JP2001126259A - Laser output setting method for optical disk recording/ reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser output setting method used for an optical disk recording/reproducing device recording a signal on a disk by a laser emitted from an optical pickup. SOLUTION: In the optical disk recording/reproducing device constituted so as to record the signal on the disk by alternately switching an output level of a laser beam emitted from a laser element to a recording level with a reproducing level, the reproducing level of the laser beam at a recording operation time is enlarged according to that the recording rotational speed of the disk becomes high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc recording apparatus which records a signal on a disc by a laser beam emitted from an optical pickup and reproduces a signal recorded on the disc by the laser beam. It relates to a playback device.

[0002]

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

In such an optical disk recording / reproducing apparatus, pits are formed on a disk by a laser beam. However, if the output level of the laser beam is not optimal, the pit shape may be too large. It will be too small. Therefore, a disk used in such an optical disk recording / reproducing apparatus is provided with a test writing area on the innermost side, and after recording a signal in the test writing area, reproducing the signal, and detecting the reproduced signal. The laser output for recording is set according to the method described in JP-A-6-7628.
No. 8 discloses a technique disclosed in Japanese Patent Publication No.

[0004]

The operation of recording a signal on a disk is performed by alternately switching the output level of laser light output from a laser element between a recording level and a reproduction level. That is, the recording is performed by forming pits on a signal track provided on the disk by using a laser beam for recording output, and the size of the pits is set to a specified size. The recording operation of such a signal is performed by rotating the disk at a predetermined constant linear velocity, but recently, the recording operation is performed with the linear velocity during the recording operation being several times the predetermined velocity. An optical disk recording / reproducing device capable of performing such operations has been commercialized.

The operation of forming pits on a signal track provided on a disk is performed by a temperature increasing operation using a laser beam. However, if the pits have a specified size or an accurate shape, the heat propagation characteristics are complicated. It is very difficult to change. That is, the heating operation for forming the pits and the cooling operation between the pits are performed alternately, but the shape of the pits is distorted due to the influence of the temperature change.

In order to improve such a point, a method of correcting and shaping the waveform of a pulse signal for recording a signal has been performed. There is a problem that the waveform correction circuit becomes very complicated.

An object of the present invention is to provide a method for setting a laser output of an optical disk recording / reproducing apparatus which solves such a problem.

[0008]

According to the present invention, a signal is recorded on a disk by alternately switching the output level of a laser beam emitted from a laser element between a recording level and a reproduction level, and the operation of recording the signal on the disk is performed by rotating the disk. In an optical disc recording / reproducing device configured so that the speed can be performed not only at the specified speed but also at a speed higher than the specified speed, the recording rotation speed of the disk is set at a high level for the reproduction of the laser beam during the recording operation. It is made to increase as it becomes.

[0009]

FIG. 1 is a block circuit diagram showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the present invention.

In FIG. 1, reference numeral 1 denotes a disk mounted on a turntable (not shown) driven by a spindle motor (not shown) and rotated by the rotation of the turntable. Data is recorded by grooves called wobbles,
The signal recording / reproducing operation is performed based on the wobble signal obtained from the groove. Reference numeral 2 denotes a laser element for irradiating the disk 1 with laser light and a monitoring diode for monitoring the laser light emitted from the laser element, and a photodetector for receiving laser reflected from the signal surface of the disk 1. The built-in optical pickup 3 is a pickup feed motor for moving the optical pickup 2 in the radial direction of the disk 1.

Reference numeral 4 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 5 denotes a signal obtained through the RF signal amplifying circuit 4. Laser light emitted from the optical pickup 2 based on the
And a pickup control circuit that performs a focusing control operation for focusing on the signal surface of the optical disk and a tracking control operation for causing the laser light to follow a signal track on the signal surface.

Reference numeral 6 denotes a digital signal processing circuit that performs digital signal processing of signals output from the RF signal amplifier circuit 4 and performs demodulation operations of various signals, and 7 denotes a digital signal processed by the digital signal processing circuit 6. 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 a function of outputting the digital signal to the computer device 8 as it is.

A system control circuit 9 receives a signal demodulated by the digital signal processing circuit 6 and performs various control operations in response to an operation switching control signal output from the computer device 8. Disc 1
A memory circuit in which a program for recording a test signal is stored in a test writing area provided in a memory device and a memory circuit in which data for setting a drive current supplied to a laser element are stored are incorporated. . Reference numeral 10 denotes a pickup feed motor driving circuit whose operation is controlled by the system control circuit 9, which has an operation of controlling the rotation of the pickup feed motor 3.

Reference numeral 11 denotes a laser drive circuit for supplying a drive signal to a laser element incorporated in the optical pickup 2, and 12 denotes a laser output control circuit whose operation is controlled by the system control circuit 9. The laser output is set by controlling the circuit 11. A signal recording circuit 13 receives a recording signal such as a test signal and an information signal, and controls the laser light irradiation operation of the laser driving circuit 11 in accordance with the signal to record the signal on the disk 1. It is.

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 reproduction switching signal output from the computer device 8 is input to the system control circuit 9, a control operation for a reproduction operation by the system control circuit 9 is started. When such a reproducing operation is performed, the laser drive incorporated in the optical pickup 2 is supplied with a drive current for obtaining a laser output for performing a signal read operation from the laser drive circuit 11. Is set to

When the control operation for such a reproduction operation is started, a rotation control operation of a spindle motor by a spindle motor drive circuit (not shown) is performed, and a focusing control operation and a tracking control operation of the optical pickup 2 are performed. Is started, and the reading operation of the signal from the disk 1 by the optical pickup 2 is started. The signal read by the optical pickup 2 is input to the digital signal processing circuit 6 through the RF signal amplifier circuit 4 and the signal is demodulated. When signal processing is performed by the digital signal processing circuit 6 to extract information data, the information data is subjected to signal processing such as error correction and then applied to a signal reproduction circuit 7.

When the information data read from the disk 1 is an audio signal, the signal reproducing circuit 7 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 8 as it is.

In such a circuit configuration, when the disc 1 is inserted into the mounting portion of the disc in order to perform a signal recording operation, a laser output setting operation is performed. Such an operation for setting the laser output is performed based on a program stored in a memory circuit provided in the system control circuit 9. The operation of setting the laser output is performed in a stepwise manner by the control signal output from the laser output control circuit 12 to control the magnitude of the drive current supplied from the laser drive circuit 11 to the laser element incorporated in the optical pickup 2. This is performed by recording the test signal while changing it to the above and reproducing the recorded signal.

When the magnitude of the driving current supplied to the laser element is changed stepwise, the output of the laser light output from the laser element changes, so that the level of the signal recorded on the disk 1 also changes. Become. Then, the level of the signal recorded on the disc 1 with respect to the laser output is detected, and when the level of the signal to be reproduced reaches a desired value, the laser output at that time is set as the laser output for performing the recording operation.

The signal recording operation is started by the laser output set as described above. When the signal recording operation is being performed, the change in the laser light reflected from the disk 1 is monitored to monitor the laser light. The configuration is such that the value of the drive current supplied from the drive circuit 12 to the laser element is changed so that the laser output is always optimal for the recording operation.

As described above, the operation of setting the laser output is performed by the operation of recording and reproducing the test signal in the test writing area. Next, the method of setting the laser output, which is the gist of the present invention, will be described.

The waveform diagram shown in FIG. 2A shows the output level of a laser beam when a signal is recorded on the disk 1 which is driven to rotate at a specified linear velocity. The output level P2 is an output level for reproduction.
As is clear from FIG. 5, the output level P1 of the recording laser beam is higher than the output level P2 for reproduction. At the output level P1, pits can be formed on the signal track of the disk 1. At P2, the value is set to a value at which a pit cannot be formed.

The operation of recording a signal on the disk 1 driven to rotate at a specified linear velocity can be performed by the output of the laser beam having the relationship shown in FIG. A case where a signal recording operation is performed at a speed higher than the speed, for example, eight times the linear speed will be described.

When an instruction signal for performing a signal recording operation at eight times the speed of the computer device 8 is output to the system control circuit 9, each circuit and the like controls the recording operation at that speed. It is in a state to perform operation. FIG.
(B) shows the output level of the laser beam when recording a signal on the disk 1 which is driven to rotate at a linear velocity eight times the specified linear velocity. , P3 is an output level for reproduction. As is clear from FIG. 3, the output level P1 of the recording laser beam is the same as the output level during the recording operation at the above-mentioned prescribed linear velocity, but the output level P3 for reproduction is the recording level at the prescribed linear velocity. The output level is set to be higher than the output level P2 during operation. In this case as well, a pit can be formed on the signal track of the disk 1 at the output level P1, but the output level P3 is set so that a pit cannot be formed.

When the recording operation is performed at a high linear velocity as described above, the pits are formed because the output level for reproduction of the laser beam is set higher than that during the recording operation at a prescribed linear velocity. The temperature between the pits, which is the cooling period with respect to the heating period, can be increased. Therefore,
Since the temperature can be increased quickly and efficiently during the heating period, the signal recording operation, that is, the pit forming operation can be accurately performed even when the rotation speed of the disk is increased. Therefore, it is not necessary to strictly perform the waveform correction operation of the pulse signal corresponding to the recording speed, and the circuit configuration can be simplified.

In this embodiment, the level of the laser beam reproduction output during the recording operation is changed in accordance with the recording rotation speed of the disk. However, it is possible to change the level in accordance with the type of the disk. More accurate recording operation can be performed.

Further, the reproduction level is changed when the recording rotation speed is higher than the prescribed recording speed. However, the recording operation is performed at a predetermined rotation speed, for example, 8 times or more. In such a case, it is possible to change the reproduction level. In the present embodiment, the reproduction level is increased as the rotation speed is increased. However, the recording level can be increased as the rotation speed increases.

[0028]

According to the present invention, a signal is recorded on a disk by alternately switching the output level of a laser beam emitted from a laser element between a recording level and a reproduction level, and the operation of recording a signal on the disk is performed. In an optical disc recording / reproducing apparatus configured so that the rotation speed of the disc can be performed not only at a specified speed but also at a speed higher than the specified speed, the output level for reproducing the laser beam at the time of the recording operation is set to the recording speed of the disc. As the speed is increased as the speed is increased, the disk can be heated between pits generated by recording. Therefore, according to the present invention, the temperature can be efficiently raised during the heating period during which the pits are formed on the disk, and the pit forming operation can be performed accurately. As a result, there is no need to strictly perform a pulse signal waveform correction operation for correcting the pit shape,
The present invention has an effect that the circuit configuration can be simplified.

Further, according to the present invention, when the recording rotation speed of the disk is higher than a predetermined speed, the reproduction level of the laser beam is increased. This has the advantage that the circuit configuration is simplified.

According to the present invention, since the reproducing level of the laser beam is changed in accordance with the type of the disk, the recording operation can be performed in a good condition in accordance with various types of disks.

[Brief description of the drawings]

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

FIG. 2 is a waveform chart for explaining the operation of the laser output setting method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 disc 2 optical pickup 4 RF signal amplification circuit 5 pickup control circuit 6 digital signal processing circuit 8 computer device 9 system control circuit 11 laser drive circuit 12 laser output control circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D090 AA01 BB05 CC01 DD03 EE01 HH01 HH03 JJ12 KK03 5D119 AA24 AA41 BA01 BB04 DA01 FA05 HA45 HA54

Claims (3)

[Claims] 1. A signal is recorded on a disk by alternately switching an output level of a laser beam emitted from a laser element between a recording level and a reproduction level, and the operation of recording the signal on the disk is performed by controlling the rotation speed of the disk. In an optical disc recording / reproducing apparatus configured to be able to perform not only a prescribed speed but also a speed higher than a prescribed speed, the recording rotation speed of the disc is increased by a laser light reproducing level during a recording operation. A laser output setting method for an optical disk recording / reproducing apparatus, the method comprising: 2. The laser output setting method according to claim 1, wherein when the recording rotation speed of the disk becomes higher than a predetermined speed, the reproduction level of the laser light is increased. 3. The laser output setting method according to claim 1, wherein the reproduction level of the laser beam is changed according to the type of the disc.