JP3075116B2 - Tracking control device for disk device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking control device for a disk drive used in a device for recording or reproducing information.

[0002]

2. Description of the Related Art In recent years, disk devices for recording information signals on a disk using a laser beam or reproducing information signals recorded on the disk have been put to practical use.

In this disk device, tracking control is used in order to accurately irradiate light from an optical pickup onto a track of the disk.

FIG. 7 is a block diagram showing a schematic configuration of a conventional tracking control device for a disk drive. 7, a signal output from a tracking signal detection sensor incorporated in an optical pickup 701 is amplified by a tracking error signal detection circuit 702 and output from the tracking error signal detection circuit 702 as a tracking error signal TE. The tracking error signal TE is converted from an analog signal to digital data by the A / D converter 703 and is input to the tracking control circuit 704. The tracking control circuit 704 outputs, based on the tracking error signal TE, a tracking control signal for driving the tracking actuator 706 so that the light beam emitted from the optical pickup 701 traces a track formed on the optical disk 705. I do. The disk motor 707 includes a rotation detection signal generator 708 for detecting rotation of the disk motor 707, and a disk motor FG for detecting a rotation speed.
A signal is output from the rotation detection signal generator 708. The ID signal pre-formatted on the optical disk 705 is subjected to signal processing in the ID signal processing circuit 709, so that a VMARK signal of one pulse per rotation of the disk indicating a predetermined absolute rotation position during one rotation of the optical disk 705 can be obtained. . The rotation position detection circuit 710 receives the disk motor FG signal from the rotation detection signal generator 708 and outputs the VMM signal from the ID signal processing circuit 709 to the VMAR.
The K signal is input, and the rotation position detection circuit 710 outputs a rotation position detection signal for the rotation position of the optical pickup 701 with respect to the optical disk 705. The memory circuit 711 is set to the write mode by a write command signal (WR signal) output from the memory control circuit 712. The tracking error signal converted into digital data by the A / D converter 703 is input to the storage circuit 711, and specified by the rotation position detection signal output from the rotation position detection circuit 710 during one rotation of the optical disk 705. At each address, the tracking error data corresponding to the rotational position is stored. Therefore, the storage circuit 711 stores the tracking error data for one rotation of the disk. After the tracking error data for one rotation of the disk is written into the storage circuit 711, a read command signal (RD signal) output from the memory control circuit 712
As a result, the storage circuit 711 is set to the reading mode,
The tracking error data written in the storage circuit 711 is read out corresponding to the rotational position of the optical disc 705, converted into an analog signal by the D / A converter 713, and input to the addition circuit 714. A tracking control signal output from the tracking control circuit 704 is turned on / off by a tracking servo loop by a switch circuit 715, and then added to a tracking error signal read from a storage circuit 711 by an addition circuit 714 and D / A converted. The added signal is input to the driving circuit 716. The drive voltage output from the drive circuit 716 is applied to the tracking actuator 706, and the tracking actuator 706 is displaced by an amount corresponding to the drive voltage.

[0005] The tracking error signal stored in the storage circuit 711 is dominated by the component of the track deviated from the center of the optical disk 705, that is, the so-called eccentricity.

At this time, the tracking error signal read from the storage circuit 711 and converted to an analog signal by the D / A converter 713 becomes a feedforward signal,
The eccentric component is determined in advance by the tracking actuator 70.
When the tracking control is performed in this state, the tracking error signal becomes almost zero, that is, the head can trace on the track without error.

[0007]

FIG. 8 shows waveforms of eccentric components at the inner, middle and outer circumferences of the disk. This eccentric component has different waveforms at the inner, middle, and outer circumferences, but the low-frequency component of the eccentric component (the waveform shown by the broken line in the figure) has a high correlation regardless of the position, and the high-frequency component differs. , The eccentric waveform is different.

[0008] The distortion of a track on a disk is dominated by factors such as mechanical displacement when the disk is mounted on the apparatus and center deviation of the disk itself, and the eccentric component due to these factors has a relatively low frequency. However, in recent years, in order to realize high-density recording, the track pitch has to be 1.2.
In order to improve the tracking accuracy, it is necessary to correct even the track distortion at the time of producing a disc having a high frequency component.

When the tracking control is on, the eccentricity component including the track distortion can be corrected by always adding the track distortion correction signal including the high frequency component stored in the storage circuit to the tracking control signal and correcting the tracking control signal. The light beam can be tracked well, but the tracking control is turned off once, and the optical pickup is moved by the linear motor at high speed, as in the search operation, and then the tracking control error is turned on again near the target address. If a high-frequency component is added to the tracking control signal during the tracking-on operation, the tracking control pull-in becomes unstable, and the tracking pull-in time becomes slow or the search operation becomes unstable. There are problems such as worsening.

Also, the eccentricity of relatively low frequency components such as mechanical displacement when the disk is mounted on the apparatus and deviation of the center of the disk itself is caused by the fact that the optical pickup has an inner circumference, a middle circumference,
Regardless of which position on the outer circumference is scanned, the pattern is almost the same. However, since the track distortion having a high frequency component greatly changes depending on the radial position of the disk, the scanning position of the optical pickup moves from the inner circumference to the outer circumference in the search operation. When you do
If the tracking actuator is driven in the same manner in the outer peripheral portion by the distortion correction signal of the inner peripheral portion including the high frequency component, there is a problem that the pull-in of the tracking control becomes more unstable.

The present invention solves the above-mentioned conventional problems. According to the operation mode of the optical pickup, the eccentricity correction signal is made only of the low frequency component, or the high frequency component is corrected to correct the track distortion of the high frequency component. Provided is a tracking control device for a disk device that realizes stable tracking control by switching to an eccentricity correction signal including a track distortion, improves the effect of eccentricity correction including track distortion, and improves tracking accuracy. With the goal.

[0012]

In order to achieve this object, a tracking control device for a disk drive according to the present invention comprises an optical pickup having a light receiving element for irradiating a laser beam on a disk surface and receiving a reflected light from the disk. A tracking actuator that changes a tracking position of a light beam emitted from the optical pickup;
A tracking error detecting means for outputting a tracking error signal corresponding to a tracking deviation from a detection signal detected by the optical pickup; and a light beam emitted from the optical pickup with the tracking error signal as input, on-track scanning on the recording track. Tracking control means for outputting a tracking control signal for displacing the tracking actuator, sampling means for sampling the tracking error signal corresponding to the disk rotational position, and tracking error data output from the sampling means. Storage means, digital-to-analog conversion means for converting a signal output from the storage means to an analog signal, first and second low-pass filters having a signal output from the digital-to-analog conversion means as an input, , A switch circuit for switching between the output signal of the low-pass filter and the output signal of the second low-pass filter, mode setting means for setting an operation mode of the optical pickup, and a switch circuit for the switch circuit based on mode information output from the mode setting means. It has a configuration including switch switching means for performing switching, addition means for adding the tracking control signal and the output signal of the switch circuit, and driving means for driving the tracking actuator by the output signal of the addition means.

[0013]

According to the present invention, in the tracking control off mode, the tracking actuator is driven by the eccentricity correction signal composed of the low frequency component, and conversely, once the tracking control is performed, the tracking actuator is driven by the eccentricity correction signal including the high frequency component. Since the tracking actuator is driven, the pull-in when the tracking control is turned on from off to on is stable, and after the tracking control is pulled in, the eccentricity component including the track distortion can be corrected. It is possible to provide a tracking control device of a disk drive capable of scanning an irradiated light beam on-track on a track.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic block diagram of a tracking control device for a disk drive according to a first embodiment of the present invention.

In FIG. 1, a signal output from a tracking signal detection sensor incorporated in an optical pickup 101 is amplified by a tracking error signal detection circuit 102 and output from the tracking error signal detection circuit 102 as a tracking error signal TE. The tracking error signal TE is converted from an analog signal into digital data by the A / D converter 103 and is input to the tracking control circuit 104. The tracking control circuit 104 outputs a tracking control signal for driving a tracking actuator 106 such that the light beam emitted from the optical pickup 101 traces a track formed on the optical disk 105 based on the tracking error signal TE. I do. The disk motor 107 is provided with a rotation detection signal generator 108 for detecting the rotation of the disk motor 107. The disk motor FG signal for detecting the rotation speed of the disk motor 107 is output from the rotation detection signal generator 108. Is output.

An ID signal pre-formatted on the optical disk 105 is signal-processed in an ID signal processing circuit 109 to obtain a VMARK signal of one pulse per rotation of the disk indicating a predetermined absolute rotation position during one rotation of the disk. Can be. The rotation position detection circuit 110 receives the disk motor FG signal from the rotation detection signal generator 108 and the ID signal processing circuit 109
ARK signal is input, and thus the rotational position detection circuit 110
From this, a rotation position detection signal for the rotation position of the optical disk 105 of the optical pickup 101 is output. The rotation position detection circuit 110 can be normally realized by a counter circuit. The VMMARK signal is input to a reset input terminal, the disk motor FG signal is input to a clock input terminal, and the count value of the counter circuit is changed from the output position of the VMARK signal. Of the optical disk 105 of FIG.

The memory circuit 111 is set to a write mode by a write command signal (WR signal) output from the memory control circuit 112. The tracking error signal converted into digital data by the A / D converter 103 is input to the storage circuit 111, and is designated by the rotation position detection signal output from the rotation position detection circuit 110 during one rotation of the optical disk 105. At each address, tracking error data corresponding to the rotation position is stored, and the storage circuit 111 stores tracking error data for one rotation of the disk. After the tracking error data for one rotation of the disk is written into the storage circuit 111, the storage circuit 111 is set to the read mode by the read command signal (RD signal) output from the memory control circuit 112, and the storage circuit 111 The written tracking error data is read out corresponding to the rotational position of the disk, converted into an analog signal by the D / A converter 113, and then converted into a first low-pass filter (abbreviated as LPF in FIG. 1).
19 and the second low-pass filter (abbreviated as LPF in the figure)
120 is input. Here, the cut-off frequency of the first low-pass filter 119 is f1, and the cut-off frequency of the second low-pass filter 120 is f2.
1 is set to be approximately f2 / 5 to f2 / 10. The output signal of the first low-pass filter 119 and the output signal of the second low-pass filter 120 are input to the switch circuit 121. The circuit of the switch circuit 121 is switched by a switch switching signal output from the switch switching circuit 117.

The mode setting circuit 118 manages the operation mode of the disk drive, outputs mode information, and outputs a tracking control on / off switching signal. The switch switching circuit 117 generates a switch switching signal based on the mode information output from the mode setting circuit 118 and the tracking control pull-in detection signal output from the tracking control circuit 104.

A switch switching signal output from the switch switching circuit 117 causes the switch circuit 121 to
The output signal of the first low-pass filter 119 and the output signal of the second low-pass filter 120 are switched and input to the adding circuit 114.

The tracking control signal output from the tracking control circuit 104 is input to an adding circuit 114 after the tracking servo loop is turned on / off by a switch circuit 115.

The eccentricity correction signal output from the switch circuit 121 and the tracking control signal output from the tracking control circuit 104 are added by an adding circuit 114 and then input to a driving circuit 116, and the driving signal output from the driving circuit 116 is output. The voltage is applied to the tracking actuator 106
Is applied to

Here, referring to FIG.
The operation of the switch switching circuit 117 will be described.

FIG. 2A shows a signal obtained by converting the eccentricity correction data output from the storage circuit 111 into an analog signal by the D / A converter 113. FIG. 2B is an eccentricity correction signal obtained by passing the signal shown in FIG. 2A through the second low-pass filter 120, and similarly, FIG. 2C is an eccentricity correction signal obtained through the first low-pass filter 119. It is.

First, in the normal reproduction mode, the tracking control is pulled in. At this time, the output signal of the second low-pass filter 120 is switched to the switch circuit 121.
The eccentricity correction signal is selected as shown in FIG. 2 and is input to the adding circuit 114. The eccentricity correction signal is as shown in FIG. The irradiated light beam scans on the track on-track.

In this state, when the operation mode is switched to the search mode by the mode setting circuit 118, the switching circuit 11 is switched by the tracking control on / off switching signal output from the mode setting circuit 118 to the switch circuit 115.
5 is open, and the tracking control loop is open. Further, the switch switching circuit 117 outputs a switch switching signal so that the output signal of the first low-pass filter 119 is selected by the switch circuit 121 and input to the adding circuit 114 in accordance with the search mode information. The eccentricity correction signal input to the addition circuit 114 at this time is as shown in FIG. 2C, and has only low-frequency components. The low-frequency component of the eccentricity is dominated by factors such as mechanical displacement when the disc is mounted on the apparatus and the center shift of the disc itself, and almost no matter where on the radius of the optical disc the optical pickup scans. The pattern is the same, and the coarse search operation ends, and the mode setting circuit 118
When the switching circuit 115 is closed by the tracking control on / off switching signal output from the switch and the tracking control is turned on, the tracking control is pulled in stably.

When the tracking control is pulled in, a tracking control pull-in detection signal is input from the tracking control circuit 104 to the switch switching circuit 117, and
The mode setting circuit 118 sets the mode to the normal reproduction mode.

When the normal reproduction mode is set, the switch switching circuit 117 switches the switch circuit 121 so that the output signal of the second low-pass filter 120 is input to the addition circuit 114 again. At this time, the eccentricity correction signal shown in FIG.
The light beam irradiated from 1 can scan on the track on-track.

As described above, according to the first embodiment of the present invention, the high frequency component contained in the eccentricity correction signal is cut off in the tracking control off mode, so that the tracking control becomes stable when the tracking control is turned on again. In addition to realizing the pull-in of the tracking control, in the tracking control on mode, the eccentricity of the high frequency component including the track distortion can be corrected and the on-track can be accurately performed.

Regarding the pull-in of the tracking control,
The high frequency component of the eccentricity correction component whose pattern changes greatly according to the radial position of the disk is cut,
Regardless of the position in the radial direction, the eccentricity is corrected by a low-frequency component that produces a similar pattern at almost any position, thereby improving the pull-in stability, particularly from the inner circumference to the outer circumference of the disk, or from the outer circumference to the middle circumference. The effect is remarkable when a search operation is performed in the section.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 shows a schematic configuration diagram of a tracking control device for a disk drive according to a second embodiment of the present invention.

In FIG. 3, components performing the same operations as those of the first embodiment of the present invention shown in FIG. 1 are denoted by the same reference numerals, and detailed description of the operations is omitted.

In FIG. 3, an output data operation circuit 301
Then, based on the storage data stored at a predetermined address of the storage circuit 111, the output is performed in accordance with the mode information output from the mode setting circuit 118 and the tracking control pull-in detection signal output from the tracking control circuit 104. Selects and outputs data operation. The eccentricity correction data output from the output data calculation circuit 301 is D /
After being converted into an analog signal by the A converter 302, the signal is added to the output signal of the tracking control circuit 104 by the addition circuit 114 via a low-pass filter.

Here, the operation of the output data calculation circuit 301 will be described with reference to FIG. FIG. 4A shows the storage circuit 11.
1 shows the eccentricity correction data stored in the eccentricity correction data. In the normal reproduction mode, the tracking control is in a retracted state. At this time, the eccentricity correction data AD (i) output from the output data calculation circuit 301 is the rotation position detection circuit. 110
Is the same as the eccentricity correction data D (i) read from the storage means 111 in correspondence with the rotational position information data i output from, and has a relationship of AD (i) = D (i). Accordingly, the eccentricity correction signal output from the output data arithmetic circuit 301 and output through the D / A converter 302 and the low-pass filter 303 is as shown in FIG. 4B, and the eccentricity of the high frequency component including the track distortion of the disk is obtained. The light beam emitted from the optical pickup 101 scans on the track on-track with high accuracy.

In this state, when the operation mode is switched to the search mode by the mode setting circuit 118, the switching circuit 1 is switched by the tracking control on / off switching signal output from the mode setting circuit 118 to the switching circuit 115.
15 is open, and the tracking control loop is open. Further, the mode information output from the mode setting circuit 118 is input, and the output data arithmetic circuit 301 switches the arithmetic processing. In the output data calculation circuit 301, the eccentricity correction data AD output from the output data calculation circuit 301 when i is a multiple of 5 corresponding to the rotation position information i output from the rotation position detection circuit 110.
(I) performs the operation of (Equation 1) and calculates the AD of the operation result.
The value of (i) is held during the period from the rotational position information i to i + 4.

[0036]

(Equation 1)

At this time, the eccentricity correction data output from the output data calculation circuit 301 is as shown in FIG. Therefore, it is output from the output data operation circuit 301,
The eccentricity correction signal output through the D / A converter 302 and the low-pass filter 303 is as shown in FIG. 4D, and therefore, the eccentricity correction signal input to the addition circuit 114 has only low-frequency components. It will be. The low-frequency component of the eccentricity is dominated by factors such as mechanical displacement when the disc is mounted on the apparatus and the center shift of the disc itself, and almost no matter where on the radius of the optical disc the optical pickup scans. This is the same pattern. When the coarse search operation is completed, the switching circuit 115 is closed by the tracking control on / off switching signal output from the mode setting circuit 118, and the tracking control is turned on, the tracking control is pulled in. Is performed stably.

When the tracking control is performed, a tracking control pull-in detection signal is input from the tracking control circuit 104 to the output data calculation circuit 301, and the mode setting circuit 118 sets the mode to the normal reproduction mode.

The output data operation circuit 301 performs the operation at the time of normal reproduction again, that is, the eccentricity correction data AD (i) output from the output data operation circuit 301 corresponds to the rotation position information i output from the rotation position detection circuit 110. And is the same as the eccentricity correction data D (i) read from the storage circuit 111, and has a relationship of AD (i) = D (i). At this time, the eccentricity correction signal output through the low-pass filter 303 is as shown in FIG. 4B, and the light beam emitted from the optical pickup 101 can accurately scan the track on-track. it can.

As described above, according to the second embodiment of the present invention, when the tracking control is turned on again, the high frequency component included in the eccentricity correction signal is cut off in the tracking control off mode. In addition to realizing the pull-in of the tracking control, in the tracking control on mode, the eccentricity of the high frequency component including the track distortion can be corrected and the on-track can be accurately performed.

With respect to the pull-in of the tracking control,
The high frequency component of the eccentricity correction component whose pattern changes greatly according to the radial position of the disk is cut,
Regardless of the position in the radial direction, the eccentricity is corrected by a low-frequency component that produces a similar pattern at almost any position, thereby improving the pull-in stability, particularly from the inner circumference to the outer circumference of the disk, or from the outer circumference to the middle circumference. The effect is remarkable when a search operation is performed in the section.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram of a storage circuit 511 according to the third embodiment of the present invention.

Other than the memory circuit 511, the first real circuit shown in FIG.
The configuration is the same as that of the embodiment. In FIG. 5, reference numeral 501 denotes a memory circuit for storing eccentricity correction data, in which tracking error data converted into digital data is written.

Reference numeral 504 denotes an average value calculation circuit, which receives the tracking error data similarly converted into digital data, calculates the average value of the tracking error data during one rotation period of the disk, and outputs the calculation result AVE to the comparison circuit 503. I do. The comparison circuit 503 compares the calculation result AVE output from the average value calculation circuit 504 with the tracking error data converted into digital data, and outputs a high, low, and middle ternary logic signal according to the comparison result. I do. The ternary logic signal output from the comparison circuit 503 is input to the correction operation circuit 502. Here, the output of the rotational position detecting circuit 110 for detecting the rotational position of the head based on the disk motor FG signal and the VMARK signal is
The average value calculation circuit 504, the comparison circuit 503, the correction calculation circuit 502, and the memory circuit 501 are input, and needless to say, these circuits perform processing in synchronization.

The correction arithmetic circuit 502 stores the tracking error data corresponding to the rotational position of the disk in the memory circuit 50.
1, the eccentricity correction data is changed by a small amount in accordance with the logic level of the ternary logic signal of the comparison circuit 503, and is written into the memory circuit 501 again.

FIG. 6A shows tracking error data stored in the memory circuit 501 at the time T1. 1 to N indicate the rotational position of the disk.
Eccentricity correction data corresponding to the rotational position of the disk is stored in addresses 1 to N of 01. FIG. 6B shows tracking error data during one rotation period of the disk from time T1 to T2.

FIG. 9C shows the state of the memory circuit 5 at time T1.
After the value of the eccentricity correction data (shown by a black circle) stored in the memory circuit 501 is slightly changed during one rotation of the disk, the eccentricity correction data (open circles) stored in the memory circuit 501 at time T2 is stored. ). FIG. 9D shows tracking error data during one rotation period of the disk from time T2 to T3.

In FIG. 6A, the memory circuit 501
Has already stored the eccentricity correction data. The addresses of the memory circuit 501 are 1 to N, where N corresponds to the number of FG pulses in one rotation of the disk motor 107. The eccentricity correction signal read from the memory circuit 501 and converted into an analog signal by the D / A converter is added to the tracking control signal to become a tracking actuator drive signal. The tracking error signal obtained by driving the tracking actuator is as shown in FIG.
1 to N shown in FIG. 6B correspond to 1 to N in FIG. 6A and indicate the rotational position of the disk. The average value calculation circuit 504 calculates the average value of the tracking error data for one rotation of the disk motor, and outputs the average value data AVE1. The average value data AVE1 is calculated during one rotation of the disk motor immediately before, and the average value data is newly calculated during one rotation of FIG. 6B.

In the comparison circuit 503, the average value calculation circuit 504
Is compared with the average value data AVE1 output from the CPU and the magnitude of the tracking error data TD (i), and a comparison result output process shown in (Expression 2) is performed (where i is an integer of 1 to N, and the rotational position of the disk). Corresponding to.).

[0050]

(Equation 2)

In the correction operation circuit 502, the comparison circuit 503
The eccentricity correction data MD (i) stored in the memory circuit 501 is changed by a small amount on the basis of the logical level of the output of, and is stored in the memory circuit 501 as new eccentricity correction data MDD (i). Here, the change processing of the eccentricity correction data is performed by processing shown in (Equation 3).

[0052]

(Equation 3)

After the tracking error signal shown in FIG. 6B is input and the eccentricity correction data stored in the memory circuit 501 is changed by a small amount, the eccentricity correction data stored in the memory circuit 501 is as shown in FIG. 6 (c). Here, the eccentricity correction data stored in the memory circuit 501 at the timing of FIG. 6A is indicated by black circles. By correcting the eccentricity correction data by a small amount, the eccentricity correction data shown in FIG. 6C reproduces the track distortion component more faithfully.
The tracking error signal is, as shown in FIG.
Less residual error. As described above, by correcting the eccentricity correction data stored in the memory circuit 501 based on the tracking error signal, the residual component of the tracking error data becomes almost zero as shown in FIG.

As described above, according to the third embodiment of the present invention, even if the track distortion differs depending on which position on the radius of the disk the head scans, it is stored in the storage circuit. By changing the eccentricity correction data by a small amount based on the direction of deviation from the average value of the tracking error signal, the change in the tracking error signal can be made zero, that is, the tracking error can be made zero. The eccentricity correction data to be stored in the disk device performs a stable eccentricity correction operation regardless of the tracking error data when the scanning position of the head scans the inner, middle, or outer circumference of the disk. A control device can be provided.

Further, in response to different eccentric patterns depending on the inner circumference, middle circumference, and outer circumference of the disk as shown in FIG.
By correcting the eccentricity correction data stored in the storage circuit by a small amount, the eccentricity correction data that provides the best correction effect is stored in the storage circuit regardless of the scanning position of the head, and the eccentricity is corrected by the scanning position of the head. The high-frequency component of the component can also be optimized, and the effect is great.

[0056]

As described above, the present invention realizes a stable pull-in of the tracking control when the tracking control is turned on again by cutting off the high frequency component included in the eccentricity correction signal in the tracking control off mode. In addition, in the tracking control on mode, the eccentricity of the high frequency component including the track distortion can be corrected, and the on-track can be accurately performed.

Regarding the pull-in of the tracking control,
The high frequency component of the eccentricity correction component whose pattern changes greatly according to the radial position of the disk is cut,
Regardless of the position in the radial direction, the eccentricity is corrected by a low-frequency component that produces a similar pattern at almost any position, thereby improving the pull-in stability, particularly from the inner circumference to the outer circumference of the disk, or from the outer circumference to the middle circumference. The effect is remarkable when a search operation is performed in the section, and the practical effect is large.

Further, even if the track distortion varies in the radial direction of the disk, the eccentricity correction data stored in the storage means is changed by a very small amount based on the direction of deviation from the average value of the tracking error signal. The change in the tracking error signal can be made zero, that is, the tracking error can be made zero, and the tracking error signal stored in the storage means can be scanned at any position of the inner, middle, and outer circumferences of the disk. Thus, it is possible to provide a tracking control device for a disk device that performs a stable eccentricity correction operation even when the operation is performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a tracking control device of a disk drive according to a first embodiment of the present invention;

FIG. 2 is a waveform chart for explaining the operation of the tracking control device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a tracking control device for a disk drive according to a second embodiment of the present invention;

FIG. 4 is a waveform chart for explaining the operation of the tracking control device according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of a storage circuit according to a third embodiment of the present invention.

FIG. 6 is a waveform chart for explaining the operation of the tracking control device according to the third embodiment of the present invention.

FIG. 7 is a block diagram showing a schematic configuration of a conventional tracking control device for a disk drive.

FIG. 8 is a waveform chart for explaining a problem of the tracking control device of the conventional disk drive.

[Explanation of symbols]

 Reference Signs List 101 optical pickup 102 tracking error signal detection circuit 103 A / D converter 104 tracking control circuit 105 optical disk 106 tracking actuator 108 rotation detection signal generator 109 ID signal processing circuit 110 rotation position detection circuit 111, 511 storage circuit 112 memory control circuit 113 , 302 D / A converter 114 Adder circuit 116 Drive circuit 117 Switch switching circuit 118 Mode setting circuit 119 First low-pass filter 120 Second low-pass filter 121 Switch circuit 301 Output data operation circuit 303 Low-pass filter 501 Memory circuit 502 Correction operation Circuit 503 Comparison circuit 504 Average value calculation circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G11B 7/085 G11B 7/09 G11B 7/095 G11B 21/08 G11B 21/10

Claims (2)

(57) [Claims] An optical pickup having a light receiving element for irradiating a laser beam onto a disk surface and receiving reflected light from the disk; a tracking actuator for changing a tracking position of a light beam emitted from the optical pickup; A tracking error detection unit that outputs a tracking error signal corresponding to a tracking error from a detection signal detected by the optical pickup; and a light beam emitted from the optical pickup using the tracking error signal as an input on-tracks a recording track. Tracking control means for outputting a tracking control signal for displacing the tracking actuator so as to perform scanning, sampling means for sampling the tracking error signal corresponding to the disk rotation position, and output from the sampling means. Storage means for storing the tracking error data to be obtained, a digital-analog conversion means for converting a signal output from the storage means into an analog signal, and a first signal to which a signal output from the digital-analog conversion means is input. A low-pass filter and a second low-pass filter, a switch circuit for switching an output signal of the first low-pass filter and an output signal of the second low-pass filter, and mode setting means for setting an operation mode of the optical pickup; Switch switching means for switching the switch circuit based on mode information output from the mode setting means, addition means for adding the tracking control signal and an output signal of the switch circuit,
A driving unit for driving the tracking actuator by an output signal of the adding unit; and a relationship between a cutoff frequency f1 of the first low-pass filter and a cutoff frequency f2 of the second low-pass filter is f1 <f2.
Wherein the switch switching means operates such that an output signal of the first low-pass filter is input to the adding means in a tracking control off mode, and an output signal of the second low-pass filter in a tracking control on mode. The tracking control device for a disk drive, wherein the controller is operated so that is input to the adding means. 2. An optical pickup having a light receiving element for irradiating a laser beam onto a disk surface and receiving reflected light from the disk, a tracking actuator for changing a tracking position of a light beam emitted from the optical pickup, and A tracking error detection unit that outputs a tracking error signal corresponding to a tracking error from a detection signal detected by the optical pickup; and a light beam emitted from the optical pickup using the tracking error signal as an input on-tracks a recording track. Tracking control means for outputting a tracking control signal for displacing the tracking actuator so as to perform scanning, sampling means for sampling the tracking error signal corresponding to the disk rotation position, and output from the sampling means. Storage means for storing tracking error data to be obtained, mode setting means for setting an operation mode of the optical pickup, and performing a calculation process based on the data stored in the storage means to generate a correction signal and Correction signal calculation means for switching calculation processing based on mode information output from the mode setting means,
Digital-to-analog converting means for converting the output signal of the correction signal calculating means into an analog signal; adding means for adding the tracking control signal and the output signal of the digital-to-analog converting means; A driving unit for driving a tracking actuator; wherein the correction signal calculation unit outputs, in the tracking control on mode, tracking error data written at a predetermined address of the storage unit corresponding to the rotational position of the disk as output data. With the tracking control
Mode uses multiple tracking error data
The calculated correction signal is divided into the plurality of tracking error data.
Data at all disk rotation positions
A tracking control device for a disk device, which is commonly used .