JPH06267070A - Information storage medium using hologram and method and device for reading information thereof - Google Patents

Abstract

PURPOSE:To give safety of high degree by making each element hologram have two-dimensional data being different from others so that the sum of reproduced data of a plurality of element holograms in a predetermined combination may represent one information. CONSTITUTION:A hologram of a multi-dot system prepared by a method wherein a plurality of dot-shaped element holograms 1B wherein patterns having two-dimensional data different from one another are recorded is formed on a hologram surface 1A having a photosensitive material. An original picture pattern prepared by a computer on the basis of input data is displayed on a liquid crystal panel 10 being an amplitude modulation element, and an object light transmitted through the panel is converged on a hologram plate surface 14 through a lens 14. A reference light is cast on this part of convergence from the same direction and a pattern of interference fringes of the object light and the reference light is recorded as the dot-shaped element hologram on the hologram surface 14. Then, exposure is executed sequentially with a hologram film moved little by little in longitudinal and lateral directions, and thus the dot-shaped element holograms are exposed on the whole of the hologram surface 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information storage medium using a hologram and an information reading method and apparatus therefor, and particularly makes it difficult to read information and provides higher security (data confidentiality). The present invention relates to an information storage medium using such a hologram and a method and apparatus for reading the information.

[0002]

2. Description of the Related Art In recent years, holograms have been used in various fields as a technique for displaying three-dimensional information of an object by making good use of light interference and diffraction phenomena. Among them, recently, holograms have been increasingly used in the field of information storage.

That is, the hologram memory used for information storage is (a) compatible with both redundancy and high-density recording. (B) The information reading mechanism has a high-speed and highly reliable structure. (C) Memory is inexpensive. Since it has unique characteristics such as mass copying, it has attracted attention as a digital memory or image memory.

Incidentally, the currently proposed hologram memory is constructed by using a hologram formed by forming a plurality of element holograms on the surface of a base material, and illuminating light (reproducing light) for each element hologram unit to obtain information. Is being read.

Therefore, the information can be easily read by shining laser light or white light on anyone, either visually or with a sensor, so that security (data confidentiality) is maintained. There is a problem with.

[0006]

As described above, in the conventional hologram memory, information is easily read, and there is a problem in terms of security.

The present invention makes it difficult to read information,
It is an object of the present invention to provide an information storage medium using a hologram capable of providing higher security and an information reading method and apparatus for the same.

[0008]

In order to achieve the above object, an information storage medium using a hologram of the present invention is a hologram formed by forming a plurality of dot-shaped element holograms on the surface of a substrate. In an information storage medium in which data is recorded by dividing it into element holograms, the element holograms are different from each other so that the sum of reproduction data of a plurality of element holograms of a predetermined combination represents one piece of information. It consists of recording a pattern with two-dimensional data.

In order to achieve the above object, the information reading method of the information storage medium using another hologram of the present invention reads the information of the information storage medium using the hologram described in claim 1. In the method, a plurality of element holograms of a predetermined combination are simultaneously illuminated with illumination light, and the sum of the reproduction data of the patterns recorded in each element hologram is read as one piece of information. ing. Further, in order to achieve the above-mentioned object, an information reading device of an information storage medium using another hologram of the present invention is the device for reading information of an information storage medium using the hologram according to claim 1 above. An amplitude modulation element that is disposed on the incident side of the illumination light of the information storage medium and that selects a plurality of element holograms of a predetermined combination, and an amplitude modulation element that is disposed on the opposite side of the amplitude modulation element Data reading means for reading the sum of the reproduction data of the pattern recorded on each element hologram exposed to the illumination light as one information is provided.

Here, in particular, as the amplitude modulation element,
A liquid crystal panel or the like can be considered.

[0011]

Therefore, in the information storage medium using the hologram of the present invention, two-dimensional information different for each element hologram is provided so that the sum of the reproduction data of a plurality of element holograms of a predetermined combination represents one information. If you are recording a pattern with the data of, and you want to read the information, select a plurality of element holograms of a predetermined combination with an amplitude modulation element and irradiate them with illumination light at the same time. Thus, the sum of the reproduction data of the patterns recorded in each element hologram is read as one information by the data reading means.

As a result, the information cannot be read unless the irradiation pattern of the encrypted illumination light is known, that is, the combination of a plurality of element holograms selected by the amplitude modulation element is encrypted to read the information. Higher security (data confidentiality)
Can have

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a plan view showing a configuration example of an information storage medium using the hologram of this embodiment.

That is, in the information storage medium 1 using the hologram of the present embodiment, as shown in FIG. 1, a hologram surface (dry plate) 1A having a photosensitive material has a pattern having different two-dimensional data. It is composed of a multi-dot type hologram formed by forming a plurality of recorded dot-shaped element holograms 1B.

Next, the optical system used in the manufacturing method of this embodiment will be described with reference to FIG.

An original pattern created by a computer from input data is displayed on the liquid crystal panel 10 which is an amplitude modulation element,
The object light that is the transmitted light is condensed on the hologram surface (hologram dry plate) 14 via the lens 12. Further, the reference light is made incident on the condensing portion from the same direction, and the interference fringe pattern of the object light and the reference light is recorded on the hologram surface 14 as a dot-shaped element hologram.

Then, the hologram film is moved little by little in the vertical and horizontal directions for sequential exposure to expose the entire hologram surface 14 with dot-shaped element holograms.
In this case, exposure is performed while changing the original image pattern displayed on the liquid crystal panel 10 for each element hologram.

Next, the production system using the one-step Lippmann HS will be described in detail with reference to FIG.

FIG. 3 is a schematic diagram showing a concrete example of the configuration of the system. In FIG. 3, helium neon ray
The laser beam from the laser 20 is separated into object light and reference light by a beam splitter 22.

Of these, the object light becomes parallel light through the lens 24, illuminates the liquid crystal panel 10, and the liquid crystal panel 1
The amplitude (intensity) is modulated by 0. Further, the amplitude-modulated object light is guided to a spherical lens 34 having a large power through a lens 26, a slit 28, a lens 30, and a mirror 32, and is collected on the hologram surface 14 by the lens 34. Be illuminated. The reference light is Mira-3.
The light is focused on the hologram surface 14 from the same direction as the object light via 8.

Here, the lens 26, the slit 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 hologram surface 14 has an XY station.
It is fixed to the jig 36 and is movable in the vertical and horizontal directions. Then, while changing the information of the liquid crystal panel 10, the XY stage 36 is moved to form a dot-shaped element hologram on the entire surface of the hologram surface 14. The entire system is controlled by a personal computer. The photosensitive material used for the hologram surface 14 may be, for example, a silver salt photosensitive material.

Next, a configuration example of the hologram creating apparatus (printer) according to the present embodiment will be described with reference to FIGS.

That is, first, in step A of FIG. 5, a plurality of different two-dimensional data to be recorded are collectively input to the host computer 40.

Next, in step B, the hologram dry plate 14 is moved by the film moving controller 46 to set the hologram dry plate 14 at a desired position (origin of the exposure position).

Next, in step C, the graphic processor 42 creates an original image corresponding to the coordinate position of the converging portion on the hologram surface 14 from the predetermined one data of the plurality of two-dimensional data. It is calculated and stored in the frame memory 44.

Next, in step D, the liquid crystal panel 1
The original pattern is displayed at 0.

Next, 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 divided into object light and reference light by the beam splitter 22, and the object light is amplitude-modulated by the original image pattern of the liquid crystal panel 10 to produce a hologram surface. It is focused on 14 and forms one element hologram with the reference light.

Next, in step F, the hologram dry plate 14 is sequentially moved by the film moving controller 46, and the operations of steps C, D, and E are repeated until the exposure through step G is completed. The hologram surface 14 is exposed so as to fill the entire surface.

In this case, in step C, the plurality of 2
One data different from the previous one is sequentially selected from the dimensional data, and the original pattern different for each element hologram is calculated from the selected data, and in step D, the liquid crystal panel 10 is calculated. A different original pattern is displayed for each element hologram.

Then, in step H, the developing process of the hologram 14 is performed by the developing machine 50, and the hologram is automatically created.

As described above, the hologram 1 can be obtained in which a plurality of dot-shaped element holograms in which original image patterns having different two-dimensional data are recorded are formed on the hologram surface 14.

The graphic processor 42, the film moving controller 46, and the developing machine 50 are C
It is controlled by the PU.

Next, FIG. 6 is a schematic diagram showing a configuration example of an information reading device for an information storage medium using the hologram of this embodiment.

That is, as shown in FIG. 6, the information reading apparatus of this embodiment includes a liquid crystal panel 2 which is an amplitude modulation element,
It is composed of a sensor (for example, an area sensor such as CCD) which is a data reading means.

Here, the liquid crystal panel 2 is disposed on the incident side of the illumination light of the information storage medium 1 and selects a plurality of element holograms 1B in a predetermined combination.

The sensor 3 is arranged on the opposite side of the liquid crystal panel 2, and is selected by the liquid crystal panel 2 and recorded on each element hologram 1B irradiated with the illumination light.
The sum of the reproduced data of the video is read as one piece of information.

Next, an information reading method of the information storage medium using the hologram of the present embodiment created as described above will be described with reference to FIGS. 6 and 7.

In the information storage medium 1 using the multi-dot type hologram of the present embodiment, a hologram is formed as a collection of minute element holograms, and the reproduced image is represented as a collection of the images. Therefore, the reproduction pattern is reproduced as the sum of the original image patterns recorded on the element holograms illuminated by the illumination light.

Therefore, as shown in FIG. 6, among the original image patterns recorded in the respective element holograms of the information storage medium 1, a plurality of element holograms (for example, two) 1B in a predetermined combination are converted into liquid crystal. The sum of the reproduction data of the original image patterns recorded on each of the two element holograms 1B selected and illuminated by the illumination light is selected by irradiating them with the illumination light at the same time. -It is read as one piece of information on three sides.

For example, when two element holograms 1B as shown in FIG. 7 are selected, the original pattern as shown in FIG. 7 is read as one piece of information.

As described above, the information storage medium 1 using the hologram of the present embodiment is configured such that the sum of the reproduction data of a plurality of element holograms 1B of a predetermined combination represents one piece of information. A pattern having two-dimensional data different from each other is recorded for each 1B, and when reading the information, a plurality of element holograms 1B in a predetermined combination are used for the liquid crystal panel 2 which is an amplitude modulation element. By irradiating them with illumination light at the same time, the sum of the reproduction data of the patterns recorded in each element hologram 1B is treated as one information by the sensor 3 which is the data reading means. It is intended to be read.

Therefore, the following various effects can be obtained.

(A) The liquid crystal panel 2 allows the liquid crystal panel 2 to select a plurality of predetermined combinations among the patterns recorded in advance on each element hologram 1B of the information storage medium 1. The sum of the reproduction data of the recording patterns of each element hologram 1B selected and illuminated by the illumination light is obtained as one piece of information.

As a result, in the conventional holographic memory, since the reproduction light is illuminated for each element hologram unit and read out, anyone can easily read the data visually or by the sensor. On the other hand, in the information storage medium 1 using the hologram of the present embodiment, the information cannot be read unless the irradiation pattern of the encrypted illumination light is known, that is, a plurality of information selected by the liquid crystal panel 2 is selected. It becomes possible to encrypt the combination of the element holograms 1B of No. 1 to make it difficult to read information and to provide higher security (data confidentiality).

(B) In the case of handling two-dimensional image data, the data to be stored can be written and read as image data in this embodiment. And the encoding process is unnecessary. Of course, it can also be used for recording other data.

(C) According to the hologram creating apparatus (printer) of this embodiment, the information storage medium 1 can be created automatically.

The present invention is not limited to the above embodiments, but can be carried out in various modifications as follows without departing from the gist of the present invention.

(A) In the above embodiment, as the display means,
The case of using a liquid crystal panel which is an amplitude modulation element for amplitude-modulating laser light has been described, but the invention is not limited to this, and the number of pixels is 256 × for use in this system.
An amplitude 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. For example, a mask may be used.

(B) In the above embodiments, the case where the liquid crystal panel 10 for modulating the intensity of light is used as the amplitude modulation element has been described. Good.

(C) In the above embodiment, the case where the Lippmann hologram dry plate is used as the hologram dry plate has been described, but the hologram dry plate is not limited to this, and other hologram dry plates may be used.

(D) In the above embodiment, the silver salt photosensitive material was used as the photosensitive material, but a polymer photosensitive material can be used for recording a Lippmann hologram with high image quality.

(E) In the above embodiment, a case has been described in which a plurality of different two-dimensional data to be recorded are input to the host computer 40 all at once. However, the present invention is not limited to this. Each time recording is performed, in step A of FIG. 5, two-dimensional data different from the previous one may be input to the host computer 40 each time.

(F) In the above embodiment, the information storage medium 1
In the above, the case of recording with a multi-dot hologram formed by forming a plurality of dot-shaped element holograms on the surface of the substrate has been described, but the present invention is not limited to this, and a method of directly recording a grating with an electron beam may be used.

(G) In the above embodiment, the hologram forming optical system is described as a case where the reference light enters from the same side as the object light and is used as a transmission type, but the invention is not limited to this.

(H) In the above embodiment, the case where the liquid crystal panel 10 selects two of the predetermined combinations among the original image patterns recorded in advance on each element hologram 1B of the information storage medium 1 Although described, the present invention is not limited to this, and a plurality of combinations other than two, which are determined in advance, may be selected by the liquid crystal panel 10.

[0058]

As described above, according to the present invention, each element hologram has a different two-dimensional shape so that the sum of the reproduction data of a plurality of element holograms of a predetermined combination represents one piece of information. When an information storage medium is constructed by recording a pattern with data and the information is read, a plurality of element holograms in a predetermined combination are selected with amplitude modulation elements, and illumination light is simultaneously applied to them. By irradiating, the sum of the reproduced data of the patterns recorded in each element hologram is read as one piece of information by the data reading means, which makes it difficult to read the information and provides a higher level of security. It is possible to provide an information storage medium using a hologram capable of imparting properties, and an information reading method and apparatus thereof.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an information storage medium using a hologram according to the present invention.

FIG. 2 is a schematic diagram showing an optical system of a one-step Lippmann HS according to the present invention.

FIG. 3 is a schematic diagram showing a detailed optical system for Lippman HS synthesis according to the present invention.

FIG. 4 is a schematic diagram showing a configuration example of a holographic printer system of the present invention.

5 is a flowchart of the holographic printer system in FIG.

FIG. 6 is a schematic diagram showing a configuration example of an information reading device of an information storage medium using a hologram according to the present invention.

FIG. 7 is a schematic diagram for explaining an information reading method of an information storage medium using a hologram according to the present invention.

[Explanation of symbols]

1 ... Information storage medium, 1A ... Hologram surface, 1B ... Element hologram, 2 ... Liquid crystal panel, 3 ... Sensor, 10 ... Liquid crystal panel, 12, 24, 26, 30, 34 ... Lens, 14
… Hologram surface, 16… Focusing part, 20… Laser, 22…
Beam splitter, 28 ... Slit, 32 ... Mira-3
6 ... XY stage, 38 ... Mirror, 40 ... Host computer, 42 ... Graphic processor, 44 ... Frame memory, 46 ... Film transfer controller, 48
… Optical system, 50… Developer.

Front Page Continuation (72) Inventor Susumu Takahashi 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Masahiro Yamaguchi 4-1-31-502 Kamada, Setagaya-ku, Tokyo (72) Inventor Yoshio Honda 1913-12 Kitahasakucho, Midori-ku, Yokohama-shi, Kanagawa (72) Inventor Nagaaki Oyama 2-3-9 Kannon, Kawasaki-ku, Kawasaki-shi, Kanagawa

Claims (4)

[Claims] 1. An information storage medium of a hologram formed by forming a plurality of dot-shaped element holograms on a surface of a base material, in which data is recorded by dividing each of the element holograms into a predetermined combination. As the sum of the reproduction data of the plurality of element holograms represents one information,
An information storage medium using a hologram, characterized in that a pattern having different two-dimensional data is recorded for each element hologram. 2. A method for reading information on an information storage medium using the hologram according to claim 1, wherein the plurality of element holograms of the predetermined combination are simultaneously irradiated with illumination light, An information reading method for an information storage medium, characterized in that information is read as a sum of reproduced data of patterns recorded on a hologram. 3. An apparatus for reading information on an information storage medium using the hologram according to claim 1, wherein a plurality of the predetermined combinations are arranged on the incident side of the illumination light of the information storage medium. An amplitude modulation element that selects an element hologram, and the reproduction data of the pattern that is arranged on the opposite side of the amplitude modulation element and that is selected by the amplitude modulation element and that is recorded on each element hologram that is illuminated by illumination light. An information reading device for an information storage medium, comprising: a data reading means for reading the sum as one piece of information. 4. The information reading device for an information storage medium according to claim 3, wherein the amplitude modulation element is a liquid crystal panel.