JPH07201127A - Spindle motor speed control device - Google Patents

Abstract

PURPOSE:To secure a stable reproducing with good accuracy by controlling rotating speed of a motor with a motor control circuit so as to make periodic difference shown by periodic difference signal from an address detecting circuit zero. CONSTITUTION:When a track address data recorded on a disk 51 is reproduced, this reproduced track address data S1 is inputted to a reproducing CLK extracting circuit 11 of the address detecting circuit 1, and an edge signal S2 and a reproducing clock signal S3 are outputted from the circuit 11 to a synchronization detecting data demodulating circuit 12, and also a reproducing control pulse S5 is outputted to a periodic difference circuit 13. When the signals S2 and S3 are inputted to the circuit 12, a demodulated track address data S4 is outputted to a system control circuit 2. On the other hand, a periodic difference between the pulse S5 and a reference pulse P is calculated in the circuit 13, and a periodic difference signal S6 is outputted to the motor control circuit 3, and then a speed correcting signal S8 is generated from the circuit 3, and is outputted to a motor driver 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor speed control device for controlling the linear speed of a disk to be constant.

[0002]

2. Description of the Related Art The angular velocity of a disk is controlled to be constant (C
In the case of an (AV control) disk device, a phase locked loop (PLL) may be applied to the REF signal to rotate the disk at a constant speed regardless of the track position of the disk. However, in the disk used in such a disk device, the recording density of the outer track must be made smaller than the recording density of the inner track, and a large amount of data cannot be recorded.

For this reason, there has been devised a disk device which controls a disk in which more data is recorded by keeping the recording density in all tracks constant. That is,
The spindle motor speed control technology is provided for controlling the disk speed so as to keep the disk linear speed constant (CLV control), and reading and writing the data of each track accurately. Conventionally, as a technique of this type, for example, Japanese Patent Laid-Open No.
No. 119664, No. 62-12956, No. 63-66761, No. 63-83
Two types of methods have been adopted, such as the techniques described in Japanese Patent No. 958 and Japanese Patent Laid-Open No. 3-44867.

That is, the first method is a method in which the disk device receives position information for each track from a linear scaler of a positioner motor, obtains a rotation speed at that position, and changes the rotation speed for each track. is there. The second method is a method in which a physical mark is previously engraved on each track of the disc, and the disc device reads the mark to obtain the rotation speed at each track position.

[0005]

However, in the above-mentioned first method, the accuracy of the rotation speed control is only accurate to the pitch of the linear scaler, and it takes time to pull in the necessary rotation speed, and the access time is long. It will be long. Further, in the case of continuous reproduction, the change control of the rotation speed cannot keep up with the reproduction. On the other hand, in the above-mentioned second method, it is not possible to stably and quickly pull in the rotation of a disc having no mark, and the versatility of the disc is poor.

The present invention has been made in view of the above problems, and in a CLV-controlled disk device, the rotational speed of the disk is instantly pulled to a desired speed at the time of reproduction to obtain stable and accurate reproduction. It is an object of the present invention to provide a spindle motor speed control device capable of achieving the above.

[0007]

In order to achieve the above object, a spindle motor speed control device according to the present invention comprises a preamplifier, a SYNC (synchronization signal), an address data and an RS.
It is composed of a code (Reed-Solomon code), extracts an edge signal from the reproduction track address data recorded on the disc, and outputs a cycle difference signal indicating the cycle difference between the reproduction control pulse and the reference pulse obtained from this edge signal. In addition, an address detection circuit that demodulates and outputs the address data of the reproduction track address data, and a control that checks the current address based on the demodulated address data and indicates the rotation speed of the next track stored in the internal table. The system control circuit that outputs a signal and the rotation speed of the motor are controlled so that the cycle difference indicated by the cycle difference signal from the address detection circuit becomes zero, and the rotation speed indicated by the control signal from the system control circuit Control the rotation speed of the motor to A configuration equipped with a motor control circuit 3.

According to a second aspect of the present invention, in the spindle motor speed control device, the address detection circuit outputs an edge signal extracted from the reproduction track address data and a reproduction clock signal generated based on the edge signal. A reproduction CLK extraction circuit for outputting a reproduction control pulse generated based on the edge signal, and a sync pattern of the edge signal based on the reproduction clock signal, and recorded after the edge signal for each sync detection. While demodulating the address data, error correction of the address data demodulated based on the RS code,
A synchronization detection data demodulation circuit that outputs only error-free address data to the system control circuit, and a cycle difference signal between the reproduction control pulse from the reproduction CLK extraction circuit and the reference pulse, and a cycle difference signal indicating the result. With a period difference circuit for outputting to the motor control circuit.

[0009]

According to the above spindle motor speed control device,
An edge signal is extracted from the reproduction track address data by the address detection circuit, and a cycle difference signal indicating the cycle difference between the reproduction control pulse and the reference pulse obtained from this edge signal is output from the address detection circuit and the reproduction track address is output. The address data of the data is demodulated and output. Then, in the system control circuit, the current address is checked based on the demodulated address data, and the control signal indicating the rotation speed of the next track stored in the internal table is output. Then, the motor control circuit controls the rotation speed of the motor so that the cycle difference indicated by the cycle difference signal from the address detection circuit becomes zero and the rotation speed indicated by the control signal from the system control circuit. The rotation speed of the motor is controlled.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a spindle motor speed control device according to an embodiment of the present invention. The spindle motor speed control device of this embodiment is a CLV control device, and includes an address detection circuit 1, a system control circuit 2, a motor control circuit 3, and a motor driver 4.

The track address data S1 is composed of a preamplifier, a SYNC (synchronization signal), address data, and an RS code (Reed Solomon code). The track address data S1 is generated by the address generation circuit 15, is bi-phase modulated by the recording circuit 16, and is recorded N times on the disk 51.

The address detection circuit 1 includes a reproduction CLK extraction circuit 11, a sync detection data demodulation circuit 12, and a cycle difference circuit 1.
3 and 3. The reproduction CLK extraction circuit 11 uses the reproduction track address data S read from the disk 51.
1 is input, the edge signal S2 extracted from the reproduction track address data S1 and the reproduction clock signal S3 generated based on the edge signal S2 are extracted and output to the sync detection data demodulation circuit 12, and at the same time, the edge signal S2. It has a function of outputting the reproduction control pulse S5 generated based on the above to the period difference circuit 13.

The sync detection data demodulation circuit 12 has a function of detecting the sync pattern of the edge signal S2 based on the reproduction clock signal S3, and demodulating the track address data recorded after the edge signal S2 for each sync detection.
The synchronization detection data demodulation circuit 12 also performs error correction on the N address data demodulated based on the RS code, and outputs only error-free address data to the system control circuit 2. The cycle difference circuit 13 uses the reproduction CL
The reproduction control pulse S5 from the K extraction circuit 11 is input, the period difference between the reference pulse P having a predetermined constant period and the reproduction control pulse S5 is calculated, and the period difference signal S6 indicating the result is calculated as the motor control circuit 3 It has a function to output to.

On the other hand, the system control circuit 2 has a table (not shown) inside. This table stores the rotational speed of each track located in the radial direction of the disk 51. The system control circuit 2 then uses the demodulated track address data S4 input from the sync detection data demodulation circuit 12 to
The rotation speed of the corresponding track is extracted from the above table, and the current rotation speed of the disk 51 is determined by a motor control signal S7 described later input from the motor control circuit 3 to determine the rotation speed of the track to be reproduced next. The control signal S9 shown is output to the motor control circuit 3.

The motor control circuit 3 has a function of outputting a motor control signal S7 for controlling the output voltage of the motor driver 4 based on the rotation speed indicated by the control signal S9 from the system control circuit 2. Further, the motor control circuit 3 receives the period difference signal S6 from the period difference circuit 13, and a speed correction signal for controlling the spindle motor 5 so that the period difference indicated by the period difference signal S6 becomes zero. It also has a function of outputting S8 to the motor driver 4. The motor driver 4 is a motor control circuit 3
Has a function of outputting a drive signal S10 for controlling the rotation speed of the spindle motor 5 to the spindle motor 5 at the rotation speed indicated by the motor control signal S7 or the speed correction signal S8.

Reference numeral 6 is a photodetector, which has a function of outputting to the motor control circuit 3 a destack signal S11 indicating the rotational speed of the disk 51 read from the mark printed on the inner side of the track of the disk 51. Have. Further, the motor control circuit 3 includes a disk 51 detected by a hall element of the spindle motor 5 or the like.
The feedback signal S12 indicating the rotation speed of is input. As a result, the destack signal S
11 and the feedback signal S12 from the disk 51
It is possible to know the approximate rotation speed of.

Next, the operation of this embodiment will be described.
When the track address data S1 is recorded N times on the disk 51, the system control circuit 2 outputs a control signal S9 indicating the rotation speed corresponding to the track position.
Is output to the motor control circuit 3. As a result, the motor control circuit 3 outputs a motor control signal S7 for making the linear velocity of the track constant to the motor driver 4, and the drive signal S10 from the motor driver 4 causes the spindle motor 5 to move the disk 51 to the line of the track. Rotate to keep speed constant. With the linear velocity kept constant in this way, the track address data S1 generated by the address generation circuit 15 is recorded on the disk 51 N times using the recording circuit 16.

When the track address data recorded on the disk 51 is reproduced in this way, the reproduced track address data S1 is input to the reproduction CLK extraction circuit 11 of the address detection circuit 1 and the reproduction CLK extraction circuit 1 is reproduced.
The edge signal S2 and the reproduction clock signal S3 from 1 are output to the synchronization detection data demodulation circuit 12, and the reproduction control pulse S5 is output to the period difference circuit 13.

When the edge signal S2 and the reproduced clock signal S3 are input to the sync detection data demodulation circuit 12, the track address data is demodulated, and the demodulated track address data S4 containing only error-free address data is sent to the system control circuit 2. Is output. When the demodulated track address data S4 is input to the system control circuit 2, the system control circuit 2 extracts the rotation speed of the corresponding track from the internal table, and the motor control signal S7 from the motor control circuit 3 causes the present disk 51 to rotate. Is determined and the control signal S9 indicating the rotation speed of the truck is output to the motor control circuit 3.

On the other hand, when the reproduction control pulse S5 from the reproduction CLK extraction circuit 11 is input to the cycle difference circuit 13, the cycle difference circuit 13 calculates the cycle difference between the reproduction control pulse S5 and the reference pulse P, and the cycle difference is calculated. The difference signal S6 is output to the motor control circuit 3. Then, the motor control circuit 3 generates a speed correction signal S8 that makes the cycle difference indicated by the cycle difference signal S6 zero, and outputs it to the motor driver 4.

That is, when the cycle of the reproduction control pulse S5 is shorter than the cycle of the reference pulse P, the rotation speed of the disk 51 is too fast, so that the cycle difference is made zero and the rotation speed of the disk 51 is slowed. The correction signal S8 is output to the motor driver 4. Conversely, when the cycle of the reproduction control pulse S5 is larger than the cycle of the reference pulse P, the rotation speed of the disk 51 is slow, so the speed correction signal S8 for increasing the rotation speed of the disk 51 by making the cycle difference zero. Is output to the motor driver 4. As a result, the drive signal S10 is output from the motor driver 4 to the spindle motor 5, the rotation of the spindle motor 5 is controlled, and the linear velocity of all the tracks of the disk 51 becomes constant.

[0022]

As described above, according to the spindle motor speed control device of the present invention, the motor control circuit controls the rotation speed of the motor so that the cycle difference indicated by the cycle difference signal from the address detection circuit becomes zero. Therefore, the rotational speed of the disk can be instantly pulled to a desired speed during reproduction, and stable and highly accurate reproduction can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a spindle motor speed control device according to an embodiment of the present invention.

[Explanation of symbols]

 1 address detection circuit 2 system control circuit 3 motor control circuit 4 motor driver 5 spindle motor 11 reproduction CLK extraction circuit 12 sync detection data demodulation circuit 13 cycle difference resolution path

Claims (3)

[Claims] 1. An edge signal is extracted from reproduction track address data recorded on a disc, which is composed of a preamplifier, a SYNC (synchronization signal), address data and an RS code (Reed Solomon code), and is obtained from this edge signal. An address detection circuit that outputs a period difference signal indicating the period difference between the reproduction control pulse and the reference pulse, demodulates and outputs the address data of the reproduction track address data, and checks the current address based on the demodulated address data. , A system control circuit that outputs a control signal indicating the rotation speed of the next track stored in the internal table, and the motor rotation speed so that the cycle difference indicated by the cycle difference signal from the address detection circuit becomes zero. In addition to controlling, Spindle motor speed control apparatus comprising: a motor control circuit 3 for controlling the rotational speed of the motor so that the rotational speed indicated by the trawl signal. 2. The address detection circuit outputs an edge signal extracted from the reproduction track address data and a reproduction clock signal generated based on the edge signal, and a reproduction control pulse generated based on the edge signal. A reproduction CLK extraction circuit for outputting and a synchronization pattern of the edge signal are detected based on the reproduction clock signal, and the address data recorded after the edge signal is demodulated every time the synchronization is detected.
A sync detection data demodulation circuit for correcting the error of the address data demodulated based on the S code and outputting only address data having no error to the system control circuit, a reproduction control pulse from the reproduction CLK extraction circuit, and the reference pulse. 2. The spindle motor speed control device according to claim 1, further comprising: a cycle difference circuit that calculates a cycle difference between the motor control circuit and a cycle difference signal indicating the result. 3. The spindle motor speed control device according to claim 2, further comprising a motor driver for controlling the rotation speed of the spindle motor based on a motor control signal or a speed correction signal from the motor control circuit.