JPH10105975A - Optical disk and its reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent illegal copies of optical disks recorded with music software and game software, etc. SOLUTION: A bar code symbol 5 consisting of bar elements 5a formed as through holes in a radial pattern is constituted in a specular surface area 4 in the innermost circumference of the optical disk 1, and this bar code symbol 5 is given identification information of the optical disk 1, while the surface of individual reflecting layers between individual adjacent bar elements 5a are formed with a large number of long and narrow grooves 6 in the radial direction as seen from the center of the disk 1. A signal obtained from the bar code symbol 5 and a modulation signal by the narrow grooves 6 are individually detected by the reproducing device, and the former signal is decoded, and the latter signal is detected and then decoded to obtaine their bar code data respectively. Then, by confirming one data to be reasonable and coincidence of both data, reproducing permission of main information of the disk 1 is given as the legal disk 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk and a reproducing apparatus for the same, and in particular, strictly checks whether an optical disk on which music software, game software, etc. are recorded is a genuine product,
Regarding measures to prevent unauthorized duplication that constitutes copyright infringement.

[0002]

2. Description of the Related Art Audio discs such as CDs (Compact
Discs), optical discs used as recording media for video games, and DVDs (Digital Video Discs), which are recently attracting attention, are recorded many times because their information is recorded as digital data. Therefore, there is no deterioration in sound quality or image quality, and illegal duplication is more likely to occur than in a recording medium such as an analog magnetic music tape. Especially,
If these optical disks are copied as optical disks called "pirated", they will bring great disadvantages to copyright owners and publishers.

[0003] Therefore, special consideration is also taken into account in the Copyright Act, and the publisher side provides identification information (manufacturing lot number) on the label surface or the innermost mirror surface area of the optical disc to indicate that the product is a legitimate product. And serial numbers) are printed and stamped to control production and shipment. . However, if the identification information is printed or stamped, it is easy to duplicate the identification information.
Before or after the formation of the protective layer, a high-power laser beam is used to form a through-hole serving as a barcode element that is long in the radial direction as viewed from the center of the disk in the reflective layer in the mirror region to form a barcode symbol. A method has been proposed (JP-A-6-203412). In addition, the applicant of the present application records the main information by a certain encoding means, and records key information indicating the decoding means of the main information in a bar code symbol in the above-mentioned mirror area or the like. A method of reading the key information and decoding / reproducing the main information in a decoding method indicated by the information (Japanese Patent Laid-Open No. 7-85574), or by giving the key information in a modified form of the pits constituting the main information In addition, a reproduction method (Japanese Patent Laid-Open No. 8-124219) has been proposed in which the key information is read first to select a decryption means and the like.

[0004] As a countermeasure to prevent duplication of a software product, there is a countermeasure using only a logical method which does not involve the physical method as described above, but the physical method is generally more effective.

[0005]

Problems to be solved by the invention
With the method of No. 3412, duplication is more difficult than the conventional method of printing on the label surface or engraving on the mirror surface area, but using a high power laser beam, a wide bar code element and a unique bar code symbol Can be easily formed with relatively simple equipment, and the processing cost is low. Therefore, the duplication is easy to this extent, and it is questionable how effective the effect of preventing the duplication of the optical disk is in practice.

On the other hand, JP-A-7-85574 and JP-A-8-12421
In the method of No. 9, the decryption method on the reproducing apparatus side is a more effective countermeasure against duplication because the reproduction permission / non-permission is determined. However, in Japanese Patent Application Laid-Open No. 7-85574, as in the case of Japanese Patent Application Laid-Open No. 6-203412, since the formation of barcode symbols is relatively easy, its effectiveness is lost. Also, Japanese Patent Application Laid-Open No. 8-124219 can realize an extremely high security function by adopting a special method of pit deformation, but it is complicated to modulate extremely fine pits at a disk manufacturing stage or after manufacturing. It requires advanced technology, requires expensive manufacturing equipment, and inevitably reduces the yield. On the other hand, forming a shallow groove densely in the mirror surface region at the stage of manufacturing the disk or after the manufacturing can be performed by a relatively inexpensive groove forming apparatus.

Therefore, the present invention provides an optical disk which can be determined by using a bar code as to whether or not it is a legitimate product and which is difficult to copy with relatively inexpensive equipment. It was created to effectively prevent duplication.

[0008]

The optical disk of the present invention comprises:
A bar code symbol consisting of a bar element formed as a long through hole in the radial direction as viewed from the center of the disc is formed on the reflective layer in an area other than the main information recording area and readable by the optical pickup, The barcode symbol has information for identifying the optical disk, and a number of narrow grooves are formed on the surface of each reflective layer between adjacent bar elements in the radial direction as viewed from the center of the disk. An optical disc characterized by the above.

In reproducing the optical disk, prior to reproducing the main information of the optical disk, read control means for moving the optical pickup to a bar code symbol forming area while rotating the optical disk and reading a signal is provided. A first filter means for passing only a signal component obtained from a bar code symbol from a signal read by the optical pickup in a control process by the reading control means, and a signal read by the optical pickup in a control process by the reading control means. A second filter means for passing only a signal component obtained based on a narrow groove formed between adjacent bar elements of a barcode symbol; a detection means for detecting an output signal of the second filter means; A first step of generating barcode data based on an output signal of the first filter means; Data creating means, second data creating means for creating bar code data based on a detection output signal of the detection means, and switching means for selectively outputting each bar code data by each of the data creating means. Storage means for storing each barcode data by switching of the switching means, and determination means for determining whether any one of the barcode data stored in the storage means is identification data given to a regular optical disc, Comparing means for comparing both barcode data stored in the storage means, and the discriminating means discriminating that the discriminating data is to be given to a regular optical disc, and only when the comparing means confirms a match. A reproducing apparatus including a determination unit that gives permission to reproduce main information of an optical disk is applied.

[0010] In the optical disk of the present invention, in addition to the bar code symbol in which the bar element is formed by the through hole, the space element for the reflection layer other than the main information recording area and the area readable by the optical pickup is provided. A number of narrow grooves are formed between each bar element corresponding to. Then, it is possible to provide a configuration in which the presence of these narrow grooves cannot be recognized simply by making the spaces between the bar elements slightly darker evenly in a manner in which the bar elements are camouflaged.

By the way, the barcode symbol has a content for giving the identification information of the optical disk, but the arrangement of the narrow groove itself does not give any special information.
However, when the barcode symbol and the narrow groove are read by the optical pickup of the reproducing apparatus, the output signal of the first filter means and the signal after the output signal of the second filter signal detected by the detection means are almost the same signal. It becomes a waveform. Therefore, if the output signal of the first filter means and the detection signal of the detection means are used to create barcode data by the first and second data creation means, respectively, they become coincident data. In other words, the presence of the narrow groove can be confirmed by making the respective barcode data the same, and if the narrow groove is not formed, the sameness cannot be ensured, so that it can be confirmed that the optical disk is not a regular optical disk. According to the present invention, each bar code data is stored in the storage means via the switching means, and first, the discriminating means judges whether or not any one of the bar code data is identification data which can be given to a regular optical disc. The comparison means checks whether or not each bar code data is the same, and checks whether or not a narrow groove is formed on the optical disc. If the double conditions are satisfied, the optical disc is determined to be a legitimate product. Then, the reproduction permission of the main information is given.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of an optical disk and a reproducing apparatus thereof according to the present invention will be described in detail with reference to the drawings.
First, FIG. 1 shows a plan view (B) on the reading surface side of the optical disc according to the embodiment and an enlarged view (A) of a main part thereof. In FIG. 1, reference numeral 1 denotes an optical disc, and an annular mirror area 4 is formed in an area corresponding to the outside of the clamper area 3 inside the lead-in portion of the main information recording area 2. Here, the mirror surface area 4 is a transparent plastic layer in the optical disc 1.
Reflective layer interposed between (carbonate layer) and protective layer
The main information is not recorded on (a metal layer such as aluminum) and is configured as a mirror-like reflecting surface.

In this embodiment, a bar code symbol 5 having a relatively large module width is formed by a bar element 5a formed as a through hole long in a radial direction as viewed from the center of the optical disc 1 in the reflection layer of the mirror surface area 4. Further, between the bar elements 5a, that is, in a portion corresponding to the space element 5b, a large number of narrow grooves 6 which are long in the radial direction when viewed from the center of the optical disc 1 are formed at a minute pitch. The barcode symbol 5 is configured to give identification information including a serial number and a lot number of the optical disc. The narrow groove 6 is not a through hole but a shallow groove formed on the surface of the reflection layer, and the width thereof is set to be much smaller than the width of the bar element 5a.

Therefore, the presence of the bar element 5a of the bar code symbol 5 can be visually confirmed, but the space element 5b can be seen only as a slightly dark surface due to the light diffraction phenomenon by the many narrow grooves 6, The presence of the narrow groove 6 cannot be confirmed unless viewed with a microscope or the like. Also,
Since the narrow groove 6 is camouflaged by the bar element 5a, it is difficult to visually detect the presence of the narrow groove 6.

FIG. 2 is a sectional view of a portion on which the barcode symbol 5 is applied, which is viewed in a circumferential section passing through a substantially center of a width of the mirror surface region 4 in a radial direction. In the figure, 10 is a carbonate layer, 11 is a protective layer, and a reflective layer 12 is interposed between those layers.
The space element 5b indicated by SE is continuous, and the bar element 5a indicated by BE is discontinuous because it is formed as a through hole. And the reflective layer 12
On the surface of a portion corresponding to the space element 5b, a narrow groove 6 is formed with a small period.

Here, each bar element 5a is formed before applying the protective layer 11 or curing the applied protective layer 11 in the manufacturing process of the optical disk 1 based on the method described in Japanese Patent Laid-Open No. 6-203412. The high power laser beam is focused on the reflective layer 12 to form a through hole in the aluminum layer. On the other hand, the narrow groove 6 allows the small output laser beam to
To form concavities and convexities with a small period on the surface of the aluminum layer. Note that the formation of the narrow groove 6 requires relatively high technology, but can be performed with inexpensive equipment. Therefore, when the mirror area 4 of the optical disc 1 is scanned in the circumferential direction by the beam spot of the reading light, the light is not reflected by the bar element 5a, and reflected light modulated by the narrow groove 6 is generated by the space element 5b.

The optical disc 1 is reproduced by the reproducing apparatus shown in FIG. However, the system circuit of FIG. 3 is a system circuit of a part mainly related to disc confirmation in the reproducing apparatus, and other parts are omitted. In the figure, 21 is an optical pickup, 22 is a spindle motor, 23 is a servo circuit for executing spindle tracking control, etc., 24 is an actuator driver for the optical pickup 21, and 25 is a light amount detection amplifier for amplifying a detection signal of the optical pickup 21. , 26 is an amplifier, 27 is a low-pass filter (LPF) that allows only the light detection signal component appearing with a large amplitude and period by the bar element 5a and the space element 5b of the barcode symbol 5, and 28 is a threshold voltage Vtb.
A comparator for binarizing the output signal of the LPF 27,
29 is an amplifier, 30 is a band-pass filter (BPF) that passes only the light detection signal component that is modulated by the narrow groove 6 and appears with a small amplitude and cycle, 31 is a detection circuit that detects the output signal of the BPF 30, and 32 is a threshold voltage Is a comparator which binarizes the output signal of the detection circuit 31 with Vtl as Vtl.
A switch circuit to which the output of 2 is input and selectively outputting the input by control, 34 is a switching circuit
Barcode decoder that decodes 33 output data, 35
Is a microcomputer circuit (hereinafter, referred to as a "microcomputer circuit") that controls the entire system of the reproducing apparatus and determines permission / non-permission of reproduction of the optical disk 1 set in the disk confirmation mode.

Next, an operation procedure for reproducing the optical disk 1 in the above-described system circuit will be described with reference to a flowchart of FIG. 1 to 10 will be referred to as needed in the course of the description. In FIG. 3, when a reproduction instruction of the optical disk 1 is given to the microcomputer circuit 35, the CPU executes the following procedure based on the control program stored in the ROM. First, the disc confirmation mode is set by the reproduction instruction, and the switch circuit 33 is set.
To the a side, and immediately outputs control data in the same mode to the servo circuit 23 (S1 to S4). Then, the servo circuit 23 sets the optical pickup 21 at a substantially central position in the radial direction in the annular mirror surface area 4 and the spindle motor 22
Is started to rotate the optical disk 1 at a constant speed of 360 ° or more (S5).

In the rotating state, the optical pickup 21 always scans the bar code symbol 5a. When the bar code symbol 5 is crossed, the signal waveform of the output signal (read signal) is as shown in FIG. It becomes a waveform. That is, as is apparent from the correspondence of FIG. 2, during the time zone in which the bar code symbol 5 crosses the bar element 5a, since it is formed as a through hole, the amount of reflected light is extremely reduced, and the space element 5b A large amount of reflected light can be obtained because of the presence of the reflective layer 12 in the time zone that crosses the light, but the amount of reflected light is modulated by the narrow groove 6 formed on the surface of the reflective layer 12, and as a result, the optical pickup 21 The output signal is obtained by superimposing a signal component appearing with a large amplitude and a period by the bar element 5a and the space element 5b of the barcode symbol 5 and a signal component appearing at a small amplitude and the period modulated by the narrow groove 6 of the space element 5b. It becomes a waveform.

The read signal is inputted from the light quantity detection amplifier 25 to the LPF 27 via the amplifier 26, and is inputted from the light quantity detection amplifier 25 to the BPF 30 via the amplifier 29. Here, since the LPF 27 allows only the signal components of the bar element 5a and the space element 5b to pass, the signal component modulated by the narrow groove 6 of the space element 5b is cut and the signal shown in the signal waveform of FIG. 5 is output. .
On the other hand, the BPF30 has a narrow groove on the space element 5b.
In order to pass only the signal component modulated by 6, the signal component by the bar element 5a and the space element 5b is cut, and the signal shown in the signal waveform of FIG. 7 is output. More specifically, the LPF 27 and the BPF 30 have frequency characteristics as indicated by the dotted lines in FIG. 10, and the respective pass bands are modulated by the spectrum of the signal component by the bar element 5a and the space element 5b and the narrow groove 6. It contains the spectrum of the signal component.

Next, the output signal of the LPF 27 is
The output signal of the BPF 30 is input to the comparator 32 after being detected by the detection circuit 31. Here, since the comparator 28 sets the threshold voltage Vtb at substantially the middle of the PP value of the signal waveform shown in FIG. 5 and binarizes the output signal of the LPF 27, the output signal of the comparator 28 is shown in FIG. A signal having such a pulse waveform is obtained. On the other hand, the output signal of the BPF 30 input to the detection circuit 31 has a high voltage only in the signal portion modulated by the narrow groove 6 because the direct current component is removed by detection, and the other portions have a low voltage. ,
The output of the detection circuit 31 has a signal waveform similar to the output signal (FIG. 5) of the LPF 27 as shown in FIG. Then, when this signal is binarized by the comparator 32 in which the threshold voltage Vt1 is set almost at the middle of the PP value of the detection signal, a signal having a pulse waveform as shown in FIG. 9 is obtained. Therefore, the pulse signal of FIG. 6 is input to the a side of the switch circuit 33, and the pulse signal of FIG. 9 is input to the b side.

Returning to the flowchart of FIG. 11, the optical disk is connected with the switch circuit 33 connected to the side a.
When 1 is rotated once (S3 to S5), the pulse signal of FIG. 6 is input to the barcode decoder 34. Since the pulse signal corresponds to the barcode symbol 5, the barcode decoder 34 Outputs decoded data (bar code data) Db obtained by decoding the decoded data to the microcomputer circuit 35 (S6).
The microcomputer circuit 35 outputs the decoded data Db to the I / O
The data is taken from the port and stored in the built-in RAM (S6).

Next, the CPU of the microcomputer circuit 35 outputs a switching control signal to the switch circuit 33 via the I / O port, and switches the connection state from the a side to the b side (S7). Then, in the second rotation of the optical disc 1, the pulse signal of FIG. 9 input to the b side of the switch circuit 33 is input to the bar code decoder 34, and the bar code decoder 34 decodes the decoded data (bar code data). Dm is output to the microcomputer circuit 35 (S8). Further, the microcomputer circuit 35 fetches the decoded data Dm from the I / O port and stores it in the built-in RAM in the same manner as described above (S8).

According to the above procedure, R
In AM, the decoded data Db based on the bar code symbol 5 of the optical disk 1 and the decoded data D based on the narrow groove 6 are stored.
m is stored. Therefore, the microcomputer circuit 35
First compares the decoded data Db with the discrimination data stored in the ROM in advance (S9). The discrimination data is data indicating a range of identification information that can be given to the barcode symbol 5 of the optical disc 1. If the identification information given to the set optical disc is included in the range, the disc is discriminated. It can be determined that the product is genuine.

Therefore, in the comparison result, if the decoded data Db is included in the range of the discrimination data, it seems that the optical disc 1 should be determined to be a legitimate product. Further, the CPU compares the decoded data Db and the decoded data Dm, and only when the comparison results match, definitely determines that the optical disc 1 is a legitimate product (S9, S10).

As described above, judging the normality of the optical disc 1 by imposing a double confirmation condition has the following significance. First, the confirmation condition of S9 is to confirm whether the barcode symbol 5 accurately represents the identification information that can be given to the optical disc 1, and whether such a barcode symbol 5 is not attached or is not allowed. If a possible serial number or the like is not accurately expressed, it means that the optical disk is illegally copied. However, barcode symbols composed of relatively low density
Since the formation of 5 can be easily performed with inexpensive manufacturing equipment, the bar code symbol 5 of the legitimate optical disk to be duplicated even if the optical disk is illegally duplicated
Can be satisfied as it is, the confirmation condition of S9 can be cleared, and the effectiveness of eliminating illegally copied products is lost.

If a large number of narrow grooves 6 are formed in the space element 5b of the barcode symbol 5 of the optical disk 1, as described above, the pulse signal obtained from the barcode symbol 5 itself in FIG. The pulse signal obtained based on the narrow groove 6 should match. This is because, in the output signal of the BPF 30 in FIG. 7, the DC portion where no signal appears corresponds to the bar element 5b of the bar code symbol 5, which is transformed into the signal waveform of FIG. This is because the pulse signal of FIG. 9 is obtained by binarization at 32. Conversely, if a large number of narrow grooves 6 are not formed in the space element 5b of the bar code symbol 5, the modulated waveform due to the narrow grooves 6 does not appear in the output of the optical pickup 21 and the output of the BPF 30 in FIG. The signal has only a DC component, the output of the detection circuit 31 in FIG. 8 becomes 0, and the output of the comparator 32 in FIG. 9 has a continuous L level and no pulse signal appears. As a result, the decoded data Db and Dm Will not match.

Therefore, in order to clear the check condition of S10, a large number of narrow grooves 6 camouflaged on the bar element 5a of the bar code symbol 5 are found out, and narrow grooves that require equipment modification or advanced technology are required. A large number of 6 must be formed, and most illegal copies cannot meet this condition. That is, the security against unauthorized duplication can be drastically improved under the double confirmation condition.

Therefore, when both of the above conditions S9 and S10 are cleared, the microcomputer circuit 35 definitely determines that the set optical disk 1 is a legitimate product and changes the initially set disk confirmation mode. Release and shift to the original playback mode (S9, S10 → S15). In this embodiment, Db is compared with the discrimination data in the ROM in the procedure of S9. However, since Db = Dm holds if the optical disc 1 is a regular optical disc, Dm and the discrimination data may be compared. Good.

On the other hand, when the condition of S9 is not satisfied,
If the condition of S10 is not satisfied even if it is satisfied, the data stored in the RAM is immediately cleared and
If the procedure of S10 is re-executed (S9-S12 → S3), and the procedure is repeated three times and the check conditions in S7 and S8 cannot be cleared, the microcomputer circuit 35 sets the optical disk 1
Is regarded as a completely illegally copied product, a display control signal indicating that reproduction is not permitted is output, and the ejection operation of the optical disc 1 is executed to exit the present disc confirmation mode (S
12 to S14). The reason why the steps S3 to S10 are executed three times is to take care of final determination.

According to this reproducing apparatus, if the execution program relating to the disk confirmation mode of the microcomputer circuit 35 is switched by a dip switch or the like so as to correspond to an optical disk on which only the barcode symbol 5 is applied, it is easy. Compatibility can be provided. Further, in this embodiment, the arrangement is such that the barcode symbol 5 of the optical disc 1 and the narrow groove 6 formed on the space element 5b thereof always appear on almost the same radius, but both are on different radii. In that case, the movement control of the optical pickup 21 is performed so that the servo circuit 23 can scan on each radius. Furthermore, based on the above basic principle, not only the barcode symbol but also a variety of character forms of through holes and narrow grooves formed therebetween to determine the validity of the optical disc. Can be similarly performed. This embodiment can be applied to any type of optical disk as long as it has an area corresponding to the mirror surface area 4. Not only a typical optical disk such as a CD, but also a
The invention can be applied to various kinds of optical disks such as surface-attached MO disks and DVD-ROMs.

[0032]

The optical disk of the present invention and the reproducing apparatus for the same have the following effects by the above configuration. According to the first aspect of the present invention, it is possible to relatively easily duplicate the mirror surface area of the optical disc by applying the identification information to the mirror area by using a bar code symbol. Many narrow grooves are provided between the elements, which can be realized using relatively inexpensive equipment, but require advanced manufacturing technology. provide. Further, since the narrow groove is camouflaged by the bar element, it is possible to make it difficult to detect the presence of the high-density barcode symbol. According to a second aspect of the present invention, as a playback apparatus for the optical disk of the first aspect, reproduction of an optical disk that does not satisfy the conditions of the optical disk is not permitted, and illegal duplication of music software, game software, and the like is invalidated. Become In addition, the transfer rate of signals obtained based on barcode symbols and narrow grooves is much lower than the transfer rate of main information on the optical disk, and the amount of data processed during the procedure is small. For the main circuits such as these, the hardware included in a normal reproducing apparatus can be shared, and the production cost of the reproducing apparatus does not increase so much. Furthermore, even if an optical disk that has been protected from duplication by using only barcode symbols becomes widespread, it is possible to deal with it simply by switching a program for determining permission / non-permission of reproduction with a dip switch or the like. There is also an advantage that compatibility can be ensured without any change in the.

[Brief description of the drawings]

FIG. 1 is a plan view (B) of a reading surface side of an optical disc according to an embodiment of the present invention, and an enlarged view (A) of a main part thereof.

FIG. 2 is a cross-sectional view of a portion on which a barcode symbol is applied, as viewed in a circumferential cross section passing through a substantially center of a width in a radial direction of a mirror surface region.

FIG. 3 is a system circuit diagram of an optical disk reproducing apparatus.

FIG. 4 is a graph showing an output signal of an optical pickup in a disk confirmation mode.

FIG. 5 is a graph showing an output signal of an LPF.

FIG. 6 is a graph showing an output signal of a comparator (a signal system side related to a barcode symbol).

FIG. 7 is a graph showing an output signal of a BPF.

FIG. 8 is a graph showing an output signal of a detection circuit.

FIG. 9 is a graph showing an output signal of a comparator (a signal system side related to a narrow groove).

FIG. 10 is a graph showing frequency characteristics of LPF and BPF, and a spectrum of a signal related to a bar code symbol and a narrow groove.

FIG. 11 is a flowchart showing an operation procedure in a disc confirmation mode of the playback device.

[Explanation of symbols]

1 ... optical disc, 2 ... main information recording area, 3 ... clamper area, 4 ... mirror area, 5 ... barcode symbol, 5a ... bar element, 5b ... space element, 6 ... narrow groove, 10 ... carbonate layer, 11 ... Protective layer, 12 ... Reflective layer, 21 ... Optical pickup, 22 ... Spindle motor, 23 ... Servo circuit, 24 ...
Actuator driver, 25 ... Light intensity detection amplifier, 26,29
... Amplifier, 27 ... LPF, 28,32 ... Comparator, 30 ... B
PF, 31: detection circuit, 33: switch circuit, 34: bar code decoder, 35: microcomputer circuit.

Claims (2)

[Claims] 1. A bar comprising a bar element formed as a through hole long in a radial direction when viewed from the center of a disc, in a reflective layer of an optical disc other than a recording area of main information and readable by an optical pickup. The bar code symbol has information for identifying the optical disk, and is provided on the surface of each reflective layer between the adjacent bar elements in a radial direction when viewed from the center of the disk. An optical disc characterized by forming many long narrow grooves. 2. The optical disk reproducing apparatus according to claim 1, wherein, prior to reproduction of main information of the optical disk, a signal is read by moving an optical pickup to a bar code symbol configuration area while rotating the optical disk. Reading control means for causing the optical pickup to pass only a signal component obtained from a bar code symbol from a signal read by the optical pickup in the control process by the read control means; and an optical pickup in the control process by the read control means. A second filter means for passing only a signal component obtained based on a narrow groove formed between adjacent bar elements of a bar code symbol from a signal read by the second filter means, and an output signal of the second filter means is detected. Detecting means for generating bar code data based on an output signal of the first filter means; Data creating means, second data creating means for creating barcode data based on a detection output signal of the detection means, switching means for selectively outputting each barcode data by each of the data creating means, Storage means for storing each barcode data by switching the switching means; determining means for determining whether any one of the barcode data stored in the storage means is identification data given to a legitimate optical disc; Comparing means for comparing both barcode data stored in the storage means, and an optical disc only when the discriminating means discriminates that the discrimination data is identification data to be given to a regular optical disc, and the comparing means confirms a match. An optical disc reproducing apparatus, comprising: a determination unit for giving permission to reproduce the main information.