JP2003030830A - Optical disk discrimination method and optical disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for more accurately discriminating an optical disk having a plurality of recording layers. SOLUTION: In an optical disk unit for recording/reproducing information by using a plurality of optical disks, when address information recorded in the optical disk is read and layer information contained in the address information indicates that this layer information corresponds to the recording layer of an n-th layer, where n represents an integer of >=1, the optical disk is discriminated as having at least n recording layers and processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc discriminating method and an optical disc apparatus for recording or reproducing information using an optical disc, and more particularly to an optical disc reproducing technique for reproducing an optical disc having a plurality of information recording surfaces. Regarding

[0002]

2. Description of the Related Art Conventionally, an optical disc device which optically reads recorded information from an optical disc which is an optical information recording medium in which information is recorded by forming pits or the like on a disc-shaped optical recording medium is, for example, , CD, etc. are known, and as an optical recording medium having a large amount of information, there is a DVD, for example. Such a DVD or CD has a recording medium (DVD-RO) that can only reproduce information.
M, CD-ROM), recording media capable of recording once (CD-R, DVD-R), and recording media capable of recording a plurality of times (DVD-RAM, DVD-RW, CD).
Various recording media such as -RW) have been proposed.

The above various recording media can be roughly classified into a read-only type and a recordable type. The read-only type has information recorded in concave and convex pits, and the recordable type has a groove called a groove. Information is recorded along the groove in the groove (groove) or in the groove (land). In the DVD-RAM, recording is performed on both the groove and the land. DVD-RA
M includes a first-generation DVD-RAM of 2.6 GB on one side and a second-generation DVD-RAM of 4.7 GB on one side of a high-density type.
There is. Further, the DVD-ROM is classified into a single-layer type and a double-layer type with a read surface when viewed from one side.
The two-layer type includes a parallel type in which the second layer recording is from the inner circumference to the outer circumference and an opposite type in which the second recording is from the outer circumference to the inner circumference. Control information called control data is recorded on the inner circumference of the DVD disc. Information indicating the type of the disc is recorded in this control data, and the type of the disc inserted in the optical disc device can be specified by reading this information. In order to accurately perform the recording / reproducing operation on the various recording media, the optical disk device needs to be operated in a state suitable for each medium. Therefore, in the optical disk device, it is determined which kind of the recording medium is inserted in the device, and the inserted medium is set to the recordable / reproducible state according to the content of the determination. There is a need.

As a method of discriminating a recording medium inserted in an optical disc device, for example, in Japanese Patent Laid-Open No. 11-213530, various laser signals obtained by irradiating an optical disc with a laser for CD and a laser for DVD are sequentially applied. The recording medium inserted into the device is identified from. Further, in Japanese Patent Laid-Open No. 2000-311427, the above-mentioned Japanese Patent Laid-Open No. 11-
As in Japanese Patent No. 2153030, the optical disc is irradiated with a laser, and the recording medium inserted in the apparatus is discriminated by utilizing the time difference between the reflection from the recording surface and the disc surface. Also,
In the determination of the recording medium, the focus obtained when the optical disk is irradiated with laser light, the focus servo is turned off, and then the focus sweep operation (the objective lens is raised from the lowest point at a predetermined speed) is performed. If the number of error signals is two, it is discriminated as a DVD dual-layer disc,
If there is only one optical disc, a method of judging it as another optical disc is proposed.

As described above, by irradiating the optical disc with laser light and using various signals obtained from the reflected light, the type of the optical disc inserted in the device is discriminated from the difference in the characteristics of the optical disc. The method is often used. However, in the method of discriminating the type of the inserted optical disc only from the amount of reflected light with respect to the irradiation laser beam, it is difficult to discriminate accurately and in detail because of variations in the reflectance of the optical disc. Further, in a method of discriminating a DVD dual-layer disc from the number of focus error signals, a slice level is set in the focus error signal in order to prevent erroneous measurement due to reflected light from the disc surface, and a signal amplitude above the slice level is set. However, when the reflectance of the recording layer is low, only the signal amplitude below the slice level can be obtained, and the number measurement may be erroneous. Since the type and the number of layers of the optical disc inserted in such a device may be erroneously determined, in the case of a DVD disc, the information about the disc type finally recorded in the control data is acquired to determine the disc type. To determine.

FIG. 5 shows a processing flow embodying the above method.
Shown in. FIG. 5 is a flowchart showing a conventional optical disc discriminating method. In the figure, in step 1, the optical disc is inserted into the optical disc device. In step 2, the presence / absence of a disc is determined. If N (No) in step 2, that is, if no optical disc is detected, the process proceeds to step 14 and the optical disc device is stopped. Y in step 2
In the case of (Yes), that is, when it is detected that the optical disc is on the spindle, the spindle motor is rotated in step 3, and after the focus sweep operation, step 4 is performed.
Then, the focus servo control is turned on. In step 5, while utilizing the information on the focus sweep operation,
The type of the inserted optical disc is determined. Then, the rotation speed of the spindle motor, the servo control gain, the circuit gain related to the information reproduction, and the like are set according to the discriminated optical disc type. Next, in step 6, the tracking servo control is turned on. Now that you have made the basic settings, you can read the data. So in step 7,
The current track address is confirmed, and in step 8, it moves to the inner circumference, and in step 9, the control data located in the inner circumference of the data range used by the user is read. As a result of reading in step 10, it is determined whether or not the optical disc is different from the result of determination in step 5, and if the setting needs to be changed, that is, if Y (Yes) in step 10, then in step 11, The setting is changed according to the acquired control data, and activation is awaited in step 12. N (No) in step 10, that is, if there is no need to change,
The type of optical disc judged from the control data,
Since the optical disk types set in step 5 match, the process proceeds to step 12 and waits for activation. In step 13, the information is reproduced.

[0007]

Although most of the discrimination by the above-mentioned analog signal processing can be performed without any problem, the discrimination can be made when the amount of reflected light is partially reduced due to dust on the surface of the optical disk. May be mistaken. Even in that case, the next process cannot be performed normally, so that the process is performed again but the time is slightly increased, but this is not a big problem. In an example of the case where the error proceeds to step 6 in FIG. 5 without any problem and the address cannot be obtained in step 7, in the case where the two-layer disc is erroneously determined as the one-layer disc and the second layer is focused, Although the optical disk device searches for the address of the first layer, the address to be detected is the address of the second layer, so that the address is searched for all the time, and it takes time for the recovery process.

An object of the present invention is to provide a method in the case where the above-mentioned conventional disc discriminating process centered on the analog process makes an erroneous decision.
It is to provide a determination technique capable of proceeding to the next appropriate process in a short time.

[0009]

In order to achieve the above object, according to the present invention, focusing is performed on an optical disc inserted in an optical disc device in an area having address information of the optical disc, and an address of an information recording surface is obtained. Information is read, information regarding the layer of the recording surface of the optical disc is acquired from the read information, and when the number of layers of the recording face is two or more, the information is moved to the first layer and the information regarding the optical disc is acquired.

Further, according to the present invention, the address information of the optical disc inserted in the optical disc device is read, information on the number of recording layers of the optical disc is acquired from the read information, and the number of recording layers is obtained. When the information is 2 or more, the direction in which the track address of the layer currently reading information is increasing is determined to determine whether it is the parallel type or the opposite type. In the case of the parallel type, the control of the layer is performed. The data is read, and in the case of the opposite type, the control data recorded in the first layer is read.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings using examples. FIG. 1 is a block diagram showing an embodiment of a recordable / reproducible optical disk device according to the present invention. First, in FIG. 1, reference numeral 100 denotes an optical disc. An optical pickup 200 is an optical reproducing means.
Inside, a semiconductor laser 210 which is a light emitting element for generating a laser beam of a desired wavelength, a collimator lens 220 for collimating the emitted laser beam, an incident light to a mirror to be described later, and a reflected light to be described later. Half mirror 230 leading to the light receiving element, mirror 240 for changing the direction of light, objective lens 250 for irradiating the recording surface of optical disc 100 with a laser beam converged to a predetermined beam diameter, reflection from the half mirror 230 A light receiving element 260 for receiving and detecting light is provided.

Further, in FIG. 1, reference numeral 300 denotes a signal processing unit for converting the reflected light detected by the light receiving element 260 of the optical reproducing means into an electric signal and performing a predetermined process. The signal processing unit 300 is connected to a system controller 400 provided for controlling the entire optical disc device, and performs various drive controls including an optical disc discriminating method described in detail below. That is, the system controller 400 is capable of performing various controls, and the laser drive unit 500 and the feed control unit 60.
0, the spindle control unit 700, and the two-dimensional actuator control unit 800.

That is, in the above structure, the system controller 400 controls the current supplied to the semiconductor laser 210 to control the light emission intensity thereof, and also controls the rotation of the feed control motor 650, thereby The position of the optical pickup 200 in the radial direction of the optical disc 100 is controlled. In this embodiment, as a mechanism for moving the optical disc 100 in the radial direction, a motor 65 for feed control is used.
A gear 660 for moving the optical pickup 200 in the radial direction by the rotation of 0 is shown. However, it is not limited to this.

Further, the system controller 400 controls the rotation of the motor 750 that rotationally drives the spindle, so that the CAV (Constant) control, which is widely adopted in such optical disk devices, is constant angular velocity control.
Angular Velocity) or CLV (Constant Lin), which is a constant linear velocity control.
realizes the ear velocity) control and the like. Further, the system controller 400 realizes the focus position control of the objective lens 250 of the optical pickup 200 by the two-dimensional actuator control unit 800, for example, by driving the electromagnetic coil 850 or the like as its operating means. The two-dimensional position control realized by the two-dimensional actuator control unit 800 includes the position control (focus control) of the objective lens 250 in the direction perpendicular to the recording surface of the optical disc 100, and
The tracking position control for following the track is performed by minute position adjustment in the radial direction at right angles thereto.

In the above-mentioned optical disk device, a host (external device) (not shown) such as a personal computer
The interface control circuit (not shown) decodes the command and information data from the device, and under the control of the system controller 400, information recording, reproduction, seek operation, and the like are executed. In addition, the signal processing unit 300 performs signal conversion to record information on the optical disc 100 via the optical pickup 200, and various signals read via the light receiving element 260 are converted into original data via the signal processing unit 300. It is also possible to demodulate and transfer the demodulated data from the interface control circuit to the host in response to a reproduction command.
A detailed description of the information recording / reproducing operation will be omitted.

At the time of recording / reproducing, various control information recorded on the optical disc 100 is generated by the signal processing unit 300 and used for the control signals of the various control units described above. The optical disk device is required to record / reproduce various kinds of optical disks. CD-ROM, CD-R,
CD-RW, DVD-ROM (one-layer disc and two-layer disc are available), DVD-R, DVD-RW, DVD-R
There are many types of optical discs such as AM, and it is necessary to discriminate the types of these optical discs and perform recording or reproduction under conditions suitable for each.

FIG. 2 is a block diagram showing a detailed embodiment of a recordable / reproducible optical disc device according to the present invention. A light receiving element 260 in the optical pickup 200 which is an optical reproducing means in the optical disc device for recording / reproducing the optical disc. And a signal processing unit 300 for processing the detection signal thereof
A detailed configuration including the and surrounding areas is shown. As is apparent from FIG. 2, the light receiving element 260 is divided into four detecting portions A, B, C, and D, and the reflected light reflected by the recording surface of the optical disc 100 and incident on the light receiving element 260. Is an I / V connected to each of the divided detection units.
The conversion unit 261 converts each to an electric signal and outputs the electric signal. The I / V conversion unit 261 includes a gain switching unit 37.
0 is provided, and the gain can be switched according to an instruction from the system controller 400. This I
The / V converter 261 converts the current flowing through the light receiving element into a voltage and outputs the voltage, and switches the conversion gain by changing the conversion resistance value (I / V resistance).

The outputs from the I / V converter 261 are input to the adder circuits 301 to 304, respectively (A + C),
Addition of (B + D), (A + D), and (B + C) is performed. Furthermore, the outputs from the adder circuits 301 and 302 are input to the adder circuit 305, whereby all the outputs from the detection units A, B, C, D are added (A + B +).
The sum signal of (C + D) is output. In addition, the addition circuit 301
The outputs from the and 302 are also input to the subtraction circuit 306 at the same time, whereby ((A + C)-
A tracking error signal TE, which is a signal for tracking control represented by (B + D)), is output.

On the other hand, this tracking error signal TE
At the same time, after passing through the low-frequency pass filter (LPF) 308, the offset setting 350 and the gain setting 35
1, sent to the two-dimensional actuator control unit 800 through the polarity setting 352. Here, the offset value and the gain value are set as the TEOF (tracking error offset) and the TEG (tracking error gain) from the system controller 400, respectively. The polarity setting 352 is used for the DVD-RAM disc, and the polarity of the land and the groove is switched for each circumference of the disc according to an instruction from the system controller 400. The TE amplitude detection circuit 353 measures the amplitude of the tracking error signal TE and reports the measurement data to the system controller 400. On the other hand, the signals (A + D) and (B + C) output from the adder circuits 303 and 304 are input to the subtraction circuit 311, thereby obtaining the focus error signal FE represented by ((A + D)-(B + C)). To be The focus error signal FE is sent to the two-dimensional actuator control unit 800 via the offset setting 330 and the gain setting 332, and controls the focus position of the objective lens 250 of the optical pickup 200 (direction perpendicular to the recording surface of the optical disc 100). . Here, the offset value and the gain value are FEO, respectively.
An instruction is sent from the system controller 400 as F and FEG and set to the value. FE amplitude detection circuit 333
Is to measure the amplitude of the focus error signal FE and report the measurement data to the system controller 400.

Further, the sum signal (A +
B + C + D) is then a low frequency pass filter (LP
F) 320, and is sent to the PE amplitude detection circuit 363 through the offset setting 360 and the gain setting 361. The PE amplitude detection circuit 363 measures the amplitude of the sum signal (PE signal) and outputs the measured data to the system controller 400.
To be reported to. Here, the offset value and the gain value are set as PEOF and PEG, respectively, as instructed by the system controller 400.

Next, an outline of the optical disc discriminating method of the optical disc device will be described with reference to FIG. FIG. 3 is a flow chart for explaining an embodiment of the optical disc discriminating method according to the present invention. Although FIG. 3 shows only the case where the optical disc to be inserted into the optical disc device is a DVD single layer disc or a DVD double layer disc,
When another optical disk is inserted, for example, Japanese Unexamined Patent Publication No.
It is possible to determine the type of the optical disc inserted in such a device by using the method disclosed in Japanese Patent Publication 1-213530. That is, when the type of the optical disc is determined to be the DVD single-layer disc or the DVD double-layer disc by the above method, the present invention may be applied to finally determine whether it is the DVD single-layer disc or the DVD double-layer disc. , And can be easily combined with other discrimination methods.

In the following description, the same contents as those of the prior art made with reference to FIG. 5 are indicated by the same numbers. In FIG. 3, when the optical disc is inserted into the optical disc device in step 1, the disc presence / absence determination is first performed in step 2. In the step of judging the presence or absence of this disc,
It also includes an item for determining whether the optical disk inserted in the device is normally chucked. In step 2, N
In the case of (No), that is, when it is determined that there is no disc or the chucking is not normally performed, the optical disc device determines that there is no disc, and proceeds to step 14.
It ends as it is. If it is determined in step 2 that the disc is present, that is, if Y (Yes), the process proceeds to step 3 to activate the spindle motor and rotate the disc at a predetermined rotation speed. After the rotation of the spindle motor is settled, various adjustments for turning on the focus servo are performed, and in step 4, the focus servo is turned on. After the focus servo is turned on, in step 5,
Various adjustments are performed to turn on the tracking servo, and in step 6, the tracking servo is turned on. After that, or before turning on the focus servo and the tracking servo, the system controller 400 is set so that the information from the optical disc can be read.

The process of turning on the focus servo will be described with reference to FIG. FIG. 4 is a characteristic diagram showing a focus error signal and a focus actuator drive voltage, and FIG. 4A is a characteristic diagram showing a focus error signal from the surface of the optical disc, the first layer and the second layer. The focus error signal FE is plotted on the vertical axis with time t.
FIG. 4B is a characteristic diagram showing the focus actuator drive voltage, in which the horizontal axis shows time t and the vertical axis shows the focus actuator drive voltage FA.

First, as shown in FIG. 4B, a focus actuator drive voltage is applied so that the focus actuator moves vertically downward with respect to the information recording surface of the optical disc. This applied voltage is assumed to move the actuator to a position sufficiently distant from the position where the focus servo is turned on. After that, the focus actuator drive voltage is applied in the direction in which the focus actuator approaches the information recording surface of the optical disc. This is called a focus sweep operation. During this focus sweep operation, the optical disc is irradiated with laser light, and the focus error signal FE generated from the reflected light is
Observation is performed at predetermined time intervals using the amplitude detection circuit 333. During this focus sweep operation, as shown in FIG. 4A, first, a focus error signal FE1 due to reflection from the optical disk surface is observed. If the focus servo is turned on at this position, the information recorded on the recording surface cannot be read. Therefore, in order not to turn on the focus servo on the surface of the optical disk, the determination level for turning on the focus servo is set by the level of the focus error signal FE. At this time, the determination level is set to a level at which the focus servo is not turned on by the focus error signal FE1 from the optical disk surface. When the focus sweep operation is further continued after observing the focus error signal FE1, the focus error signal FE due to reflection from the information recording surface is observed.
One focus error signal FE is observed in the case of an optical disc having only one information recording surface and two in the case of an optical disc having two information recording surfaces.

In a DVD dual-layer disc, the reflectance of the first layer is generally lower than that of the second layer, so that the focus error signal FE2 of the judgment level L or higher is generated from the first layer due to various factors of variation. However, the focus error signal FE3 exceeding the determination level may be generated in the second layer, and the focus servo may be turned on in the second layer. Of course 1
The focus error signal FE2 obtained from the layer may exceed the determination level L. On the other hand, since the DVD single-layer disc has only one recording surface, the focus servo can always be turned on at the first recording surface by setting the determination level in consideration of the influence of surface reflection. . Therefore, in the case of a DVD single-layer disc, the focus servo can be turned on without fail in the first layer. DV
In the case of the D2 layer disc, there are two cases, that is, the focus servo is turned on in the first layer and the focus servo is turned on in the second layer.

Returning to FIG. 3, description will be made. After the focus and tracking servo are turned on in step 6, the address information recorded on the optical disk is read in step 7. The read information includes information about the address. In the case of a DVD, layer information is recorded at this address. Therefore, it is possible to determine whether the position where the information is read from the optical disc is the first layer or the second layer. D
In the case of the VD 1-layer disc, the focus servo is always turned on in the first layer, so that information indicating the first layer is always read from the layer information. On the other hand, D
In the case of the VD dual-layer disc, as described above, there are two types of layer information, that is, the first layer and the second layer depending on the condition that the focus servo is turned on. In step 15, if the layer information indicates that it is the second layer, that is, if Y (Yes), it means that the optical disc has two or more information recording surfaces. It can be determined that there is.

There are two types of DVD dual-layer discs, a parallel type in which the track of the second layer goes from the inner side to the outer side like the first layer, and an opposite type in which the track of the second layer goes from the outer side to the inner side. At the moment when is read, it is not possible to determine which type it is. for that reason,
If it is determined in step 15 that the second layer or more is present, the process proceeds to step 16 and a focus jump is performed (the focused layer is moved to the upper or lower recording layer) to perform 1 Move to the layer, move to the inner circumference side in step 8, and read the control data in step 9. As a result of acquiring the control data in step 9,
If the condition is different from the one you initially set, step 1
If the change is required at 0, that is, if Y (Yes), the setting is changed at step 11, and the start command is waited at step 12. If it is determined in step 10 that the setting need not be changed, that is, if N (No), then in step 12, the activation command is awaited.

In the case of this embodiment, it is considered that the focus error signal of the first layer is small at the time of the focus jump of step 16, so that the gain of the focus error signal is set to a larger value in advance or the focus jump fails. However, it is necessary to surely move to the first layer by accelerating so as to return to the original second layer and repeating the method while changing the gain of the focus error signal. The method for surely moving to the first layer in the focus jump is not limited to the above, and various other methods and combinations thereof can be used.

The second embodiment for reading the control data without the focus jump as described above will be described below. In the parallel type two-layer disc, the control data is also recorded in the second layer. Therefore, the second embodiment is a method of reading the control data of the second layer. When it is determined that the second layer is present, it is necessary to determine whether it is the parallel type or the opposite type as described above. As a means therefor, for example, a track jump is continuously performed on the inner circumference side of the optical disc. Since one track jump is completed in 5 msec or less, the track jump can be performed several times while the optical disk makes one rotation. Therefore, for example, after performing track jumps for 5 tracks in succession, the track address is read out and compared with the address at the start of the track jump, and it can be seen that if the track address is large, it is the opposite type, and if it is small, it is the parallel type. This makes it possible to determine which type it is. Therefore, in the case of the parallel type, it is possible to obtain the track address of the control data position, move the focus for reading, and acquire the control track information.

Further, as described above, the present invention can be easily combined with other discrimination methods, the probability of erroneous discrimination can be dramatically reduced, and it is a very effective means.

As described above, according to the present invention, the DV
In the case of a D disc, it can be known from the acquired address information whether it is a single-layer disc or a dual-layer disc. In the case of a DVD single layer disc, the focus servo is turned on in the first layer,
By acquiring the control data, it can be surely known that the disc is a single-layer disc. In the case of a DVD dual-layer disc, the focus servo may be turned on in the first layer and may be turned on in the second layer. In this case, the address information recorded on the disc is read to know the address. Since the address includes information on the first layer or the second layer, in the case of the second layer, the focus jump is performed on the first layer, the pickup is moved to the inside of the disc, and the control data is transmitted. By acquiring it, the disc type can be accurately determined. If it is found from the acquired track address that the focus is on for the second layer, the track jump is performed a plurality of times inside the optical disc to obtain the track address, and whether the parallel type or opposite type is to be obtained. In the case of the parallel type, the pickup can be moved to the control data position to acquire the control data. In the case of the opposite type, by performing a focus jump on the first layer and moving the pickup to the control data position,
The control data can be acquired and the disc type can be accurately determined.

[0032]

As described above, according to the present invention, an optical disc having a plurality of recording layers can be discriminated probabilistically at an early stage, so that the setting operation of the optical disc recording / reproducing apparatus can be performed in a short time. Therefore, there is an effect that the recording / reproducing operation of information under the optimum recording / reproducing conditions can be started quickly.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a recordable / reproducible optical disk device according to the present invention.

FIG. 2 is a block diagram showing a detailed embodiment of an optical disk device capable of recording and reproducing according to the present invention.

FIG. 3 is a flow chart for explaining an embodiment of an optical disc discriminating method according to the present invention.

FIG. 4 is a characteristic diagram showing a focus error signal and a focus actuator drive voltage.

FIG. 5 is a flowchart showing a conventional optical disc discriminating method.

[Explanation of symbols]

100 ... Optical disc, 210 ... Semiconductor laser, 220 ...
Collimating lens, 230 ... Half mirror, 250 ... Objective lens, 260 ... Light receiving element (detector), 261 ...
I / V converters, 303, 304 ... Addition circuit, 311 ... Subtraction circuit, 333 ... FE amplitude detection circuit, 353 ... TE amplitude detection circuit, 363 ... PE amplitude detection circuit, 370 ... Gain switching, 400 ... System controller, 800 … Two-dimensional actuator controller.

Continued front page    F-term (reference) 5D066 DA12 HA01                 5D090 AA01 BB04 BB12 CC04 CC16                       CC18 EE16 EE18 FF21 FF49                       GG11 HH01 JJ11 LL08                 5D117 AA02 AA09 CC01 DD10 FF02                       GG02

Claims (7)

[Claims] 1. A step of obtaining address information of an optical disc inserted in an optical disc device, a step of obtaining information on the number of layers of a recording surface of the disc from the address information, and a number of layers of two or more from the information. In Case of,
A method of discriminating an optical disc, comprising: focusing the pickup on the first layer to obtain the control data recorded on the first layer. 2. A step of reading address information of an optical disk inserted in an optical disk apparatus, a step of obtaining information on the number of recording layers of the optical disk from the read information, and a number of layers of the recording surface. When the information indicates two or more, the information reading means is moved so that the layer from which information is read is the first layer, and the control data recorded on the first layer is read. An optical disc discriminating method comprising: 3. A step of reading address information of an optical disk inserted in an optical disk apparatus, a step of acquiring information on the number of recording layers of the optical disk from the read information, and a number of layers of the recording surface. When the information indicates that the number is 2 or more, the step of determining the increasing direction of the track address of the layer from which the information is currently read is determined, and based on the determination result, the information is recorded in the layer or the first layer. And a step of reading control data. 4. The optical disc discriminating method according to claim 3, wherein in the track address discriminating step, when it is found that the optical disc is a parallel type, the control data of the layer is read. . 5. A means for reading address information of an optical disk inserted in the storage, and acquiring information on the number of recording layers of the optical disk from the read information.
An optical disk device comprising: a means for moving the information reading means to the first layer and reading the control data recorded on the first layer when the information regarding the number of layers on the recording surface is two or more. 6. A unit for reading address information of an optical disk inserted in an apparatus and acquiring information about the number of recording layers of the optical disk from the read information; When the above is indicated, the means for discriminating the increasing direction of the track address of the layer currently reading information, and the control data recorded in the layer or the first layer are determined based on the discrimination result. An optical disk device comprising: a reading unit. 7. The optical disk device according to claim 6,
When the means for determining the direction of the track address determines that the optical disc is an opposite type, the information reading means is moved to the first layer to read the control data recorded on the first layer. Optical disk device.