JP3526797B2 - Disk unit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device which performs a still operation by a hold track operation on a disk having information signals recorded on spiral tracks.

[0002]

2. Description of the Related Art In a conventional disc apparatus, when a disc having a frame structure in which an information signal is recorded on a spiral track and separated by a synchronizing signal is normally continuously reproduced, a pickup is not used. Since the track continues to track and the information signal is spirally recorded on the track, the playback position keeps changing with the rotation of the disc, and the playback position is sequentially changed to the next track every time the disc rotates once. Move.

In such a disc device, when the disc is reproduced by pausing, the pickup is moved to the track while the disc motor is not stopped and the disc is continuously rotated. It is necessary to make a track jump to the original position (near the playback position at the time of pause) at regular intervals during the tracking of, and by executing this track jump, the pickup can be performed only on the track near the playback position at the time of pause. The hold track operation is executed by repeatedly following the operation (hereinafter referred to as the still operation).

The above disk device will be described below. FIG. 7 is a block diagram showing the configuration of a conventional disc device. Here, as a disc, a system for reading information on the information recording surface by irradiating a light spot on the information recording surface and detecting the reflected light is used. 1 illustrates an optical disk device that uses an optical disk. In FIG. 7, reference numeral 1 is an optical disk having an information signal recorded on a spiral track and divided by a synchronization signal to have a frame structure, 2 is a disk motor for rotating the optical disk 1, and 3 is a light beam on the information surface of the optical disk 1. An optical pickup that reads and outputs information on the information surface of the optical disc 1 by converging to form a light spot and detecting the reflected light.
Is an RF amplifier that amplifies the output information signal of the optical pickup 3, and 5 is a reference of the control timing of the rotation drive for the optical disc 1 using the PLL from the output signal of the RF amplifier 4 (hereinafter, referred to as a reproduction RF signal). A clock extraction circuit for extracting a clock, 6 is a sync detection circuit for detecting a sync signal forming a frame structure by using the reproduced RF signal and the extracted clock from the clock extraction circuit 5, and 7 is a reproduction position by an output of the sync detection circuit 6. Demodulation circuit for generating the address of the demodulator, 8 is a system controller for judging the current reproduction position based on the output address from the demodulation circuit 7, 9 is an access control circuit for controlling the track jump according to a command from the system controller 8, and 10 is access control. A driver for driving the optical pickup 3 by the output of the circuit 9 and a driver 11 for driving the optical pickup 3. A frequency generator that is attached to detect the rotation speed of the motor 2 and that generates a rotation detection signal of N pulses per rotation, and 12 divides the frequency of the rotation detection signal generated by the frequency generator 11 into 1 / N. A reference numeral 15 is a rotation control circuit for controlling the number of rotations of the disk motor 2 to be constant by using a synchronization signal from the synchronization detection circuit 6.

The operation of the disk device configured as described above will be described below. FIG. 8 is a waveform diagram of each part during the still operation using the frequency generator 11 in the conventional disk device shown in FIG.
Reference numeral 81 is an output signal waveform of the frequency generator 11, H82 of FIG. 8B is a waveform for showing the internal state of the frequency dividing circuit 12, and H83 of FIG. 8C is an output signal waveform of the frequency dividing circuit 12. .

A signal read from the optical disc 1 by the optical pickup 3 is amplified by an RF amplifier 4 and input to a clock extraction circuit 5. In the clock extraction circuit 5, PL
A clock is extracted using the L circuit and input to the sync detection circuit 6 together with the reproduction RF signal. The synchronization detection circuit 6 generates a synchronization signal using the input extracted clock and the reproduced RF signal, and inputs the synchronization signal to the demodulation circuit 7 and the rotation control circuit 15.

The rotation control circuit 15 uses the synchronization signal from the synchronization detection circuit 6 to control the rotation speed of the disk motor 2 to be constant. The demodulation circuit 7 detects the address of the reproduction position recorded on the optical disc 1 using the synchronization signal from the synchronization detection circuit 6 and inputs it to the system controller 8. The system controller 8 compares the address obtained from the demodulation circuit 7 with the address of the temporary stop position, and issues a track jump command to the access control circuit 9 if the address is far from the vicinity of the temporary stop position. The optical pickup 3 is moved to the vicinity. The still operation is executed by repeating the above operation.

Here, the optical pickup 3 and the RF amplifier 4
The reproduction quality of the reproduced information differs depending on the variation of the disc and the disc type (for example, a read-only disc and a writable / readable disc). Therefore, the electric balance correction circuit and the characteristic of the read RF signal are improved in the RF amplifier 4. A waveform equivalent circuit for doing so is incorporated. The above correction circuit is in the initial state at system startup,
Therefore, before optimizing the correction circuit, the demodulation circuit 7
There is a case where the address cannot be detected by, and the situation where the above still operation cannot be executed occurs.

Therefore, as a still operation method, there is a method using the frequency generator 11. In a disc in which information signals are spirally recorded on the optical disc 1, the optical disc 1 is rotated once to perform reproduction while following the track, which is equivalent to moving to an apparently adjacent track. Here, the still operation is executed when the track jumps to the adjacent original track each time it makes one rotation.

A rotation detection signal (waveform H81 in FIG. 8 (a)) generated by the frequency generator 11 attached to the disk motor 2 is input to the frequency dividing circuit 12, and one rotation is performed.
Output a pulse (waveform H82 in FIG. 8B, FIG.
(C) Waveform H83). The still operation is completed by inputting this pulse to the access control circuit 9 and jumping to an adjacent track.

[0011]

However, in the conventional disk device as described above, the still operation is performed even when the address cannot be detected by using the frequency generator and the frequency dividing circuit for detecting the address on the track. However, a disk motor with such a built-in frequency generator is disadvantageous in cost, and depending on the model, it may be possible to use a general-purpose inexpensive motor. In this case, there is a problem that the still operation cannot be performed when the address cannot be detected.

The present invention solves the above-mentioned problems of the prior art, and has a simplified structure, which reliably holds and tracks even in a state where address demodulation from a disk is impossible,
A disk device capable of performing a still operation on a disk is provided.

[0013]

In order to solve this problem, the disk device of the present invention records in one rotation of the disk by counting the frame synchronization signals obtained based on the information read from the pickup. Detecting that the disc has made one revolution using the specified number of frames,
At that point, the pickup is jumped to the adjacent original track, and this is repeated to execute the hold track. Also track jump
Prevents incorrect counting of sync signal during
Characterized by compensating for the number of counts to be counted in
It

As described above, with the simplified structure, even when the address demodulation from the disk is impossible, the hold track can be surely performed and the still operation can be performed on the disk.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk device according to claim 1 of the present invention rotates a disk having a frame structure in which an information signal recorded on a spiral track is separated by a sync signal, A disc device configured to read information on an arbitrary track of the disc while jumping the information reading position by the pickup between the tracks, and an RF amplifier for amplifying a read information signal of the pickup; A
Control of rotation drive for the disc from the amplified signal of the pump.
Clock that extracts the clock that serves as the timing reference
An extraction circuit, a synchronous detection circuit for detecting the <br/> the synchronization signal from the extracted clock of the clock extraction circuit, the synchronous detection
The synchronization signal from the circuit is counted, and the pulse
A counter for outputting a scan, with respect to the counter, the
During the jump operation between tracks, the count of the sync signal is
Pause and use the interval of the sync signal immediately before that as a reference
To compensate the count value according to the jump operation period
Access compensation circuit, and the compensation by the access compensation circuit
For each output pulse of the counter based on the compensation count value ,
And an access control circuit for causing the pickup to jump from the track being read to the original track.

The disk device according to claim 2, claim
1. The disk device according to 1, wherein an access compensation circuit
To the counter for counting the synchronization signal.
Compensation of the count value by stopping at the time
Based on the average value of the sync signal intervals for one cycle other than during production
Then, the operation is performed according to the track jump operation period .

According to these configurations, by counting the frame synchronization signals obtained based on the information read from the pickup, the disc makes one revolution by utilizing the specified number of frames recorded in one revolution of the disc. By doing so, at that point, the pickup jumps to the adjacent original track, and by repeating this, the hold track is executed. Also, synchronization during track jump
Prevents false counting of signals and counts during track jumps.
Compensate for the number of counts to be made .

[0018]

[0019]

Hereinafter, a disk device showing an embodiment of the present invention will be specifically described with reference to the drawings. (Embodiment 1) A disk device according to Embodiment 1 of the present invention will be described. FIG. 1 is a block diagram showing the configuration of the disc device according to the first embodiment. Here, as a disc, an information spot on the information recording surface is irradiated with a light spot and the reflected light is detected to detect information on the information recording surface. 1 shows an optical disk device using an optical disk of a method of reading the. In FIG. 1, reference numeral 1 is an optical disk having an information signal recorded on a spiral track and divided by a synchronization signal to have a frame structure. Reference numeral 2 is a disk motor for rotating the optical disk 1.
Is an optical pickup for reading and outputting information on the information surface of the optical disc 1 by converging a light beam on the information surface of the optical disc 1 to form a light spot and detecting the reflected light. An RF amplifier 5 for amplifying the output information signal is an output signal of the RF amplifier 4 (hereinafter,
A clock extraction circuit for extracting a clock that serves as a reference for control timing of rotation driving of the optical disc 1 from the reproduction RF signal) by using a PLL, and 6 using the reproduction RF signal and the extraction clock from the clock extraction circuit 5. ,
A sync detection circuit for detecting a sync signal having a frame structure,
Reference numeral 15 is a rotation control circuit for controlling the number of rotations of the disk motor 2 to be constant using a synchronization signal from the synchronization detection circuit 6, 13
Is a counter that counts the synchronization signals from the synchronization detection circuit 6 and outputs a pulse every predetermined count number, and 9 is a counter 13
An access control circuit 10 for causing the optical pickup 3 to jump to an adjacent track which is the original track by an output pulse from the drive controller 10 is a driver for driving the optical pickup 3 by the output of the access control circuit 9.

FIG. 2 is a waveform diagram for explaining the operation of the disk device of the first embodiment, which is a waveform diagram of each portion during the still operation. In FIG. 2A, H21 is a synchronization detection circuit 6
Of the sync signal which is the output signal of H22 of FIG.
Is a waveform showing the count value of the synchronization signal H21 by the counter 13, H23 in FIG. 2 (c) is the waveform of the output pulse from the counter 13, and H24 in FIG. 2 (d) is an access obtained as an output from the access control circuit 9. It is a waveform of a signal indicating that the operation is in progress. In FIG. 2, the horizontal axis represents time and the vertical axis represents voltage.

FIG. 5 is a schematic diagram showing movement between tracks during a track jump operation in the disk device of the first embodiment, and FIG. 6 is a waveform of a reproduction RF signal during the track jump operation in the disk device of the first embodiment. It is a figure.
In FIG. 6, the horizontal axis represents time and the vertical axis represents voltage.
When the still operation is performed, first, as a predetermined count value for the counter 13, as shown in FIG.
N2, which is the number of 1, is set, and the counter 13 counts the sync signal H21 from the sync detection circuit 6. The waveform corresponding to the counting operation in this case is H22 in FIG.

Next, when the count value of the counter 13 reaches a predetermined count value N2 with the waveform H22 (time t1),
As shown in FIG. 2C, the pulse H2 is output from the counter 13.
3 is output, and at the same time, as shown at H22 in FIG. 2B, the count value of the counter 13 is reset and becomes 0 from N2. Further, the access control circuit 9 outputs the pulse H2 output from the counter 13 and shown in FIG.
3 is received, a track jump command to an adjacent track is output, and as shown in FIG.
Based on the period T of 24, the driver 10 drives the optical pickup 3 and the track jump operation in the still operation is completed.

Here, as shown in FIG. 5, when the track jumps from the track A to the track B, that is, when the area where the information signal to be reproduced is not written is passed (when moving between tracks), FIG. As shown in, the waveform of the reproduction RF signal is distorted. At this time, in the sync detection circuit 6, as shown in FIG. 2A, a pseudo sync signal E or a missing sync signal F may occur in the sync signal indicated by the waveform H21. is there. Therefore, FIG. 2 (d)
During the track jump shown in period T, the access control circuit 9 controls the counter 13 to temporarily stop the counting of the synchronization signal shown in FIG.

As described above, erroneous detection of the synchronization signal H21 during the track jump can be eliminated. Counter 1
As shown in FIG. 2C, 3 is set every time a predetermined count value N2 of the synchronization signal is input (time t1, time t
2) Since the pulse H23 is sent to the access control circuit 9, the access control circuit 9 is based on the pulse H23.
Thus, the track jump to the adjacent track is executed, and the still operation becomes possible.

As described above, even when using a general-purpose inexpensive motor which does not include the frequency generator 11 as shown in FIG. 7 and which is advantageous in terms of cost, the counter 13 having a simple structure can be incorporated. The still operation becomes possible, which can contribute to cost reduction. (Second Embodiment) A disk device according to a second embodiment of the present invention will be described.

FIG. 3 is a block diagram showing the configuration of the disk device according to the second embodiment. In FIG. 3, reference numeral 1 is an optical disk having an information signal recorded on a spiral track and divided by a synchronization signal to have a frame structure, 2 is a disk motor for rotating the optical disk 1, and 3 is a light beam on the information surface of the optical disk 1. An optical pickup 4 which reads and outputs information on the information surface of the optical disc 1 by converging to form a light spot and detecting the reflected light, 4 is an RF amplifier for amplifying the output information signal of the optical pickup 3,
Reference numeral 5 is a clock extraction circuit for extracting a clock serving as a reference of rotation drive control timing for the optical disc 1 from the output signal of the RF amplifier 4 (hereinafter, referred to as reproduction RF signal) by using a PLL, and 6 is a clock extraction circuit 5 A sync detecting circuit for detecting a sync signal having a frame structure by using the reproduced RF signal from the disk and the extraction clock, and a rotation 15 for controlling the rotation speed of the disk motor 2 to be constant by using the sync signal from the sync detecting circuit 6. Control circuit, 13 is synchronization detection circuit 6
A counter for counting the sync signal from the counter and outputting a pulse for each predetermined number of counts; 9 is an access control circuit for causing the optical pickup 3 to jump to the adjacent track which is the original track by the output pulse from the counter 13; A driver for driving the optical pickup 3 by the output of the circuit 9 and an access compensating circuit 14 for compensating the count value of the counter 13 with the output of the access control circuit 9 as an input.

FIG. 4 is a waveform diagram for explaining the operation of the disk device of the second embodiment, and is a waveform diagram of each portion during the still operation. In FIG. 4A, H41 is a synchronization detection circuit 6
Of the sync signal which is the output signal of H42 of FIG.
Is a waveform showing the count value of the synchronization signal H41 by the counter 13, H43 of FIG. 4C is the waveform of the output pulse from the counter 13, and H44 of FIG. 4D is an access obtained as an output from the access control circuit 9. It is a waveform of a signal indicating that the operation is in progress. In FIG. 4, the horizontal axis represents time and the vertical axis represents voltage.

FIG. 5 is a schematic diagram showing movement between tracks during a track jump operation in the disk device of the second embodiment, and FIG. 6 is a waveform of a reproduction RF signal during the track jump operation in the disk device of the first embodiment. It is a figure.
In FIG. 6, the horizontal axis represents time and the vertical axis represents voltage.
When the still operation is performed, first, as a predetermined count value in the counter 13, as shown in FIG.
N2, which is the number of 1, is set, and the counter 13 counts the synchronization signal H41 from the synchronization detection circuit 6. The waveform corresponding to the counting operation in this case is H42 in FIG.

Here, as shown in FIG. 5, when the track jumps from the track A to the track B, that is, when the area where the information signal to be reproduced is not written is passed (when moving between tracks), FIG. As shown in, the waveform of the reproduction RF signal is distorted. At this time, in the sync detection circuit 6, as shown in FIG. 4A, a pseudo sync signal C or a missing sync signal D may occur in the sync signal indicated by the waveform H41. is there.

Therefore, during the track jump shown in the period T of FIG. 4 (d), the access compensating circuit 14 controls the counter 13 to temporarily stop the counting of the synchronizing signal shown in FIG. 4 (a). The access compensating circuit 14 counts the period T of FIG. 4 (d), and determines the number of synchronization signals H41 that should be generated during that period by the counter 1 after the period T ends.
By adding to 3, the synchronization signal H41 during the track jump is compensated.

Here, the number of synchronization signals H41 to be generated in the period T during the track jump is obtained by dividing the period T by the synchronization detection interval (period T2) immediately before the track jump (2 in the example of FIG. 4). ) Or the period T is divided by the average value of the synchronization detection intervals for one rotation of the disk 1 (period T3) other than during the track jump. next,
When the count value of the counter 13 reaches a predetermined count value N2 with the waveform H42 (time t2), the pulse H43 is output from the counter 13 as shown in FIG. 4C, and at the same time, as shown in FIG. As indicated by H42, the count value of the counter 13 is reset and becomes 0 from N2.

Further, the access control circuit 9 receives the pulse H43 shown in FIG. 4 (c) output from the counter 13 and outputs a track jump command to an adjacent track, as shown in FIG. 4 (d). Then, the driver 10 drives the optical pickup 3 based on the period T of the output waveform H44, and the track jump operation in the still operation is completed.

From the above, the counter 13 is shown in FIG.
As shown in, the pulse H43 is sent to the access control circuit 9 every time the predetermined count value N2 of the synchronization signal is input (time t1, time t2).
Based on the above, the access control circuit 9 executes the track jump to the adjacent track, and the still operation becomes possible.

As described above, the counter 13 and the access compensation which can be simply constructed can be used even in the case of using the general-purpose inexpensive motor which does not have the frequency generator 11 as shown in FIG. By incorporating the circuit 14, it is possible to prevent erroneous counting of the synchronization signal during the track jump, and to perform the still operation capable of compensating the number of counts to be counted during the track jump, which can contribute to cost reduction.

Although the counter 13 is an up counter in the first and second embodiments, the counter 13 may be a down counter.

[0037]

As described above, according to the present invention, the specified number of frames recorded in one rotation of the disc is utilized by counting the frame synchronization signals obtained based on the read information from the pickup. Then, it detects that the disc has made one revolution, and at that point, the pickup jumps to the adjacent original track, and by repeating this,
Hold track can be performed.

Further, it is possible to prevent erroneous counting of the sync signal during the track jump, and to compensate for the number of counts to be counted during the track jump. Therefore, with a simplified configuration, even when the address demodulation from the disk is impossible, the hold track can be surely performed, the still operation can be performed on the disk, and the disk motor for detecting the address on the track can be performed. It is not necessary to install a rotation detection mechanism, the overall configuration is simplified, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a disk device according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the disk device according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a disk device according to a second embodiment of the present invention.

FIG. 4 is a waveform diagram for explaining the operation of the disk device according to the second embodiment.

FIG. 5 is a schematic diagram for explaining a track jump operation in each of the above embodiments.

FIG. 6 is a reproduction signal waveform diagram for explaining a track jump operation in the same embodiment.

FIG. 7 is a block diagram showing the configuration of a conventional disk device.

FIG. 8 is a waveform diagram for explaining the operation of the disk device of the conventional example.

[Explanation of symbols]

1 optical disc 2 disk motor 3 optical pickup 4 RF amplifier 5 clock extraction circuit 6 Synchronization detection circuit 9 Access control circuit 10 drivers 13 counter 14 Access compensation circuit 15 Rotation control circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-290497 (JP, A) JP-A-10-228722 (JP, A) JP-A-11-53828 (JP, A) JP-A-11- 296906 (JP, A) JP 8-87819 (JP, A) JP 10-334478 (JP, A) JP 62-52381 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B ^7/ 08-7/10 G11B 21/08

Claims (2)

(57) [Claims] 1. A disc having a frame structure in which an information signal recorded on a spiral track is divided by a synchronization signal is rotated to jump the information reading position by the pickup on the disc between the tracks. A disc device configured to read information on an arbitrary track of the disc, the RF amplifier amplifying a read information signal of the pickup ;
Rotation drive for the disk from the amplified signal of the F amplifier
The clock that extracts the clock that becomes the reference for the control timing of the
Clock extraction circuit and extracted clock of the clock extraction circuit
A synchronous detection circuit for detecting said synchronization signal from said synchronization
The synchronization signal from the detection circuit is counted, and every predetermined number of counts
For a counter that outputs a pulse and the counter ,
During the jump operation between the tracks, the counting of the sync signal is temporarily stopped, and the interval of the sync signal immediately before that is stopped.
As a standard, the count value is supplemented according to the jump operation period.
And an access compensation circuit for compensating
An access control circuit that causes the pickup to jump from the track being read to the original track for each output pulse of the counter based on the compensation count value . 2. An access compensation circuit for a counter
Counter by suspending counting for that sync signal.
Value compensation for one lap other than during track jump operation
Track jump based on the average sync signal interval
A contract characterized by being configured according to the operation period
The disk device according to claim 1 .