JP2000285485A - Optical disk recording and reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the level of an optimum offset signal by a method wherein, in a state that a laser output is constant, a test signal is recorded in a trial write region while the level of an offset signal to be added to a focus control signal is being changed stepwise and its recording state is detected. SOLUTION: In a prescribed adjusting operation, while the level of an offset signal to be added to a focus control signal by a control operation by an offset control circuit 15 is being changed stepwise, a test signal is first recorded in a trial write region which is formed on a disk D. Then, the reproducing operation of the test signal is performed, and its recording state is detected by a recording-state detection circuit 14. That is to say, the level of the offset signal in which a best β value is ontained is selected from the detected signal at this time. The setting operation of the level of the offset signal to be added to the focus control signal by the offset control circuit 15 is performed. As a result, a state which is optimum for the disk D is set.

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 radiated from an optical pickup and to reproduce a signal recorded on the disk by the laser. About.

[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 recent years, it has been difficult to record a signal while controlling the rotation of the disk at a constant high linear velocity of 2 times, 4 times, 6 times, and 8 times the prescribed recording linear velocity. An optical disk recording / reproducing device configured to be capable of being developed has been developed.

In such an optical disk recording / reproducing apparatus, pits are formed on a disk by a laser. However, if the laser output is not optimal, the pit shape may be too large or too small. Will do. Therefore, a disk used in such an optical disk recording / reproducing apparatus has a recording area called a test writing area formed on the inner peripheral side. After recording a test signal in the test writing area, The laser output is set by reproducing the recorded test signal. Such a technique is disclosed, for example, in Japanese Patent Application Laid-Open No. 8-45099.

FIG. 2 is a signal waveform diagram of an EFM data signal read from a disk used when setting the laser output of the optical pickup, and shows A1 and A2.
Are the positive peak level and the negative peak level of the high frequency signal. Under such conditions, β = (A1 +
When A2) / (A1−A2) is represented, for example, the value of β is, for example, 0.04, and the laser output is set to be optimum.

The above-mentioned publication discloses a technique in which the value of β is detected and adjusted so that the value becomes an appropriate level.

[0007]

Some optical pickups used in an optical disk recording / reproducing apparatus have a large focus shift or tracking shift during a recording operation. The causes include a change in the emission pattern of the laser element and a change in the characteristics of the servo circuit or the like or an adjustment error.

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

[0009]

According to the present invention, a test signal is recorded in a test writing area while a laser output is constant and the level of an offset signal added to a focus control signal is gradually changed. The optimum offset signal level is set by detecting the recording state of the test signal.

[0010]

1 is a block circuit diagram showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention. FIG. 2 is an EFM data signal read from a disk used when setting a laser output of an optical pickup. 3 is a signal waveform diagram of FIG.

In FIG. 1, reference numeral 1 denotes a turntable which is rotated by an electric motor 2 and on which a disk D is mounted, and 3 denotes a signal surface of the disk D which incorporates a laser element for irradiating the disk D with a light beam. The optical pickup incorporates a photodetector that receives a light beam that is reflected more, and an objective lens that is displaced by a focus servo operation and a tracking servo operation.

Reference numeral 4 denotes an RF signal amplifying circuit for amplifying an RF signal obtained from a photodetector of the optical pickup 3 and shaping the waveform, and 5 denotes an optical signal based on the signal obtained via the RF signal amplifying circuit 4. The pickup control circuit performs a focusing control operation for focusing a light beam of the pickup 3 on a signal surface of the disk D and a tracking control operation for causing the light beam 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. This is a signal reproduction circuit to which signals are input. If the signal reproduced from the disc D is an audio signal, it is converted to an analog signal and then output to an amplifier or the like. Are configured to be output as digital signals to a computer device 8 provided as a host.

Reference numeral 9 denotes a system control circuit which receives a signal demodulated by the digital signal processing circuit 6 and performs various control operations in accordance with a command signal output from the computer device 8. Reference numeral 10 denotes a motor drive circuit whose operation is controlled by the system control circuit 9, which is configured to perform a rotation drive control operation of the motor 2. In such a configuration, the rotation driving operation by the motor drive circuit 10 is configured to control the rotation speed of the disk D so that the linear speed becomes constant.

A laser driving circuit 11 for driving a laser element incorporated in the optical pickup 3;
Reference numeral 12 denotes a laser output setting circuit whose operation is controlled by the system control circuit 9, which is configured to set the output of the laser element by controlling the laser drive circuit 11. Reference numeral 13 denotes a signal recording circuit that records a signal on the disk D by receiving a recording signal and controlling a laser irradiation operation by the laser driving circuit 11 in accordance with the signal.

A recording state detector 14 receives a signal output from the RF signal amplifier circuit 4 and outputs a signal for measuring the value of β from the signal level to the system control circuit 9. Since this is a circuit and can be configured by a well-known circuit, its description is omitted.

Reference numeral 15 denotes an offset control circuit whose operation is controlled by the system control circuit 9. The offset control circuit 15 receives a focus control signal from a focus servo circuit incorporated in the pickup control circuit 5 and a tracking control signal from a tracking servo circuit. On the other hand, it has the function of adding an offset signal. The operation of adding an offset signal by the offset control circuit 15 is as follows.
The configuration is such that the additional level is changed stepwise during the recording operation of the test signal.

The optical disk recording / reproducing apparatus according to the present invention is configured as described above. 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 8, the optical disk recording / reproducing device enters a state of performing a reproducing operation under the control operation of the system control circuit 9. When the control operation for such reproduction is started, the motor drive circuit 10
, The laser output setting operation for reproducing the optical pickup 3, the focus control operation and the tracking control operation are started, and the optical pickup 3 reads a signal from the disk D. Is started.

The signal read by the optical pickup 3 is input to a digital signal processing circuit 6 through an RF signal amplifier circuit 4 to perform a signal demodulation operation. When signal processing is performed by the digital signal processing circuit 6 to extract information data, the information data is input to a signal reproduction circuit 7 after signal processing operations such as error correction are performed. When the information data read from the disk D 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. The data is output to the computer device 8 as it is.

As described above, the reproducing operation in this embodiment is performed. Next, the adjusting operation which is the gist of the present invention will be described. First, the operation for setting the output of the laser output from the laser element incorporated in the optical pickup 3 will be described.

This operation is performed in a state where the offset control circuit 15 adds an offset signal of a preset level to the focus control signal and the tracking control signal. In such a state, the adjustment operation of the laser output is performed by recording the test signal in the test writing area provided on the disc D while changing the laser output for recording stepwise by the control operation of the laser output setting circuit 12, This is performed by performing a reproducing operation of the recorded test signal and detecting a recording state of the reproduced signal by the recording state detecting circuit 14.
That is, a laser output having the best value of β is selected from the signals detected by the recording state detection circuit 14, and the laser output setting circuit 12 performs a laser output setting operation. By doing so, it is possible to set the laser output to a recording value most suitable for the characteristics of the disk D.

The operation of adjusting the laser output is performed as described above. Next, the focus control operation will be described. Such an adjustment operation is performed by the laser output set by the above-described operation. The adjustment operation is performed while changing the level of the offset signal added to the focus control signal by the control operation of the offset control circuit 15 stepwise. The test signal is recorded in a test writing area provided on the disk D, the recorded test signal is reproduced, and the recording state of the reproduced signal is detected by the recording state detection circuit 14. . That is, the level of the offset signal at which the best β value is obtained is selected from the signals detected by the recording state detection circuit 14, and the level of the offset signal added to the focus control signal by the offset control circuit 15 is selected. Perform the setting operation. By doing so, it is possible to bring the optical pickup 3 into a state where the focus control operation can be performed in a state most suitable for the disk D.

Although the focus adjustment operation is performed as described above, the tracking control operation will be described. Such an adjustment operation is performed by the laser output set in the above-described operation in the same manner as the above-described focus control operation. A test signal is recorded in a test writing area provided on the disk D while changing the signal level in a stepwise manner, and the recorded test signal is reproduced and the recorded state of the reproduced signal is recorded. The detection is performed by the detection circuit 14. That is, the level of the offset signal having the best value of β is selected from the signals detected by the recording state detection circuit 14, and the level of the offset signal added to the tracking control signal by the offset control circuit 15 is selected. Perform the setting operation. By doing so, the tracking control operation of the optical pickup 3 can be performed in a state that can be performed in a state most suitable for the disk D.

As described above, the focus control operation and the tracking control operation of the optical pickup 3 can be set to the most suitable state for recording a signal on the disk D, but after performing such adjustment, By performing the above-described laser output adjustment operation, the laser output can be set to a better output.

By the above-described operation, the focus control operation and the tracking control operation of the optical pickup 3 can be set to a state most suitable for recording a signal on the disk D. By storing the adjustment operation in the memory, the adjustment operation described above need not be performed again. Also, in an optical disk recording / reproducing apparatus capable of performing a recording operation at different rotational speeds of a disk, the level of an offset signal stored in a memory is corrected in accordance with the recording rotational speed to support different rotational speeds. By configuring so as to set the level of the offset signal, it is not necessary to perform the above-described adjustment operation for each rotation speed.

[0026]

According to the present invention, a test signal is recorded in the test writing area while the laser output is constant and the level of the offset signal added to the focus control signal is changed stepwise. Since the optimum offset signal level is set by detecting the recording state, it is possible to prevent the occurrence of a focus shift during the recording operation.

Further, according to the present invention, a test signal is recorded in a test writing area while the laser output is constant and the level of the offset signal added to the tracking control signal is changed stepwise. Since the optimum offset signal level is set by detecting the recording state, it is possible to prevent occurrence of tracking deviation during the recording operation.

In the present invention, the set level of the offset signal is stored in the non-volatile memory, so that it is not necessary to repeat the adjustment operation by the recording operation of the test signal.

According to the present invention, in an optical disk recording / reproducing apparatus capable of performing a recording operation at different rotational speeds of a disk, the level of an offset signal stored in a memory is corrected in accordance with the recording rotational speed. Since the configuration is such that the level of the offset signal corresponding to different rotation speeds is set, it is not necessary to perform the adjustment operation by the recording operation of the test signal every time the rotation speed is changed, and the operability is excellent.

[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.

FIG. 2 is a signal waveform diagram of an EFM data signal.

[Explanation of symbols]

 Reference Signs List 3 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 setting circuit 14 recording state detection circuit 15 offset control circuit

Claims (4)

[Claims] 1. A test signal is recorded on a test writing area provided on a disc by a laser radiated from an optical pickup, and then the recorded test signal is reproduced, and the recorded test signal is reproduced according to the recording state of the test signal. In an optical disc recording / reproducing apparatus configured to set a laser output, a test signal is recorded in a test writing area while a laser output is constant and a level of an offset signal added to a focus control signal is changed stepwise. An optical disk recording / reproducing apparatus characterized in that an optimum offset signal level is set by detecting a recording state of a recorded test signal. 2. A test signal is recorded on a test writing area provided on a disc by a laser radiated from an optical pickup, and then the recorded test signal is reproduced, and the recorded test signal is reproduced according to the recording state of the test signal. In an optical disc recording / reproducing apparatus configured to set a laser output, a test signal is recorded in a test writing area while the laser output is constant and the level of an offset signal added to a tracking control signal is changed stepwise. An optical disk recording / reproducing apparatus characterized in that an optimum offset signal level is set by detecting a recording state of a recorded test signal. 3. The optical disk recording / reproducing apparatus according to claim 1, wherein the set level of the offset signal is stored in a nonvolatile memory. 4. An optical disk recording / reproducing apparatus capable of performing a recording operation at different rotational speeds of a disk, wherein the level of an offset signal corresponding to a different rotational speed is corrected by correcting the level of an offset signal stored in a memory. 3. The optical disk recording / reproducing apparatus according to claim 1, wherein the setting is performed.