JP2010113786A - Optical information recording medium, recording apparatus and recording method, reproducing apparatus and reproducing method, counterfeiting preventing system, authorizing terminal, and information reproducing terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an optical information recording medium in which recording capacity is increased and both of main data and sub-data are recorded; a recording apparatus which can record the sub-data; a counterfeiting preventing system which can prevent counterfeiting of the main data; and an authorizing terminal which can record code information. <P>SOLUTION: An absorption change area RA is formed according to a recording light beam L1a using a recording material such as a photochromic material in which two-photon absorption reaction is caused, and the absorption change area RA and a refractive index modulation area RB are combined as a recording mark RM using characteristics of the optical information recording medium which forms the refractive index modulation area RB according to a recording light beam L1b, thereby recording both of the main data and the sub-data in the optical information recording medium as the recording mark RM. Further, a code generating section is provided which generates the code information as the sub-data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical information recording medium, a recording apparatus and a recording method, a reproducing apparatus and a reproducing method, an anti-counterfeit system, an approval terminal, and an information reproducing terminal. For example, information is applied to a recording optical information recording medium by irradiation with a light beam. Is preferred.

  Conventionally, as an optical information recording medium, a disc-shaped optical disk is widely used as an optical information recording medium. As an optical disk, a CD (Compact Disc), a DVD (Digital Versatile Disc), and a Blu-ray Disc (registered trademark) are generally used. (Hereinafter referred to as BD).

  Generally, in these conventional optical discs, main data as recording information is recorded as recording marks on a signal recording surface that reflects a light beam by forming irregularities or changing reflectance. . Some of these optical disc apparatuses are designed to record sub-data as encryption information by superimposing code marks with different reflectivities on recording tracks on which recording marks are formed. (For example, refer to Patent Document 1).

  By the way, in an optical disc apparatus for recording or reproducing an optical disc, various kinds of information such as various contents such as music contents and video contents or various data for computers are recorded on the optical disc. In particular, in recent years, the amount of information has increased due to higher definition of video and higher sound quality of music, and an increase in the number of contents to be recorded on one optical disc has been demanded. It has been demanded.

Therefore, as one of the techniques for increasing the capacity of the optical information recording medium, using a material that forms a recording mark by two-photon absorption, using a laser light source with a high peak power, in the thickness direction of the optical information recording medium, An optical information recording medium designed to record information three-dimensionally has been proposed (see, for example, Patent Document 2).
Japanese Patent No. 354410 JP-A-2005-37658

  By the way, in the optical disc apparatus described in Patent Document 2, a method for recording or reproducing only main data has been proposed, but both a method for recording sub data as in a conventional optical disc apparatus, and both main data and sub data. No method has been proposed for reproducing main data from an optical information recording medium on which is recorded.

  The present invention has been made in consideration of the above points. An optical information recording medium on which both main data and sub data are recorded, a recording apparatus and a recording method capable of recording sub data, main data and sub data. Can reproduce main data from an optical information recording medium on which both are recorded, a reproduction method, a forgery prevention system capable of suppressing forgery of main data in the optical information recording medium, and encryption information can be recorded It is an object of the present invention to propose an information reproducing terminal capable of reproducing recorded information from an optical information recording medium on which both an approved terminal and recorded information and encrypted information are recorded.

  In order to solve such a problem, in the optical information recording medium of the present invention, main data is recorded as an absorption change region in which the optical absorptance changes from the surroundings and a refractive index modulation region in which the refractive index is modulated from the absorption change region, A recording layer in which sub-data different from the main data is recorded is provided as the refractive index modulation region.

  Thereby, in the optical information recording medium, it is possible to superimpose and record the sub data on the main data.

  Further, in the recording apparatus and the recording method of the present invention, the superposed recording light is emitted and recorded on the optical information recording medium, and the absorption change region in which the optical absorptance with respect to the superposed recording light is changed from the surroundings is detected. According to the sub data different from the main data to be represented and the detection result by the detection unit, the superimposed recording light is emitted to the absorption change area so as to emit a part of the absorption change area. .

  Thereby, in the recording apparatus and the recording method, the sub data can be superimposed and recorded on the main data.

  Furthermore, in the reproducing apparatus and the reproducing method of the present invention, a light source that emits readout light, an absorption change region in which the optical absorptance changes from the surroundings, and a refractive index modulation region in which the refractive index is modulated from the absorption change region are formed. A light irradiating unit that irradiates the optical information recording medium with the reading light, a light receiving unit that receives the modulated light obtained by modulating the reading light by the absorption change region and the refractive index modulation region, and an absorption change based on the modulated light. And a reproducing unit that reproduces main data represented by both the region and the refractive index modulation region.

  Thereby, in the reproducing apparatus and the reproducing method, the main data can be reproduced from the optical information recording medium on which the sub data is superimposed and recorded on the main data.

  Further, in the forgery prevention system according to the present invention, an encryption information generating unit that generates encryption information, and recording light is irradiated onto an absorption change area that represents the recording information in the optical information recording medium and the light absorption rate has changed from the surroundings. By forming a refractive index modulation region in which the refractive index is modulated from the region, a cryptographic information superimposing unit that superimposes the cryptographic information on the absorption change region, and a key information generating unit that generates key information corresponding to the cryptographic information A key information acquisition unit for acquiring key information, and reproducing the recorded information when the cryptographic information recorded in the optical information recording medium on which the cryptographic information is superimposed corresponds to the key information. On the other hand, when the encryption information does not correspond to the key information, an information reproducing terminal including a reproducing unit that does not reproduce the recorded information is provided.

  Thereby, in the forgery prevention system, the recorded information can be reproduced only when the encryption information and the key information match, and the forgery of the optical information recording medium is suppressed by improving the forgery of the optical information recording medium. be able to.

  Further, in the approval terminal of the present invention, an encryption information generating unit that generates encryption information, and recording light is irradiated onto an absorption change area where the optical absorptance changes from the surroundings and represents the recording information in the optical information recording medium, and the absorption change area Forming a refractive index modulation region in which the refractive index is modulated from the encryption information superimposing unit for superimposing the cryptographic information on the absorption change region, and a key information generating unit for generating key information corresponding to the cryptographic information, It was made to provide.

  As a result, the approval terminal can record the encrypted information superimposed on the recorded information.

  Furthermore, in the information reproducing terminal of the present invention, the recording light is recorded on the optical information recording medium and the recording light is irradiated onto the absorption change region where the light absorption rate is changed from the surroundings, and the refractive index is modulated from the absorption change region. A key information acquisition unit that acquires key information corresponding to the encrypted information superimposed by forming the rate modulation area, and the encrypted information recorded in the optical information recording medium on which the encrypted information is superimposed corresponds to the key information. In this case, the recorded information is reproduced, and when the encrypted information does not correspond to the key information, a reproducing unit that does not reproduce the recorded information is provided.

  As a result, the information reproducing terminal can reproduce the recorded information from the optical information recording medium on which the encrypted information is superimposed and recorded on the recorded information.

  According to the present invention, it is possible to superimpose and record sub data on main data, and thus an optical information recording medium on which both main data and sub data are recorded, and a recording apparatus capable of recording sub data. And a recording method can be realized.

  Further, according to the present invention, the main data can be reproduced from the optical information recording medium in which the sub data is superimposed on the main data, and thus both the main data and the sub data are recorded. A reproducing apparatus and a reproducing method capable of reproducing main data from a medium can be realized.

  Furthermore, according to the present invention, the recorded information can be reproduced only when the encryption information and the key information match, and the forgery of the optical information recording medium is suppressed by improving the forgery of the optical information recording medium. Thus, it is possible to realize a forgery prevention system that can suppress forgery of recorded information in an optical information recording medium.

  Further, according to the present invention, it is possible to realize the approval terminal capable of recording the encryption information superimposed on the recording information, and thus recording the encryption information.

  Furthermore, according to the present invention, the recorded information can be reproduced from the optical information recording medium in which the encrypted information is superimposed on the recorded information, and thus both the recorded information and the encrypted information are recorded. An information reproducing terminal capable of reproducing recorded information from a medium can be realized.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(1) Principle Generally, assuming that the numerical aperture of the objective lens is NA and the wavelength of the light beam is λ, the spot diameter d when the light beam is condensed is expressed by the following equation.

  That is, when the same objective lens is used, since the numerical aperture NA is constant, the spot diameter d is proportional to the wavelength λ of the light beam.

  As shown in FIG. 1, the intensity of the collected light beam is greatest near the focal point Fb and decreases as the distance from the focal point Fb increases. For example, in the case of a general optical information recording medium that forms a recording mark RM whose refractive index is modulated, for example, by one-photon absorption, a photoreaction occurs by absorbing one photon, and therefore is proportional to the light intensity. Photoreaction occurs. For this reason, in the optical information recording medium, the recording mark RM is formed in a region having a predetermined intensity or more in the recording light beam L1. FIG. 1 shows a case where a recording mark RM having the same size as the spot diameter d is formed.

  In contrast, in the case of two-photon absorption, a reaction occurs only when two photons are absorbed at the same time. Therefore, a two-photon absorption reaction occurs in proportion to the square of the light intensity. Therefore, in the optical information recording medium 100 according to the present embodiment, as shown in FIG. 2, the refractive index modulation region RB as the recording mark RM is formed only in the vicinity of the focal point Fb having a very high light intensity in the recording light beam L1. The

  The refractive index modulation region RB has a smaller size than the spot diameter d of the recording light beam L1, and its diameter da is also reduced. Therefore, in the optical information recording medium 100, the recording capacity can be increased by forming the recording marks RM at a high density.

By the way, among the two-photon absorption materials, there are known compounds that cause a chemical change by a two-photon absorption reaction and change the light absorption characteristics (hereinafter referred to as a light characteristic change material) (for example, non-patent). Reference 1).
A. Toriumi and S. Kawata, Opt.Lett / Vol. 23, No.24, 1998, 1924-1926

  In this optical characteristic changing material, for example, as shown in the light emission waveform WL of FIG. 3A, when a recording light beam L1 having a wavelength that is not originally absorbed is irradiated with a large light intensity over a certain irradiation time, FIG. As shown in (B), the light absorption of the light characteristic changing material is changed by the two-photon absorption reaction, and an absorption change region RA smaller than the spot P by the recording light beam L1 is formed. In the absorption change region RA, the recording light beam L1 is absorbed and heat is generated due to the change in the light absorption of the optical property changing material. The arrow in the light emission waveform WL represents the time point in the upper diagram showing the state of irradiation of the recording light beam L1.

  That is, as shown in FIG. 3C, the two-photon characteristic changing material absorbs the recording light beam L1 by being continuously irradiated with the recording light beam L1, and generates heat, and the refractive index modulation by the thermal reaction or the like. By forming the cavity, the refractive index modulation region RB as the recording mark RM can be formed.

  In the present invention, as shown in the light emission waveform WL of FIG. 4B, the recording light beam L1a having a very high light intensity is irradiated for a short time, whereby the absorption change region RA ( FIG. 4A is formed.

  In the absorption change area RA, when the reading light beam L2 for information reproduction is irradiated, the reading light beam L2 is absorbed and passed through the optical information recording medium as shown in FIG. 4C. The amount of light of the beam L2 (hereinafter referred to as the transmitted light beam L3) is reduced.

  Therefore, the optical reproducing apparatus irradiates the optical information recording medium with the reading light beam L2, generates a reproduction signal SRF corresponding to the change in the light amount of the transmitted light beam L3, and determines whether there is an absorption change region RA from the reproduction signal SRF. Information can be reproduced by detecting. In other words, the optical information recording medium can record information by forming the absorption change region RA as the recording mark RM.

  Further, as shown in FIG. 5, in the absorption change region RA, as shown in the light emission waveform WL of FIG. 5B, the recording light beam L1b having a relatively large light intensity is irradiated for a predetermined irradiation time. Thus, the refractive index modulation region RB (FIG. 5A) is changed by a thermal reaction. Therefore, in the refractive index modulation region RB, when the readout light beam L2 for information reproduction is irradiated, the readout light beam L2 is reflected by the difference in refractive index from the surroundings, and the light amount of the transmitted light beam L3 is reduced. Become.

  Therefore, the optical reproducing apparatus irradiates the optical information recording medium with the reading light beam L2, generates a reproduction signal SRF corresponding to the change in the light amount of the transmitted light beam L3, and generates the reproduction signal SRF from the reproduction signal SRF. Information can be reproduced by detecting the presence or absence. In other words, the optical information recording medium can record information by forming the refractive index modulation region RB as the recording mark RM.

  That is, in the present invention, as shown in FIGS. 6A and 6B, for example, main data is recorded in advance on the optical information recording medium as the absorption change area RA. In the present invention, as shown in FIG. 6C, by forming the refractive index modulation region RB in a part of the absorption change region RA, the sub data can be recorded so as to be superimposed on the main data. ing.

(2) Configuration of Anti-Counterfeit System As shown in FIG. 7, the anti-counterfeit system according to the present embodiment is assumed to be used for storing, for example, in-house documents. That is, in the forgery prevention system, the information recording terminal 2 records recording information RI such as a document to be recorded on the optical information recording medium 100 as main data. This corresponds to the case where a document creator or the like records a document on the optical information recording medium 100.

  In the forgery prevention system, the approval terminal 3 records the encryption information CI indicating that the record information RI is approved as sub data. This corresponds to the case where a document approver such as a general manager or officer approves a document.

  Specifically, in the forgery prevention system, first, the recording information RI is recorded on the optical information recording medium 100 by the information recording terminal 2. At this time, the information recording terminal 2 records the recording information RI on the optical information recording medium 100 by forming the absorption change region RA by a two-photon absorption reaction. A unique identification number is added to the optical information recording medium 100, and the identification number is recorded on the optical information recording medium 100.

  Next, in the forgery prevention system, the encryption information CI is recorded on the optical information recording medium 100 by the approval terminal 3. As a result, the optical information recording medium 100 on which the record information RI is recorded is approved as having the official record information RI recorded thereon.

  At this time, the approval terminal 3 records the encryption information CI on the optical information recording medium 100 by changing a part of the absorption change region RA to the refractive index modulation region RB by a thermal reaction. Furthermore, the approval terminal 3 generates key information KI corresponding to the encryption information CI. The key information KI is stored separately from the optical information recording medium 100 in a state associated with the identification number of the optical information recording medium 100.

  The encryption information CI is generated based on, for example, the date and time when the approval terminal 3 records the encryption information CI, the identification number ID of the approval terminal 3, and the like, and the same pattern cannot be generated. . That is, even in the optical information recording medium 100 in which the same recording information RI is recorded, different encryption information CI is recorded when it is approved by different approval terminals 3a and 3b.

  As shown in FIG. 8, in the forgery prevention system, the information reproduction terminal 4 reproduces the recorded information RI recorded using the optical information recording medium 100 and the key information KI associated with the optical information recording medium 100. To do.

  At this time, the information reproducing terminal 4 can reproduce the recorded information RI when the encryption information CI and the key information KI recorded in the optical information recording medium 100 correspond to each other. On the other hand, the information reproducing terminal 4 cannot reproduce the recorded information RI when the encryption information CI recorded on the optical information recording medium 100 does not correspond to the key information KI.

  That is, in the forgery prevention system, it is possible to determine whether or not the optical information recording medium 100 is authorized and valid depending on whether or not the key information KI and the encryption information CI correspond to each other.

  Accordingly, in the forgery prevention system, for example, when the optical information recording medium 100 is forged and replaced with an approved optical information recording medium 100, the forged optical information recording medium 100 is not approved. Can be detected. As a result, in the forgery prevention system, the forgery of the optical information recording medium 100 can be improved, so that the forgery of the optical information recording medium 100 can be suppressed.

(3) Configuration of Optical Information Recording Medium As shown in FIGS. 9A and 9B, the optical information recording medium 100 has a disc shape as a whole, and is provided with a hole 100H for chucking at the center. It has been. The optical information recording medium 100 functions as a medium for recording information as a whole by forming a recording layer 101 between substrates 102 and 103.

  The substrates 102 and 103 are made of an optical material such as glass or polycarbonate, and transmit light at a high rate. The thicknesses t2 and t3 of the substrates 102 and 103 can be appropriately selected from the range of 0.05 [mm] to 1.2 [mm]. The thicknesses t2 and t3 may be the same or different.

  The recording layer 101 has a characteristic that the light absorption characteristics of the binder resin as a main component are changed by changing the chemical structure due to the two-photon absorption of the recording light beam L1a, and as a result, the recording light beam L1b is absorbed to generate heat. The optical property changing material is dispersed.

  Specifically, as the optical property changing material, a general two-photon absorption material, a photochromic material that changes its chemical structure according to light, or the like can be used. Specifically, as the two-photon absorption material, various organic dyes such as cyanine dyes, merocyanine dyes, arylidene dyes, oxonol dyes, squalium dyes, azo dyes, and phthalocyanine dyes or various inorganic crystals can be used.

As the photochromic material, azobenzenes, spiropyrans, spirooxazines or diarylethenes are preferably used. For example, 1,2-bis (2-methylbenzo [b] thiophen-3-yl described in Non-Patent Document 2 is used. ) perfluorocyclopentene and the like are particularly preferably used.

  As the binder resin, various resin materials having high transmittance with respect to the light beam can be used. For example, a thermoplastic resin that is softened by heat, a photocurable resin that is cured by a crosslinking or polymerization reaction by light, a thermosetting resin that is cured by a crosslinking or polymerization reaction by heat, and the like can be used.

  The resin material is not particularly limited, but PMMA (Polymethylmethacrylate) resin, polycarbonate resin, or the like is preferably used from the viewpoint of weather resistance, light transmittance, and the like. Various additives may be added to the binder resin.

  The recording layer 101 is configured to generate a refractive index modulation according to the heat generation of the optical property changing material. Examples of this refractive index modulation include a local change in refractive index due to a chemical change, and formation of a cavity due to vaporization of the vaporized material contained therein. The recording layer 101 may cause refractive index modulation by further chemical change of the optical property changing material due to thermal reaction, and the refractive index modulation by the chemical change of the binder resin or the additive added to the binder resin. May be generated.

  For example, when a thermoplastic resin is used as the binder resin, the optical property changing material is added to the heated thermoplastic resin and kneaded by a kneader to disperse the optical property changing material in the binder resin.

  Then, after the binder resin in which the optical property changing material is dispersed is spread on the substrate 103 and cooled, the recording layer 101 is manufactured, and then the substrate 102 is bonded to the recording layer 101 using, for example, a UV adhesive. The information recording medium 100 can be manufactured.

  When the thermoplastic resin is diluted with an organic solvent or the like (hereinafter, this thermoplastic resin is called a solvent-diluted resin and is distinguished from a thermoplastic resin that is molded by heating), the optical property changing material is preliminarily used as the organic solvent. Dissolve or disperse the light characteristic changing material in the binder by dissolving or dispersing the solvent diluting resin in the organic solvent or adding the light characteristic changing material to the solvent diluting resin diluted with the organic solvent and stirring. Let

  Then, after the binder resin in which the optical property changing material is dispersed is spread on the substrate 103 and dried by heating, the recording layer 101 is produced, and then the substrate 102 is adhered to the recording layer 101 using, for example, a UV adhesive. The optical information recording medium 100 can be manufactured.

  Further, when a thermosetting resin or a photocurable resin is used as the binder resin, the optical property changing material is dispersed in the binder resin by adding the optical property changing material to the uncured resin material and stirring.

  Then, the binder resin in which the optical property changing material is dispersed is spread on the substrate 103, and the optical information recording medium 100 is obtained by photocuring or thermosetting the uncured recording layer 101 with the substrate 103 placed thereon. Can be produced.

  In the optical information recording medium 100, as described above, both the absorption change region RA due to the two-photon absorption reaction and the refractive index change region RB due to the thermal reaction in the absorption change region RA are formed as the recording mark RM. .

  When the recording layer 101 is irradiated with a recording light beam L1 having a very high light intensity (that is, the recording light beam L1a), the recording layer 101 changes the chemical structure of the optical property changing material by a two-photon absorption reaction. An absorption change region RA that absorbs light having the same wavelength as that of the recording light beam L1 is formed. When the recording layer 101 is irradiated with a recording light beam L1 having a relatively high light intensity (that is, the recording light beam L1b), the refractive index changes according to the heat generation in the absorption changing region RA. Region RB is formed.

  At this time, the optical information recording medium 100 is irradiated with the recording light beams L1a and L1b while being rotated, thereby forming a track TR in which the recording marks RM are arranged on a substantially spiral line or concentric circle.

  The recording marks RM formed in this way are arranged in a plane substantially parallel to each surface such as the first surface 100A of the optical information recording medium 100 (FIG. 9B), and a plurality of recording marks RM are formed. The mark layer Y is formed.

  On the other hand, when reproducing information, the optical information recording medium 100 condenses the reading light beam L2 from the first surface 100A side to the target position PG (that is, the position where the light beam is to be irradiated). Here, when the recording mark RM (either the absorption change region RA or the refractive index modulation region RB) is formed at the position of the focal point FM (that is, the target position PG), the reading light beam L2 is absorbed or recorded by the recording mark RM. The amount of light of the reflected light beam L3 is reflected and reduced.

  The optical information recording medium 100 can detect the presence or absence of the recording mark RM based on the transmitted light beam L3 by detecting the light amount of the transmitted light beam L3.

  Thus, the optical information recording medium 100 forms the absorption change region RA in the portion where the two-photon absorption reaction has occurred, and the refractive index modulation region RB in the portion where both the two-photon absorption reaction and the thermal reaction have occurred. As a result, the optical information recording medium 100 can record two types of information of main data and sub data by the absorption change region RA and the refractive index modulation region RB.

(4) Recording of Main Data by Formation of Absorption Change Region As shown in FIG. 10, the information recording terminal 2 is configured around a system controller 21. The system controller 21 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) in which various programs are stored, and a RAM (Random Access Memory) used as a work memory of the CPU. .

  When recording main data on the optical information recording medium 100, the system controller 21 controls the optical recording device 23 to record information RI as main data on the optical information recording medium 100 loaded in the optical recording device 23. Has been made to record.

  When a recording request for recording main data is supplied in response to a user operation input via an operation unit (not shown), the system controller 21 represents the main data from the data holding unit 22 such as a ROM or a hard disk drive. The recording information RI is read and supplied to the control unit 51 of the optical recording device 23.

  Further, the system controller 21 controls the control unit 51 having a CPU configuration to execute main data recording processing. Specifically, the control unit 51 rotates the spindle motor 55 via the optical drive control unit 52 to rotate the optical information recording medium 100 placed on a turntable (not shown) at a desired speed.

  Further, the control unit 51 drives the sled motor 56 via the drive control unit 52 to move the optical pickup 57 in the radial direction along the movement axes G1 and G2, that is, the inner peripheral side or the outer peripheral side of the optical information recording medium 100. It is made to move greatly in the direction toward.

  Further, when recording information on the optical information recording medium 100, the control unit 51 supplies recording information RI as main data supplied from the data holding unit 22 to the signal processing unit 53. The signal processing unit 53 performs predetermined modulation processing and binarization processing on the recording information RI, so that the recording data Swa that rises and falls according to the cycle of the recording clock Ca (FIGS. 11A and 11B). B)) is generated and supplied to the drive controller 52. The recording clock Ca is generated by a clock generator (not shown).

  The drive controller 52 generates a laser drive current based on the recording data Sw and supplies it to the light source 60 in the optical pickup 57. As a result, the recording light beam L1a (FIG. 11C) modulated according to the information is emitted from the light source 60. Since the recording light beam L1a needs to cause a two-photon absorption reaction, the recording light beam L1a is emitted for a short time with a very high light intensity.

  The control unit 51 controls the optical pickup 57 to irradiate the recording light beam L1a from the optical pickup 57 to the target position PG to which the recording light beam L1a of the optical information recording medium 100 is to be irradiated. An absorption change area RA (FIG. 11D) is formed in 101 to record the record information RI.

  As shown in FIG. 12, the optical pickup 57 emits a recording light beam L1a having a wavelength of, for example, 405 [nm] from the light source 60 under the control of the system controller 21 during the main data recording process, and the recording light beam L1a. Is converted from divergent light into parallel light by a collimator lens 61 and then incident on a beam splitter 62.

  The beam splitter 62 has a reflection / transmission surface 62S that reflects or transmits the light beam at a predetermined ratio. When the recording light beam L1a is incident, the reflection / transmission surface 62S transmits the recording light beam L1a and makes the recording light beam L1a enter the objective lens 63. The objective lens 63 focuses the recording light beam L1a to focus on the target position PG in the optical information recording medium 100, thereby forming an absorption change region RA.

  At this time, in the optical information recording medium 100, an absorption change area RA having a diameter da smaller than the spot diameter d (FIG. 2) of the recording light beam L1a is formed near the focal point Fb of the recording light beam L1a.

  Thus, the optical recording device 23 can record main data as the absorption change area RA on the optical information recording medium 100.

(5) Recording of Sub Data by Forming Refractive Index Modulation Region As shown in FIG. 13, the approval terminal 3 is configured with a system controller 31 as the center. Like the system controller 21, a CPU, ROM, It is comprised by RAM. In FIG. 13, portions corresponding to those of the information recording terminal 2 (FIG. 10) are denoted by the same reference numerals, and description of the same processing is omitted.

  When recording the sub data on the optical information recording medium 100, the system controller 31 controls the optical recording device 33 so that the optical information recording medium 100 loaded in the optical recording device 33 has the cipher information CI as sub data. Record. That is, the system controller 31 detects the absorption change area RA from the recording layer 101 and changes a part of the absorption change area RA to the refractive index modulation area RB.

  When a recording request for recording sub data is supplied in response to a user operation input via an operation unit (not shown), the system controller 31 receives the cipher information CI as sub data and the cipher information from the cipher generation unit 32. Key information KI corresponding to the information CI is generated. The system controller 31 sends the key information KI together with the identification information of the optical information recording medium 100 to, for example, a server (not shown) connected via a network. As a result, the key information KI and the identification information are stored in the server in association with each other.

  Further, the system controller 31 supplies the encryption information CI generated by the encryption generation unit 32 to the control unit 51 of the optical recording device 33.

  The control unit 51 supplies the encryption information CI to the signal processing unit 53. The signal processing unit 53 performs predetermined modulation processing, binarization processing, and the like on the encryption information CI, so that the recording data Swb that rises and falls according to the cycle of the recording clock Cb (FIG. 14B and FIG. C)) is generated and supplied to the drive controller 52.

  At this time, the signal processing unit 53 generates the recording data Swb so that the recording data Swb rises or falls, for example, with the recording clock Cb for five cycles as one cycle.

  The drive controller 52 generates a laser drive current based on the recording data Swb and supplies it to the light source 60 in the optical pickup 58. As a result, a recording light beam L1b (FIG. 14D) modulated in accordance with information is emitted from the light source 60. The recording light beam L1b is continuously emitted with a relatively large light intensity in order to cause a thermal reaction.

  The control unit 51 controls the optical pickup 58 so that the recording light beam L1b is emitted from the optical pickup 58 to the target position PG where the recording light beam L1b of the optical information recording medium 100 is to be emitted. As a result, the control unit 51 causes the thermal change in accordance with the recording light beam L1b in the absorption change area RA formed in the recording layer 101 to form the refractive index modulation area RB, and records the sub data. ing.

  Here, the recording data Swb has a recording clock Cb for five periods as one period. Therefore, the recording light beam L1b is irradiated or not irradiated every five target mark positions where the recording clock Cb for five cycles, that is, the absorption change region RA may be formed. Each bit represents one bit of information.

  As a result, the optical recording device 33 can record the sub data superimposed on the absorption change area RA if at least one absorption change area RA is formed at the five target mark positions. As a result, since the absorption change area RA is not formed at the target mark position, the optical recording device 33 can prevent a situation in which the sub data is not recorded, and can reliably record the sub data.

  FIG. 15 shows the configuration of the optical pickup 58. In FIG. 15, parts corresponding to those of the optical pickup 57 (FIG. 12) are denoted by the same reference numerals, and description of the same processing is omitted.

  The optical pickup 58 emits a recording light beam L1b having a wavelength of, for example, 405 [nm] from the light source 60 and irradiates the target position PG of the optical information recording medium 100 based on the control of the control unit 51 during the sub data recording process. To do. Thereby, the optical pickup 58 is configured to form the refractive index modulation region RB in accordance with the encryption information CI.

  At this time, the optical pickup 58 receives the transmitted light beam L3 transmitted through the optical information recording medium 100 by the condenser lens 64 disposed at a position facing the objective lens 63, and condenses the transmitted light beam L3. The light receiving element 65 is irradiated.

  The light receiving element 65 generates a detection signal corresponding to the amount of light and supplies it to the signal processing unit 59. The signal processing unit 59 generates a reproduction signal SRF from the detection signal, and generates a recording clock Cb from the reproduction signal SRF by a PLL circuit (not shown). The recording clock Cb is a timing signal indicating the timing at which the absorption change area RA is formed (that is, the target mark position interval).

  In other words, the optical pickup 58 detects the recording position of the actually recorded absorption change area RA, and irradiates the recording light beam L1b in accordance with the recording position, so that a part of the absorption change area RA representing the main data is obtained. That is, the recording light beam L1b can be appropriately applied to (that is, the target position PG). As a result, the optical pickup 58 can appropriately superimpose the sub data on the main data.

  As described above, the optical recording device 33 can record the sub data as the refractive index modulation region RB on the optical information recording medium 100.

(6) Reproduction of information As shown in FIG. 16, the information reproduction terminal 4 is mainly composed of a system controller 41. Like the system controller 21 (FIG. 10), the information reproduction terminal 4 includes a CPU, ROM, and RAM (not shown). It is configured. In FIG. 16, portions corresponding to the information recording terminal 2 (FIG. 10) are denoted by the same reference numerals, and description of the same processing is omitted.

  Here, in the optical information recording medium 100, the main data is recorded as the absorption change region RA, and a part of the absorption change region RA is changed to the refractive index modulation region RB. That is, in the optical information recording medium 100, main data is recorded by the absorption change region RA and the refractive index modulation region RB.

  Therefore, the information reproducing terminal 4 reproduces the main data by detecting whether one of the absorption change area RA and the refractive index modulation area RB is recorded.

  When a recording request for recording sub data is supplied in response to a user operation input via an operation unit (not shown), the system controller 31 is connected to, for example, a network or an external device based on the identification information of the optical information recording medium 100 The key information KI supplied via the storage device or the like is sent to the encryption reproduction unit 42. The encryption reproduction unit 42 generates encryption information CI based on the key information KI, and supplies it to the control unit 71 of the optical recording device 43.

  The control unit (FIG. 11B) 71 supplies the encryption information CI to the signal processing unit 73. The signal processing unit 73 generates encrypted data Sc (FIG. 17E) that rises and falls according to the period of the reproduction clock Cr.

  Further, when reproducing information from the optical information recording medium 100, the control unit 71 generates a laser drive current having a substantially constant value and supplies this to the light source 60 (FIG. 15). As a result, the reading light beam L2 (FIG. 17C) having a substantially constant emitted light intensity is emitted from the light source 60.

  The optical pickup 77 receives the transmitted light beam L3 that has passed through the optical information recording medium 100, and supplies a detection signal corresponding to the amount of received light of the transmitted light beam L3 to the signal processing unit 73.

  The signal processing unit 73 generates a reproduction signal SRF (FIG. 17D) representing the amount of received light of the transmitted light beam L3 based on the detection signal, and performs predetermined binarization processing and demodulation on the reproduction signal SRF. Reproduction data is generated by performing processing and the like, and is supplied to the system controller 41 via the control unit 51.

  At this time, the signal processing unit 73 sets the reproduction threshold when binarizing the reproduction signal SRF in accordance with the rise and fall of the encrypted data Sc (FIG. 17E) as the first reproduction threshold and the second reproduction threshold. It has been made to switch to either.

  That is, for example, when the encrypted data Sc is “Low”, the signal processing unit 73 should set the binarization threshold value to the first reproduction threshold value because the absorption change region RA should be formed as the recording mark RM at the target mark position. Set to threshold. The first reproduction threshold is determined so that the “High” level period and the “Low” level period of the binarized signal DRF are substantially the same when the encrypted data Sc is “Low”.

  As a result, the signal processing unit 73 can appropriately detect the presence or absence of the actually recorded absorption change area RA at the target mark position where the absorption change area RA should be recorded. Can be played.

  On the other hand, for example, when the encrypted data Sc is “High”, the signal processing unit 73 should set the binarization threshold to the second threshold value because the refractive index modulation region RB should be formed as the recording mark RM at the target mark position. Set to playback threshold. The second reproduction threshold is determined so that the “High” level period and the “Low” level period of the binarized signal DRF are substantially the same when the encrypted data Sc is “Low”.

  Accordingly, the signal processing unit 73 can appropriately detect the presence or absence of the actually recorded refractive index modulation region RB at the target mark position where the refractive index modulation region RB should be recorded. It can be played back properly.

  That is, when the sub data based on the regular encryption information CI is recorded on the optical information recording medium 100, the information reproducing terminal 4 appropriately detects the presence or absence of the recording mark RM and appropriately reproduces the main data. Can do. On the other hand, the information reproducing terminal 4 cannot properly detect the presence / absence of the recording mark RM and reproduces the main data when the sub data based on the legitimate encryption information CI is not recorded on the optical information recording medium 100. It is made so that it cannot be done.

  The signal processing unit 73 generates a reproduction clock Cr from the reproduction signal SRF by a PLL circuit (not shown). The reproduction clock Cr is a timing signal representing the timing at which the recording mark RM is formed (that is, the target mark position interval).

  As described above, the information reproducing terminal 4 can reproduce information from the optical information recording medium 100 only when the sub data based on the regular encryption information CI is recorded on the optical information recording medium 100.

(7) Operation and Effect In the above configuration, in the recording layer 101 of the optical information recording medium 100, the absorption change region RA in which the light absorption rate has changed from the surroundings, and the refractive index modulation in which the refractive index has been modulated from the absorption change region RA. Main data is recorded in the area RB. In the recording layer 101, sub data different from the main data is recorded as the refractive index modulation region RB.

  That is, in the recording layer 101, a refractive index modulation region RB representing sub data is formed in a part of the absorption change region RA formed as main data. Thereby, in the recording layer 101, the sub data can be superimposed and recorded on the main data.

  In the recording layer 101, an absorption change region RA is formed by a two-photon absorption reaction caused by irradiation with the recording light beam L1a as information recording light. In the recording layer 101, a refractive index modulation region RB is formed by a thermal reaction caused by irradiating the recording light beam L1b as superimposed recording light to the absorption change region RA.

  Thereby, in the recording layer 101, the absorption change region RA and the refractive index modulation region RB can be formed by two different reactions. Therefore, when the absorption change region RA is to be formed, the refractive index is increased by over-irradiation of the recording light beam L1a. A situation in which the modulation region RB is erroneously formed can be prevented in advance.

  Further, the recording layer 101 can record a forgery prevention system for the optical information recording medium 100 using the encryption information CI by recording the encryption information CI as sub data.

  In the optical recording device 33, the recording is recorded on the optical information recording medium 100, the absorption change area RA in which the light absorption rate is changed from the surroundings is detected by the signal processing unit 59 as the detection unit, and the recording emitted from the light source 60 as the superimposed recording light. The light beam L1a is irradiated to the absorption change region RA. The optical recording device 33 emits superimposed recording light to a part of the absorption change area RA in accordance with sub data different from the main data represented by the absorption change area RA and the detection result of the signal processing unit 59. To control.

  Accordingly, the optical recording device 33 can form the refractive index modulation region RB representing the sub data in a part of the absorption change region RA representing the main data, and superimpose and record the sub data on the main data. Can do.

  The optical reproducing device 43 reads the read light with respect to the optical information recording medium 100 in which the absorption change region RA in which the light absorption rate has changed from the surroundings and the refractive index modulation region RB in which the refractive index is modulated from the absorption change region RA is formed. The reading light beam L2 is irradiated. The optical reproducing device 43 receives the transmitted light beam L3 as modulated light obtained by modulating the reading light beam L2 by the absorption change region RA and the refractive index modulation region RB, and based on the transmitted light beam L3, the absorption change region RA. And main data represented by both the refractive index modulation region RB.

  Thereby, the optical reproducing device 43 can appropriately reproduce the main data from the optical information recording medium 100.

  Further, the optical reproduction device 43 acquires the sub data represented by the refractive index modulation region RB by generating the encryption information CI from the key information KI, and any of the absorption change region RA and the refractive index modulation region RB is acquired from the acquired sub data. Whether it is recorded is predicted by a signal processing unit 73 as a prediction unit. The information reproduction terminal 4 generates a reproduction signal SRF representing the sum light amount of the transmitted light beam L3 from the detection signal, and a first reproduction threshold value for determining the presence or absence of the absorption change region RA according to the prediction result of the signal processing unit 73 The second reproduction threshold value for determining the presence / absence of the refractive index modulation region RB is switched to generate a binarized signal DRF representing main data.

  Thereby, the optical reproducing device 43 can appropriately reproduce the main data represented by the absorption change region RA and the refractive index modulation region RB.

  In the forgery prevention system, the approval terminal 3 generates encryption information CI and irradiates the recording light beam L1b on the absorption change area RA representing the recording information RI in the optical information recording medium 100. The approval terminal 3 forms the refractive index modulation region RB, thereby superimposing the encryption information CI on the absorption change region RA and generating key information KI corresponding to the encryption information CI.

  In the forgery prevention system, the information reproducing terminal 4 acquires the key information CI, and when the encryption information CI recorded in the optical information recording medium 100 on which the encryption information CI is superimposed corresponds to the key information KI, the main data On the other hand, if the encryption information CI does not correspond to the key information KI, the main data is not reproduced.

  As a result, in the forgery prevention system, the main data can be reproduced only when the key information CI and the encryption information CI recorded on the optical information recording medium 100 coincide with each other. Therefore, it is necessary to correctly record the encryption information CI in order to execute forgery. As a result, in the forgery prevention system, falsification of the main data and forgery of the optical information recording medium 100 can be suppressed.

  According to the above configuration, in the present invention, the characteristic of the optical information recording medium 100 is that the absorption change region RA is formed according to the recording light beam L1a and the refractive index modulation region RB is formed according to the recording light beam L1b. Use.

  Thereby, in the present invention, the main data and the sub data can be recorded by combining the absorption change region RA and the refractive index modulation region RB as the recording mark RM, and thus the light in which both the main data and the sub data are recorded. Information recording medium, recording apparatus and recording method capable of recording sub data, reproducing apparatus and reproducing method capable of reproducing main data from an optical information recording medium on which both main data and sub data are recorded, and the above It is possible to realize a forgery prevention system, an approval terminal, and an information reproduction terminal that can suppress forgery of main data in an optical information recording medium.

(8) Other Embodiments In the above-described embodiment, the case where the light absorption characteristic of the absorption change region RA is changed by the two-photon absorption reaction has been described. The present invention is not limited to this. For example, the absorption change region RA may be formed by a photopolymerization reaction based on a one-photon absorption reaction. Even in this case, the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the case where various resin materials are used as the binder resin has been described. However, the present invention is not limited to this. For example, various additives and, for example, cyanine-based and coumarin-based materials are used. Further, a sensitizing dye such as a quinoline dye may be added.

  Further, in the above-described embodiment, the case where the encryption information CI is recorded as the sub data has been described. The present invention is not limited to this, and various other information such as approval date and time may be recorded as sub data.

  Further, in the above-described embodiment, it is determined which of the absorption change region RA or the refractive index modulation region RB should be recorded based on the key information KI, and whether the reproduction signal SRF is “High” or “Low”. In the above description, the threshold value indicating whether or not is switched between the first reproduction threshold value and the second reproduction threshold value has been described. The present invention is not limited to this. For example, instead of the reproduction threshold value, the amplification factor for generating the reproduction signal SRF may be switched.

  In the present invention, the reproduction threshold value may be set in two stages to determine whether there is no recording mark, the absorption change region RA, or the refractive index modulation region RB. In this case, according to the present invention, the sub data can be reproduced by generating a reproduction signal corresponding to the refractive index modulation region RB. At this time, the optical reproducing apparatus inquires whether or not the sub data corresponds to the key information KI, and determines whether or not reproduction is permitted.

  Further, in the above-described embodiment, the first and second reproduction thresholds are determined so that the “High” level period and the “Low” level period in the binarized signal DRF are substantially the same. Said about the case. The present invention is not limited to this, and the first and second reproduction thresholds can be determined by various other methods. For example, the present invention may use first and second reproduction threshold values stored in advance.

  Further, in the above-described embodiment, the case where the refractive index modulation region RB is formed or not formed for each 5-bit absorption change region RA has been described. The present invention is not limited to this. For example, the refractive index modulation region RB may not be formed or formed for each 1-bit absorption change region RA. In addition, by using the number of bits itself as a part of the encryption, it is possible to increase the difficulty of forging the optical information recording medium 100 and further enhance the effect of preventing the forgery of the optical information recording medium 100.

Further, in the above-described embodiment, the case where the recording light beam L1 and the reading light beam L2 are respectively irradiated from the surface on the substrate 102 side of the optical information recording medium 100 has been described, but the present invention is not limited to this. For example, the recording light beam L1 may be irradiated from the surface on the substrate 103 side, and each light or light beam may be irradiated from any surface or both surfaces. A technique for irradiating the recording light beam from both sides is described in, for example, Patent Document 3.
JP 2008-71433 A

  Further, in the above-described embodiment, the case where the transmitted light beam L3 that has passed through the optical information recording medium 100 is received has been described. The present invention is not limited to this. For example, when the absorption change region RA is accompanied by refractive index modulation, a return light beam reflected by the recording mark RM may be received.

  Further, in the above-described embodiment, the servo control of the objective lens 63 is not particularly described. For example, as described in Patent Document 3, the servo layer 104 is irradiated with a servo light beam for servo control. Servo control can be executed. Also, servo marks for servo control may be formed in the recording layer 101 in advance, and servo control may be executed using the servo marks. In this case, the servo layer 104 is not necessary in the optical information recording medium 100.

  Further, in the above-described embodiment, the case where the refractive index modulation region RB made of a cavity is formed has been described. The present invention is not limited to this. For example, the refractive index modulation region RB may be formed by locally changing the refractive index by a chemical change.

  Further, in the embodiment described above, the recording light beam L1 and the reading light beam L2 emitted from the light source 60 may have other wavelengths in addition to the wavelength 405 [nm]. In other words, the recording mark RM may be appropriately formed in the vicinity of the target position PG in the recording layer 101. Further, the wavelengths of the recording light beams L1a and L1b may be different.

  Furthermore, in the above-described embodiment, the optical information recording medium 100 is formed in a disc shape, and the recording marks RM are formed in a concentric or spiral shape while the optical information recording medium 100 is rotated. Said. The present invention is not limited to this. For example, the optical information recording medium may be formed in a rectangular plate shape or a square plate shape, and the optical information recording medium may be stage-driven. It is also possible to displace the objective lens while fixing the position of the optical information recording medium. In order to obtain the optical information recording medium 100 having a capacity of 5 times or more that of a two-layer BD having a recording capacity of 250 GB, the thickness of the recording layer 101 is preferably 100 [μm] or more.

  Further, in the above-described embodiment, the case where one recording mark RM represents 1-bit information has been described. The present invention is not limited to this. For example, a recording mark RM having various mark lengths such as a recording mark RM having 2T to 11T may be formed. In this case, for example, the refractive index modulation region may be formed only in a part of the absorption change region RA having a relatively long mark length.

  Further, in the above-described embodiment, the information recording terminal 2 and the approval terminal 3 only record information from the optical information recording medium 100, and the information reproducing terminal 4 only reproduces information from the optical information recording medium 100. Said about the case. The present invention is not limited to this, and the information recording terminal 2, the approval terminal 3, and the information reproducing terminal 4 may both record and reproduce information with respect to the optical information recording medium 100. That is, one terminal may have the two functions of the information recording terminal 2 or the approval terminal 3 and the information reproduction terminal 4.

  Further, in the above-described embodiment, the case where the forgery prevention system is used as an in-house document storage system has been described. The present invention is not limited to this, and may be used in various anti-counterfeit systems, such as an anti-counterfeit system for music and video data. In this case, the key information KI is stored by a vendor such as music data and distributed only to authorized users via a network such as the Internet.

  In the forgery prevention system, it is not always necessary to separately prepare key information. For example, permission information for permitting reproduction of main data can be recorded as sub data.

  Further, in the above-described embodiment, the case where the optical information recording medium 100 as the optical information recording medium is configured by the recording layer 101 as the recording layer has been described. However, the present invention is not limited to this, and has other various configurations. An optical information recording medium may be constituted by the recording layer.

  Further, in the above-described embodiment, the optical recording device 23 as a recording device is configured by the light source 60 as the light source, the objective lens 63 as the light irradiation unit, and the signal processing unit 53 as the detection unit and the light source control unit. The case where you want to be described. The present invention is not limited to this, and the recording apparatus of the present invention may be configured by a light source having various configurations, a light irradiation unit, a detection unit, and a light source control unit.

  Further, in the above-described embodiment, the light as a reproducing device includes the light source 60 as the light source, the objective lens 63 as the light irradiating unit, the light receiving element 65 as the light receiving unit, and the signal processing unit 73 as the reproducing unit. The case where the playback device 43 is configured has been described. The present invention is not limited to this, and the reproducing apparatus of the present invention may be configured by a light source, a light irradiation unit, a light receiving unit, and a reproducing unit having various other configurations.

  Further, in the above-described embodiment, the approval terminal 3 as the approval terminal is configured by the encryption generation unit 32 as the encryption information generation unit and the key information generation unit, and the optical recording device 33 as the encryption information superimposition unit. If you said. The present invention is not limited to this, and the recording apparatus of the present invention may be configured by an encryption information generation unit, a key information generation unit, and an encryption information superimposition unit having various other configurations.

  Further, in the above-described embodiment, the case where the information reproduction terminal 4 as the information reproduction terminal is configured by the encryption reproduction unit 42 as the key information acquisition unit and the optical reproduction device 43 as the reproduction unit has been described. . The present invention is not limited to this, and the playback apparatus of the present invention may be configured by a key information acquisition unit having various other configurations and a playback unit.

  The present invention can be used for, for example, a document approval system used in the company, an official document storage system for storing an official document, and the like.

It is a basic diagram with which it uses for description of formation of the recording mark by 1 photon absorption. It is a basic diagram with which it uses for description of formation of the recording mark by two photon absorption. It is a basic diagram with which it uses for description of formation of the conventional recording mark. It is a basic diagram with which it uses for description of recording and reproduction | regeneration of an absorption change area | region. It is a basic diagram with which it uses for description of recording and reproduction | regeneration of an absorption change area | region. It is a basic diagram with which it uses for description of recording and reproduction | regeneration of main data and subdata. It is a basic diagram with which it uses for description of the structure (1) of a forgery prevention system. It is a basic diagram with which it uses for description of the structure (1) of a forgery prevention system. It is a basic diagram which shows the structure of an optical information recording medium. It is a basic diagram which shows the structure of an information recording terminal. It is an approximate line figure used for explanation of recording of main data. It is a basic diagram which shows the structure of an optical pick-up. It is a basic diagram which shows the structure of an approval terminal. It is an approximate line figure used for explanation of sub data recording. It is a basic diagram which shows the structure of an optical pick-up. It is a basic diagram which shows the structure of an information reproduction terminal. It is an approximate line figure used for explanation of reproduction of information.

Explanation of symbols

  2... Information recording terminal, 3... Approval terminal, 4. , 57, 67, 77... Optical pickup, 60... Light source, 53, 59, 73... Signal processing unit 59. t3: Thickness, L1, L1a, L1b: Recording light beam, L2: Reading light beam, L3: Transmitted light beam, RA: Absorption change region, RB: Refractive index modulation region, SRF: Reproduction Signal, DRF ... Binary reproduction signal.

Claims (15)

Main data is recorded as an absorption change region in which the optical absorptance has changed from the surroundings and a refractive index modulation region in which the refractive index is modulated from the absorption change region, and sub data different from the main data is recorded as the refractive index modulation region. An optical information recording medium having a recorded layer. The absorption change region is
The optical information recording medium according to claim 1, wherein a two-photon absorption reaction is caused by irradiation of information recording light. The refractive index modulation region is
The optical information recording medium according to claim 2, wherein the optical information recording medium is formed by a thermal reaction caused by irradiating the absorption change region with superimposed recording light. The recording layer is
The optical information according to claim 3, further comprising a light absorption change material that changes a light absorption characteristic by a two-photon absorption reaction according to the irradiation of the information recording light and causes a thermal reaction according to the irradiation of the superimposed recording light. recoding media. The light absorption change material is
The optical information recording medium according to claim 4, wherein the optical information recording medium is a photochromic material that changes light absorption characteristics by reversibly changing a chemical structure in response to light irradiation. The above secondary data is
The optical information recording medium according to claim 1, wherein the optical information recording medium is encrypted information. A light source that emits superimposed recording light; and
A light irradiation unit that irradiates the superimposed recording light to the absorption change region;
A detection unit that is recorded on the optical information recording medium and detects an absorption change region in which the light absorption rate has changed from the surroundings;
A light source control unit that controls the light source to emit the superimposed recording light to a part of the absorption change region according to sub data different from the main data represented by the absorption change region and a detection result by the detection unit. And a recording device. The recording apparatus according to claim 7, further comprising: an encryption generation unit that generates encryption information as the sub data. An emission step of emitting superimposed recording light;
A detection step of detecting an absorption change region recorded on an optical information recording medium and having a light absorption rate with respect to the superimposed recording light changed from the surroundings;
In response to sub data different from the main data represented by the absorption change region and the detection result by the detection unit, the superposition recording light is emitted to a part of the absorption change region with respect to the absorption change region. A light irradiation step of irradiating the superimposed recording light. A light source that emits readout light;
A light irradiating unit that irradiates the readout light to the optical information recording medium in which the absorption change region in which the light absorption rate has changed from the surroundings and the refractive index modulation region in which the refractive index is modulated from the absorption change region is formed;
A light receiving unit that receives the modulated light obtained by modulating the readout light by the absorption change region and the refractive index modulation region;
A reproducing unit that reproduces main data represented by both the absorption change region and the refractive index modulation region based on the modulated light. A sub data acquisition unit for acquiring sub data represented by the refractive index modulation region;
A prediction unit that predicts which of the absorption change region and the refractive index modulation region is recorded from the acquired sub-data, and
The playback unit
A first reproduction threshold value for generating a reproduction signal representing the sum light amount of the modulated light from the detection signal and determining the presence / absence of the absorption change region according to a prediction result of the prediction unit, and the presence / absence of the refractive index modulation region The reproduction apparatus according to claim 10, wherein the second reproduction threshold value for determining the second data is switched to generate a binary signal representing main data. An emission step for emitting the readout light;
A light irradiating step of irradiating the readout light to the optical information recording medium in which the absorption change region in which the light absorption rate is changed from the surroundings and the refractive index modulation region in which the refractive index is modulated from the absorption change region is formed;
A light receiving step of receiving modulated light obtained by modulating the readout light by the absorption change region and the refractive index modulation region;
A reproduction step of reproducing main data represented by both the absorption change region and the refractive index modulation region based on the modulated light. An encryption information generation unit for generating encryption information;
By irradiating recording light on an absorption change region where the light absorption rate is changed from the surroundings and representing the recording information in the optical information recording medium, and forming a refractive index modulation region in which the refractive index is modulated from the absorption change region, An encryption information superimposing unit that superimposes encryption information on the absorption change region;
An approval terminal comprising: a key information generation unit that generates key information corresponding to the encryption information;
A key information acquisition unit for acquiring the key information;
When the encrypted information recorded on the optical information recording medium on which the encrypted information is superimposed corresponds to the key information, the recorded information is reproduced, whereas when the encrypted information does not correspond to the key information. An anti-counterfeit system comprising: an information reproduction terminal comprising: a reproduction unit that does not reproduce the recorded information. An encryption information generation unit for generating encryption information;
By irradiating recording light on an absorption change region where the light absorption rate is changed from the surroundings and representing the recording information in the optical information recording medium, and forming a refractive index modulation region in which the refractive index is modulated from the absorption change region, An encryption information superimposing unit that superimposes encryption information on the absorption change region;
An approval terminal comprising: a key information generation unit that generates key information corresponding to the encryption information. Recording light is irradiated onto the absorption change area where the optical absorption rate is recorded from the surroundings as the record information in the optical information recording medium, and a refractive index modulation area is formed by modulating the refractive index from the absorption change area. A key information acquisition unit for acquiring key information corresponding to the encryption information superimposed by
When the encrypted information recorded on the optical information recording medium on which the encrypted information is superimposed corresponds to the key information, the recorded information is reproduced, whereas when the encrypted information does not correspond to the key information. An information reproduction terminal comprising: a reproduction unit that does not reproduce the recorded information.

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