JP2003016654A - Disk driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reproducing performance by minimizing the leakage of a wobbling component into a reproducing RF signal. SOLUTION: In accordance with a wobbling component leaked into a reproduced information component (reproducing RF signal), a variable amplifier 43 is controlled for a second reflected light information signal. That is, the amount of amplification at the variable amplifier 43 is controlled so that wobbling components included in the first and second reflected light information signals are equal to each other and, when the first and second reflected light information signals are added to obtain a reproduced information component, the wobbling components are property canceled. Thus, the wobbling component leaked to the reproduced information component is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device for recording on a disk recording medium such as an optical disk.

[0002]

2. Description of the Related Art In order to record data on a disc, a means for guiding to form a data track is required. For this reason, a groove is formed in advance as a pre-groove and the groove or land is formed. It has been practiced to use (a groove and a site having a cross-sectional plateau sandwiched between the grooves) as a data track. It is also necessary to record address information so that data can be recorded at a predetermined position on the data track, but this address information may be recorded by wobbling (meandering) the groove.

That is, a track for recording data is formed in advance as, for example, a pregroup, and the side wall of this pregroup is wobbled corresponding to the address information. By doing this, the address can be read from the wobbling information obtained as the reflected light information at the time of recording or reproducing, and for example, even if the pit data indicating the address is not formed on the track in advance, the desired position can be obtained. Data can be recorded and played back. The wobbling groove wobbles slightly sinusoidally as shown in FIG. 6B. For example, the center frequency is 22.05 kHz and the wobbling amount is about ± 0.03 μm.

By adding address information as a wobbling groove in this way, it becomes unnecessary to provide address areas discretely on a track and record addresses as, for example, pit data, and the address area becomes unnecessary. The recording capacity of actual data can be increased. The absolute time (address) information expressed by such wobbling groove is
ATIP (Absolute Time In Pregroove) or ADIP
(Adress In Pregroove).

A typical optical disc using the wobbling groove is a CD-R (CD-Recordable),
CD-RW (CD-ReWritable), DVD-R, CD-R
W, DVD + RW, etc. CD-RW, DVD-R
W and DVD + RW are phase change recording type rewritable discs, and CD-R and DVD-R are organic dye changing type write-once discs.

In the case of a recording method in which data is recorded by using a groove as a data track, for example, a dye change mark (pit) or a phase change mark (pit) is recorded, at the time of data reproduction, a track formed by a groove as shown in FIG. To irradiate the laser spot LS to obtain the reflected light information. FIG. 6A shows a method of extracting a reproduction RF signal corresponding to pit data recorded on the groove track. The photodetector 150 is a detector that detects reflected light when the disc is irradiated with the laser spot LS, and in this case, for example, as shown in the drawing, the light receiving unit A,
It is a 4-division detector composed of B, C, and D. Each of the light receiving parts A, B, C, D outputs a current according to the amount of received light.

The reproduced RF signal is basically the detector 1
The signal becomes a signal according to the amount of reflected light detected at 50. Play R
When obtaining the F signal, the signals I1 and I2 shown in the figure are used. The signal I1 is obtained by converting the currents obtained at the light receiving portions A and C into voltages and adding them. The signal I2 is obtained by converting the currents obtained at the light receiving portions B and D into voltages and adding them. In this case, each of the signals I1 and I2 is as shown in FIG.
As shown in (b), when the laser spot LS is irradiated onto the track, a reflected light amount signal corresponding to the left half and a reflected light amount signal corresponding to the right half of the laser spot LS with respect to the track line direction. Becomes And each signal I1, I
2 is amplified by the head amplifiers 151 and 152, respectively, and added by the adder 153. The output of the adder 153 becomes a reproduction RF signal, that is, a signal component corresponding to the pit data on the track, and is decoded as reproduction data by a decoder in the subsequent stage. Although not shown, AD
A wobble component for obtaining IP data and a tracking error signal for tracking control are generated as the calculation result of I1-I2, that is, a push-pull signal.

[0008]

By the way, pit data is not always recorded at the track center on the data track formed by the wobbling groove. For example, a pit mark may be formed in a detracked state to some extent due to some factors at the time of a recording operation in a recording device, a disc warp, or a disc factor such as an asymmetry of a formed wobbling groove. Although FIG. 8A shows a state in which a pit mark row is formed at the track center,
FIGS. 8B and 8C show a state in which detracking is performed for recording and the pit mark row is displaced from the track center.

Basically, the wobble component as reflected light information is obtained as a push-pull signal, and is the signal (I1-I2) of the signals I1 and I2 in FIG. In other words, the signal I1 and the signal I2 include wobble components in opposite phases. Since the reproduction RF signal is the signal of (I1 + I2) as described above, if the pit mark row is recorded in the track center as shown in FIG. 8A, normally the reproduction RF signal is not reproduced. Wobble component does not leak. That is, it is canceled at the time of addition. However, FIG. 8 (b)
In the detracked state as shown in (c), since the wobble components in the signal I1 and the signal I2 are not evenly divided,
A wobble component leaks into the reproduced RF signal of (I1 + I2).

FIG. 7 shows a servo signal band and an RF signal band as a signal spectrum, and a wobble component band centered at 22.05 KHz, but the RF signal and the wobble component partially overlap in the frequency band. Therefore, if the wobble component leaks into the reproduction RF signal, the reproduction R
This will affect the quality of the F signal. FIG. 9 (a)
FIG. 9B schematically shows a state of the normal reproduction RF signal and the reproduction RF signal in which the wobble component leaks. However, when the wobble component leaks, the reproduction RF signal becomes as shown in FIG. 9B. The envelope of is modulated by the wobble component. This eventually results in a jitter component in the time axis direction, which deteriorates the error rate of the reproduced data.

The wobble component leaks into the reproduction RF signal when the data recorded by detracking is reproduced, but the wobble component may leak even when the data is recorded in the track center. obtain. For example, if the left / right detector output balance is lost due to optical asymmetry in the pickup of the reproducing apparatus, the signal I
The wobble components contained in 1 and I2 are not evenly divided,
Leakage may occur because it cannot be canceled when adding. In this case, the same problem occurs.

[0012]

In view of such circumstances, the present invention aims to minimize the wobble component leaking to the reproduction RF signal at the time of reproduction and reduce the jitter in the disk drive device to improve the reproduction performance. With the goal.

Therefore, the disk drive apparatus of the present invention corresponds to the head means for irradiating the wobbled track of the disk with the laser to obtain the reflected light information and the direction of the track as the reflected light information signal. Regarding the first reflected light information signal and the second reflected light information signal divided by the dividing line, at least the second reflected light information signal is passed through the variable amplifier, and then the first reflected light information signal and the first reflected light information signal Regarding the reproduction information component extracting means for obtaining the reproduction information component corresponding to the data recorded on the track by adding the reflected light information signals of 2, and the reproduction information component obtained by the reproduction information component extracting means. Decoding means for performing a decoding process to obtain reproduced data, wobble component detecting means for detecting a wobble component of a track leaked into the reproduction information component, As the wobble component detected by the serial wobble component detecting means becomes minimum, so that a control means for variably controlling the variable amplifier.

The wobble component detecting means detects the amplitude of the wobble component from the reproduction information component, and the control means variably controls the variable amplifier so that the amplitude value is minimized. Alternatively, the wobble component detection means adds a first addition signal obtained by adding the first reflected light information signal and the second reflected light information signal that has passed through the variable amplifier at a first addition ratio. , A second addition signal obtained by adding a second addition ratio opposite to the first addition ratio, and outputting a comparison result of each wobble component in the first and second addition signals. Then, the control means variably controls the variable amplifier so that the comparison result becomes a coincident state.

According to the present invention as described above, the variable amplifier for the second reflected light information signal is controlled according to the wobble component leaking into the reproduction information component (reproduction RF signal) to obtain the reproduction information component. Therefore, the wobble component can be appropriately canceled at the time of the addition process of the first reflected light information signal and the second reflected light information signal.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, as embodiments of the present invention, a CD-R, a CD-RW, a DVD-R, and a DVD-RW.
A disk drive device (recording / reproducing device) corresponding to such a disk will be described in the following order. 1. 1. Configuration of disk drive device Wobble component minimization process (1) 3. Minimize wobble component (2)

1. Configuration of Disk Drive Device FIG. 1 shows the configuration of a disk drive device 30 of this example.
The disc 100 is loaded on the turntable 7 and is rotationally driven at a constant linear velocity (CLV) by the spindle motor 6 during the recording / reproducing operation. Then, the optical pickup 1 reads out pit data recorded on the track on the disc 100 and wobbling information of the track. Pits recorded as data on tracks formed as grooves are so-called dye change pits or phase change pits.

In the pickup 1, a laser diode 4 serving as a laser light source, a photodetector 5 for detecting reflected light, an objective lens 2 serving as an output end of laser light,
An optical system (not shown) is formed which irradiates the disk recording surface with laser light through the objective lens 2 and guides the reflected light to the photodetector 5. A monitor detector 22 that receives a part of the output light from the laser diode 4
Is also provided.

The objective lens 2 is held by a biaxial mechanism 3 so as to be movable in the tracking direction and the focus direction. The entire pickup 1 can be moved in the disk radial direction by a sled mechanism 8. The laser diode 4 in the pickup 1 is driven to emit laser light by a drive signal (drive current) from the laser driver 18.

Information on the light reflected from the disk 90 is detected by the photodetector 5, converted into an electric signal corresponding to the amount of received light, and supplied to the matrix circuit 9. The matrix circuit 9 is provided with a current-voltage conversion circuit, a matrix calculation / amplification circuit, etc. corresponding to output currents from a plurality of light receiving elements as the photodetector 5, and generates necessary signals by matrix calculation processing. For example, an RF signal corresponding to reproduction data, a focus error signal F for servo control
E, tracking error signal TE (push-pull signal P
/ P) etc. are generated. Also push-pull signal P / P
Is also output as a signal related to groove wobbling. Further, as will be described later, the matrix circuit 9 is provided with a variable amplifier corresponding to a predetermined reflected light information signal,
The amplification amount is variably controlled by a control signal Cg from the system controller 10.

The RF signal output from the matrix circuit 9 is sent to the binarization circuit 11, the focus error signal FE and the tracking error signal (push-pull signal) TE are sent to the servo circuit 14, and the push-pull signal P / P is sent to the wobble extraction section. 24 and wobble PLL 25, respectively.

Further, the matrix circuit 9 outputs a signal for detecting a wobble component leaking into the reproduction RF signal, and the signal is supplied to the wobble component detecting section 28. As will be described later, the signal for detecting the wobble component is the reproduction RF.
It becomes a reflected light information signal before addition for obtaining a signal or a reproduction RF signal. The wobble component detection unit 28 performs a detection process of the wobble component leaking into the reproduction RF signal, and supplies the detection result to the system controller 10. The system controller 10 generates a control signal Cg according to the detection result, and controls the amplification amount of the variable amplifier in the matrix circuit 9.

The push-pull signal P / P is binarized and demodulated as ADIP information in the wobble extraction section 24 and supplied to the address decoder 26. Then, the address decoder 26 decodes the preformatted address information. The decoded address information is supplied to the system controller 10. A wobble clock WCK is generated from the push-pull signal P / P by a PLL operation in the wobble PLL 25. The wobble clock WCK is supplied to the encode clock generator 25, the address decoder 26, and the spindle servo circuit 23.

The RF signal obtained by the matrix circuit 9 is 2
It is binarized by the binarization circuit 11 and then supplied to the encoding / decoding unit 12. Encoding / decoding unit 12
Has a functional portion as a decoder at the time of reproduction and a functional portion as an encoder at the time of recording. At the time of reproduction, as a decoding process, a run length limited code demodulation process, an error correction process, a deinterleave process, and the like are performed to obtain reproduced data.

Further, the encode / decode section 12 generates a reproduction clock synchronized with the RF signal by the PLL process during reproduction, and executes the decoding process based on the reproduction clock. At the time of reproduction, the encoding / decoding unit 12 accumulates the data decoded as described above in the buffer memory 20. The reproduction output from the disk drive device 30 is the buffer memory 20.
The data buffered by is read, transferred, and output.

The interface unit 13 is connected to an external host computer 80, and the host computer 80
Communication of recorded data, reproduced data, various commands, and the like is performed with. During reproduction, the reproduction data decoded and stored in the buffer memory 20 is transferred and output to the host computer 80 via the interface unit 13. The host computer 80
Read commands, write commands, and other signals from the device are supplied to the system controller 10 via the interface unit 13.

On the other hand, at the time of recording, the host computer 8
The print data is transferred from 0, but the print data is sent from the interface unit 13 to the buffer memory 20 and buffered. In this case, the encoding / decoding unit 12 performs encoding such as error correction code addition, interleaving, addition of subcodes, and run length limited code modulation as recording data on the disc 100 as encoding processing of the buffered recording data. Run.

An encode clock, which serves as a reference clock for encoding during recording, is generated by the encode clock generating section 27, and the encode / decode section 1
2 performs an encoding process using this encode clock. The encode clock generator 27 uses the wobble P
An encode clock is generated based on the wobble clock WCK supplied from the LL 25.

The recording data generated by the encoding process in the encoding / decoding unit 12 is converted into a recording pulse (laser driving pulse) in the recording pulse generating unit 21,
It is sent to the laser driver 18. The recording pulse generator 21 also performs recording compensation, that is, fine adjustment of the optimum recording power and adjustment of the laser drive pulse waveform with respect to the characteristics of the recording layer, the spot shape of laser light, the recording linear velocity, and the like.

The laser driver 18 supplies a drive current based on the supplied laser drive pulse to the laser diode 4 to drive laser emission. As a result, pits (dye change pits / phase change pits) corresponding to the recording data are formed on the disc 90.

APC circuit (Auto Power Control) 19
Is a circuit unit that controls the laser output power by the output of the monitor detector 22 so that the laser output becomes constant irrespective of temperature. The target value of the laser output is given from the system controller 10, and the laser driver 18 is controlled so that the laser output level becomes the target value.

The servo circuit 14 generates various servo drive signals for focus, tracking and sled from the focus error signal FE and the tracking error signal TE from the matrix circuit 9 and executes the servo operation.
That is, the focus drive signal FD and the tracking drive signal TD are generated according to the focus error signal FE and the tracking error signal TE, and are supplied to the biaxial driver 16. The biaxial driver 16 drives the focus coil and tracking coil of the biaxial mechanism 3 in the pickup 1. As a result, the pickup 1, the matrix circuit 9, the servo processor 14, the biaxial driver 1
6. A tracking servo loop and a focus servo loop are formed by the biaxial mechanism 3.

In accordance with a track jump command from the system controller 10, the tracking servo loop is turned off and a jump drive signal is output to the biaxial driver 16 to execute the track jump operation.

Further, the servo processor 14 generates a sled drive signal based on a sled error signal obtained as a low frequency component of the tracking error signal TE, an access execution control from the system controller 10, etc., and supplies it to the sled driver 15. . The thread driver 15 responds to the thread drive signal by the thread mechanism 8
To drive. Although not shown, the sled mechanism 8 has a mechanism including a main shaft that holds the pickup 1, a sled motor, a transmission gear, and the like.
5 drives the sled motor 8 in response to the sled drive signal, so that the required slide movement of the pickup 1 is performed.

The spindle servo circuit 23 controls the spindle motor 6 to rotate it by CLV. At the time of data recording, the spindle servo circuit 23 obtains the current rotation speed information of the spindle motor 6 from the wobble clock WCK generated by the wobble PLL, and compares this with the predetermined CLV reference speed information to obtain a spindle error signal. SP
Generate E. During data reproduction, the reproduction clock generated by the PLL in the encoding / decoding unit 21 (clock that serves as the reference for decoding processing) becomes the current rotation speed information of the spindle motor 6, and this is used as the predetermined CLV. The spindle error signal SPE is generated by comparing with the reference speed information. Then, the spindle servo circuit 23 supplies the spindle drive signal generated according to the spindle error signal SPE to the spindle motor driver 17. The spindle motor driver 17 applies, for example, a three-phase drive signal to the spindle motor 6 according to the spindle drive signal, and causes the spindle motor 6 to perform CLV rotation. The spindle servo circuit 23 also generates a spindle drive signal in response to a spindle kick / brake control signal from the system controller 10, and causes the spindle motor driver 17 to execute operations such as starting, stopping, accelerating, and decelerating the spindle motor 6. .

Various operations of the servo system and the recording / reproducing system as described above are controlled by the system controller 10 formed by a microcomputer. The system controller 10 executes various processes according to commands from the host computer 80. For example, when a read command requesting the transfer of certain data recorded on the disc 100 is supplied from the host computer 80, first, seek operation control is performed for the designated address. That is, a command is issued to the servo circuit 14 to execute the access operation of the pickup 1 targeting the address designated by the seek command. Then, the operation control necessary for transferring the data in the designated data section to the host computer 80 is performed. That is, data read / decode / buffering from the disk 100 is performed to transfer the requested data.

When a write command (write command) is issued from the host computer 80, the system controller 10 first picks up the pickup 1 at the address to be written.
To move. Then, the encoding / decoding unit 12 causes the data transferred from the host computer 80 to perform the encoding process as described above.
Then, as described above, by supplying the laser driving pulse from the recording pulse generating unit 21 to the laser driver 18,
Recording is executed.

By the way, although the example of FIG. 1 shows the disk drive device 30 connected to the host computer 80, the disk drive device of the present invention may have a form not connected to the host computer 80 or the like. In that case, an operation unit and a display unit are provided, and the configuration of the interface part for data input / output is different from that of FIG. That is, recording and reproduction may be performed according to a user's operation, and a terminal unit for inputting / outputting various data may be formed.

2. Wobble Component Minimization Process (1) FIG. 2 shows a configuration example for extracting the reproduction RF signal and minimizing the wobble component leaking into the reproduction RF signal in the disk drive device 30. In FIG.
The photo detector 5, the matrix circuit 9, the wobble component detector 28, and the system controller 10 in the pickup 1 are shown.

In the matrix circuit 9, only the circuit components for generating the reproduction RF signal are shown, and the push-pull signal P / P (tracking error signal TE), the focus error signal FE, etc. described above are generated. Illustration and description of the circuit components to be performed are omitted.

As shown in the figure, the photodetector 5 is a four-divided detector composed of light receiving portions A, B, C and D. Actually, the reflected light (current corresponding to the amount of received light) detected by each light receiving portion is A / B converted into a voltage value by current / voltage conversion in the matrix circuit 9, respectively.
The signals C and D are calculated to generate required signals such as a reproduction RF signal, a focus error FE, and a push-pull signal P / P. Here, the signals I1 and I2 for generating the reproduction RF signal will be described, but the arithmetic circuit configuration for obtaining the current / voltage conversion and the signals I1 and I2 is not shown. Actually, the signal I1 is obtained by converting the currents obtained in the light receiving parts A and C into voltages and adding them. The signal I2 is obtained by converting the currents obtained at the light receiving portions B and D into voltages and adding them.

The signal I for obtaining the reproduced RF signal
Reference numerals 1 and I2 represent a reflected light amount signal corresponding to the left half of the laser spot LS and a reflection light corresponding to the right half of the laser spot LS in the track line direction when the laser spot LS is irradiated onto the track as shown in the figure. It becomes a light quantity signal. Then, basically, the sum of the signals I1 and I2 is used as the reproduction RF signal.
Accordingly, although not shown, a circuit system for obtaining the difference between the signals I1 and I2 is formed, which serves as the tracking error signal TE and the push-pull signal P / P as ADIP information.

The reflected light information signals I1 and I2 generated from the reflected light received by the photodetector 5 by the arithmetic processing in the matrix circuit 9 are supplied to the head amplifiers 41 and 42, respectively, and a predetermined amplification processing is performed. The signal I1 amplified by the head amplifier 41 is supplied to the adder 44. The signal I2 amplified by the head amplifier 42 is
Adder 4 via variable gain amplifier (variable amplifier) 43
4 is supplied. As described above, the gain of the variable gain amplifier 43 is controlled by the control signal C from the system controller 10.
It is variably controlled by g.

In the adder 44, the input signals I1 and I2 are input.
Is added and output. This addition output becomes a reproduction RF signal, is supplied to the encoding / decoding unit 12 via the binarization circuit 11 as shown in FIG. 1, and is used for decoding processing.

In this case, the reproduced RF signal is also supplied to the wobble component detecting section 28. Wobble component detector 2
8 includes a bandpass filter 51 and an amplitude detection circuit 52. The band pass filter 51 has a center frequency of the pass band as a wobbling frequency (for example, 22.05 KHz), that is, a filter for extracting a wobble component leaking into the reproduction RF signal. The amplitude detection circuit 52 detects the amplitude level of the wobble component that is the output of the bandpass filter 51 and supplies the amplitude value to the system controller 10. As a method of detecting the amplitude, for example, envelope detection processing or waveform integration processing may be used.

The system controller 10 inputs the output of the amplitude detection circuit 52 through the A / D conversion port and obtains digital data as the detected amplitude value. Then, the control signal Cg is generated according to the amplitude value data, and the gain of the variable gain amplifier 43 is controlled.

As described above, the wobble component leaks into the reproduced RF signal due to the fact that the data is detrack-recorded or due to the optical asymmetry, and the reason why the signals I1 and I2 are opposite to each other This is because the wobble component of the phase could not be canceled during the addition processing in the adder 44. That is, this is a case where the amplitude levels of the wobble components included in the signal I1 and the signal I2 are not equal. Therefore, a gain variable amplifier 43 is provided for one signal, in this case, the signal I2, and the gain variability control is performed to perform the signal I1.
By making the amplitude levels of the wobble components included in the signal I2 equal, it is possible to eliminate the leakage of the wobble components into the reproduction RF signal.

The relationship between the gain of the variable gain amplifier 43 which is variably controlled by the system controller 10 and the amplitude level of the wobble component leaking into the reproduced RF signal is as shown in FIG. That is, the system controller 10 monitors the amplitude level supplied from the amplitude detection circuit 52,
The gain may be changed by the control signal Cg, and the variable gain control may be performed so that the point where the amplitude level becomes the minimum value converges as the best point.

Although various concrete processes of the system controller 10 can be considered, as an example, it is conceivable that the variable gain width is changed and converged. In this case, basically, at the start of the variable control processing, the gain is first changed in the up direction (or the down direction), and depending on whether the amplitude level of the wobble component is increased or decreased at that time, the It is determined whether it is in the area a or the area b of 3. If it is in the area a, then the amplitude level is monitored while gradually increasing the gain. In this case, the amplitude level gradually decreases at first. Then, when the amplitude level shifts from a decrease to an increase, it is judged that the maximum point is exceeded, and the amplitude level is monitored by, for example, gradually decreasing the gain with a finer variable width. When the amplitude level rises, the amplitude level immediately before that is set to the minimum level, and the gain at that time is set to the optimum gain. On the other hand, if it is in the region b first, then the amplitude level is monitored while gradually lowering the gain. Also in this case, the amplitude level gradually decreases at first. Then, when the amplitude level changes from a decrease to an increase, it is judged that the maximum point is exceeded, and the amplitude level is monitored by, for example, gradually increasing the gain with a finer variable width. When the amplitude level rises, the amplitude level immediately before that is set to the minimum level, and the gain at that time is set to the optimum gain. This processing is, for example, a case where the gain variable width is changed in two steps to converge to the best point, but of course, the gain variable width may be changed in three or more steps to converge more precisely.

Alternatively, a method may be considered in which the gain variable width is fixed and the amplitude level at each gain is monitored to find the best point. That is, the amplitude value at each gain is stored while changing the gain stepwise. Then, the minimum value among the stored amplitude level values is searched for, and the gain at the minimum value is set as the optimum gain.

The system controller 10 performs such processing, and adjusts the gain of the variable gain amplifier 43 so that the amplitude level of the detected wobble component is minimized, so that the reproduced RF signal leaks. The wobble component can be minimized. Therefore, the jitter of the reproduced RF signal can be reduced and the error rate can be improved. In other words, for example, even detrack-recorded data can be sufficiently reproduced.

The gain adjustment processing of the variable gain amplifier 43 according to the configuration of FIG. 2 may be always performed, but may be performed regularly, for example, every predetermined time. Alternatively, it may be performed at a specific time. For example, it is conceivable to perform the above gain optimization processing when a reproduction error occurs during data reproduction and reproduction retry is performed on the data. Further, the gain optimization process may be performed first when the disc is loaded. Further, for example, it may be performed when the reproduction error rate deteriorates.

3. Wobble component minimization process (2) Another example is shown in FIG. 4 as a configuration example for extracting the reproduction RF signal and minimizing the wobble component leaking into the reproduction RF signal. Similar to FIG. 2, FIG. 4 shows the photodetector 5, the matrix circuit 9, the wobble component detection unit 28, and the system controller 10 in the pickup 1.

Also in this case, the reflected light information signals I1 and I2 generated by the calculation processing in the matrix circuit 9 from the reflected light received by the photodetector 5 are supplied to the head amplifiers 41 and 42, respectively, and a predetermined amplification processing is performed. Is done. Then, the signal I amplified by the head amplifier 41
1 is supplied to the adder 44, and the signal I2 amplified by the head amplifier 42 is a gain variable amplifier (variable amplifier) 43.
Is supplied to the adder 44 via the
Similar to FIG. 2, the reproduction RF signal can be obtained by adding 1 and I2 and outputting.

In the case of this example, the structure of the wobble component detecting section 28 is different from that of the example of FIG. The wobble component detection unit 28
Multipliers 61 and 62, adders 63 and 64, band pass filters 65 and 66, amplitude detection circuits 67 and 68, and a comparator 69 are provided.

Signal I1 output from head amplifier 41
Is supplied to the multiplier 61 and the adder 64. The signal I2 output from the variable gain amplifier 43 is supplied to the multiplier 62 and the adder 63. The multipliers 61 and 62 each carry out multiplication by multiplying the input signal by 1.5. 1.5
The doubling is an example, and the multiplication value may be another value. However, the multiplication values of the multiplier 61 and the multiplier 62 are the same value.
The output of the multiplier 61 is supplied to the adder 63, and the multiplier 62
Is supplied to the adder 64.

Therefore, the output of the adder 63 is the output of the adder 44.
The signals I1 and I2 at the stage of addition in are:
The signals are added at the addition ratio of 1. Also, the adder 64
The output of is a signal obtained by adding the signals I1 and I2 at the stage of addition in the adder 44 at an addition ratio of 1: 1.5, which is the reverse of the above addition ratio.

From the output of the adder 63, the wobble component is extracted by the bandpass filter 65 having the wobble frequency as the pass center frequency, and the amplitude level is detected by the amplitude detection circuit 67. From the output of the adder 64,
The wobble component is extracted by the bandpass filter 66 having the wobble frequency as the pass center frequency, and the amplitude level is detected by the amplitude detection circuit 68. Amplitude detection circuit 6
The amplitude levels detected by 7 and 68 are compared by a comparator 69, and the difference is output as a comparison result CP and supplied to the system controller 10.
The system controller 10 adjusts the gain of the variable gain amplifier 43 by the control signal Cg with the point at which the comparison result CP becomes zero as the optimum point.

FIG. 5A shows the system controller 10
The relationship between the gain of the gain variable amplifier 43 that is variably controlled by the amplitude control and the amplitude level of the wobble component leaking into the reproduction RF signal is shown. In this configuration, the amplitude values detected by the amplitude detection circuits 67 and 68 are shown. When there is a wobble component leak, for example, the levels are L1 and L2. That is, the gain of the variable gain amplifier 43 is now P
If they are values, the amplitude values L1 and L2 corresponding to the gains P1 and P2 are obtained. Note that P = (P1
+ P2) / 2. And in that case, the comparator 6
The comparison result CP corresponding to the value of (L2-L1) by 9
Is obtained. On the other hand, the gain of the variable gain amplifier 43 at the best point where the amplitude level of the wobble component is the minimum is Q.
Then, the gain Q1, which is Q = (Q1 + Q2) / 2,
The amplitude values at Q2 are obtained, and these amplitude values match as L0. In that case, the comparator 69 obtains the comparison result CP that satisfies (L0−L0) = 0.

That is, the comparison result CP output from the comparator 69 has a linear characteristic of "0" in the optimum state as shown in FIG. 5 (b). Therefore, the system controller 10 raises the gain of the variable gain amplifier 43 if the comparison result CP is a negative value, and the comparison result C
If P is a positive value, the gain of the variable gain amplifier 43 may be reduced so that the comparison result CP becomes “0”. When the comparison result CP is "0", the wobble component leaking into the reproduction RF signal is minimized.

In the case of this example, the system controller 1
0 is a “0” by monitoring the comparison result CP that has a linear characteristic.
Since gain control is performed with a point as a target, there are advantages that the process is simple and that the optimum point is easy to find and the adjustment sensitivity is high. Also in this case, various timings for performing the gain adjustment processing can be considered as in the case of the example of FIG.

Although the disk drive device according to the embodiment has been described above, the present invention is not limited to these examples, and various modifications can be considered within the scope of the invention. For example, although a configuration using a bandpass filter and an amplitude detection circuit has been illustrated for detecting the wobble component, for example, it is a method of detecting the envelope of the reproduction RF signal by the peak hold circuit and detecting the wobble component appearing in the envelope. May be. Further, as the disc drive device, a disc drive device capable of recording and reproducing is given as an example in FIG. 1, but the disc drive device as a reproduction-only machine may be used.

[0063]

As can be understood from the above description, according to the present invention, the variable amplifier for the second reflected light information signal is controlled according to the wobble component leaking into the reproduction information component (reproduction RF signal). It That is, the amount of amplification in the variable amplifier is controlled so that the wobble components included in each of the first reflected light information signal and the second reflected light information signal become equal. Therefore, the wobble component can be properly canceled during the addition process of the first reflected light information signal and the second reflected light information signal for obtaining the reproduction information component, and the wobble component leaking into the reproduction information component is generated. Can be minimized. This reduces the jitter of the reproduction information component and improves the error rate. That is, according to the present invention, even when data is recorded by detracking, or even when a wobble component leaks due to an optical system malfunction or the like, it is possible to eliminate it and perform the reproduction process. And the reproduction performance can be improved.

The variable amplifier can be controlled by detecting the amplitude of the wobble component from the reproduction information component and minimizing the amplitude value. Alternatively, the first reflected light information signal and the second reflected light information signal via the variable amplifier are:
The first addition signal obtained by the addition at the first addition ratio and the second addition signal obtained by the addition at the second addition ratio opposite to the first addition ratio are obtained, and the first and second addition signals are obtained. The comparison result of each wobble component in is output. Then, by variably controlling the variable amplifier so that the comparison result becomes in agreement, it is possible to improve the sensitivity for control and make the control easier.

[Brief description of drawings]

FIG. 1 is a block diagram of a disk drive device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a configuration for minimizing a leaking wobble component of the disk drive device according to the embodiment.

FIG. 3 is an explanatory diagram of a wobble component amplitude and a gain characteristic of a variable gain amplifier according to the embodiment.

FIG. 4 is a block diagram of another configuration for minimizing the leaking wobble component of the disk drive device according to the embodiment.

FIG. 5 is an explanatory diagram of a characteristic of a wobble component amplitude and a gain of a variable gain amplifier according to the embodiment, and a comparison result.

FIG. 6 is an explanatory diagram of a conventional reproduction RF signal generation method.

FIG. 7 is an explanatory diagram of frequency characteristics of a reproduction RF signal and a wobble component.

FIG. 8 is an explanatory diagram of detrack recording.

FIG. 9 is an explanatory diagram of a reproduction RF signal in which a wobble component leaks.

[Explanation of symbols]

1 pickup, 2 objective lens, 3 biaxial mechanism, 4
Laser diode, 5 photo detector, 6 spindle motor, 8 thread mechanism, 9 matrix circuit, 10 system controller, 12 encode /
Decoding unit, 13 interface unit, 14 servo circuit, 20 buffer memory, 21 recording pulse generating unit,
23 spindle servo circuit, 24 wobble extractor,
25 wobble PLL, 26 address decoder, 27
Encode clock generator, 28 wobble component detector, 30 disk drive device, 41, 42 head amplifier, 43 variable gain amplifier, 44, 63, 64
Adder, 51, 65, 66 band pass filter, 52,
67,68 Amplitude detection circuit, 61,62 Multiplier, 69
Comparator, 100 discs

Claims (3)

[Claims] 1. A head means for irradiating a wobbled track of a disc with laser to obtain reflected light information, and a first dividing line corresponding to the direction of the track as the reflected light information signal. Regarding the reflected light information signal and the second reflected light information signal, at least the second reflected light information is passed through a variable amplifier, and the first reflected light information signal and the second reflected light information signal are added. By doing so, reproduction information component extraction means for obtaining a reproduction information component corresponding to the data recorded on the track, and decoding processing for the reproduction information component obtained by the reproduction information component extraction means to reproduce the reproduction data. Decoding means for obtaining, wobble component detecting means for detecting the wobble component of the track leaked into the reproduction information component, and wobble component detecting means for detecting the wobble component. As wobble component is minimized, a disk drive apparatus characterized by comprising a control means for variably controlling the variable amplifier. 2. The wobble component detecting means detects the amplitude of the wobble component from the reproduction information component, and the control means variably controls the variable amplifier so that the amplitude value is minimized. The disk drive device according to claim 1. 3. The wobble component detecting means adds a first reflected light information signal and the second reflected light information signal that has passed through the variable amplifier at a first addition ratio. An addition signal and a second addition signal obtained by adding a second addition ratio opposite to the first addition ratio are obtained, and a comparison result of each wobble component in the first and second addition signals is output. 2. The disk drive device according to claim 1, wherein the control means variably controls the variable amplifier so that the comparison result is in a coincident state.