JPH0773480A - Optical information recording/reproducing device - Google Patents

Abstract

PURPOSE:To detect prescribed excellent information even when the central position is shifted from an optimum detection position of a signal of prescribed information on a pregroove by adding an offset to an output signal of a servo circuit of an actuator. CONSTITUTION:By a micro computer 20, the ATIP information 23 on the pre- groove is read, and an offset control signal 27 is outputted. The offset from an offset generation circuit 26 is added to an output value of a radial servo circuit 7 based on the signal 27, and thus, a track actuator 6 is displaced. At this time, the number of the error data in the information 23 are counted by checking a cyclic inspection character added to the information 23. Further, an offset amount added to the circuit 7 is varied, and the offset amount when the number of the error data in the information 23 is the least, is made an optimum offset amount, and the offset control signal equivalent to the optimum offset amount is outputted from the micro computer. Since the offset is added to the output value of the circuit 7 based on the offset control signal, the ATIP information with a less error rate is read in.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for recording / reproducing information on / from an optical information recording medium in which predetermined information such as an address is modulated on a pre-groove.

[0002]

2. Description of the Related Art FIG. 11 is a block diagram showing a radial control device and a track control device in a conventional optical information recording / reproducing apparatus. In the figure, reference numeral 1 denotes a laser beam applied to an information recording medium such as an optical disk (not shown). 4 split detector that detects the return light of the
A tracking error amplifier (hereinafter referred to as "TE amplifier") that is connected to the split detector 1 and outputs a tracking error signal.
3) is connected to the 4-division detector 1, and a high-frequency amplifier for extracting high-frequency components (hereinafter referred to as “HF amplifier”) 4 receives the output signal of the TE amplifier 2 and applies track servo to track servo compensation A circuit (hereinafter referred to as “TS compensation circuit”) 5, a driver for amplifying the signal of the TS compensation circuit 4, and 6 is a track actuator driven by the output of the driver 5.

Reference numeral 7 denotes a radial servo compensating circuit (hereinafter referred to as "RS compensating circuit") which receives the output signal of the TS compensating circuit 4 and applies a radial servo, 8 is a driver for amplifying the signal of the RS compensating circuit 7, and 9 is a driver. A linear motor coil for driving a radial feed mechanism (not shown) with an output of 8 is a bandpass filter (hereinafter referred to as "BPF-") for extracting an output of a predetermined frequency band from the output of the TE amplifier 2.
A) is used to extract the wobble signal 22 that has been pre-modulated on the pre-groove. Reference numeral 11 is a waveform shaping unit B that receives the output of the BPF-A 10 and shapes the waveform, and 12 is a constant linear velocity control circuit B (hereinafter referred to as "CLVB") that receives the output from the waveform shaping unit B11. Either of the outputs of the CLVA 16 is switched by the CLV switching means 17, which will be described later, and output.

Reference numeral 15 is a waveform shaping means A for receiving the output from the HF amplifier 3 and shaping the waveform. Reference numeral 16 is a waveform shaping means A15.
Constant linear velocity control circuit A (hereinafter "C
LVA "), 17 is CLVA 16 and the above-mentioned CLV
CLV switching means for switching the output between B12 and 13, C
A driver that amplifies the output signal from the LV switching means 17, and 14 is a disk motor that is driven by the output of the driver 13.

Reference numeral 18 denotes an output F of the waveform shaping means B11.
An FM demodulation circuit that performs M demodulation, 19 is a data demodulation circuit that receives the output of the FM demodulation circuit 18, and performs data demodulation. 23 is an ATIP (Absolute Tim) that is absolute time information on the pre-groove that is output from the data demodulation circuit 19.
e In Pregroove) information, 21 is a CD decoder for receiving the output of the waveform shaping means A15, and 24 is C
Subcode output of D decoder 21, 25 is data output of CD decoder 21, and 20 is A of data demodulation circuit 19.
Subcode 2 of TIP information 23 and CD decoder 21
It is a microcomputer that monitors 4.

Next, the operation of the optical information recording / reproducing apparatus configured as described above will be described by taking the case of a CD-R which is a standard of a compact disc as an information recording medium as an example. A pre-groove is provided as a guide groove for tracking when recording pits in the unrecorded portion of the CD-R disc, and the pre-groove has an address and an AT.
Predetermined information such as IP is pre-modulated. By the way, C
Various methods have been proposed as a method for detecting a tracking error (TE) signal of a D- and signal-recorded CD-R disc, and the push-pull method is widely known as one of them. By this push-pull method, it is possible to detect the TE signal from the above-mentioned pre-groove.

The signal detected by the four-division detector 1 for the returning light from the disk is IV (current-voltage) converted, and then arithmetically amplified by the TE amplifier 2 and the HF amplifier 3. TE
In order to detect the displacement in the track direction, the amplifier 2
From the signal on the split detector 1, TE = (A + D) − (B +
The TE signal can be output by calculating C). The HF amplifier 3 outputs HF signal which is a reproduction signal from the disc by calculating HF = A + B + C + D. The TE signal output from the TE amplifier 2 is T
The signal is input to the S compensation circuit 4, and the TS compensation circuit 4 performs phase compensation or the like for ensuring the stability of the track servo system.
The signal compensated by the TS compensation circuit 4 is current-amplified by the driver 5 and the track actuator 6 is driven to form a track servo system.

The output signal of the TS compensation circuit 4 is also output to the RS compensation circuit 7. The RS compensation circuit 7 performs phase compensation and the like for ensuring the stability of the radial servo system. The output of the RS compensating circuit 7 is subjected to current amplification by the driver 8 and then sent to the linear motor coil 9 which drives the radial feeding mechanism to form a radial servo system. The radial servo system controls the position of the optical pickup itself including the track actuator 6 in the radial direction of the disk, and controls the area beyond the movable range of the track actuator 6 and suppresses the deviation with respect to the eccentricity of the disk.

The calculation target value of the radial servo system is usually set to zero. When the target value of the radial servo system is set to zero, the track actuator 6 is controlled to the center position of the track following range. Eccentricity of the disc,
When the position of the track actuator 6 is displaced from the center position of the track following range due to a change in the track position due to reproduction, an error signal is generated in the radial servo system, and the track actuator 6 is again operated by the operation of the radial servo system.
Will operate at the center position, and the track actuator 6 will always be controlled at the center position of the track following range. As described above, by allowing the radial servo system to constantly operate at the center position of the track following range of the track actuator 6, it is possible to suppress the TE signal offset generation unique to the push-pull method and improve the tracking performance.

Next, a technique for controlling the rotation of the disk will be described. For CD and CD-R, the disc rotation speed is C
Control with LV. For CDs and recorded CD-Rs, the reference clock is extracted from the recorded HF signal, and the APC
(Automatic Phase Control)
Control or AFC (Automatic Frequency)
ncy Control) control is performed. In the case of an unrecorded CD-R, it is usually 22.05 on the pregroove.
APC control or AFC control is performed by detecting the wobble signal amplitude-modulated at KHz. Figure 11
In the case of recording or reproducing on a CD-R unrecorded disc, the CLV switching means 17 is set to CLVB.
When switching to the 12 side and playing the EFM signal by playing the recorded disc of CD or CD-R, CLV
Switch to the A16 side and properly control the disk rotation speed.

In FIG. 11, a CD or a recorded CD
To explain the disk rotation control in the case of -R, the HF signal obtained by the HF amplifier 3 is waveform-shaped by the waveform shaping means A15, and is not shown in the PLL.
The circuit synchronizes the reference clock with the HF signal and CL
The VA 16 compensates the characteristics of the disk servo system so as to improve the stability. The characteristic-compensated signal is the driver 13
The current is amplified by and the disk motor 14 is driven to form a disk servo system. On the other hand, a part of the waveform-shaped HF signal is EFM (8 to 14
Modulation) demodulation, CIRC (Cross)
Interleaved Read-Solomon
Code) Error correction demodulation is performed, and error-corrected data 25 and subcode 24 are output. The subcode 24 includes information such as the absolute playback time of the disc playback position and can be used for data access.

Disc rotation control in the case of an unrecorded CD-R will be described below. Wobble signal 22
Is amplitude-modulated at 22.05 KHz on the pre-groove, so the wobble signal can be detected by the same calculation as the TE signal. Therefore, the output of the TE amplifier 2 is the BPF-A1 of 22.05 KHz which is the carrier frequency of the wobble signal.
The wobble signal 22 can be extracted by passing 0. The wobble signal 22 is waveform shaping means B11.
The waveform is shaped in (1), characteristic compensation is performed in CLVB 12 so that the disk rotation control is stable, and APC control or AFC control is performed. The characteristic-compensated signal is current-amplified by the driver 13 to drive the disk motor 14 to form a disk servo system.

On the other hand, the wobble signal is waveform shaping means B11.
After the waveform is shaped by, a part of the waveform is input to the FM demodulation circuit 18. The wobble signal includes disk information such as absolute time on the disk that plays the role of address by FM modulation and recommended recording power information. When recording, the information is read to search the recording start position and optimize recording conditions. It is possible to set (optimum recording power). FM
The signal demodulated by the demodulation circuit 18 is demodulated by the data demodulation circuit 1
By further demodulating BIPHASE (two-phase) with 9,
Bytes of ATIP information 23 can be obtained.

[0014]

Since the conventional optical information recording / reproducing apparatus is constructed as described above, the servo circuit servos the track actuator on the basis of the track position. Due to variations in characteristics, the position of the track actuator where the C / N (carrier noise ratio) of the wobble signal modulated on the pre-groove of a CD-R disc or the like becomes optimum deviates from the target value of the radial servo. was there. FIG. 12 is a correlation diagram showing the C / N characteristic of the wobble signal with respect to the position of the track actuator. The best C / N point of the track actuator 6 (position A in the figure) and the target value (zero) of the radial servo do not necessarily match. Even in such a state, normally, when the ATIP information 23 of the unrecorded portion of the CD-R disc is read, it is possible to reproduce the ATIP information 23 without any problem, and in many cases, there is no practical problem.

However, even after the signal is recorded once along the pre-groove, it is often necessary to read the ATIP information from the wobble signal included in the pre-groove as in the case of additional recording. In such a case, the pre-groove of the track in which the EFM signal is once recorded has the wobble signal reproduced from the pre-groove because the low frequency component of the EFM signal affects the band of the wobble signal when the pit is recorded. The C / N of the signal is considerably deteriorated as compared with the case of an unrecorded disc. If the deterioration amount of the wobble signal is large, in the process of reproducing the ATIP information from the wobble signal,
ATIP sync signal could not be detected and read ATIP
There has been a problem that a problem such as a large amount of error in information occurs and a control operation such as seek control on a CD-R disc is hindered.

Further, conventionally, as a radial servo system error signal, a signal is received from the track servo system as shown in FIG. In the position control system of the track actuator in the disk radial direction, the control band of the track servo system is DC (0 Hz) to 2 KHz, and the control band of the radial servo system is DC (0 Hz) to 70 Hz.
In the control band of up to 70 Hz, the radial servo system and the track servo system form a two-stage servo that operates in parallel. Therefore, the radial servo system can be constructed by utilizing the low frequency component of the TE signal.

In this case, the amount of low frequency TE signal generated depends on the low frequency sensitivity of the track actuator. If the sensitivity is low, the TE signal generated decreases, and if the sensitivity is high, the TE signal generated increases. Further, the low-range sensitivity of the track actuator is likely to fluctuate due to environmental changes, changes over time, non-linear characteristics, etc. due to the influence of dampers of the track actuator. Therefore, when the radial servo system is controlled based on such a TE signal, there is a problem that accurate control cannot be performed.

The present invention has been made in order to solve the above-mentioned problems, and the optimum position of the signal of the predetermined information modulated to the center position of the actuator and the pre-groove by the servo due to the variations in the characteristics of the optical pickup and the disk. It is an object of the present invention to provide an optical information recording / reproducing device capable of detecting predetermined information of high quality even when the detection position is deviated.

[0019]

In an optical information recording / reproducing apparatus according to the present invention, an actuator relatively moves an information recording medium in which predetermined information such as an address is pre-modulated in a pre-groove to optically move the information recording medium. In recording and reading information, detection means for detecting the predetermined information,
Evaluation means for evaluating the output signal from the detection means, control means for outputting a control signal so that the signal evaluation by the evaluation means is optimal, and output of the servo circuit of the actuator based on the output signal from the control means. Offset means for adding an offset to the signal.

Further, the first detection means for detecting the movement amount of the actuator and the predetermined information, the second detection means for detecting the movement amount of the actuator, and the actuator based on the output signal from the first detection means On the other hand, a track servo circuit that applies servo to a track on the information recording medium, a radial servo circuit that applies servo to the actuator in a direction traversing the track based on an output signal from the second detecting means, and a first servo circuit. Evaluation means for evaluating an output signal from the detection means, control means for outputting a control signal so that the evaluation of the signal of the predetermined information by the evaluation means is optimal, and a radial servo circuit based on the output signal from the control means. And an offset means for adding an offset to the output signal of.

Further, the evaluation means evaluates the output signal from the detection means based on the number of error data of the predetermined information.

The evaluating means evaluates the noise level in the frequency band in which the predetermined information on the pre-groove is not modulated.

[0023]

The optical information recording / reproducing apparatus according to the present invention is
The offset means adds an offset to the output signal of the servo circuit of the actuator so that the evaluation means optimizes the signal evaluation of the predetermined information on the pre-groove to correct the position of the actuator.

Further, the second detecting means detects the error signal of the radial servo circuit and the first detecting means detects the predetermined information on the pre-groove so that the signal evaluation of the predetermined information by the evaluating means becomes optimum. The offset means adds an offset to the output signal of the radial servo circuit of the actuator to correct the position of the actuator.

The evaluation means counts the number of error data of the predetermined information, and the offset means adds an offset to the output signal of the servo circuit so that the actuator is located at the position where the number of error data is the smallest.

Further, the evaluation means measures the noise level in the frequency band in which the predetermined information is not modulated, and the offset means adds an offset to the output signal of the servo circuit so as to reduce the noise level.

[0027]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a radial control device and a track control device of an optical information recording / reproducing apparatus according to the present invention. In the figure, 1 to 25 are the same as or similar to those of the conventional configuration shown in FIG. Is shown and the description thereof is omitted. Reference numeral 26 is an offset generation circuit that generates a voltage for adding an offset to the output of the RS compensation circuit 7, and reference numeral 27 is an offset control signal that instructs the offset generation circuit 26 from the microcomputer 20 that is the control unit.

Next, the operation will be described. Microcomputer 20
At, the ATIP information 23 on the pre-groove is read. AT
In the IP information 23, CRC (cyclic check character) data is added to the ATIP frame in addition to the time information,
By checking this CRC data, it can be confirmed whether or not an error has occurred in the ATIP data. CD
When the ATIP information is read from the recording area of the −R disc, the quality of the wobble signal can be evaluated by using the ATIP error rate as the evaluation standard of the wobble signal.

As an evaluation method, for example, the offset control signal 27 is changed by three points or more, and the offset control signal having the smallest number of each ATIP error at this time is determined. The offset control signal 27 is changed by three points or more, There are a method of calculating the offset control signal that minimizes the ATIP error from the number of each ATIP error at this time, a method of gradually changing the offset control signal 27, and a method of searching for a point where the ATIP error signal becomes small at this time. However, it is not limited to this.

Such an evaluation method is actually still accurate ATIP information when necessary, at the start of reading information, at the end of track search, immediately before the start of recording, at the first time when the optical disk device is started. If the optimum offset is found once, the stable ATIP can be read if it is fixed after that. Further, even when the actual data is read, the above process can be performed to find the optimum point when the number of ATIP errors exceeds the device reproduction limit. In this way, the ATIP information can be read for signal evaluation. Instability can be effectively prevented.

ATIP from the recording area of the CD-R disc
When reading information, the microcomputer 20 outputs an offset control signal 27 to control the offset generation circuit 26 to add the offset to the output value of the radial servo circuit. The track actuator 6 is displaced by adding the offset to the radial servo system. At that time, a predetermined amount of ATIP information 23 is read by the microcomputer 20, and A
The CRC of TIP is checked and the number of error data is counted.

Further, as shown in FIG. 2, the offset added to the radial servo system is changed, the number of errors (ATER) in the ATIP data is counted, and the offset when the number of errors is the smallest is taken as the optimum offset amount. Then, the microcomputer 20 outputs an offset control signal 27 corresponding to the optimum offset amount, and the offset generation circuit 26 adds an offset to the output value of the radial servo circuit based on the offset control signal 27. By performing the above processing, ATIP information with a low error rate can be read.

Example 2. FIG. 3 is a block diagram showing a radial control device and a track control device of an optical information recording / reproducing apparatus according to a second embodiment. In the figure, 1-27 are the same as or similar to those of the configuration of the first embodiment shown in FIG. And the description thereof is omitted. In the figure, 28
Is a two-division detector which is the second detection means for detecting the position of the actuator together with the four-division detector 1 which is the first detection means, and 29 is the actuator position by taking the differential of the output of the two-division detector 28. A PE amplifier that generates and outputs a signal (hereinafter referred to as “PE signal”) 30, and a PP offset correction amplifier 31 that adds the PE signal 30 to the track servo system.

Next, the operation will be described. The output of the two-divided detector 28 is operationally amplified by the PE amplifier 29 to generate the PE signal 30. The PE signal 30 is sent to the PP offset correction amplifier 31 and the RS compensation circuit 7. PP
The offset correction amplifier 31 is a PE for the track servo system.
It is known that the TE signal obtained by the push-pull method has a function of adding the signal 30, and an offset proportional to the displacement of the track actuator 6 is generated as shown in FIG. 4A. Therefore, the TE signal shown in FIG.
By adding the PE signals 30 as in (b),
As shown in FIG. 4C, the offset generated in the TE signal can be canceled.

Further, the PE signal 30 sent to the RS compensating circuit 7 constitutes a radial servo system as an error signal of the radial servo system. The output of the offset generation circuit 26 is added to the radial servo system, and the radial servo system is controlled so that the PE signal 30 corresponding to the output of the offset generation circuit 26 is generated.

As shown in FIG. 5, in the radial servo system of the present invention, the position of the track actuator 6 is set to T.
Since it is detected separately from the E signal, environmental changes,
Even if the characteristics of the track actuator 6 change due to changes over time, the position of the track actuator can be accurately detected. Therefore, it is possible to obtain the displacement of the track actuator that accurately corresponds to the signal output from the offset generation circuit 26, and as a result, it is possible to always call a stable wobble signal.

In the above embodiment, the PE signal 30 from the PE amplifier 29 is added to the track servo system via the PP offset correction amplifier 31, but the PP offset correction amplifier 31 is not always necessary.

Example 3. FIG. 6 is a block diagram showing a radial control device and a track control device of an optical information recording / reproducing apparatus according to a third embodiment. In the figure, 1 to 31 are the same as or similar to those of the configuration of the second embodiment shown in FIG. And the description thereof is omitted. 32 is a 100 KHz bandpass filter (hereinafter referred to as "BPF-B") that receives the output of the TE amplifier 2; 33 is a BPF-B.
It is a detection circuit that detects the output of 32.

Next, the operation will be described. In FIG. 6, the TE signal output from the TE amplifier 2 includes a wobble signal 22. The frequency characteristic of the TE signal level is shown in FIG. DC (Device control)
The low frequency including the (Character) component includes the TE signal component required for tracking control. Also,
At F = 22,05 KHz, the wobble signal included in the pre-groove is included.

However, when the track actuator 6 is displaced and the C / N of the wobble signal is deteriorated, as shown in FIG.
As indicated by the wavy line in (1), there is little variation in the carrier component at 22,05 KHz, and rather the noise level other than the carrier frequency tends to increase. By utilizing this characteristic and measuring and evaluating the amplitude of the noise level other than the wobble signal component, it is possible to judge whether the C / N of the wobble signal is good or bad.

In the case of the present embodiment, the TE signal is made a noise component by removing the carrier frequency of the wobble signal, for example, passing through the BPF-B32 of about 100 KHz. And
The detection circuit 33 can detect the signal level from the output of the BPF-B 32 and measure the noise of the wobble signal. With such a configuration, even if the position of the track actuator 6 where the C / N of the wobble signal is maximum (best) is deviated from the center position of the track as shown in FIG. 8, the offset control signal 27 is output from the microcomputer 20. By offsetting the output of the servo system by the offset generating means 26, the position of the track actuator 6 is displaced and the output of the detection circuit 33 is monitored.
It is possible to detect and correct the position of the track actuator 6 that gives the best C / N.

Although the RS compensating circuit 7 inputs the error signal from the two-divided detector 28 in the above-mentioned embodiment, it may be constructed so as to obtain the output signal from the TS compensating circuit 4 as in the first embodiment. . Further, the PP offset correction amplifier 31 may be omitted. That is, a configuration in which the BPF-B 32 and the detection circuit 33 are added to the configuration of FIG. 1 may be used.

Example 4. FIG. 9 is a block diagram showing a radial control device and a track control device of an optical information recording / reproducing apparatus according to a fourth embodiment. In the figure, 1 to 27 are the same as or similar to those of the configuration of the first embodiment shown in FIG. And the description thereof is omitted. The offset generation circuit 26, the two-divided detector 28, the PE amplifier 29, and the PP offset correction amplifier 31 are the same as those in the first, second, and third embodiments, but the connection arrangement is different. That is, in the first embodiment, the output of the offset generation circuit 26 is added to the output of the RS compensation circuit, but in the present embodiment, it is added to the output of the TS compensation circuit. In the second embodiment, the PE signal 30 is input to the RS compensation circuit 7, but in the present embodiment, the output of the TS compensation circuit 4 is input to the RS compensation circuit 7.

Next, the operation will be described. Although the input to the RS compensation circuit 7 and the addition point of the output signal of the offset generation circuit 26 to the servo system are different, the position of the track actuator 6 is corrected so that the best wobble signal is obtained, which is different from the above embodiment. It is the same.

Example 5. FIG. 10 is a block diagram showing a radial control device and a track control device of an optical information recording / reproducing apparatus according to a fifth embodiment.
Indicates the same as or similar to that of the second embodiment shown in FIG. 3, and the description thereof will be omitted. In the figure, 3
Reference numeral 4 is a recording / reproducing apparatus main body including the above-mentioned 1 to 31, and 35 is an external adjusting device capable of outputting an offset signal from the outside of the recording / reproducing apparatus main body 34.

In the above embodiment, the offset signal applied to the radial servo system is automatically controlled by the microcomputer 20 in the recording / reproducing apparatus main body 34 so that a high quality wobble signal with a low error rate is obtained, and the position of the track actuator is adjusted. However, in the present embodiment, the recording / reproducing apparatus main body 34
Is provided with an external adjusting device 35 for manually outputting an offset signal from the outside, and the offset signal 27 is sent from the external adjusting device 35 to the offset generating circuit 26 so that the position of the track actuator can be arbitrarily set. It was done.

As described above, even if the signal from the offset generating circuit 26 can be manually adjusted, the same effect as in the above embodiment can be obtained. Further, an external adjustment device 35 and a measuring device may be provided outside the recording / reproducing device main body 34. Further, the automatic adjustment of the offset of the radial servo may be performed at any time, or may be performed only when necessary.

[0048]

As described above, according to the present invention, the actuator relatively moves the information recording medium in which the predetermined information such as the address is pre-modulated in the pre-groove to optically record and read the information. What is performed is a detection means for detecting the predetermined information, an evaluation means for evaluating an output signal from the detection means, a control means for outputting a control signal so that the signal evaluation by the evaluation means is optimal, and this control. Since the offset means for adding an offset to the output signal of the servo circuit of the actuator based on the output signal from the means is provided, a predetermined position modulated to the center position of the actuator and the pre-groove by the servo due to variations in the characteristics of the optical pickup or the disk is provided. Even if the optimum detection position of the information signal is deviated, it is possible to detect high-quality predetermined information. It is.

Further, first detecting means for detecting the movement amount of the actuator and predetermined information on the pre-groove, second detecting means for detecting the movement amount of the actuator, and the first detecting means.
Track servo circuit that servos the actuator centering on the track on the information recording medium based on the output signal from the detecting means, and the direction across the track to the actuator based on the output signal from the second detecting means. A radial servo circuit for applying servo to, an evaluation means for evaluating an output signal from the first detection means, a control means for outputting a control signal so that the signal evaluation of the predetermined information by the evaluation means is optimum, and Since an offset means for adding an offset to the output signal of the radial servo circuit based on the output signal from the control means is provided, accurate displacement of the actuator can be detected even if the characteristics of the actuator change due to environmental changes or the like. At the same time, it is possible to obtain the effect that high quality predetermined information can be detected.

Further, since the evaluation means is configured to evaluate the output signal from the detection means by the number of error data of the predetermined information, it is possible to obtain the effect that the signal of the predetermined information in the optimum state can be detected. .

Further, since the evaluation means is configured to evaluate the noise level in the frequency band in which the predetermined information on the pre-groove is not modulated, it is possible to obtain a more accurate signal evaluation of the predetermined information.

[Brief description of drawings]

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

FIG. 2 Position characteristics of a track actuator and ATIP
It is a correlation diagram showing the relationship with the error rate of.

FIG. 3 is a block diagram showing an optical information recording / reproducing apparatus according to Embodiment 2 of the present invention.

FIG. 4 is a correlation diagram showing the output waveform of the 4-division detector with respect to the position of the track actuator of the optical information recording / reproducing apparatus according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a servo system of an optical information recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing an optical information recording / reproducing apparatus according to Embodiment 3 of the present invention.

FIG. 7 is a correlation diagram showing a frequency characteristic of a wobble signal of the optical information recording / reproducing apparatus according to the third embodiment of the present invention.

FIG. 8 is a correlation diagram showing the relationship between the position characteristics of the track actuator of the optical information recording / reproducing apparatus according to the third embodiment of the present invention, the C / N characteristics of the ATIP signal, and the noise level of the TE signal.

FIG. 9 is a block diagram showing an optical information recording / reproducing apparatus according to Embodiment 4 of the present invention.

FIG. 10 is a block diagram showing an optical information recording / reproducing apparatus according to Embodiment 5 of the present invention.

FIG. 11 is a block diagram showing a conventional optical information recording / reproducing apparatus.

FIG. 12 is a correlation diagram showing the relationship between the C / N characteristic of the ATIP signal and the position characteristic of the track actuator of the conventional optical information recording / reproducing apparatus.

FIG. 13 is a block diagram showing a servo system of a conventional optical information recording / reproducing apparatus.

[Explanation of symbols]

 26 Offset Generation Circuit 28 Two-Division Detector 29 PE Amplifier 31 PP Offset Correction Amplifier 32 BPF-B 33 Detection Circuit 35 External Adjustment Device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takuma Sato Takuma Sato 800 Iwamatsu, Oshima-cho, Nitta-gun, Gunma Sanryo Electric Co., Ltd. Gunma Manufacturing (72) Naoki Ueda 800 Iwamatsu, Ojima-cho, Nitta-gun, Gunma Prefecture Address Sanryo Electric Engineering Co., Ltd. Kamakura Office Gunma Branch

Claims (4)

[Claims] 1. An optical information recording / reproducing apparatus for optically recording and reading information by moving an actuator relative to an information recording medium in which predetermined information such as an address is pre-modulated in a pre-groove, Detecting means for detecting predetermined information, evaluating means for evaluating an output signal from this detecting means, control means for outputting a control signal so that signal evaluation by this evaluating means is optimum, and output signal from this controlling means An optical information recording / reproducing apparatus comprising: an offset means for adding an offset to the output signal of the servo circuit of the actuator based on the above. 2. An optical information recording / reproducing apparatus for optically recording and reading information by an actuator relatively moving on an information recording medium in which predetermined information such as an address is pre-modulated in a pre-groove, A first detection unit that detects the movement amount of the actuator and the predetermined information, a second detection unit that detects the movement amount of the actuator, and a second detection unit for the actuator based on an output signal from the first detection unit. A track servo circuit that applies servo to a track on the information recording medium, a radial servo circuit that applies servo to the actuator in a direction traversing the track based on an output signal from the second detecting means; The evaluation means for evaluating the output signal from the first detection means and the signal evaluation of the predetermined information by this evaluation means are the best. The optical information recording / reproducing apparatus is provided with a control means for outputting a control signal so that the output signal from the radial servo circuit is offset based on the output signal from the control means. . 3. The optical information recording / reproducing apparatus according to claim 1, wherein the evaluation means evaluates the number of error data of the predetermined information. 4. The optical information recording / reproducing apparatus according to claim 1, wherein the evaluation means evaluates a noise level in a frequency band in which the predetermined information on the pre-groove is not modulated.