JPH0729299A - Disk device - Google Patents

Abstract

(57) [Abstract] [Purpose] To enable high-speed access and low power consumption in a disk device for reproducing or recording a disk configured to reproduce and record data at a constant linear velocity. [Structure] A switching command device 18 divides an optical disc 1 recorded at a constant linear velocity into a plurality of blocks, and outputs a command value according to a block to be reproduced. In the block, the synchronous clock generator 9 and the disk rotation controller 16 control so that the number of revolutions continuously changes according to the reproduction position, so that the linear velocity is constant. When the reproduction position changes from one block to another block, the frequency division numbers of the frequency dividers 19, 20, and 21 are changed at the same ratio according to the command value, and the frequency of the reference clock of the maximum time width detector is changed. And changing the center frequency of the sync clock generator and the frequency of the reference clock used in the frame sync detector.

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 is connected to a controller or the like to record / reproduce data.

[0002]

2. Description of the Related Art Magnetic disks and optical disks have been used as data storage media. In particular, optical disks have a high storage density and can be applied to various fields as a medium capable of large-capacity recording and development for higher performance. It is active. In recent years, a CD-ROM (compact disc-read only memory) drive device has been attracting attention as a data reproducing device for a computer as a center of multimedia. CD-ROM is a compact disc for playing music
(CD) is an application as a read-only memory, and a large-capacity storage medium with a storage capacity of about 600MB on a disk with a diameter of 12cm by reproducing and recording data at a constant linear velocity like a CD. Has become. There are also write-once CD-WOs, rewritable CD-Rs, and the like that are not only for reproduction.

A conventional disk device for reproducing data at a constant linear velocity will be described below by taking a CD-ROM drive device as an example. FIG. 4 shows the configuration of a conventional disk device, and its operation will be described below.
FIG. 4 is a block diagram of a conventional disc device. The data string recorded on the optical disc 1 is read by the optical pickup 2, and the servo controller 3 drives the optical pickup 2 to the optical disc 1.
Follow the surface runout and eccentricity of. And the reproduction signal detector 4
Is detected and binarized. Maximum time width detector 5
Detects the maximum time width of the bit pattern of the reproduction signal and counts the maximum time width (11 channel clock length in CD-ROM) with the output from the reference oscillator 6, and this maximum time width is the line at the time of reproduction. In order to correspond to the speed, the reference count number and the count number of the maximum time width are compared with each other. If the maximum time width is short, the rotation speed of the spindle motor 7 is increased, and if it is long, the spindle motor 7 is rotated. 7
The rotation control signal is output so that the number of rotations becomes slower. Then, the spindle driver 8 drives the spindle motor 7 by the rotation control signal. In this way, the synchronous clock generator 9 for generating the synchronous clock of the reproduction signal is PL
It is composed of L (phase locked loop), and roughly controls the rotation speed of the spindle motor 7 within the pulling range. Then, for example, the synchronous clock generator 9 is
A phase comparator 11 that compares the phased reproduction signal with the phase of the output from the voltage controlled oscillator (hereinafter referred to as VCO) 10 and outputs a phase difference signal, and removes high frequency noise of the phase difference signal. A loop filter 12 that determines the response characteristics of the PLL,
It is composed of a VCO 10 that changes the oscillation frequency of the output clock according to the output voltage from the loop filter 12, and generates a synchronous clock for reproduction. As described above, the synchronous clock generator 9 is locked by the rough rotation control and the synchronous clock of the reproduction signal is generated. Also, the optical disc 1
A data string is collectively recorded in one block called a frame, and a pattern having two maximum time widths called a frame synchronization signal is continuously recorded at the beginning of the frame. The rotation control of the disk after the synchronization clock generator 9 is locked uses a frame synchronization signal for rotation speed detection, and controls the interval of the frame synchronization signal to be constant, thereby controlling the rotation of the disk at the linear velocity. Control to constant.

The operation of rotation control by the frame synchronization signal will be described below. The frame detector 13 detects the frame synchronization signal from the binarized reproduction signal according to the synchronization clock. However, since there is a possibility that the frame sync signal may be miss-detected or erroneously detected due to the influence of dropout or jitter, the frame sync signal is protected and interpolated. Since the frame synchronization signal is generated at a cycle corresponding to the linear velocity at the time of reproduction, the phase difference between the phase synchronization signal and the output from the reference oscillator 14 is detected by the phase comparator 15.
Then, the spindle motor 7 is controlled so that the cycle of the frame synchronization signal becomes constant. As a result, even if the reproduction position changes due to the movement of the optical pickup 2, as shown in FIG. 5, the synchronous clock generator 9 and the disc rotation controller 16 are
The linear velocity is always controlled to be constant by controlling the rotational speed so as to continuously change depending on the reproduction position. The data string is taken into the signal processor 17 by the synchronous clock obtained as described above. For example, the signal processor 17 is composed of a demodulation unit, an error correction unit, a read / write address counter, etc., writes the fetched data string in a memory, demodulates the data, and then performs error correction and sends it to an external circuit. .

[0005]

However, the following problems have been encountered in the above conventional configuration. In other words, (a) Since it is necessary to keep the linear velocity constant, if the playback position of the optical pickup changes, such as when accessing, there will be a considerable time delay until the rotation of the spindle motor changes. , The access time was extremely slow. (b) Since a large torque is required to rapidly change the rotation of the spindle motor, unnecessary power consumption is increased, heat generated by the spindle motor is large, and miniaturization of the device is difficult. It was The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a disk device capable of high-speed access and low power consumption in a disk recorded at a constant linear velocity.

[0006]

In order to achieve the above object, the disk device of the present invention is a disk device for reproducing or recording a disk configured to be reproduced / recorded in a data stream at a constant linear velocity. Is divided into multiple blocks,
A switching command device that sends a command value according to the block to be played or recorded, a disk rotation controller that controls the linear velocity within the block at a constant speed, and switches the linear velocity according to the command value for each block, and a command value According to the above, the synchronous clock generator for switching the synchronous clock frequency for data reproduction or recording is configured.

[0007]

With this configuration, the disk recorded at a constant linear velocity is divided into a plurality of blocks, and the rotation controller controls the linear velocity within the block, and the linear velocity is switched for each block. Change according to the command value. At the same time, by changing the reproduction synchronous clock frequency generated by the synchronous clock generator according to the command value of the switching command device, the rotation speed of the spindle motor changes when the reproduction position of the optical pickup changes like access. Since the amount can be reduced, access time can be shortened and driving can be performed with low power consumption.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a disk device according to the first embodiment of the present invention. In FIG. 1, 1 is an optical disc recorded at a constant linear velocity, 2 is an optical pickup for reading a recorded data string, 3 is a servo controller for causing the optical pickup 2 to follow the surface runout and eccentricity of the optical disc 1,
Reference numeral 4 is a reproduction signal detector for binarizing the read reproduction signal, 18 is a switching commander for outputting a command value according to a block in the optical disc 1 which is divided into a plurality of blocks, and 5 is a switching commander. The maximum time width detector that detects the maximum time width of the bit pattern of the reproduction signal, further measures the maximum time width by the output of the frequency divider 19, and outputs the rotation control signal according to the result, 19 is the reference oscillator A frequency divider that changes the frequency division number of the output of 6 according to the command value, 7 is a spindle motor that rotates by mounting the optical disk 1, 8 is a spindle driver that drives the spindle motor 7 by the rotation control signal, Reference numeral 10 is a VCO that changes the oscillation frequency of the output clock according to the input voltage, 20 is a frequency divider that changes the center frequency of the synchronous clock generator 9 by changing the frequency division number according to the command value, and 11 is 2 Of reproduced signal and the divider 20
, A phase comparator that outputs a phase difference signal by comparing the phases of the output from, 12 removes high frequency noise of the phase difference signal,
A loop filter that determines the response characteristics of the synchronization clock generator 9, 13 is a frame detector that detects a frame synchronization signal from a binarized reproduction signal, 14 is a reference oscillator, and 21 is a frequency division number according to the command value. Frequency divider to be changed, 15 is frequency divider 21
, A phase comparator that detects the phase difference between the frame sync signal and the frame sync signal, and outputs a phase difference signal. 17 is a signal processor that writes the captured data string to memory, demodulates the data, and performs error correction to send it to an external circuit. Is.

The operation of the disk device configured as described above will be described with reference to FIG. The optical disc 1 recorded at a constant linear velocity is divided into a plurality of blocks r ₀ to blocks r _n as shown in FIG. 2, and each frequency divider 19 is divided by a command value from the switching command device 18 corresponding to the block to be reproduced. , 20, 21 are changed. First, the operations of the synchronous clock generator 9 and the disk rotation controller 16 in the block r ₀ will be described. The reproduction signal read by the optical pickup 2 from the optical disk 1 is detected by the reproduction signal detector 4 and binarized. Maximum time width detector 5
Detects the maximum time width of the bit pattern of the playback signal,
The maximum time width is counted by the reference clock f0 output from the frequency divider 19, and since this maximum time width corresponds to the linear velocity at the time of reproduction, the maximum time width depends on the count number of the maximum time width as in the conventional example. Outputs a rotation control signal. The spindle driver 8 drives the spindle motor 7 by the output.
In this way, the rotation speed is roughly controlled within the pull-in range of the synchronous clock generator 9. Then, for example, the synchronous clock generator 9 uses the binarized reproduction signal and the frequency divider 20.
Comparator that compares the phase of the output of and outputs the phase difference signal
11, a loop filter 12, and a VCO 10 that changes the oscillation frequency by the output from the loop filter 12, and generates a synchronous clock for reproduction. As described above, the synchronous clock generator 9 is locked by the rough rotation control and the synchronous clock of the reproduction signal is generated. Further, the rotation control of the disc after the synchronization clock generator 9 is locked is controlled so that the intervals of the frame synchronization signals in the optical disc 1 become constant as in the above-mentioned conventional example, so that the disc is rotated within the block r ₀ . Is controlled at a constant linear velocity.

The operation of rotation control by the frame synchronization signal will be described below. The frame detector 13 detects the frame sync signal from the binarized reproduced signal by the sync clock, and protects and interpolates the frame sync signal as in the conventional example. Since the frame sync signal is generated in a cycle corresponding to the linear velocity at the time of reproduction, the phase difference between the frame sync signal and the output from the frequency divider 21 is calculated by the phase comparator 15.
Then, the spindle motor 7 is controlled so that the cycle of the frame synchronization signal becomes constant. As a result, block r
_{Even if the} reproduction position changes in ₀ , the synchronous clock generator 9 and the disk rotation controller 16 are set so that the rotation speed continuously changes between Nmax and Nmin in the block r _{0 as} shown in FIG. Is controlled to maintain a constant linear velocity,
The frequency of the reproduction signal is f0. Also, each block r
_The rotation control is performed in _n (n = 0, 1, 2, ...) In the same manner as the control in block r ₀ , and the frequency of the reproduction signal is fn (n = 0, 1, 2, 3, ...) In each block. …) The data string is processed by the signal processor by the synchronous clock obtained as described above.
Captured by 17. For example, the signal processor 17 includes a demodulation unit, an error correction unit, a read / write address counter, etc., and writes the fetched data string in the memory.
After demodulating the data, error correction is performed and the data is sent to an external circuit.

Next, a case where the reproducing apparatus changes to another block by access will be described. For example, when the reproduction position changes from the block r ₀ to the block r ₁ , the switching commander 18 commands each frequency divider 19, 20, 21 to change the frequency division number, and each frequency divider 19, 20. , 21 changes the frequency division number at the same rate. The frequency of the reference clock for counting the maximum time width and the center frequency of the PLL become f1 according to the command, and the interval of the reference clock also changes at the same time.
As described above, the output from each frequency divider 19, 20, 21 changes,
The synchronous clock generator 9 and the disk rotation controller 16 operate in the block r ₁ in the same manner as the operation in the block r ₀ , so that the rotation speed changes from Nmax depending on the reproduction position in the block r ₁ . By changing continuously during Nmin,
The linear velocity is controlled to be constant, and the frequency of the reproduction signal becomes f1. Also, when the block at the playback position changes due to an arbitrary access from one block to another block, the frequency divider is divided into the frequency division numbers according to the block at the playback position in the same manner as above.
By changing 19, 20, and 21, the linear velocity is controlled to be constant at the frequency of the reproduction signal according to the block. Further, in the case of continuously reproducing the data string, at the boundary portion between the blocks where the reproduction position moves from the block r ₀ to the block r ₁ , the frequency division number is changed by the command value, and the synchronous clock generator 9 and The disk rotation controller 16 controls the rotation of the disk at a constant linear velocity, and it takes time until the frequency of the reproduction signal becomes f1 and the synchronous clock is generated. During that time, the data string is sent to the signal processor 17. I can't capture it. Therefore, for example, the data of the boundary between the blocks is stored in advance in the memory of the signal processor 17, and when the boundary between the blocks is continuously reproduced, the data stored in the memory is Operates to send to an external circuit.

As described above, according to the present embodiment, the optical disc 1 is divided into a plurality of blocks, and the switching command device 18 for sending a command value according to the block at the reproduction position, and the linear velocity control within the block are constant. However, by providing a disk rotation controller 16 for switching the linear velocity according to the command value and a synchronous clock generator 9 for switching the synchronous clock frequency of the data reproduction according to the command value for each block, Since the amount of change can be reduced from Nmax to Nmin, the access time can be shortened and the driving can be performed with low power consumption.

As a second embodiment of the present invention, a case of recording a data string on an optical disc will be described below with reference to the drawings by taking a write-once type CD-WO which can be recorded only once as an example. FIG. 3 is a block diagram of a disk device showing a second embodiment of the present invention. In FIG. 3, 22 is an optical disc having a wobbling guide groove, 23 is an optical pickup for recording on or reproducing from the optical disc 22, and 24 is the optical pickup 23 that follows the surface wobbling and eccentricity of the optical disc 22,
A servo controller that detects wobbling and outputs a wobbling signal, 25 is a reproduction signal detector that binarizes the read reproduction signal, 26 is a spindle motor, 27 is a spindle driver that drives the spindle motor 26, 28 Is a switching command device that outputs a command value according to a block to be reproduced or recorded on the optical disc 22 divided into a plurality of blocks, 29
Is a synchronous clock generator for generating a synchronous clock for the reproduction signal, and 30 is a disk rotation controller for controlling the frequency of the wobbling signal to be constant within the block, as in the first embodiment. This is different from the rotation control in which the frame synchronization signal is used as the rotation speed detection and its cycle is made constant. Reference numeral 31 is a reference clock generator that generates a reference clock, 32 is a frequency divider that changes the frequency division number according to the command value of the switching commander 28, and 33 is a recording that is synchronized with the clock of the output of the frequency divider 32. A data generator 34 outputs a data string, and a signal processor 34 writes the fetched data string in a memory, demodulates the data, corrects errors, and sends the data to an external circuit.

The operation of the disk device configured as described above will be described with reference to FIG. First,
A case where recording is performed in the block r _{0 of the} optical disc 22 will be described. The servo controller 24 detects the wobbling of the guide groove on the optical disk 22 from the reproduction signal output from the optical pickup 23 and outputs the wobbling signal. Since the wobbling signal is generated at a cycle corresponding to the linear velocity at the time of reproduction, the phase difference between the wobbling signal and the output from the frequency divider 35 is detected by the phase comparator 36 so that the cycle of the wobbling signal becomes constant. And controls the spindle motor 26. In this way, the rotation control can be performed by using the wobbling signal for detecting the rotation speed. Then, the data generator 33 outputs a data string synchronized with the clock of the frequency f0 output from the frequency divider 32,
The data string is recorded on the optical disk 22 by the optical pickup 23. As a result, even after changing the recording position is in block r _0, in the block r ₀ as shown in FIG. 2,
By controlling the disk rotation controller 30 so that the rotation speed continuously changes between Nmax and Nmin, the linear velocity is controlled to be constant and the frequency of the recording signal becomes f0. Each block _{r n (n = 0,1,2, ......} ) block r ₀ even within
The frequency of the recording data string is fn (n = 0, 1, 2, 3, ...) In each block.

Next, the case where the recording position is changed to another block will be described. For example, when the recording position changes from the block r ₀ to the block r ₁ , the switching command device 28 commands each frequency divider 32, 35 to change the frequency division number, and each frequency divider 32, 35 divides the frequency. Change the number of turns at the same rate. The frequency of the recording signal becomes f1 by the command, and the frequency of the reference signal also changes at the same time. As above, each frequency divider
The outputs from 32 and 35 change, and the disk rotation controller 30 operates in the block r ₁ in the same manner as the operation in the block r ₀ , so that the rotation speed in the block r ₁ is Nm.
The linear velocity is controlled to be constant by changing from ax to Nmin. Further, even when the block at the recording position is changed by arbitrarily accessing from one block to another block, the frequency divider is divided into the frequency division number corresponding to the block at the recording position as described above.
By changing 32 and 35, the linear velocity is controlled to be constant according to the block.

Next, the operation for reproducing the data string recorded as described above will be described. Servo controller 24
Detects wobbling in the guide groove on the optical disk 22,
The phase comparator 36 detects the phase difference between the wobbling signal and the output from the frequency divider 35, and controls the spindle motor 26 so that the cycle of the wobbling signal becomes constant. In this way, by controlling in the same manner as in the case of recording, the rotation speed is controlled within the pull-in range of the synchronous clock generator 29. Then, for example, the synchronous clock generator 29 generates the synchronous clock of the reproduction signal as in the first embodiment. As a result, even if the reproduction position is changed in block r _0, in the block r ₀ 2, the disk rotation controller 30 such that the rotational speed between the Nmin continuously changes from Nmax is By controlling, the linear velocity is controlled to be constant, and the frequency of the reproduction signal becomes f0. In addition, each block r _n (n = 0, 1,
2, ...) are controlled in the same manner as the control in the block r ₀ , and the frequency of the recording data string is fn (n = n
0,1,2,3, ...).

Also when the reproducing apparatus is changed to another block, the operation is similar to that of the first embodiment, and the switching command device 28 changes the frequency division number to each of the frequency dividers 32 and 35 according to the reproduction position. The center frequency of the PLL is f1
And the wobbling frequency also changes at the same time. As described above, the outputs from the frequency dividers 32 and 35 change, and the synchronous clock generator 29 and the disk rotation controller 30 cause the block r
_By operating in the block r ₁ similarly to the operation in ₀ , the rotation speed is Nmax depending on the reproduction position in the block r ₁ .
By continuously changing from 1 to Nmin, the linear velocity is controlled to be constant, and the frequency of the reproduction signal becomes f1. Also,
Even when the block at the playback position changes due to access from one block to another block, etc., by changing the frequency dividers 32 and 35 to the frequency division number according to the block at the playback position, the block is changed to that block. The linear velocity is controlled to be constant at the frequency of the corresponding reproduction signal. As described above, even in the case of recording, it is possible to reduce the amount of change in the number of rotations of the disk between Nmax and Nmin, so that it is possible to shorten the access time and drive with low power consumption.

[0018]

As described above, according to the present invention, in a disc device for reproducing or recording a disc configured so that a data stream is reproduced and recorded at a constant linear velocity, the disc is divided into a plurality of blocks and reproduced or recorded. A switching commander that sends a command value according to the block to be recorded, a disk rotation controller that controls the linear velocity within the block at a constant speed, and switches the linear velocity according to the command value for each block, and a disk rotation controller that responds to the command value. By providing a synchronous clock generator for switching the synchronous clock frequency for data reproduction or recording, the amount of change in the number of revolutions of the disk can be reduced from Nmax to Nmin, so that the access time can be shortened. This has the effect of realizing an excellent disk device that can be driven with low power consumption.

[Brief description of drawings]

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

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

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

FIG. 4 is a configuration diagram of a conventional disk device.

FIG. 5 is a diagram for explaining the operation of a conventional disk device.

[Explanation of symbols]

1, 22 ... Optical disc, 2, 23 ... Optical pickup,
3,24 ... Servo controller, 4,25 ... Playback signal detector, 5
… Maximum time width detector, 6,14,37… Reference oscillator,
7, 26 ... Spindle motor, 8, 27 ... Spindle driver, 9, 29 ... Synchronous clock generator, 10 ... VCO,
11, 15, 36 ... Phase comparator, 12 ... Loop filter, 13
… Frame detector, 16, 30… Disk rotation controller,
17, 34 ... Signal processor, 18, 28 ... Switching command device, 1
9, 20, 21, 32, 35 ... Divider, 31 ... Reference clock generator, 33 ... Data generator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taizo Kusano 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A disk device for reproducing or recording a disk configured to reproduce and record a data string at a constant linear velocity, wherein the disk is divided into a plurality of blocks, and the linear velocity is controlled within the block. A disk rotation controller for switching the linear velocity according to the block, and a synchronous clock generator for switching the synchronous clock frequency for reproducing or recording data for each block.