium and optical recording medium reproducing apparatus are provided.

1. An optical recording medium in which the same image information is recorded in a plurality of CGH unit cells and a plurality of adjacent recording areas are arranged in the information reading direction. An optical recording medium characterized in that a still image corresponding to each frame output as a continuous image is recorded on the optical recording medium.

[0010] 2. A light emitting unit that irradiates the recording area of the optical recording medium with monochromatic light, and an output unit that receives diffracted light output from the recording area of the optical recording medium and reads out image information,
The light emitting unit irradiates each recording area of the optical recording medium with monochromatic light at predetermined time intervals in a predetermined direction, and continuously reads out image information recorded in each recording area in a predetermined order. Means for reproducing an optical recording medium.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

Since one CGH unit cell 1 can record only one two-dimensional image, a CGH unit cell corresponding to one frame is required for reproducing a moving image. It is necessary to create a recording medium and record it on an optical recording medium so that it can be continuously reproduced, and to reproduce the CGH unit cell continuously in an optical recording medium reproducing apparatus.

FIG. 3 shows an example of manufacturing a CGH unit cell necessary for forming a moving image by playing back an animation of five frames step by step. In this example, the number of frames is 5, but the number of frames can be further increased. And, even with a small number of frames, the CGH unit cell is changed to dog1,
By repeatedly arranging dog2, dog3, dog4, dog, 5, dog1, dog2, etc., a repeated moving image can be formed.

Here, a CGH unit cell corresponding to one frame among the CGH unit cells of a plurality of frames described above.
A method for creating a cell will be described. In this example, a binary phase type CGH is used. As described above, in the case of the simplest phase-type CGH, there are two values, and there are two steps including 0π. This simplifies the CGH manufacturing process,
In the case of binary, as shown in FIG. 4, there is a feature that the reproduced image is symmetric with respect to the origin. Therefore, it is necessary to design a reproduced image symmetrically with respect to the origin. Here, it is assumed that only the diffraction images (images on the left side in the figure) of the second and third quadrant central portions are projected on the screen and used.

The angle of view of the screen is 8 degrees in the X direction,
It is 12 degrees in the Y direction. In order to project only a specific angle of view from the diffracted light output from the CGH unit cell onto the screen, a shield such as an aperture is inserted into the optical path between the screen and the CGH unit cell to diffract the diffracted light. A structure may be adopted in which a portion other than the specific angle of view is shielded, or only a portion of the diffracted light to be projected is reflected by a mirror and projected on a screen. When a phase-type CGH having three or more values as shown in FIGS. 13 and 14 is used, it is possible to obtain a reproduction image asymmetrical with respect to the origin. No need to design.

Here, the maximum diffraction angle corresponding to the reproduced image of CGH is determined. The maximum diffraction angle is set based on the size of a screen or an image sensor for projecting a CGH reproduction image and the installation distance from the CGH unit / cell. In this example, X
The angle is set to ± 9.3 degrees in both the Y direction. This maximum diffraction angle is obtained by the following equation (1).

Maximum diffraction angle = arcsin (illumination light wavelength × number of diffraction dots / 2) / CGH unit cell size Expression (1) In this example, the maximum diffraction angle is 9.3 degrees, and the illumination light wavelength is 0. .65um
(Red semiconductor laser light) and the number of diffraction dots: 160, the CGH unit cell size: 320 μm can be obtained from equation (1). Here, the number of diffraction dots is the number of dots per side of an image output as diffracted light from the CGH, and corresponds to the resolution of interference fringes on the CGH (see FIG. 4). The CGH unit cell size is the size of the minimum unit of the CGH, and the interference fringe resolution is the minimum increment of the pattern width of the interference fringes on the CGH. Then, the interference fringe resolution can be obtained by the following equation (2).

Interference fringe resolution = (CGH unit cell size) / (number of diffraction dots) Expression (2) In this example, from Expression (2), the interference fringe resolution is 2.0 μm. As can be seen from Equations (1) and (2), when the CGH unit cell size is fixed, the maximum diffraction angle increases as the number of diffraction dots increases. On the other hand, the resolution of the interference fringes is reduced, which makes the manufacturing process difficult. Therefore, to obtain a desired diffraction angle, equation (1)
Using (2), it is necessary to determine the optimal CGH unit cell size and the number of diffraction dots.

The design of the CGH unit cell is, for example,
The two-dimensional diffracted light intensity distribution is created by assigning the diffracted light arrangement of the image shown in FIG. The phase distribution corresponding to the interference fringes of the CGH unit cells can be calculated by performing Fourier inverse transform on this intensity distribution using a computer. C created from the result
The GH unit cell is shown in FIG. Black indicates phase 0 and white indicates phase π. Then, the CG having the phase distribution of FIG.
When a red semiconductor laser beam having a wavelength of 0.65 μm is irradiated to the H unit cell, a diffraction image having a diffraction angle as shown in FIG. 4 can be reproduced.

In order to reproduce a continuous image from the CGH unit cells corresponding to the individual frames created as described above, the layout is made so that the CGH unit cells are arranged in a line as shown in FIG. Here, a plurality of (9 in the example in the figure) CGH unit cells having the same frame contents are gathered on the beam spot surface of the illumination light, and a plurality of CGH unit cells indicating the next frame contents are collected (recording area). ) Are sequentially laid out in a horizontal line. By scanning the beam spot of the illumination light in the order of layout, a moving image can be reproduced. Also,
By forming a recording area in which a plurality of CGH unit cells having the same frame contents are collected on an optical recording medium, it is possible to improve the SN ratio of reproduction light and to provide redundancy, thereby improving CGH.
This prevents deterioration of the reproduced image due to scratches, dirt, etc. on the unit cell.

Even if a plurality of CGH unit cells having the same frame contents are simultaneously irradiated, the reproduction position of the image by the diffracted light overlaps the same position.
There is no change in the image itself when illuminating the cell, and the brightness increases accordingly. Therefore, even if some (or a part thereof) of the plurality of CGH unit cells cannot be reproduced due to scratches, dirt, etc., the luminance of the image portion corresponding to the non-reproducible portion is slightly reduced. A reproduced image can be obtained without any.

Further, even during scanning, the position of the reproduced image does not change and the luminance only changes. Therefore, even when shifting to the next frame content, the reproduced image is temporarily blocked by a shutter or the like. No need. And here,
The pattern interval between a group of a plurality of CGH unit cells is set to be equal to or larger than the beam spot size of the illumination light, and when the CGH is scanned with the illumination light beam, the neighboring CGHs having different frame contents (neighboring recordings) Region) is reduced.

As described above, in reproducing a moving image using CGH, a plurality of transmissive or reflective CGHs are sequentially irradiated with illumination light, and diffracted light (still image) generated from the CGH is captured on a screen or captured like a movie. What is necessary is just to project on the element in a frame-by-frame manner and reproduce the image so that it looks like a moving image using the afterimage effect of the eyes.

That is, as shown in FIG. 5, for example, a plurality of transmission-type CGHs (recording areas) 11 for each frame content are arranged in a line on a card-shaped optical recording medium 10 in the order of frames. 10 is advanced by frame in parallel with the row of CGHs 11 or continuously moved. Alternatively, the optical recording medium 1
0 is fixed, and the monochromatic light emitting section 21 and the screen 22 are fixed.
Is moved in parallel with the row of CGH11. As shown in FIG. 6, a row of CGHs 11 is arranged concentrically or spirally on a disc-shaped optical recording medium 20, and the optical recording medium 20 is rotated and the monochromatic light emitting section 21 is moved on the normal line. With such a configuration, a reproduced image of CGH may be displayed on the screen 22.

FIGS. 7 to 12 show a specific example of a preferred embodiment of the optical recording medium reproducing apparatus according to the present invention, which will be described below.

The optical recording medium reproducing apparatus shown in FIG. 7 uses a transmission type CGH (recording area) 11, which is a group of the same frame contents obtained by duplicating a plurality of CGH unit cells in which a step corresponding to an image is created by an electron beam. A monochromatic light emitting device (light emitting means) 2 is applied to a disc-shaped optical recording medium (optical disc) 20 which is concentrically or spirally arranged and recorded in the order of frame contents.
1 is irradiated from below, and the diffracted light output from the CGH 11 is received by the image sensor (output means) 23 and the like. Each CGH 11 records information of image data corresponding to one frame of a moving image.

This optical recording medium reproducing apparatus uses an optical disk 2
0 is rotated at a predetermined rotation speed by a plurality of drive circuits (means for continuously reading) not shown. The rotation operation is controlled by a control circuit (not shown). Also,
The light emitting device 21 irradiates a CGH 11 on the optical disk 20 with a laser beam of a predetermined wavelength emitted from a light emitting element such as a laser diode through a lens and a pinhole. The light emitting device 21 irradiates the CGH 11 while moving from the outer circumference to the center (or from the center to the outer circumference) on the normal line of the optical disc 20, and the moving speed and the output power of the laser diode are controlled by the control circuit described above. Is done. The imaging device 23 is a CCD, a MOS, or the like.
It is arranged to capture a two-dimensional image projected by transmitted diffracted light when it irradiates 11. When a CCD is used as the image pickup device 23, a vertical synchronization signal Vsync is given to the CCD from a control circuit, and an output signal from the CCD is supplied to a display circuit and displayed.

At this time, by rotating the optical disc 20 at a predetermined speed, the CGH 11 is irradiated with laser beams one after another, and reproduced images are successively taken.
As a result, a moving image can be reproduced. Also, CGH
Even if the spot is slightly deviated from 11, the position of the reproduced image does not move, so there is no need to temporarily shut off the reproduced image by providing a shutter or the like. In addition,
Although an optical recording medium having a transmissive CGH 11 is used in the figure, a reflective CGH in which a reflective film is provided on the CGH portion of the optical recording medium (see FIG. 14) is the same as the light emitting device 21. By arranging the image sensor 23 on the side,
Similarly, an optical recording medium reproducing device can be configured.

FIGS. 8 to 10 show the emission of monochromatic light from below from a card-shaped optical recording medium (optical card) 30 in which a plurality of transmission type CGHs (recording areas) 11 are arranged in parallel at predetermined intervals. A reproducing device 31 (FIG. 8) for irradiating the optical recording medium 30 with light from a device (light emitting means) 21 and projecting diffracted light output from the CGH 11 onto a screen (reproduced image display unit, output means) 22, and imaging FIG. 11 is a flowchart (FIG. 10) for explaining an example of a reproducing apparatus (FIG. 9) for receiving light by an element (output means) 23 and a reading operation thereof. 8 and 9, an optical recording medium provided with a transmission type CGH 11 is used, but a reflection type CGH provided with a reflection film in a CGH portion is used.
In the case of an optical recording medium provided with, the light emitting device 21 and the imaging element 23 (screen 22) are arranged on the same side, whereby an optical recording medium reproducing device capable of reading a reflective CGH can be configured. In addition, each optical recording medium reproducing device 3
Each of the optical discs 1 and 32 has moving means (not shown) for moving the optical recording medium 30 in the X direction and the Y direction.

The optical recording medium reproducing device 31 shown in FIGS.
The operation of No. 32 will be described with reference to FIG. First, optical card 3
When 0 is inserted (step 101), the first column of the CGH 11 provided on the optical card 30 is scanned in the X direction in the figure, thereby displaying the contents of the first frame.
Are sequentially scanned in the order of CGH11 indicating the contents of the second frame from the third, the contents of the third frame,.
02).

When the completion of scanning of the first column is recognized by a sensor or the like (not shown) (step 103 →
Y), the optical card 30 is moved by one column in the Y direction (step 104), and the optical card 30 is scanned in the X direction from the opposite direction (or the same direction) as the first column, and the frame contents corresponding to the continuation of the first column are read. The CGH 11 is sequentially scanned to reproduce the image.

In this way, after the operation of moving in the Y direction for each row is repeated until the last row, the end of the movement in the Y direction is recognized by a sensor or the like (not shown) (step 105 → Y), the optical card 30 is ejected (step 106), and the reproduction of the moving image ends.

FIGS. 11 and 12 are views showing another embodiment of the optical recording medium reproducing apparatus of the present invention. FIG. 11 is a partially transparent configuration diagram, and FIG. 12 is a schematic configuration diagram. This optical recording medium reproducing apparatus is a mode suitable for reproducing a card-shaped optical recording medium (optical card).

The optical card 10 has a CGH with the same frame contents.
A reflection type CGH (recording area) 12 in which a plurality of unit cells are collected is provided in a row in the order of reproduction of frame contents.
In order to reproduce the row of the CGH 12, the optical card 10 is inserted into a slit (means for continuously reading) 27, and a closing portion (means for continuously reading) 28, 2
9, the light from the light emitting device (light emitting means) 21 is irradiated to the CGH 12 to be reproduced first via the mirror 24, and a part of the diffracted light is reflected by the mirror 25. , 26 via a screen (output means) 2
2 to reproduce an image.

By moving the optical card 10 in the slit 27 in the direction of the arrow while keeping the optical card 10 in contact with the closing portion 29, the CGH recorded so as to become a continuous image is obtained.
12 can be reproduced one after another, and information like a moving image can be obtained. This optical recording medium reproducing device 3
3 and the optical card 10 are both very simple configurations,
It is practically very effective as an optical recording medium reproducing apparatus and an optical recording medium capable of obtaining a moving image from the CGH 12 without a complicated configuration.

In each optical recording medium and each optical recording medium reproducing apparatus described above, it is easy to use a continuous image recorded as CGH as identification means of the card (optical recording medium) itself. In addition, a continuous image recorded on the CGH can be used to record an advertisement image of a card issuing company, an image accompanied by a trademark, or the like, and apply the authentication to the card itself. Various optical recording media including the above-described structure include IC cards, cash cards, prepaid cards, identification cards, student IDs, licenses, passports, health insurance cards, medical records, medical cards, membership cards, and entrance tickets. , Commuter pass, ticket, gift certificate, securities, amusement card, e-commerce card, automatic toll payment card, electronic publishing, software media, grade management card,
It can be applied as a medium used for ID cards, electronic voting certificates, and the like.

[0037]

The optical recording medium of the present invention has a recording area in which a still image corresponding to each frame output as a continuous image when read continuously in the information reading order is recorded. Continuous images (moving images) can be recorded and reproduced using CGH.

Since the same image information is recorded in a plurality of CGH unit cells and the recording areas are arranged adjacent to each other, the CGH unit cells may be damaged or stained.
Even when the spot irradiated with the monochromatic light is slightly shifted, the position of the reproduced image obtained from the diffracted light does not move, so that the image information can be reproduced satisfactorily.

Since the position of the reproduced image obtained from the diffracted light does not move even while the spot irradiated with the monochromatic light is moving, it is necessary to provide a shutter or the like necessary for reproducing the film image. There is no.

As an optical recording medium, a card-shaped optical recording medium having recording areas arranged at predetermined intervals in parallel, or a disk having recording areas arranged at predetermined intervals in a concentric or spiral shape An optical recording medium in the shape of a circle can be used, and a continuous image using CGH can be recorded and reproduced.

Further, the optical recording medium reproducing apparatus of the present invention
There is an effect that a continuous image recorded by CGH can be favorably reproduced.

[Brief description of the drawings]

FIG. 1 is a pattern diagram showing an example of a CGH unit cell recorded on an optical recording medium of the present invention.

FIG. 2 is an explanatory diagram for explaining a method of reading continuous image data from a CGH unit cell recorded on an optical recording medium according to the present invention.

FIG. 3 is a schematic diagram showing an example of continuous image data recorded on an optical recording medium of the present invention.

FIG. 4 is a schematic diagram showing an example of continuous image data recorded on the optical recording medium of the present invention.

FIG. 5 is a configuration diagram showing a schematic configuration example of an optical recording medium reproducing device of the present invention.

FIG. 6 is a configuration diagram showing another schematic configuration example of the optical recording medium reproducing device of the present invention.

FIG. 7 is a configuration diagram showing one embodiment of an optical recording medium reproducing apparatus of the present invention.

FIG. 8 is a configuration diagram showing another embodiment of the optical recording medium reproducing apparatus of the present invention.

FIG. 9 is a configuration diagram showing another embodiment of the optical recording medium reproducing apparatus of the present invention.

FIG. 10 is a flowchart for explaining the operation of another embodiment of the optical recording medium reproducing apparatus of the present invention.

FIG. 11 is a partial perspective view showing still another embodiment of the optical recording medium reproducing apparatus of the present invention.

FIG. 12 is a perspective view showing still another embodiment of the optical recording medium reproducing apparatus of the present invention.

FIG. 13 is a conceptual diagram showing a structure of a transmission type ternary CGH.

FIG. 14 is a conceptual diagram showing a structure of a reflection type ternary CGH.

FIG. 15 is a schematic configuration diagram for explaining a conventional optical recording medium reproducing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CGH (CGH unit cell) 3,11,12 CGH (recording area) 2 Translucent resin 4 Reflective film 5 Protective film 10,30,40 Optical card (optical recording medium) 20 Optical disk (optical recording medium) 21 Monochromatic Light emitting part (light emitting device, light emitting means) 22 Screen (reproduced image display part, output means) 23 Image sensor (output means) 24, 25, 26 Mirror 27 Slit (means for continuously reading) 28, 29 Closing part (Means for Continuously Reading) 31, 32 Optical Recording Medium Reproducing Apparatus

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // G11B 7/0065 G11B 7/00 651 F term (reference) 2H049 CA01 CA08 CA22 2K008 AA04 AA17 BB04 CC01 CC03 FF07 FF27 3E044 AA20 BA04 CA10 5C052 AA05 CC01 DD10 EE06 EE10 5D090 AA01 AA03 BB16 BB18 CC04 DD03 DD05 FF49 HH03 HH08 KK06 LL01

Claims (2)

[Claims] 1. An optical recording medium in which a plurality of recording areas in which the same image information is recorded in a plurality of CGH unit cells and arranged adjacently are arranged in an information reading direction. An optical recording medium characterized by recording a still image corresponding to each frame output as a continuous image when read out and read. 2. A light emitting means for irradiating a monochromatic light to a recording area of an optical recording medium; an output means for receiving diffracted light output from the recording area of the optical recording medium and reading image information; Means for irradiating each recording area of the optical recording medium with monochromatic light at predetermined time intervals in a predetermined direction and continuously reading out image information recorded in each recording area in a predetermined order; An optical recording medium reproducing device, comprising: