JP2002083436A - Pickup controller for optical disk recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk recording and reproducing device with which a signal can be recorded on a disk with a laser emitted by an optical pickup. SOLUTION: A driving voltage detection circuit 12 that detects a driving voltage supplied to a coil to displace an object lens is provided in order to focus a laser emitted from the optical pickup 2 on the signal recording surface of a disk 1. The warpage of the disk is detected on the basis of voltage obtained from the driving voltage detection circuit 12 and a position on the disk 1, where a laser emitted from the optical pickup 2 is located.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus configured to record a signal on a disk by a laser emitted from an optical pickup, and more particularly to a pickup control apparatus for controlling the operation of the optical pickup. Related.

[0002]

2. Description of the Related Art Disk players which read signals recorded on a disk using an optical pickup have become widespread, but recently, in addition to a reproducing function, a disk irradiated by a laser emitted from the optical pickup has been used. An optical disk recording / reproducing apparatus configured to record a signal on the optical disk has been commercialized.

In addition, the specified linear velocity is doubled,
An optical disk recording / reproducing apparatus has been developed which is capable of recording signals while controlling the rotation of the disk at a constant high linear velocity such as double, six times, eight times, ten times, and twelve times. .

[0004]

In an optical disk recording / reproducing apparatus, pits are formed on a disk by a laser. However, it is necessary to make the laser accurately follow a signal track provided on the disk. . If the operation of recording a signal on the disk is performed in a state where the rotation of the disk is inclined due to a warp or the like, the recording characteristics will be affected. In a conventional optical disc reproducing apparatus having only a reproducing function, a light emitted from a light emitting element provided for detecting a tilt on a signal surface of the disc is applied, and the tilt of the disc is detected using reflected light thereof. It is configured to control the operation of reproducing a signal from a disk.

In an optical disk recording / reproducing apparatus capable of performing a recording operation, not only the reflectance from the disk is small but also the reflectance greatly changes.
There is a problem that the operation of detecting the tilt of the disk cannot be performed accurately.

An object of the present invention is to provide a pickup control device of an optical disk recording / reproducing device which can solve such a problem.

[0007]

According to the present invention, there is provided a drive for detecting a drive voltage supplied to a focusing coil for displacing an objective lens so that a laser beam emitted from an optical pickup is focused on a signal recording surface of a disk. A voltage detection circuit is provided, and the amount of warpage of the disk is detected based on the voltage obtained from the drive voltage detection circuit and the position on the disk where the laser irradiated from the optical pickup is located.

[0008]

FIG. 1 is a block circuit diagram showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a disk mounted on a turntable (not shown) driven to rotate by a spindle motor (not shown), and is configured to be driven to rotate by rotation of the turntable. . Also. Position information data is recorded on the disc 1 by a groove called a wobble, and a signal recording / reproducing operation is performed based on a wobble signal obtained from the groove. Reference numeral 2 denotes a laser diode for irradiating the disk 1 with a laser, a monitoring diode for monitoring light emitted from the laser diode, and a photodetector for receiving a laser reflected from the signal surface of the disk 1. The optical pickup is configured to be moved in the radial direction of the disc 1 by a pickup feed motor (not shown). The optical pickup 2 has a focusing coil for displacing the objective lens in the surface direction of the disk 1 to focus the laser on the signal surface of the disk 1 and an objective lens for causing the laser to follow the signal track. A tracking coil for displacing in the radial direction of the disk 1 is incorporated.

Reference numeral 3 denotes an RF signal amplifying circuit for amplifying an RF signal obtained from a photodetector incorporated in the optical pickup 2 and shaping the waveform, and 4 denotes a signal obtained via the RF signal amplifying circuit 3. A pickup control circuit for performing a focusing control operation for focusing a laser of the optical pickup 2 on a signal surface of the disk 1 and a tracking control operation for following the laser on a signal track of the signal surface based on the focus servo circuit; A tracking servo circuit is incorporated.

Reference numeral 5 denotes a digital signal processing circuit which performs digital signal processing of signals output from the RF signal amplifier circuit 3 and performs demodulation operations of various signals, and 6 denotes a digital signal processed by the digital signal processing circuit 5. A signal reproducing circuit to which a signal is input. When the information recorded on the disc 1 is an audio signal, the signal is converted into an analog signal and then output to an amplifier or the like, and when the data signal is data such as computer software. Has the function of outputting the digital signal as it is to the computer device 7 provided as a host.

Reference numeral 8 denotes a system control circuit which receives a signal demodulated by the digital signal processing circuit 5 and performs various control operations in accordance with a command signal output from the computer device 7, and stores each data. Memory circuit (not shown) is incorporated. Reference numeral 9 denotes a signal recording circuit that receives a recording signal such as a test signal or a data signal and controls the laser irradiation operation of the laser driving circuit 10 in accordance with the signal to record a data signal or the like on the disk 1. It is. The laser drive circuit 10 functions to supply a drive current to a laser diode incorporated in the optical pickup 2 so as to irradiate a laser for reproduction operation and a laser for recording operation from the laser diode. The system control circuit 8 performs a servo operation based on a signal obtained from the monitoring diode and controls the laser output.

Reference numeral 11 denotes a buffer RAM in which data signals recorded on the disk 1 are temporarily stored, into which data signals output from the computer device 7 are written and which are stored by the control operation of the system control circuit 8. The operation and the read operation are configured to be controlled. The signal stored in the buffer RAM 11 is in a state of being stored and held even after being read to be recorded on the disk 1, and a new data signal output from the computer device 7 is stored at that position. The data is sequentially overwritten and erased.

Reference numeral 12 denotes a drive voltage detection circuit for detecting a drive voltage supplied from the pickup control circuit 4 to the focus coil. The detection signal is input to the system control circuit 8. Further, based on the position information data recorded on the disk 1, the position on the disk 1 where the laser irradiated from the optical pickup 2 is located is recognized, and based on the level of the signal obtained from the drive voltage detection circuit 12. Thus, the inclination of the disk 1, that is, the amount of warpage is determined. And
The amount of warpage detected in this manner is configured to be stored in a memory circuit incorporated in the system control circuit 8. Further, an offset signal is applied to the tracking control signal according to the amount of warpage at the position where the laser is located.

In such a configuration, at the time of a signal recording operation on the disk 1, a data signal output from the computer device 7 is stored in the buffer RAM 11, and the read operation of the stored signal is controlled. The recording operation of a signal on the disk 1 is configured to be controlled. The recording operation is performed by a recording clock signal generated based on a reference clock signal obtained from the disk 1. I have. Therefore, signals can be recorded in a prescribed recording format even when the rotational speed of the disk 1 is in various speed states. However, since such a technique is well known, description thereof will be omitted.

When the recording operation of the data signal on the disk 1 is interrupted and the recording operation is resumed, the signal stored in the buffer RAM 11 and the signal recorded on the disk 1 before the interruption are recorded. It is configured to perform a comparison operation with the existing signal and to record the signal continuously to the signal recorded before the interruption, that is, to record the data signal in a method called seamless.

When the rotation speed of the disk 1 at the time of recording is changed by the above-described operation, the laser drive circuit 10 is operated so that a laser output suitable for the rotation speed is obtained.
Is controlled by the system control circuit 8.

As described above, the optical disk recording / reproducing apparatus according to the present invention is configured. Next, the reproducing operation in the circuit configured as described above will be described. When a command signal for performing a reproducing operation is output from the computer device 7 to the system control circuit 8 constituting the disk drive device, a control operation for the reproducing operation by the system control circuit 8 is started. When such a reproducing operation is performed, a driving current for obtaining a laser output for performing a signal reading operation is supplied to the laser driving circuit 1 by a laser diode incorporated in the optical pickup 2.
It is set to be supplied from 0.

When the control operation for such a reproducing operation is started, a rotation control operation of the spindle motor is performed by a spindle motor drive circuit (not shown). The disk 1 is rotated at a constant linear velocity by comparing a synchronization signal obtained by decoding the signal with a reference signal output from a reference signal generation circuit (not shown). Such a control operation is similarly performed at the time of a signal recording operation described later.

The rotation control operation of the spindle motor is performed as described above. In the optical pickup 2 which performs a signal readout operation, the focusing control operation and the tracking control operation are started and the optical pickup 2 is started.
, The reading operation of the signal from the disc 1 is started. Before the reproducing operation, the reading operation of the TOC data recorded in the lead-in area constituting the first session of the disc 1 is performed.

The operation of reading and reproducing the signal recorded in the signal recording area of the first session provided on the disc 1 is performed based on the TOC data recorded in the lead-in area. The signal read by the optical pickup 2 is amplified and shaped by an RF signal amplifying circuit 3 and then input to a digital signal processing circuit 5 where the signal is demodulated. When signal processing is performed by the digital signal processing circuit 5 to extract information data, the information data is applied to a signal reproduction circuit 6 after signal processing such as error correction is performed.

When the information data read from the disc 1 is an audio signal, the signal reproducing circuit 6 converts the information data into an analog signal and outputs the analog signal to an amplifier or the like. In this case, the digital signal is output to the computer 7 as it is.

As described above, the reproducing operation in the present embodiment is performed. Next, the operation of recording a signal on the disk 1 will be described.

The operation of recording a signal on the disk 1 is as follows. First, a test signal is recorded in a test writing area provided on the disk 1, and then the recorded signal is reproduced to obtain an optimum laser output for the recording operation. The obtained drive current is set to be supplied to the laser diode. When such a laser output setting operation is performed, the disc 1
An operation of reading information data recorded in an area called a buffer, that is, position information of a signal recorded in a signal recording area is performed.

Based on the information data read in this manner, whether a data signal recording operation can be performed in a signal recording area provided on the disk 1 and the position at which the recording operation is performed are determined. A recognition operation is performed.

When the recognition processing operation is completed, the optical pickup 2 is moved to the position where the recording operation on the disk 1 is started, and the operation of writing the recording signal to the buffer RAM 11 is performed. RA for the buffer
When a signal writing operation to M11 is performed, the storage amount of the signal stored in the buffer RAM 11 gradually increases. When the storage amount exceeds a predetermined amount, the signal stored in the buffer RAM 11 is read, and the read signal is input to the signal recording circuit 9. As a result, the control operation of the laser drive circuit by the signal recording circuit 9 is performed, and a signal such as data is recorded on the disk 1. This recording operation is performed by setting the laser output in the test writing area. It is performed by the laser power set by the operation. In a state where the recording operation is being performed, a control operation for obtaining an optimum laser output for performing the recording operation is performed by the operation of a servo circuit or the like incorporated in the laser drive circuit 10.

With such an operation, a signal recording operation to the disk 1 is performed, but a signal writing operation to the buffer RAM 11 is performed in accordance with a signal reading operation from the buffer RAM 11. Have been. In the state where the recording operation is performed normally,
Every time a signal is recorded on the disk 1, an address indicating the position, that is, an end address is stored in a memory circuit provided in the system control circuit 8.

When the operation of recording the signal on the disk 1 is interrupted, the operation of reading the signal from the buffer RAM 11 is interrupted. In this case, the writing of the signal to the buffer RAM 11 is performed. The operation is also interrupted. When an operation of starting a signal recording operation on the disc 1 is performed from such a state, the optical pickup 2 is displaced to a position where the recording operation is started, that is, a position where the optical pickup 2 is retracted from a position where the recording operation is interrupted.
The reproduction operation is performed from that position. The position where the recording is interrupted can be easily recognized from the final address stored in the memory circuit every time a normal recording operation is performed, and the optical pickup 2 can be moved to a desired position.

The signal reproduced by the reproducing operation is a signal recorded immediately before the recording operation is interrupted, and a comparison operation between the signal and the signal stored in the buffer RAM 11 is performed. When it is determined by the comparison operation that the two signals are the same signal, the reading of the signal stored in the buffer RAM 11 and stored subsequent to the signal subjected to the above-described comparison operation is performed. The operation is performed and the signal is input to the signal recording circuit 9 to start the signal recording operation on the disk 1. By the above-described operation, the operation of interrupting the recording of the signal on the disk 1 and the operation of resuming the recording can be performed. By performing such an operation, the signal is continuously written on the disk 1 despite the interruption of the recording operation. A recording operation, that is, a so-called seamless recording operation can be performed.

As described above, the signal recording operation in this embodiment is performed. Next, the signal recording operation on the disk 1 is performed not at the specified speed but at a rotation speed higher than the specified speed. The operation when the amount of the data signal stored in the buffer RAM 11 is insufficient while the operation is being performed will be described.

Such a situation occurs when the amount of the signal output from the computer device 7 to the buffer RAM 11 and written therein is smaller than the amount of the signal read from the buffer RAM 11, and such a phenomenon occurs. This is caused by a delay in the processing operation.

In such a case, a processing operation of interrupting the recording operation of the signal on the disk 1 is performed by the operation of the system control circuit 8 based on the signal output from the computer device 7. Further, when a processing operation for interrupting the signal recording operation on the disk 1 is performed, the buffer R
The operation of writing a signal to the AM 11 also stops, but the buffer RAM 11 is in a state where the signal recorded on the disk 1 before the interruption of the recording operation is stored and held. And
The final address is stored in the memory circuit incorporated in the system control circuit 8.

When the signal recording operation to the disk 1 cannot be performed in this way, the above-described interruption processing operation is performed. However, a data signal is output from the computer device 7 and stored in the buffer RAM 11. When the data amount reaches the recordable amount, a processing operation for restarting the signal recording operation on the disk 1 is performed. When a signal can be recorded on the disk 1 by such a processing operation, the position where the optical pickup 2 starts the recording operation from the last address stored in the memory circuit, that is, the position is stored in the buffer RAM 11. After the recording operation is displaced to a position retracted from the position where the recording operation was interrupted due to the lack of the signal amount, the reproducing operation is performed from that position.

The signal reproduced by the reproducing operation is a signal recorded immediately before the recording operation is interrupted, and a comparison operation between the signal and the signal stored in the buffer RAM 11 is performed. When it is determined by the comparison operation that the two signals are the same signal, the reading of the signal stored in the buffer RAM 11 and stored subsequent to the signal subjected to the above-described comparison operation is performed. The operation is performed and the signal is input to the signal recording circuit 9 to start the signal recording operation on the disk 1. By the above-described operation, the recording interruption operation and the recording resuming operation of the signal on the disk 1 can be performed, and by performing such operations, the signal is continuously recorded on the disk 1 despite the interruption of the recording operation. A recording operation, that is, a so-called seamless recording operation can be performed.

The operation of this embodiment is performed as described above. Next, the gist of the present invention will be described. The reproduction operation of the signal recorded on the disk 1 and the recording operation of the signal on the disk 1 are performed by performing a focus control operation and a tracking control operation of the optical pickup 2 by the pickup control circuit 4. Optical pickup 2 with focus control operation
The drive voltage supplied to the focusing coil incorporated in the drive voltage is detected by the drive voltage detection circuit 12.

The drive voltage supplied from the pickup control circuit 4 to the focusing coil increases as the amount of warpage of the disk 1 increases. Further, it is possible to recognize the position on the disk 1 where the laser irradiated from the optical pickup 2 is located, that is, the distance from the center of the disk 1 based on the position information data recorded on the disk 1. Therefore, the amount of warpage of the disk 1 can be detected based on the value of the drive voltage supplied to the focusing coil and the distance from the center of the disk 1.

Such an amount of warpage can be obtained based on data stored in a memory circuit provided in the system control circuit 8 in advance. In addition, by controlling the tracking operation of the optical pickup 2 based on the amount of warpage thus obtained, the laser can accurately follow the signal track provided on the disk 1. That is, the tracking control operation of the optical pickup 2 is performed by a servo operation by a servo circuit incorporated in the pickup control circuit 4, but by applying an offset signal according to the amount of warpage of the disk 1 to the servo signal. Done. By performing such a control operation, the tracking control operation can be accurately performed even if the disk 1 is warped.

The operation of detecting the amount of warpage of the disk 1 can be performed in a state where a signal is being recorded on the disk 1, but it is also possible to detect the warpage before starting the recording operation. Also, the operation of detecting the position on the disk 1 where the laser emitted from the optical pickup 1 is located is performed based on the position information data recorded on the disk 1. It is also possible to provide a means for detecting the data and to detect the data.

[0038]

According to the present invention, there is provided an optical disk recording / reproducing apparatus configured to record a signal on a disk by a laser irradiated from an optical pickup. A drive voltage detection circuit for detecting a drive voltage supplied to a focusing coil for displacing an objective lens for focusing; a disk on which a voltage obtained from the drive voltage detection circuit and a laser irradiated from an optical pickup are located; Since the amount of warpage of the disk is detected based on the upper position, the configuration is simplified as compared with a conventional case in which means for detecting the inclination of the disk due to the warpage of the disk is separately provided. It has the advantage that.

Further, according to the present invention, the tracking operation of the optical pickup is controlled based on the detected amount of warpage, so that even if the disk is warped, the tracking operation can be performed accurately, and The reproducing operation of the recorded signal and the recording operation of the signal on the disc can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention.

[Description of Signs] 1 disk 2 optical pickup 4 pickup control circuit 5 digital signal processing circuit 7 computer device 8 system control circuit 10 laser drive circuit 11 buffer RAM 12 drive voltage detection circuit

Claims (2)

[Claims] In an optical disk recording / reproducing apparatus configured to record a signal on a disk by a laser emitted from an optical pickup, a laser emitted from the optical pickup is focused on a signal recording surface of the disk. A drive voltage detection circuit for detecting a drive voltage supplied to a focusing coil for displacing an objective lens is provided, and a voltage obtained from the drive voltage detection circuit and a position on a disk where a laser irradiated from an optical pickup is located. A pickup control device for an optical disk recording / reproducing apparatus, wherein the amount of warpage of a disk is detected based on the information. 2. The pickup control device according to claim 1, wherein a tracking operation of the optical pickup is controlled based on the detected amount of warpage.