JPH06162554A - Optical disk device - Google Patents

Abstract

PURPOSE:To shorten the time for verifying data on the entire surface of an optical disk and waiting time until starting the write operation of data by providing plural read/write means to be independently controlled. CONSTITUTION:This device is provided with the first and second read/write means composed of read/write circuits 4a and 4b for controlling the read/write of data, optical heads 8a and 8b controlled by these circuits 4a and 4b, and servo circuits 5a and 5b for controlling the positions of optical heads 8a and 8b to a prescribed track. Thus, since the format verify from an intermediate track to an outermost peripheral track is performed under the control of one read/write circuit 4b while the format verify from an innermost peripheral track to the intermediate track is performed under the control of the other read/write circuit 4b, time for verifying the entire surface of a magneto-optical disk 9 is reduced by half, and format verify time is considerably shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device for reading / writing data from / on optical recording media such as magneto-optical disks and optical disks.

[0002]

2. Description of the Related Art FIG. 1 is a schematic configuration diagram of a conventional magneto-optical disk device shown on page 10 of the book "Signal processing technology in optical recording" issued by Trikeps Co., Ltd. on February 20, 1989, for example. Is. The magneto-optical disk device 2 is controlled by a command from the host computer 1. The host computer 1 is connected to an internal controller 14 that controls the servo circuit 5, the loading mechanism 11 and the exciting coil driver 13 via an interface circuit 3 including a memory etc.
It is connected to a read / write circuit 4 which demodulates when receiving a read command and modulates when receiving a write command.

The internal controller 14 is connected to an excitation control driver 13 that controls the excitation coil 12, and the excitation coil driver 13 is connected to the excitation coil 12 that applies a magnetic field to the magneto-optical disk 9. The internal controller 14 also controls the magneto-optical disk 9 for storing data to the magneto-optical disk device 2
It is connected to a loading mechanism 11 for loading inside. Further, when the internal controller receives a seek command via the interface circuit 3, it is connected to the servo circuit 5 for controlling the position of the optical head 8 on a predetermined track of the magneto-optical disk 9 by this seek command. The read / write circuit 4 is connected to the servo circuit 5, and is also mounted on the optical head carriage 7 and is connected to the optical head 8 which projects light onto the magneto-optical disk 9 and receives the reflected light.

The servo circuit 5 is connected to a linear motor 6 for moving an optical head carriage 7 carrying an optical head 8 and a servo coil 15 for performing tracking servo and focus servo of the optical head 8. It is connected to a spindle motor 10 that rotates the magneto-optical disk 9.

Next, the operation of this magneto-optical disk device will be described. First, the case of reading data from the magneto-optical disk will be described. When the magneto-optical disk 9 is loaded into the magneto-optical disk device 2 by the loading mechanism 11,
The magneto-optical disk 9 is rotated at high speed by a spindle motor 10. When the rotation of the magneto-optical disk 9 becomes a constant speed and the data can be read and written, a seek command for moving the optical head 8 from the host computer 1 to the track position where the data is written is issued by the magneto-optical disk device. 2 is sent. When this seek command is input to the interface circuit 3, the interface circuit 3
Interprets this and supplies it to the internal controller 14, which controls the read / write circuit 4 and supplies the moving direction data and distance data to the servo circuit 5.

The servo circuit 5 drives the linear motor 6 based on the given movement direction data and distance data to move the optical head carriage 7 in the radial direction of the magneto-optical disk 9. Then, the position data recorded on the magneto-optical disk 9 is read by the read / write circuit 4 via the optical head 8 and is applied to the servo circuit 5 to perform feedback control of the data to position the optical head 8 on the target track. Let When this seek command is completed, a read command for reading data is transmitted from the host computer 1. Then, a light beam having a low light output is emitted from the optical head 8 and projected onto the magneto-optical disk 9, and the reflected light is received by the optical head 8 and photoelectrically converted, and the read / write circuit 4 demodulates the interface circuit. Data is sent to the host computer 1 via 3 and a series of data read operations is completed.

When a data write operation is performed next, a write command for writing data is transmitted from the host computer 1 after the seek command is completed as in the data read operation. This data write operation first erases the data before writing the data. For erasing data, the exciting coil 12 is excited by the exciting coil driver 13 with the magnetization direction facing upward, and a light beam with a high optical output is continuously emitted from the optical head 8 so that the magnetization direction of the magneto-optical disk 9 faces upward. It will be achieved by aligning with, and then the data will be written.

Therefore, first, the exciting coil driver 13 excites the magnetizing direction of the exciting coil 12 downward. The read / write circuit 4 modulates the data according to the write command transmitted to the read / write circuit 4 via the interface circuit 3, and when the modulated data is (1), the optical head 8
The magnetization direction is changed to downward by emitting a high-power optical beam from. Then, this operation is repeated according to the data to be written, and a series of write operations is completed.

Next, the format verify will be described. The format verify operation is performed for the purpose of inspecting the magneto-optical disk 9. After erasing data as described above, a predetermined data pattern is written on the magneto-optical disk 9 by the method described above, and then by the method described above. By reading the written data pattern, the read / write circuit 4 compares whether the written data and the read data are the same, and the result of comparison is that the magneto-optical disk 9 is designated. Defect data called a defect list is registered in the position.

[0010]

As described above, since the conventional magneto-optical disk device has a single optical head, it takes a long time to perform format verification on the entire surface of the magneto-optical disk, for example. And Further, when the data writing operation is completed, the verification is subsequently performed, so that there is a problem that it takes a long time until the data is correctly written, that is, the data writing is completed. In view of such a problem, the present invention provides an optical disc device that can shorten the time for formatting and verifying the entire surface of an optical recording medium, and that, when the data writing operation is completed, the verification of the written data is completed. To aim.

[0011]

An optical disk device according to a first aspect of the present invention includes a circuit for reading and writing data, an optical head for projecting light on an optical recording medium and receiving the reflected light, and an optical recording medium. The first and second read / write means each of which includes a servo circuit for controlling the position of the optical head on the predetermined track. An optical disk device according to a second aspect of the present invention includes a first optical head and a second optical head that are interlocked with each other in the radial direction of an optical recording medium. The head is configured to perform an operation of verifying the written data. Further, a high light output optical head is used for one optical head, and a low light output optical head is used for the other optical head.

[0012]

According to the first aspect of the present invention, the servo circuit of the first read / write means moves the optical head to a predetermined track of the optical recording medium to write, read or verify data from the predetermined track. The servo circuit of the second read / write means moves the optical head to a predetermined track of the optical recording medium to write data from the predetermined track,
Read or verify. As a result, when both read / write means perform verification, the time required for format verification of the entire surface of the optical recording medium is shortened. When one of the read / write means is made to write and the other read / write means is made to verify, the waiting time at the time of shifting to the write operation is shortened.

In the second invention, data is written by one of the first optical head and the second optical head, and the data written by the other optical head is simultaneously verified.
As a result, when data is written, the written data can be verified at the same time, and the data write completion time is shortened. Further, the cost can be reduced by using an optical head having a low light output as one of the optical heads.

[0014]

The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 2 is a schematic configuration diagram of a magneto-optical disk device which is an optical disk device according to the present invention. The magneto-optical disk device 2 is controlled by a command from the host computer 1. The host computer 1 is an internal controller that controls the servo circuit 5a, the loading mechanism 11 and the exciting coil driver 13a via the interface circuit 3 including a memory etc.
14a and a read / write circuit 4a that demodulates when a read command is received and modulates when a write command is received. The internal controller 14a is connected to an exciting coil driver 13a which controls the exciting coil 12a, and the exciting coil driver 13a gives an exciting magnetic field to the magneto-optical disk 9.
Connected with 12a.

The internal controller 14a is connected to a loading mechanism 11 for loading the magneto-optical disk 9 for storing data into the magneto-optical disk device 2.
Further, when the internal controller 14a receives a seek command via the interface circuit 3, the internal controller 14a is connected to the servo circuit 5a for controlling the position of the optical head 8a on a predetermined track of the magneto-optical disk 9 by the seek command.

The read / write circuit 4a is an optical head carriage
It is mounted on 7a and is connected to an optical head 8a that projects light onto the magneto-optical disk 9 and receives the reflected light, and is also connected to the servo circuit 5a. The servo circuit 5a is connected to a linear motor 6a for moving the optical head carriage 7a carrying the optical head 8a along the radial direction of the magneto-optical disk 9, and a servo for performing tracking servo and focus servo of the optical head 8a. It is connected to the coil 15a and further connected to a spindle motor 10 for rotating the magneto-optical disk 9.

The host computer 1 also controls, via the interface circuit 3, an internal controller 14b for controlling the exciting coil driver 13b, a read / write circuit 4b for demodulating when receiving a read command and modulating when receiving a write command, When the seek command is received, the seek command is connected to the servo circuit 5b for controlling the position of the optical head 8b on a predetermined track of the magneto-optical disk 9.

The internal controller 14b is connected to an exciting coil driver 13b which controls the exciting coil 12b, and the exciting coil driver 13b is connected to the exciting coil 12b which gives a magnetic field to the magneto-optical disk 9. The read / write circuit 4b is mounted on the optical head carriage 7b, is connected to the optical head 8b that projects light onto the magneto-optical disk 9 and receives the reflected light, and is also connected to the servo circuit 5b. The servo circuit 5b is a linear motor 6b for moving the optical head carriage 7b carrying the optical head 8b along the radial direction of the magneto-optical disk 9.
And a servo coil 15b for performing tracking servo and focus servo of the optical head 8b. The optical heads 8a and 8b are arranged symmetrically in the radial direction of the magneto-optical disk 9. The exciting coils 12a, 12b are arranged at positions facing the optical heads 8a, 8b with the magneto-optical disk 9 in between.

Next, the operation of the magneto-optical disk device configured as described above will be described. First, the magneto-optical disk 9 is loaded into the magneto-optical disk device 2 by the loading mechanism 11 according to an instruction from the host computer 1.
The loaded magneto-optical disk 9 is rotated at a high speed by the spindle motor 10, and when the rotation of the magneto-optical disk 9 becomes a constant speed and data can be read and written, the magneto-optical disk 9 from the host computer 1 is read.
A seek command for moving the optical heads 8a and 8b to the predetermined track position is transmitted to the magneto-optical disk device 2.

When this seek command is input to the interface circuit 3, the interface circuit 3 interprets it and gives it to the internal controllers 14a and 14b.
Reference numeral b controls the read / write circuits 4a and 4b to drive the linear motor 6 based on the moving direction data and the distance data to move the optical head carriage 7. Thereby, for example, the optical head 8a moves to the innermost track of the magneto-optical disk 9 and the optical head 8b moves to the intermediate track located between the innermost track and the outermost track of the magneto-optical disk 9. Here, when the format verify command is transmitted from the host computer 1, the format verify command is input to the interface circuit 3 and is interpreted by the interface circuit 3 to be interpreted by the internal controller.
14a and 14b control the read / write circuits 4a and 4b together.

As a result, the one read / write circuit 4a and the servo circuit 5a are controlled to erase the data from the innermost track to the intermediate track of the magneto-optical disk 9, and then write and write a predetermined data pattern. The data pattern is read, and the read / write circuit 4a compares whether the written data is equal to the read data, and the format verify is performed. The other internal controller 14b controls the read / write circuit 4b, and the servo circuit 5b is controlled to erase data from the middle track to the outermost track of the magneto-optical disk 9,
A predetermined data pattern is written, the written data pattern is further read, and the read / write circuit 4b compares the written data with the read data to perform format verification. Then, defective data called a defect list is registered in the designated position of the magneto-optical disk 9 as a result of comparison, but is additionally written in the designated position of the magneto-optical disk 9 by mutual communication between the internal controllers 14a and 14b.

With this arrangement, when the read / write circuit 4a on one side controls the format and verify from the innermost track to the intermediate track,
Since the format read / verify from the intermediate track to the outermost track is performed by the other read / write circuit 4b, the time to format / verify the entire surface of the magneto-optical disk 9 is halved, and the time to format / verify the entire surface of the magneto-optical disk 9 is reduced. Can be significantly shortened.

If write verification is performed by one read / write circuit 4a, data is written to the magneto-optical disk 9 under the control of the other read / write circuit 4b. It is not necessary to shift to the data write operation, and the waiting time before shifting to the data write operation can be shortened.

In this embodiment, two read / write circuits are provided and an optical head is provided corresponding to them, but this is an example, and the number of circuits is within a range in which the physical space of the magneto-optical disk device is allowed. Also, the number of optical heads may be increased. In that case, the time can be further shortened as the number of read / write circuits increases. Although the present embodiment has been described with respect to the magneto-optical disk device, the same effect can be obtained with an optical disk device that reads and writes data on the optical disk. Of course, the same effect can be obtained even if the data is read or written only.

FIG. 3 is a schematic block diagram showing another embodiment of the optical disk device according to the present invention. The host computer 1 demodulates when it receives a read command and an internal controller 14 that controls the servo circuit 5 and the excitation coil driver 13 via the interface circuit 3 in the magneto-optical disk device 2, and modulates when it receives a write command. It is connected to the read / write circuit 4. Internal controller 14 is an exciting coil
The excitation coil driver 13 is connected to the excitation coil driver 13, which controls the coil 12, and the excitation coil driver 13 is connected to the excitation coil 12. When the internal controller 14 receives a seek command through the interface circuit 3, the seek command causes the magneto-optical disk 9 to operate.
Is connected to the servo circuit 5 for controlling the optical head carriage 7 to move the optical head 8a for high light output dedicated to reading and writing and the optical head 8b for low light output dedicated to verify.

The read / write circuit 4 is connected to the servo circuit 5 and is mounted on the optical head carriage 7, and is connected to an optical head 8a (8b) that projects light onto the magneto-optical disk 9 and receives the reflected light. To be done. The servo circuit 5 is an optical head 8a
A servo coil 15a (which is connected to the linear motor 6 for moving the optical head carriage 7 having (8b) mounted therein in the radial direction of the magneto-optical disk 9 and for performing tracking servo and focus servo of the optical head 8a (8b) ( 15b), and further connected to a spindle motor 10 for rotating the magneto-optical disk 9. The exciting coil 12 is arranged at a position facing the read-only optical head 8a via the magneto-optical disk 9. Note that the loading mechanism is not shown for convenience.

FIG. 4 shows a magneto-optical disk 9 and optical heads 8a and 8b.
It is a state diagram showing a positional relationship with. An optical head carriage 7 is provided on the lower surface side of the magneto-optical disk 9 so as to be movable in the radial direction of the magneto-optical disk 9 through the axis of a spindle motor 10 for rotating the magneto-optical disk 9. An optical head 8a dedicated to reading and writing and an optical head 8b dedicated to verifying are juxtaposed on the upper surface of the optical head carriage 7 in a direction orthogonal to the moving direction of the optical head carriage 7 with a proper distance.

Next, the operation of the magneto-optical disk device configured as described above will be described. When a seek command from the host computer 1 is input to the interface circuit 3, the interface circuit 3 interprets the input command, whereby the internal controller 14 controls the servo circuit 5 and the servo circuit 5 causes the linear motor to operate. 6 is driven to move the optical head carriage 7 to move the optical heads 8a and 8b to predetermined track positions. When a write command for writing data is transmitted from the spindle computer 1 after completion of the seek command, the interface circuit 3 interprets the write command and the internal controller 14 controls the read / write circuit 4 to control the light beam from the optical head 8a. Is emitted to irradiate the magneto-optical disk 9 to write data on a predetermined track. The optical head 8b dedicated to verification is written at the same time when data is written in this way.
The written data is read by the optical head 8a and the written data is verified. If the written data is defective, the write operation is immediately performed, and the data write operation and the verify operation are repeated until the written data and the read data are equal, and the data write operation is performed. Ends.

In this way, the verification can be performed at the same time as writing the data, so that it does not take a long time to complete the data writing operation. Further, the cost of the magneto-optical disk device can be reduced by using an expensive optical head having a high optical output as an optical head dedicated to reading and writing and using an inexpensive optical head having a low optical output as an optical head dedicated to verifying.

In this embodiment, data writing and
Write (verify) ・ Verify was performed at the same time, but
It is also possible to simultaneously perform format verify and write (write) verify when initializing the magneto-optical disk. Also, even if two optical heads are used,
The number of control circuits does not have to be the same as the number of optical heads, and the control circuits can be simplified. Furthermore, although the magneto-optical disk device has been described,
The same effect can be obtained even in the optical disk device for writing. Of course, the same effect can be obtained even if the data is read or written only.

[0031]

As described above in detail, according to the first invention,
Since a plurality of read / write means that can be controlled independently are provided, when performing format verify on the entire surface of the optical recording medium, format verify can be performed by different read / write means from different tracks of the optical recording medium. The time required to format and verify the entire surface can be greatly reduced. In addition, while data is being verified by one read / write means, data can be written in parallel by another read / write means. Need not be written, and the waiting time before shifting to the data write operation can be shortened. According to the second aspect of the invention, the data is written by one optical head and the data is verified by the other optical head at the same time. Therefore, when the data writing operation is completed, the operation for verifying the data is completed. Further, there is an excellent effect that the time until the data writing is completed can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a conventional magneto-optical disk device.

FIG. 2 is a schematic configuration diagram of an optical disk device according to the present invention.

FIG. 3 is a schematic configuration diagram showing another embodiment of the optical disk device according to the present invention.

FIG. 4 is a state diagram showing a positional relationship between a magneto-optical disk and an optical head.

[Explanation of symbols]

 1 host computer 3 interface circuit 4a, 4b read / write circuit 5a, 5b servo circuit 6a, 6b linear motor 7a, 7b optical head carriage 8a, 8b optical head 9 magneto-optical disk 10 spindle motor 11 loading mechanism 12a, 12b exciting coil 13a , 13b Excitation coil driver

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art FIG . 4 is a schematic configuration diagram of a conventional magneto-optical disk device shown on page 10 of a book "Signal processing technology in optical recording" issued by Trikeps Co., Ltd. on February 20, 1989, for example. Is. The magneto-optical disk device 2 is controlled by a command from the host computer 1. The host computer 1 is connected to an internal controller 14 that controls the servo circuit 5, the loading mechanism 11 and the exciting coil driver 13 via an interface circuit 3 including a memory etc.
It is connected to a read / write circuit 4 which demodulates when receiving a read command and modulates when receiving a write command.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic configuration diagram of a magneto-optical disk device which is an optical disk device according to the present invention. The magneto-optical disk device 2 is controlled by a command from the host computer 1. The host computer 1 is an internal controller that controls the servo circuit 5a, the loading mechanism 11 and the exciting coil driver 13a via the interface circuit 3 including a memory etc.
14a and a read / write circuit 4a that demodulates when a read command is received and modulates when a write command is received. The internal controller 14a is connected to an exciting coil driver 13a which controls the exciting coil 12a, and the exciting coil driver 13a gives an exciting magnetic field to the magneto-optical disk 9.
Connected with 12a.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

FIG . 2 is a schematic block diagram showing another embodiment of the optical disk device according to the present invention. The host computer 1 demodulates when it receives a read command and an internal controller 14 that controls the servo circuit 5 and the excitation coil driver 13 via the interface circuit 3 in the magneto-optical disk device 2, and modulates when it receives a write command. It is connected to the read / write circuit 4. Internal controller 14 is an exciting coil
The excitation coil driver 13 is connected to the excitation coil driver 13, which controls the coil 12, and the excitation coil driver 13 is connected to the excitation coil 12. When the internal controller 14 receives a seek command through the interface circuit 3, the seek command causes the magneto-optical disk 9 to operate.
Is connected to the servo circuit 5 for controlling the optical head carriage 7 to move the optical head 8a for high light output dedicated to reading and writing and the optical head 8b for low light output dedicated to verify.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

FIG . 3 shows a magneto-optical disk 9 and optical heads 8a and 8b.
It is a state diagram showing a positional relationship with. An optical head carriage 7 is provided on the lower surface side of the magneto-optical disk 9 so as to be movable in the radial direction of the magneto-optical disk 9 through the axis of a spindle motor 10 for rotating the magneto-optical disk 9. An optical head 8a dedicated to reading and writing and an optical head 8b dedicated to verifying are juxtaposed on the upper surface of the optical head carriage 7 in a direction orthogonal to the moving direction of the optical head carriage 7 with a proper distance.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

[0031]

As described above in detail, according to the first invention,
Since a plurality of read / write means that can be controlled independently are provided, when performing format verify on the entire surface of the optical recording medium, format verify can be performed by different read / write means from different tracks of the optical recording medium. The time required to format and verify the entire surface can be greatly reduced. Further, while data is being verified by one read / write means, data can be written in parallel by another read / write means. Need not be written, and the waiting time before shifting to the data write operation can be shortened. According to the second aspect of the invention, the data is written by one optical head and the data is verified by the other optical head at the same time. Therefore, when the data writing operation is completed, the operation for verifying the data is completed. Further, there is an excellent effect that the time until the data writing is completed can be shortened.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an optical disk device according to the present invention.
is there.

FIG. 2 shows another embodiment of the optical disk device according to the present invention .
It is a schematic configuration diagram.

FIG. 3 shows a positional relationship between a magneto-optical disk and an optical head.
It is a state diagram.

FIG. 4 is a schematic configuration diagram of a conventional magneto-optical disk device.
It

[Explanation of symbols] 1 host computer 3 interface circuit 4a, 4b read / write circuit 5a, 5b servo circuit 6a, 6b linear motor 7a, 7b optical head carriage 8a, 8b optical head 9 magneto-optical disk 10 spindle motor 11 loading mechanism 12a , 12b Excitation coil 13a, 13b Excitation coil driver

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroyuki Muramoto Inventor Hiroyuki Muramoto 6-16-1, Tsukaguchi Honcho, Amagasaki City, Hyogo Sanryo Electric Engineering Co., Ltd. Itami Business Office (72) Masahiko Ishihara 8 Chome, Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture 1st-1 Sanryo Electric Co., Ltd. Itami Works

Claims (3)

[Claims] 1. An optical disk device for reading and writing data to and from an optical recording medium, a circuit for controlling reading and writing of the data, and an optical head for projecting light onto the optical recording medium and receiving reflected light. And a first read / write means including a servo circuit for controlling the position of the optical head on a predetermined track of the optical recording medium, and the first read / write means are configured to be controlled independently of each other. A second circuit including a circuit for controlling reading and writing, an optical head for projecting light on the optical recording medium and receiving the reflected light, and a servo circuit for controlling the position of the optical head on a predetermined track of the optical recording medium. An optical disk device comprising a read / write means. 2. An optical disk device for reading and writing data to and from an optical recording medium, comprising a first optical head and a second optical head which are interlocked along the radial direction of the optical recording medium, and one of Write data with the optical head,
An optical disk device, which is configured to simultaneously verify data written by the other optical head. 3. The optical disk according to claim 2, wherein one of the first optical head and the second optical head is an optical head having a high optical output, and the other is an optical head having a low optical output. apparatus.