JP2000123109A - Optical recording medium and optical recording medium writer/reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent forgery and alteration by performing recording onto an optical recording medium while providing a recording part and an erasing part for a hologram pattern so that a combinational code composed of binary codes can correspond to the recording part and erasing part for the hologram pattern. SOLUTION: The information of binary codes, to which combinational coding is performed, is recorded on an optical recording medium 1 corresponding to the erasure/non-erasure of a hologram image. Every information, to which combinational coding is performed, is recorded by the erasure/non-erasure of plural holograms 2 in a group allocated for every information. As an erasing method for holograms 2, they are erased by a thermal head 3. The light of LD is reflected on the hologram 2, its image is received by an imaging device, and information is provided by judging the non-erasure/erasure of the hologram 2 corresponding to the presence/absence of the desired hologram image. In alteration analysis, the imaging device comprehends the presence/absence of the hologram image as binary codes and when the combinational code is formed as ruled, the absence of alteration is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium and an optical recording medium writing / reading apparatus, and more particularly to an optical recording medium and an optical recording medium such as a prepaid card, a credit card, a cash card, and an identification card which are difficult to be forged or tampered with. The present invention relates to a recording medium writing / reading device.

[0002]

2. Description of the Related Art Current prepaid cards, credit cards, cash cards, and the like have a magnetic recording portion called a magnetic stripe as recording means, and have a balance and an ID (identification) number for confirming the identity of the person as necessary. The record is recorded, and the record such as the balance is changed with the use of the card in the prepaid card. Such a card as a recording medium is convenient to carry and does not involve cumbersome cash transfer, and contributes to a so-called cashless society. On the other hand, in such a card, since the recording medium is a magnetic recording layer,
A general-purpose device makes it easy for a third party to read the recorded contents, and therefore it is easy to forge, and it is also possible that a large amount of telephone cards and pachinko parlor prepaid cards are forged or illegally used. Many are social issues.

[0003] In this social problem, the present applicant invented an optical recording medium capable of preventing counterfeiting prior to the present invention,
A patent application has been filed (Japanese Patent Application No. 8-359259: JP-A-10-198259). In the invention disclosed in the prior application, an optical recording medium that can record a large amount of information and is most difficult to forge or illegally use has been proposed.
That is, in the prior art, an image is represented as a hologram, an electron beam exposure device is driven by using the data, the interference fringes of the hologram are accurately drawn on the recording medium by the electron beam, and the recording medium is etched. A master disc of an optical recording medium is manufactured by using the master disc, and a plurality of recording areas showing interference fringes of a hologram are provided by replication using the master disc, and a plurality of independent areas of a corresponding reflection film are provided, or the reflection film is provided outside. The optical recording medium is manufactured as a structure in which the protective layer and the substrate are in close contact with each other over the entire circumference of the optical recording medium so as not to be exposed. Therefore, if the technology of the prior application is used, it is possible to represent information represented by a binary code in accordance with erasure / non-erasure of a hologram image, and it has advanced technology and expensive equipment, and is confidential. Only those who know the hologram image and the coding / arrangement rules can manufacture and forge. However, even in this optical recording medium that is most difficult to forge, measures to prevent the information to be written from being falsified are indispensable in order to avoid further unauthorized use, which is an important problem.

On the other hand, among the above social problems, in order to solve countermeasures against tampering, Japanese Patent Publication No. 6-6482 and Japanese Patent Publication No. 7-4
Japanese Patent Publication No. 3881 discloses a falsification detection method. However, the tampering detection methods disclosed in these publications do not exceed the principle of the Berger code as an error detection code for a one-way error communication channel. The Burger code is a systematic code in which a check bit that represents the number of 0s in this information bit by a binary number is added after the information bit, and its developer JM Berger's paper (Info
"A" in rmation and Control, Vol. 4, pp. 68-73, 1961
Note on Error Detection Codes for Asymmetric Chan
nels), and is also described in “Code Theory, 6th Edition (1996), pp. 328-329” published by the Institute of Electronics, Information and Communication Engineers. The communication path in the communication theory is the idea of the Burger code itself because it includes a recording medium in addition to the communication path. In addition, there are two types of errors: errors that occur unexpectedly as a natural phenomenon and errors that are intentionally caused by humans.Although falsification is a deliberate error, the error detection code in Burger's dissertation has the meaning of a falsification detection code. Contains. These tampering detection methods make tampering impossible, but do not prevent forgery, so countermeasures against forgery are an important issue.

[0005]

The above-mentioned methods are different from counterfeiting countermeasures and falsification countermeasures, and are not sufficient because they do not combine both countermeasures. A recording medium and a device incorporating both countermeasures are required. . Therefore, an object of the present invention is to provide an optical recording medium which is hard to be forged and which cannot be tampered with, and a writing / reading device therefor.

[0006]

In order to achieve the above object, according to the present invention, 0 and 1 of a combination code composed of binary codes of 0 and 1 representing information to be recorded, or vice versa, is a hologram pattern recording unit. A hologram pattern recording unit and an erasing unit are provided so as to correspond to the hologram pattern and the erasing unit, and recording on an optical recording medium is performed. Specifically, the information to be recorded is k
When represented by a binary code of bits, information to be recorded is represented using a combination code (constant weight code) in which k bits (n ≧ k ≧ 0) of the n bits are fixed, and the combination encoding is performed. The information of the binary code is erased from the hologram image.
Recording is performed on an optical recording medium in correspondence with non-erasing. The combination code is a code in which the number of binary codes 0 is always constant, in other words, a code in which the number of binary codes 1 is always constant. This combination code is also called a constant weight code because the Hamming weight is constant, and it is known from literature (Hideki Imai: coding theory) that it is more efficient than the Burger code.

That is, according to the present invention, a combination code of 0 and 1 consisting of binary codes of 0 and 1 representing information to be recorded is provided.
An optical recording medium provided with a hologram pattern recording section and an erasing section is provided so that the recording section and the erasing section of the hologram pattern correspond to the recording section and the erasing section, respectively.

According to the present invention, an optical recording medium in which a plurality of hologram patterns are arranged in advance is provided.
In order to record information to be recorded as a combination code composed of binary codes of 0 and 1, the hologram pattern corresponding to 0 or 1 of the combination code is left as it is in the recording section of the hologram pattern, and 1 or 0 is set. There is provided an optical recording medium writing apparatus having means for erasing the hologram pattern corresponding to (1).

According to the present invention, a means for recording the hologram pattern on an optical recording medium capable of arranging and recording a hologram pattern, and information to be recorded are represented by binary codes of 0 and 1. A means for erasing the hologram pattern corresponding to 1 or 0 while leaving the hologram pattern corresponding to 0 or 1 of the combination code in order to record the hologram pattern as a combination code. Is done.

According to the present invention, a hologram pattern recorded in advance is selectively erased according to a binary code of 0 or 1 as a combination code, and a laser beam is recorded on an optical recording medium on which the binary code is recorded. Means for irradiating a beam, means for detecting a hologram pattern reproduced by the irradiated laser beam, and means for generating a binary code according to the presence or absence of the hologram pattern in accordance with an output signal of the means for detecting And an optical recording medium reader having the following.

According to the invention, in an optical recording medium having a substrate and a plurality of recording areas, a reflective film and a protective layer on a recording layer formed on the substrate, each of the recording areas has a recording area. When the main information is represented by binary 0's and 1's binary information bits for a copy of a hologram interference fringe corresponding to a two-dimensional image drawn by an electron beam, it represents information to be recorded. A hologram pattern is recorded and erased so that 0 and 1 or the reverse of a combination code composed of binary codes of 0 and 1 correspond to the hologram pattern recording and erasing sections. Yes,
The reflective film has a region facing a plurality of the recording areas, and is located between the protective layer and the substrate so that the reflective film is not exposed to the outside, and the protective layer and the substrate are An optical recording medium is provided, which is in close contact with the entire circumference of the optical recording medium.

The optical recording medium on which information is recorded by leaving a plurality of hologram patterns previously recorded on the optical recording medium as they are or by erasing them in accordance with the combination codes of 1 and 0 or vice versa. This is a preferred embodiment of the present invention.

An information recording method for recording information by leaving or erasing a plurality of hologram patterns previously recorded on an optical recording medium in accordance with a combination code of 1 and 0 or vice versa is described in the present invention. This is a preferred embodiment of the present invention.

According to the combination code of 1 and 0 or vice versa, a plurality of hologram patterns recorded in advance on an optical recording medium may be left as they are or may be erased from those on which information has been recorded by deleting the hologram patterns. An information reading method for reading a pattern and reading a recorded combination code is a preferred embodiment of the present invention.

Further, in an optical recording medium having a substrate and a plurality of recording areas and a reflective film on a recording layer formed on the substrate, each of the recording areas has an interference of a hologram corresponding to a two-dimensional image to be recorded. For a copy obtained by drawing fringes with an electron beam, a combination code of 0 and 1 consisting of binary codes of 0 and 1 representing information to be recorded, or vice versa, corresponds to the recording portion of the hologram pattern. In order to correspond to the erasing section, a hologram pattern recording section and an erasing section are provided and recorded, and the reflection film has a plurality of areas facing each or a plurality of the recording areas, and An optical recording medium according to the present invention, wherein the optical recording medium is arranged so as to cover the entire two-dimensional image area of the recording area, and each area of the reflective film is not continuous with an adjacent area of the reflective film and is independent. Like Is have aspects.

Further, in an optical recording medium having a substrate and a plurality of recording areas and a reflective film on a recording layer formed on the substrate, each of the recording areas reads a two-dimensional image to be recorded and converts it into a numerical value. Arithmetic processing of the obtained data,
The data representing the interference pattern of the hologram is given to an electron beam exposure apparatus, the medium to be exposed is exposed by scanning with an electron beam, and the medium to be exposed is drawn. On the other hand, the recording part and the erasing part of the hologram pattern are arranged such that 0 and 1 or the reverse of a combination code composed of binary codes of 0 and 1 representing information to be recorded correspond to the recording part and the erasing part of the hologram pattern. Provided and recorded, wherein the reflective film has a plurality of areas facing each or a plurality of the recording areas, and is arranged so as to cover the entire two-dimensional image area of the individual recording area, and An optical recording medium according to a preferred aspect of the present invention is characterized in that each region of the reflection film is independent of a region of an adjacent reflection film without being continuous.

Further, in an optical recording medium having a substrate and a plurality of recording areas and a reflective film in a recording layer formed on the substrate, each of the recording areas has an interference of a hologram corresponding to a two-dimensional image to be recorded. For a copy obtained by drawing fringes with an electron beam, a combination code of 0 and 1 consisting of binary codes of 0 and 1 representing information to be recorded, or vice versa, corresponds to the recording portion of the hologram pattern. In order to correspond to the erasing section, the recording section and the erasing section of the hologram pattern are provided and recorded, and the reflective film has a plurality of regions facing each or a part of the recording area,
The optical recording medium is arranged so as to cover the entire two-dimensional image area of each of the individual recording areas, and each area of the reflection film is not continuous with and independent of an adjacent reflection film area. This is a preferred embodiment of the present invention.

Further, in an optical recording medium having a substrate and a plurality of recording areas and a reflection film on a recording layer formed on the substrate, each of the recording areas reads a two-dimensional image to be recorded and digitizes the two-dimensional image to be recorded. Arithmetic processing of the obtained data,
The data representing the interference pattern of the hologram is given to an electron beam exposure apparatus, the medium to be exposed is exposed by scanning with an electron beam, and the medium to be exposed is drawn. On the other hand, the recording part and the erasing part of the hologram pattern are arranged such that 0 and 1 or the reverse of a combination code composed of binary codes of 0 and 1 representing information to be recorded correspond to the recording part and the erasing part of the hologram pattern. Provided so that the reflective film has a plurality of areas facing each or a part of the recording area, and is arranged so as to cover the entire two-dimensional image area of the individual recording area. An optical recording medium according to a preferred aspect of the present invention, wherein each area of the reflection film is independent of an adjacent reflection film area without being continuous.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a first embodiment of the optical recording medium according to the present invention. Although there are various uses of the optical recording medium of the present invention, the embodiment will be described here as a card-type prepaid card 1. The prepaid card 1 has a large number of holograms arranged as 1-bit recording areas in order to represent a large amount of bit information. The hologram is recorded as an interference fringe of the hologram, that is, a hologram pattern 2 as one of the holograms is shown in an enlarged manner. This will be described in detail together with the form. In the example of FIG.
Three rows of hologram pattern recording portions are provided on a 5 mm × 75 mm flat synthetic resin card, and 120 hologram patterns are pre-recorded in each row, and then some are selectively erased. I have. In the figure,
The white circles are the portions that have not been erased, and the black circles are the portions that have been erased. The non-erasing section and the erasing section will be described later in detail with reference to FIG. It should be noted that in FIG. 1, a production number (PSN) and a balance (RS
V) and the number of hologram patterns (CGH) are shown. UR, MR, BR are each UPP
ER ROW (upper row), MIDDLE ROW (middle row), BOTTOM ROW (lower row).

FIG. 2A shows an example of a combination code (constant weight code) in which the number of information bits is 6 bits. Here, an example of a code in which 3 bits are 1 out of 6 bits is shown. Generally, it can be said that the code is a code in which k bits are 1 bit out of n bits. n is any positive integer, and k is n ≧ k ≧ 0. As will be described later, 0 or 1 of each bit of the combination code is satisfied as a falsification detection code, whichever is associated with hologram erasure.

The example of combination codes 1, 2, and 3 in FIG. 2A is an example of a combination code in which 3 bits are 1 out of 6 bits. The number of pieces of information that can be represented by the combination code in which 3 bits are 1 out of 6 bits is 20 kinds, and therefore, for example, 20 kinds of information from 0 to 19 can be represented. In this case, the correspondence between the information and each codeword of the combination code is 20! (= 2.43 × 10 ** 18) types of correspondences are conceivable, and any correspondence may be adopted. Here, three examples of combination codes 1, 2, and 3 are shown.

The example of combination codes 4, 5 and 6 in FIG. 2B is an example of a combination code in which 3 bits are 1 out of 6 bits. The number of pieces of information that can be represented by the combination code in which 3 bits are 1 out of 6 bits is 20 kinds, and therefore, for example, 20 kinds of information from 0 to 19 can be represented. However, since the information to be expressed is often in the form of a power of 2 (for example, 2, 4, 8, 16,...), It is assumed that the information represents 16 types of information from 0 to 15, for example. In this case, the correspondence between the information and each codeword of the combination code is 20! / 4! (= 1.01 × 10 ** 17) kinds of correspondences are conceivable, and any correspondence may be adopted. Here, three examples of combination codes 4, 5, and 6 are shown.

The combination code is described in detail in the above-mentioned document, but is a code in which the number of 0s in a binary code is always constant. According to the present invention, binary code information that has been combined and encoded is recorded on an optical recording medium in correspondence with erasure / non-erasure of a hologram image. Next, FIG. 2 (A), (B)
It will be explained that no matter which one of the binary codes 0 and 1 corresponds to the erasure of the hologram, it can be realized as a code for detecting the fact that it has been tampered with. First, if a binary code of 1 corresponds to erasure of a hologram, and a binary code of 0 corresponds to non-erasure of a hologram, the optical recording medium is assumed to be irreversible. In this case, there is a transition from 0 to 1, but 1
→ There is no transition to 0. Therefore, tampering is 0
→ It occurs only in the transition of 1. That is, at the stage where the tampering has occurred, the number of 0 or 1 immediately becomes different from the predetermined number, so that the tampering is impossible. The same applies to the case where the binary code 1 corresponds to the non-erasure of the hologram.

Each combination-encoded information is obtained by erasing a plurality of holograms 2 in a group assigned to each information.
Recorded without erasure. Various methods of erasing the hologram 2 such as a thermal head, a laser, press punching with a punch and a die, and a drill can be considered.
Here, erasing is performed by the thermal head 3 in FIG. In FIG. 3, the hologram pattern 2 remains recorded, that is, the hologram pattern (non-erased) 2A in the non-erased state, and the hologram pattern 2 is recorded and then erased by thermal melting by the thermal head 3. The hologram pattern (after erasure) 2B is shown. The operations of erasing and non-erasing these holograms 2 are recorded and
This will be referred to as recording in a reading device. On the other hand, as shown in FIG.
The light of D (laser diode 4) is reflected on the hologram 2 and received by the image pickup device 5, and the presence or absence of the desired hologram image 6 determines whether the hologram 2 is not erased or erased, and obtains information. There are two aspects here: forgery analysis and tampering analysis. First, in the forgery analysis, by imaging the hologram image 6 with the imaging device 5, if the desired hologram image 6 is obtained, it is determined that the hologram image 6 has not been forged. In such a case, it is determined to be forgery. Next, in the falsification analysis, the presence / absence (non-erasing / erasing of the hologram 2) of the hologram image 6 is determined by
It is understood as a hexadecimal code, and if the combination code is formed according to the rule, it is determined that there is no tampering, and if the combination code is formed out of the rule, it is determined that there is tampering.

FIG. 5 shows a flow from the manufacturing process to use of the optical recording medium according to the present invention. In FIG. 1, ISN
The information (IC wafer serial number) is recorded on the master in the molding process and is information that does not change even if it is replicated by press molding. Other SSN (stamper serial number), PSN (production serial number), TSN (ticket vending machine serial number), VLD (ticket issuing date and time), and RSV (balance) are information to be recorded later. Combination encoding as a falsification detection code is sequentially and independently recorded for information that is likely to be falsified and is recorded later. Also, the ISN in which the same is duplicated by the molding process is not falsified, but cannot be falsified, and therefore does not require a falsification detection code.

In FIG. 5, in each process of the ticket vending machine and the vending machine, it is recorded after checking whether the card is a forged or falsified card or a legitimate card. In this way, since each information is sequentially recorded in each process, according to the present invention, even if the card is stolen and falsified at a certain point in time, it is not possible to return to the previous step, so at any point in time the fraud is detected. You can specify if there was. In addition, before recording in each process, it is possible to perform recording after inspecting a hologram image whether it is a counterfeit card or a legitimate card, and inspecting whether the card is a falsified card or a legitimate card. Therefore, inspection for fraud can be strict.

Next, a method of writing information by performing non-erasing and erasing of holograms in correspondence with the predetermined binary code described in the first embodiment is described in Japanese Patent Application No. Hei. The case where the present invention is applied to the optical recording medium described in JP-A-359259 will be described as second to fourth embodiments of the present invention.
Also in the second to fourth embodiments, after the hologram pattern is formed, the hologram pattern is selectively erased by the thermal head according to the information bits 0 and 1 or vice versa as described with reference to FIG. I do. FIG. 6 is a plan view of a second embodiment of the optical recording medium according to the present invention. The following embodiment will be described as a card-type prepaid card 26 as in the first embodiment. A plurality of recording areas 28 are provided and arranged on the prepaid card 26. Now, it is assumed that character information is recorded in each of the recording areas 28. FIG. 7 is a cross-sectional view of the optical recording medium of FIG. 6 taken along the line II-II. The prepaid card 26 includes a substrate 27, a recording area 28 provided in the recording layer, and a plurality of areas 29 of the reflection film. The state having the protective layer 31 is shown. In FIG. 6 and other similar plan views, the optical recording medium 26 is viewed from the substrate 27 side. The recording area 28 is indicated by a solid line, and each area 29 of the reflection film is indicated by a dotted line. As the substrate 27, for example, polycarbonate or the like can be used. Further, as the protective layer 31, for example, a UV polymer coat or the like can be used.

FIG. 8 is a block diagram showing an apparatus and steps for manufacturing the optical recording medium 26 of FIG. Now, assuming that character information including numbers is recorded on the prepaid card 26 to be manufactured, a signal of the character information is input to the input terminal IN.
1 and input to the image signal conversion circuit 10. The image signal conversion circuit 10 converts the character represented by the code information of the input digital signal into an image signal of a two-dimensional image dot pattern (input data in FIG. 9).

This image signal is supplied to the numerical operation device 14 via the switch 12 or the multiplexer. The numerical operation device 14 obtains a numerical value for obtaining an interference fringe pattern of a hologram (holographic interferogram) without irradiating interference light from an image signal of a dot pattern of a two-dimensional image using a predetermined algorithm. FIG. 9 schematically shows this state. Preferably, a computer capable of high-speed operation is used as the numerical operation device. Deriving a hologram interference pattern corresponding to the two-dimensional image data, that is, a wavefront shape by calculation is known as a so-called CGH (Computer Generated Hologram).

The numerical operation device 14 is configured to output coordinate data corresponding to the resolution of an electron beam exposure device 18 which is a drawing device described later. Before actually performing drawing, coordinate data obtained by numerical operation is fed back and compared with input data, and recalculation is performed a plurality of times to reduce an error between the two. An output signal of the numerical operation device 14 is converted into a signal of a predetermined format by the encoder 16 and input to the electron beam exposure device 18. The electron beam exposure apparatus 18 is originally used to draw a circuit arrangement pattern when manufacturing an IC or LSI, and here, the interference fringe pattern (output data) shown in FIG. 20 is used to draw on. The primary recording medium 20 is referred to as a primary recording medium 20 in order to distinguish it from the optical recording medium 26 as a final product. 1
As the next recording medium 20, as shown in FIG. 10B, a substrate such as a glass 30 coated with a photoresist 32 which is a photosensitive resin as a medium to be exposed is used. 1
The next recording medium 20 is mounted on a stepper 22 (stage controller), and the stepper 22 can be moved in two directions XY on a plane perpendicular to the electron beam 34 by a signal from the electron beam exposure device 18. It should be noted that drawing with an electron beam makes it possible to draw an extremely delicate and precise pattern as compared with drawing with a laser beam used in the production of a conventional optical recording medium. It can be said that it is suitable.

Now, assuming that data consisting of 300 English characters (including numbers) is to be recorded on the prepaid card, the character string data serially input from the input terminal IN1 is sequentially transmitted to the image signal conversion circuit 10. The digital signal is converted into an image signal, subjected to numerical calculation processing by a predetermined algorithm in a numerical calculation device 14, converted into data in a predetermined format by an encoder 16, supplied to an electron beam exposure device 18, and deflected by an electron beam. Then, drawing is performed on the primary recording medium 20. At this time, the electron beam exposure device 18
Controls the stepper 22 so that 300 recording areas 28
In the rows, the primary recording medium 20 is moved in the XY direction on a plane perpendicular to the electron beam 34 so that 100 recording areas are arranged in each row.

As shown in FIG. 6, the completed prepaid card 26 has three rows of recording areas 28 arranged. Each recording area 28 is 250 μm square (A = 250 μm).
m), and the interval between adjacent recording areas 28 in the same row (horizontal row in the figure) is also 250 μm (B> A in FIG. 6).
Where A = B = 250 μm). The interval C between the recording areas 28 in the adjacent row is 5
00 μm. In one recording area 28, an interference fringe pattern of a hologram corresponding to one character is recorded, and information of each recording area is independent.
For example, as shown in FIG. 13, the interference fringe pattern of the same hologram corresponding to the same two-dimensional image is recorded in a plurality of recording areas 44a, 44b, 44c, and 44d arranged adjacent to each other. Can also. In the example shown in FIG. 6, 300 recording areas 28 are provided. For example, if one side of a card-shaped optical recording medium having the size of a business card is effectively used, the size of one recording area 28 is 250 μm, which is the same as the above. More than 1000 corners can be provided.

Returning to FIG. 8, when the recording on the primary recording medium 20 is completed, the primary recording medium 20 is removed from the stepper 22, and a known optical recording medium (optical disk) manufacturing process 24 is performed.
, A prepaid card 26 as a final product can be obtained. FIG. 10 is a diagram showing an example of an optical disk manufacturing process including the irradiation of the primary recording medium 20 with the electron beam 34 by the electron beam exposure device 18 and the subsequent etching process, plating process, and the like. The process proceeds with.
In FIG. 10, reference numeral 36 denotes a metal plating layer formed on the uneven surface formed on the photoresist 32. The substrate 30 is removed from the state shown in e, and is attached to the press member 38 as a stamper 36A as shown in f. . Reference numeral 40 denotes a PC resin constituting the optical recording medium main body 40A, which is injected from the press base 42 in a molten state, and is formed by a pressing process in which the press member 38 relatively approaches the press base 42 as shown in g. Thus, irregularities corresponding to the irregularities of the stamper 36A are formed. Thereafter, a reflective film region 29 is provided corresponding to each of the recording areas 28, and then a protective layer 31 is formed on the reflective film region (including the reflective film region 29 and the same level portion such as an intermediate portion thereof). Will be applied. In the case of this embodiment, each area 29 of the reflection film has a recording area of 250.
Since it is a μm square, it is set to a larger size. As the reflection film, for example, an aluminum film can be provided by sputtering.

In the examples shown in FIGS. 6 and 7, the reflective films are provided corresponding to the respective recording areas 28, but need not necessarily correspond one to one. For example, a plurality of recording areas 28 are grouped. , Recording area 2 of this group
It is sufficient that a single reflective film region corresponding to 8 is provided collectively, and as a result, a plurality of reflective film regions are provided independently without being continuous. In addition, stamper 3
6A may not be manufactured directly from the step e in FIG. 10, but a master disk may be manufactured first, and then a plurality of stampers 36A may be manufactured. If a large number of optical recording media are manufactured, the plurality of stampers 36A may be manufactured. Need to be manufactured.

The primary recording medium 20 is processed as a photomask master, a plurality of secondary recording media are produced from the primary recording medium by light exposure from the photomask master, and an optical disk is formed by using the secondary recording medium as the master. It is also possible to manufacture an optical recording medium 26 as a final product through a manufacturing process. FIG. 11 is a diagram showing a manufacturing process using such a photomask master in the order of A to J. According to the method shown in FIG. 11, since the number of exposure steps is increased as compared with the method shown in FIG. 10, the accuracy is slightly lowered, but the method is suitable for copying a large number of secondary masters. FIG. 12 shows another example of a manufacturing process of an optical recording medium using a silicon wafer as a primary master substrate.

The optical recording medium of the present invention has the structure shown in FIG.
The information is read by a predetermined reader shown in FIG. 24, FIG. 25, and the like. At this time, when the prepaid card 26 is sent in a predetermined direction, and a laser beam or the like as a reference light, which is a coherent light beam, is irradiated on the recording area 28, the recorded original two-dimensional image is projected. That is, when the character “A” shown in FIG. 9 is recorded,
Since this dot pattern is projected at a predetermined position, the original character information can be reproduced by imaging and decoding the image with an image pickup means such as a CCD image pickup device.

In the above description, the case where a character signal is inputted to the input terminal IN1 of FIG.
May be given an image signal. In this case, the image signal is supplied to the numerical operation device 14 via the switch 12, and the numerical operation is executed in the same manner as described above, so that the data of the interference pattern of the hologram is obtained. By irradiating the prepaid card 26 with a laser beam or the like, the original image can be reproduced. Images to be recorded include logos, barcodes,
Information specifying the owner or issuer of the card, for example, a fingerprint, voiceprint, face photograph, or information indicating that the card is genuine can be recorded.

As shown in FIG. 6, by making each region 29 of the reflection film independent and not continuous with the region 29 of another reflection film adjacent thereto, the following counterfeiting effect is obtained. That is, assuming that the reflection film is a single continuous film and covers the entire two-dimensional area of the optical recording medium 26 in FIG. 6, a counterfeiter who seeks fraud first obtains a genuine prepaid card, This is immersed in a sodium hydroxide solution and left for a while. As a result, the reflection film of aluminum or the like exposed on the side surface of the medium melts, and the entire reflection film melts and disappears, so that the protective layer 31 and the substrate 27 having the recording layer can be separated from each other.

Since the hologram in the recording area is formed by injection molding on the substrate, interference fringes of the hologram are exposed, and it is possible to forge a stamper by applying Ni sputtering or Ni plating. Can be used to forge a prepaid card. According to the configuration shown in FIG. 6, each region 29 of the reflection film is not continuous with the region 29 of the adjacent reflection film but is independent, so that even if immersed in caustic soda, most of the region 29 of the reflection film is exposed. As it does not melt, it does not melt, and the protective layer 3
Except for the recording area 28, 1 is closely adhered or adhered to the substrate 27, so that the protective layer 31 cannot be separated from the substrate 27. In order to make it more difficult to separate the protective layer 31 from the substrate 27, when selecting the material of the protective layer 31 and the substrate 27, it is necessary to select a material having a property that both are closely adhered or adhered. preferable.

Next, a third embodiment of the present invention will be described. FIG. 14 is a plan view of a third embodiment of the optical recording medium of the present invention as viewed from the substrate 27 side. The third embodiment differs from the second embodiment in the following points. That is, not only are the respective areas 29 of the reflection film provided on the recording area 28, but also the areas 29A, 29B, 29C, 29D,
9E is provided. The area of the reflection film is also provided by sputtering a metal such as aluminum. The area of the reflective film can be visually determined such as numbers and characters as shown in an area 29D.
_A fine pattern can be formed using a high-power laser beam such as a _two laser or a YAG laser. When displaying numbers or characters, the expiration date of the prepaid card and other use restriction information can be described, and when forming a fine pattern, special figures and patterns etc. should be described This facilitates visual judgment of the forged medium and the authentic medium.

In the optical recording media of the second and third embodiments, as is apparent from the sectional view of FIG. 7, each region 29 of the reflection film is provided between the recording area 28 of the substrate 27 and the protective layer 31. Have been. However, if the reflection film is extremely thin and is formed in close contact with the recording area 28, the hologram unevenness appears on the reflection film itself. In this case, to read the information of the hologram, both a method of irradiating a light beam from the protective layer 31 side and reading the reflected light and a method of irradiating the light beam from the substrate 27 side and reading the reflected light are used. It becomes possible. However, in order to deal with unauthorized use, Fig. 1
As shown in FIG. 5, it is necessary to irradiate a light beam not from the protective layer 31 side but from the substrate 27 side and read the reflected light. Hereinafter, this point will be described.

FIG. 15 schematically shows a state in which hologram information is read by a reader.
The laser beam emitted from 5 is a lens 46, a half mirror 4
7, a recording area 28 and a reflection film area 2 behind the recording area 28
9, the reflected light is received by an image sensor 48 such as a CCD, and is recognized as a two-dimensional image. Generally, information is read from an optical recording medium in a transmission type or a reflection type depending on a method of detecting a light beam. Now, assuming that there is a prepaid card using a transmission type hologram, the possibility of unauthorized use will be examined. . FIG. 16 shows a normal transmission type reproduction system.
It is conceivable that a thin dummy sheet 35 is stuck on top of this to bring about the state shown in FIG.

The prepaid card is charged for its use by reducing the balance by physically destroying the recorded portion of the predetermined amount information. In the optical recording medium according to the present invention, the recording area 28 where the hologram is recorded
Will be destroyed. As a method of physically destroying the recorded portion of the amount information, as shown in FIGS.
Examples include thermal destruction by a thermal head, destruction by a laser beam, destruction by mechanical deformation by a dot impact head, penetration or drilling destruction by a drill bit, and punching destruction by pressing a punch into a die. Among these, destruction by a laser beam (FIG. 19), penetration or punching destruction by a drill bit (FIG. 21), and punching destruction by pressing a punch into a die (FIG. 22) are effective, but destruction by a laser beam is high. However, it is necessary and expensive, and it is not very practical to perform a piercing or punching breakage by a drill bit or a punching breakage by pressing a punch into a die. Thus, thermal destruction by a thermal head (FIG. 18) or destruction by mechanical deformation by a dot impact head (FIG. 20) is practical.

Now, thermal destruction by the thermal head (FIG. 1)
8) Or, assuming that the destruction by mechanical deformation by the dot impact head (FIG. 20) is adopted, FIG.
It is assumed that a transmission type prepaid card to which the dummy sheet 35 of No. 7 is attached is used. In this case, the data of the hologram is accurately read by the image sensor 48 and used as a genuine prepaid card. Then, at the time of charging, the stage of thermal destruction or mechanical destruction occurs. Since the pressure is applied, the destruction due to thermal or mechanical deformation stops at the dummy sheet 35,
It does not extend to the recording area 28 where the hologram is recorded. At this stage of the destruction, whether or not the destruction has been normally performed is determined by using an image obtained by the image sensor 48. However, since the dummy sheet 35 has undergone thermal or mechanical deformation, this portion is not opaque. At 35 A, a normal two-dimensional pattern cannot be obtained, and it is recognized that the hologram has been destroyed. Therefore, the unauthorized user peels off the broken dummy sheet 35 and attaches a new dummy sheet to the recording area 2 where the hologram is recorded.
8, the prepaid card 26 can be used illegally and repeatedly over and over again.

Although the example of FIG. 17 is of the transmission type, even in the case of the reflection type, the reflection film is arranged on the recording medium side, that is, on the side opposite to the protective layer from the recording area 28, and the hologram is formed from the protective layer side. When trying to read data, a dummy sheet 35 is similarly stuck on the protective layer, so that the recording area 2
The dummy sheet 35 is destroyed in place of the destruction of 8, and it is recognized that the recording area 28 is destroyed.

Therefore, in the present invention, the reflection type is adopted, and the region 29 of the reflection film is formed by the recording layer and the protective layer 3 of the substrate 27.
1, a light beam is irradiated from the substrate 27 side instead of the protective layer 31 side, and the reflected light is applied to the substrate 2 side.
It is configured to take out only from the 7 side. When an unauthorized user attaches a dummy sheet 35 on the protective layer 31 to a prepaid card having such a configuration, the dummy sheet 3
5 is thermally or mechanically damaged, and the recording area 28 in which the hologram is recorded can be prevented from being destroyed. However, since the hologram is detected from the substrate 27 side, the hologram is normally detected even after the dummy sheet 35 is destroyed. Such a two-dimensional pattern is obtained by the image pickup device 48, and therefore, it is not recognized that the destruction of the recording area 28 has been completed, and it is possible to perform processing such as improper use as an unauthorized prepaid card.

Next, a fourth embodiment of the optical recording medium of the present invention will be described. In each of the embodiments described so far, the recording area 28 is entirely provided with the reflective film region 29, and the optical recording medium is a completely reflective type. 4th
In the embodiment, as shown in FIG.
Are not provided with the reflective film area 29, and some of the recording areas 28A of the plurality of recording areas 28 are not provided with the reflective film area and are of a transmission type. In other words,
The configuration is a combination of a reflection type and a transmission type. Although only one row of the recording area 28 is shown in FIG. 23, it can be configured as a plurality of rows as in FIG. Also, as shown in FIG. 14, a region of the reflective film having a predetermined pattern can be provided in a region where the recording area 28 is not provided.

FIGS. 24 and 25 are diagrams schematically showing a configuration for reading hologram data from the optical recording medium 26A of the fourth embodiment shown in FIG. 24 and 2
In FIG. 5, the optical recording medium 26A is shown in a cross-sectional view. However, as for the portion where the reflection film is provided, the reflection film region 29 is the same as the recording layer of the substrate 27 as in the second and third embodiments. It is provided between the protective layers 31.

FIG. 24 shows a method for reading recorded data from a recording area 28 provided with a reflective film area 29. In FIG. To read data, a light beam from a laser diode 45 on the substrate 27 is irradiated onto the recording area 28 from the substrate 27 side of the prepaid card 26 via a lens 46 and a half mirror 47,
Light reflected from the recording area 28 and the area 29 of the reflective film behind the recording area 28 is received by the image sensor 48. FIG. 25 shows a method for reading recording data from a recording area 28A in which the reflection film area 29 is not provided. FIG.
From the state, the prepaid card 26 is moved in the left-right direction in the figure to control the recording area 28A to be at the reading position. To read data, the recording layer 28A is irradiated from the protection layer 31 side of the prepaid card 26 via the lens 51 with a light beam from the laser diode 50 on the protection layer 31 side, and the transmitted light transmitted through the recording area 28A is captured by the image sensor. 4
At 8, light is received.

The fourth embodiment has the following features as compared with the second and third embodiments, because the reflection type and the transmission type recording areas are mixed. That is, the configuration of the reading device is slightly complicated because it has a reflective type and a transmissive type, but the resin of the protective layer 31 has the irregularities of the hologram directly because the transmissive type portion is not provided with the reflective film. Since it has entered the recording area 28A and the resin is intricately hardened in the fine striped pattern, the person who intends to forge removes the protective layer by any method and tries to copy the hologram pattern. It is difficult to remove the resin of the protective layer that has entered the fine irregularities, and it is more difficult to forge than the second and third embodiments. In addition,
The unevenness of the hologram is determined by the wavelength of the light to be used and the like, but the difference in the height is originally twice as large depending on the transmission type or the reflection type. Therefore, the transmissive recording area 28
The step at A may be changed from the reflection type. On the other hand, if this allowance is not made, and if the transmission type has the same level difference as the reflection type, the efficiency of the diffracted light is reduced in the transmission type, so that the threshold of reading the output signal of the image sensor 48 is lowered, and the transmission type is reduced. This can be dealt with by improving the sensitivity of the part.

In each of the above embodiments, at least two or more reflective film regions 29 are provided, and they are not continuous and independent, so that the reflective film can be easily dissolved even when immersed in a caustic soda solution. However, even if there is a single reflective film, if the end is not exposed to the outside on the side surface or other places of the optical recording medium, it can be easily reflected even if immersed in a caustic soda solution. The film does not melt. Therefore, as a simple configuration for preventing forgery of the optical recording medium, a protective layer 31 is provided so that the reflection film is not exposed to the outside.
And the substrate 27 can be configured to be in close contact with the entire circumference of the optical recording medium.

In the above embodiment, the combination codes 1 and 0
Although the erasure / non-erasure portion of the hologram pattern is provided corresponding to the above, it can be used in combination with the above-mentioned Burger code. That is, the combination code and the Burger code can be selectively used for each item to be recorded. In the Burger code, when the main information is represented by information bits of binary codes of 0 and 1, a check bit in which the number of 0 bits in the information bits is represented by a binary code together with the information bits is 1 and 0 or the same. Conversely, the optical recording medium is formed so as to correspond to the recording portion (non-erasing) 2A and the erasing portion 2B of the hologram pattern.

[0053]

As described above, according to the present invention, predetermined information is recorded as a hologram pattern by an electron beam, and thereafter, the information to be recorded is changed to a combination code 1 or 0 or vice versa. Since an optical recording medium having a hologram pattern recording part and an erasing part is manufactured so as to correspond to the erasing part and the erasing part, when compared with drawing by a laser beam used for manufacturing a conventional optical recording medium, It is possible to draw an extremely delicate and precise pattern, and it is extremely costly to duplicate this to produce a counterfeit product, so it is difficult to actually produce the duplicate and to tamper with it. Then, the number is changed to 0, and the falsification is easily found. Further, even if the card is stolen and falsified at a certain time, it is not possible to return to the previous process, so that it is possible to identify at which time the fraud has occurred. Before recording each process, check the hologram image for a fake card or a legitimate card,
In addition, since the recording can be performed after checking whether the card is a falsified card or a legitimate card, the inspection for fraud can be strict. Further, the reflection film has a plurality of areas facing each or a plurality of recording areas, and is arranged so as to cover the entire two-dimensional image area of each recording area, and each area of the reflection film is formed of an adjacent reflection film. If a structure in which the protective layer and the substrate are in close contact with each other over the entire circumference of the optical recording medium so as to be independent and not continuous with the region or to prevent the reflection film from being exposed to the outside, the reflection film is dissolved to form the hologram. It is difficult to forge by exposing the uneven surface. Even if it can be forged, the same production number (PS
Since only N) can be manufactured, fraud can be easily found.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of an optical recording medium according to the present invention.

FIG. 2 is an explanatory diagram of two examples of combination codes used in the present invention.

FIG. 3 is a cross-sectional view of an optical recording medium showing a state of non-erasing and erasing of a hologram pattern when writing information according to the present invention.

FIG. 4 is a perspective view showing an apparatus for reading a hologram pattern from an optical recording medium according to the present invention.

FIG. 5 is a flowchart showing a process from manufacture to use of the optical recording medium according to the present invention.

FIG. 6 is a plan view of an optical recording medium according to a second embodiment of the present invention as viewed from the substrate side.

7 is a cross-sectional view of the optical recording medium of FIG. 6, taken along the line II-II.

FIG. 8 is a block diagram schematically showing an example of a process for manufacturing an optical recording medium according to the present invention.

FIG. 9 is a diagram showing a procedure for obtaining an interference fringe pattern of a hologram from a two-dimensional image.

FIG. 10 is a cross-sectional view illustrating an example of a manufacturing process of the optical recording medium according to the present invention.

FIG. 11 is a sectional view showing another example of the manufacturing process of the optical recording medium according to the present invention.

FIG. 12 is a cross-sectional view showing another example of the manufacturing process of the optical recording medium according to the present invention.

FIG. 13 is a diagram showing another configuration of the recording area of the optical recording medium according to the present invention.

FIG. 14 is a plan view of a third embodiment of the optical recording medium according to the present invention as viewed from the substrate side.

FIG. 15 is a diagram showing a configuration for reading recorded data from an optical recording medium according to the second and third embodiments of the present invention.

FIG. 16 is a diagram showing a normal transmission type reproducing system for reading data from a transmission type optical recording medium.

FIG. 17 is a diagram showing a normal transmission type reproducing system for reading data from a transmission type optical recording medium in which a thin dummy sheet is stuck on a protective layer by an unauthorized user.

FIG. 18 is a schematic diagram showing thermal destruction by a thermal head.

FIG. 19 is a schematic view showing destruction by a laser beam.

FIG. 20 is a schematic diagram showing destruction by mechanical deformation by a dot impact head.

FIG. 21 is a schematic view showing penetration or drilling breakage by a drill bit.

FIG. 22 is a schematic view showing punching destruction for pressing a punch into a die.

FIG. 23 is a plan view of an optical recording medium according to a fourth embodiment of the present invention, as viewed from the substrate side.

FIG. 24 is a schematic diagram illustrating a configuration for reading data from a reflective recording area according to a fourth embodiment.

FIG. 25 is a schematic diagram showing a configuration for reading data from a transmission type recording area in a fourth embodiment.

[Explanation of symbols]

1, 26, 26A Optical recording medium 2 Hologram pattern 2A Non-erased part of hologram pattern (recording part) 2B Hologram pattern erasing part 3 Thermal head (erasing means) 4 Laser diode (means for irradiating laser beam) 5 Image sensor (Means for Detecting Hologram Pattern) 6 Image of Hologram Pattern 10 Image Signaling Circuit 12 Switch 14 Numerical Operation Unit 16 Encoder 18 Electron Beam Exposure Device 20 Primary Recording Medium 22 Stepper 24 Optical Recording Medium (Optical Disk) Manufacturing Process 27 Substrate 28 , 28A, 44a, 44b, 44c, 44d Recording area 29, 29A, 29B, 29C, 29D, 29E Area of reflective film 30 Substrate 31 Protective layer 32 Photoresist (medium to be exposed) 34 Electron beam 36 Metal plating layer 36A Stamper 38 Les member 40 PC resin 40A optical recording medium body 42 press base 45, 50 laser diodes 46 and 51 the lens 47 a half mirror 48 imaging element IN1, IN2 input terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2K008 AA13 BB08 CC01 CC03 DD03 EE04 GG05 HH01 HH28 5B072 BB00 CC35 5D090 AA03 BB03 CC06 CC14 DD01 EE20 GG11

Claims (6)

[Claims] 1. A hologram pattern recording section and erasing section, wherein 0 and 1 or the opposite of a combination code composed of binary codes of 0 and 1 representing information to be recorded correspond to the recording section and the erasing section, respectively.
An optical recording medium on which a hologram pattern recording section and an erasing section are provided and recorded. 2. Information to be recorded is recorded on an optical recording medium in which a plurality of hologram patterns are arranged in advance.
In order to record as a combination code consisting of binary codes of 1 and 1, the hologram pattern corresponding to 0 or 1 of the combination code is left as it is in the recording section of the hologram pattern, and the hologram pattern corresponding to 1 or 0 is left as it is. An optical recording medium writing device having a means for erasing an image. 3. An optical recording medium capable of arranging and recording a hologram pattern, means for recording the hologram pattern, and recording information to be recorded as a combination code consisting of binary codes of 0 and 1. Means for erasing the hologram pattern corresponding to 1 or 0 while leaving the hologram pattern corresponding to 0 or 1 of the combination code as it is. 4. A means for selectively erasing a hologram pattern recorded in advance according to a binary code of 0 or 1 as a combination code and irradiating a laser beam to an optical recording medium on which the binary code has been recorded. Means for detecting a hologram pattern reproduced by the irradiated laser beam; and means for generating a binary code according to the presence or absence of the hologram pattern in accordance with an output signal of the means for detecting. Recording medium reader. 5. The binary code generated by said means for generating a binary code is analyzed, and the number of information bits 0 or 1 is the same for all information, or at least the same for information of the same type. 5. The optical recording medium reading device according to claim 4, further comprising a determination unit that determines whether or not there is a recording medium. 6. An optical recording medium having a substrate and a plurality of recording areas, a reflective film, and a protective layer on a recording layer formed on the substrate, wherein each of the recording areas corresponds to a two-dimensional image to be recorded. When the main information is represented by information bits of binary codes of 0 and 1 for a copy of a hologram obtained by drawing interference fringes of the hologram with an electron beam, 0 and 1 representing information to be recorded, A hologram pattern recording section and an erasing section are provided and recorded such that 0 and 1 or the reverse of a combination code composed of hexadecimal codes correspond to the recording section and the erasing section of the hologram pattern; Has a region facing the plurality of recording areas, and is located between the protective layer and the substrate so that the reflective film is not exposed to the outside, and the protective layer and the substrate are the optical recording medium. All around the media Optical recording medium, characterized in that in close contact.