JPH0831088A - Spindle motor control circuit for optical disk recording/ reproducing device - Google Patents

Abstract

PURPOSE:To attain stable constant linear velocity(CLV) control at a regular speed and N-fold speed by switching controlling a reference clock signal frequency from a reference clock generation part through a microcomputer and controlling rotation of a spindle motor. CONSTITUTION:An FG signal from the spindle motor 2 at a regular speed is compared with a reference clock frequency corresponding to the regular speed from the reference clock generation part 6 by an FG control part 7, and the computer 9 switches a selector to a CLV side according to a rotation setting signal from the FG control part 7, and the motor 2 is CLV-controlled through a CLV control part 5 by a wobble signal from a wobble detector 4 and a reference frequency signal from the generation part 6 of which frequency is switching controlled successively by the computer 9. On the other hand, when the motor 2 is started at the N-fold speed, the reference clock frequency of the generation part 6 is made to be at the N-fold speed in a starting period through the computer 9, and thereafter, similarly the motor 2 is CLV-controlled at the N-fold speed stably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor control circuit for an optical disk recording / reproducing apparatus, and more particularly to a spindle motor control circuit for an optical disk recording / reproducing apparatus for controlling the start of disk rotation and CLV control.

[0002]

2. Description of the Related Art One method of controlling CLV of an optical disk recording / reproducing apparatus is carried out by keeping a frequency of a wobble signal detected by an optical pickup from a pre-groove for guiding a laser spot engraved on a disk. FIG. 2 shows an example of a spindle motor control circuit of a conventional optical disk recording / reproducing apparatus that performs such CLV control. The optical disk 1 with pre-grooves is rotationally driven by a spindle motor 2. The pickup 3 irradiates the pre-groove of the optical disc 1 with a laser spot, and the wobble detection unit 4 detects and amplifies the wobble signal by the reflected light. The CLV control unit 5 is controlled by the microcomputer 9,
The frequency of the wobble signal input from the wobble detector 4 and the frequency of the reference clock input from the reference clock generator 6 are compared to generate a CLV error signal. The CLV error signal from the CLV control unit 5 is output to the motor drive unit 10 via the selector 8, and the motor drive unit 10 drives the spindle motor 2.

In such a spindle motor control circuit, the F9 is controlled by the microcomputer 9 when the motor is started.
The FG error signal generated by comparing the frequency of the FG signal output from the motor 2 with the G control unit 7 and the frequency of the reference clock from the reference clock generating unit 6 is CLed by the selector 8.
Switch to V error signal and input to motor drive unit 10,
Start up the motor 2 by FG control. The spindle motor rotation speed that has been started by this FG control and has reached a predetermined rotation speed is set so as to fall within the rotation speed range (capture range) that enables CLV control. After a predetermined time, the microcomputer 8 switches the selector 8 and inputs a CLV error signal to the motor drive unit 10 to perform CLV control.

[0004]

In the conventional spindle motor control circuit described above, when the CLV control of the spindle motor is performed at N times speed (N is a positive real number), the FG control circuit for starting up the spindle motor is normally used. C at high speed
Since it is set according to LV control, C at N speed
There was a problem that the spindle motor rotation speed could not be raised to fall within the LV capture range, and CLV lock could not be performed. An object of the present invention is to provide N times speed (N
Is to provide a spindle motor control circuit of an optical disk recording / reproducing apparatus that enables stable spindle motor rotation control at the time of startup and CLV control with a positive real number.

[0005]

A spindle motor control circuit of an optical disk recording / reproducing apparatus according to the present invention can switch the rotation speed of an optical disk between normal speed and N times speed (N is a positive real number) for CLV control. A possible optical disk recording / reproducing apparatus is provided with means for switching and setting the spindle motor rotation speed at the time of starting the motor for pulling into the CLV control to the rotation speed for normal speed and the rotation speed for N times speed. The CLV control is performed by switching for each speed.

Further, the spindle motor control circuit of the optical disk recording / reproducing apparatus according to the present invention switches the rotation speed of the optical disk between the normal speed and the N times speed (N is a positive real number), and C
In an optical disk recording / reproducing apparatus capable of LV control, a wobble detecting section for detecting a wobble signal from a pre-groove of an optical disk, a reference clock generating section, a wobble signal from the wobble detecting section, and a reference from the reference clock generating section. A CLV control circuit for generating a CLV control signal based on a clock signal, and an FG from a spindle motor
An FG control unit that generates an FG control signal based on a signal and a reference clock signal from the reference clock generation unit, a motor drive unit, and the FG control signal when starting, CLV.
At the time of control, selectors for switching the CLV control signals to be supplied to the motor drive unit, and a reference clock signal frequency of the reference clock generation unit corresponding to the normal speed rotation speed and the N-fold speed rotation speed are selected. And means for variably controlling.

[0007]

In order to rotate the optical disk under the CLV control, the disk must be rotated within the rotational speed range (capture range) where the CLV control can be performed at startup. Therefore, it is necessary to give a certain drive signal to the spindle motor at the time of start-up and rotate the spindle motor at a constant speed within the capture range of CLV control. According to the present invention, when the CLV control is performed by switching between the normal speed and the N-fold speed (N is a positive real number), the rotation speed of the spindle motor at start-up is set to a constant rotation speed according to the CLV capture range of each speed. Since the switching is performed, it is possible to stably start up the spindle motor in any double speed CLV control.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a spindle motor control circuit of an optical disk device according to the present invention. In the figure, the CLV control unit 5 outputs to the selector 8 the CLV control signal generated based on the wobble signal from the wobble detection unit 4 and the reference clock signal from the reference clock generation unit 6. The FG control unit 7 includes an FG signal output from the spindle motor 2 and a reference clock generation unit 6.
The FG control signal generated on the basis of the reference clock signal from is output to the selector 8 and a lock signal is generated when the motor speed reaches the set speed.

The microcomputer 9 switches and controls the selector 8 and variably controls the reference clock frequency of the reference clock generator 6. That is, in the normal speed mode, the reference clock frequency for FG control that can obtain the rotation speed within the capture range of the normal speed CLV and the reference clock frequency for CLV control that corresponds to the normal speed wobble signal are set. First, the selector 8 is switched to the FG control side to activate the spindle motor 2, and when the lock signal from the FG control unit 7 is received, the selector 8 is switched to the CLV control side.
Perform control.

Next, in the N times speed mode (N is a positive real number) mode,
The microcomputer 9 variably controls the reference clock frequency of the reference clock generation unit 6 to obtain a reference clock frequency for FG control that can obtain a rotation speed within the capture range of N-fold speed CLV, and a CLV corresponding to the wobble signal of N-fold speed.
By switching to the reference clock frequency for control and switching the selector 8 as in the normal speed mode, the FG
It is activated on the control side and the NLV speed CLV control is performed on the CLV control side.

As described above, the frequency of the reference clock signal from the reference clock unit 6 supplied to the FG control unit 7 and the CLV control unit 5 becomes the optimum frequency according to the mode switching between the normal speed and the N-fold speed. Variably controlled.

[0012]

According to the spindle motor control circuit of the optical disk recording / reproducing apparatus of the present invention, mislock at the time of CLV control after the spindle motor is started at N times speed (N is a positive real number) is prevented, and stable CLV control is performed. Can be done.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a spindle motor control circuit of an optical disc recording / reproducing apparatus according to the present invention.

FIG. 2 is a block diagram of a spindle motor control circuit of a conventional optical disc recording / reproducing apparatus.

[Explanation of symbols]

 1 Optical Disc 2 Spindle Motor 3 Pickup 4 Wobble Detection Unit 5 CLV Control Unit 6 Reference Clock Generation Unit 7 FG Control Unit 8 Selector 9 Microcomputer 10 Motor Drive Unit

Claims (2)

[Claims] 1. In an optical disk recording / reproducing apparatus capable of CLV control by switching the rotation speed of an optical disk between a normal speed and an N times speed (N is a positive real number), a spindle motor at the time of starting the motor for pulling in the CLV control. An optical disk recording / reproducing apparatus comprising means for switching and setting the number of revolutions between the number of revolutions for normal speed and the number of revolutions for N times speed, and performing the CLV control by switching the number of revolutions for each speed. Spindle motor control circuit. 2. In an optical disk recording / reproducing apparatus capable of CLV control by switching the rotation speed of the optical disk (1) between a normal speed and an N times speed (N is a positive real number), a wobble more than a pre-groove of the optical disk (1). Based on a wobble detection unit (4) for detecting a signal, a reference clock generation unit (6), a wobble signal from the wobble detection unit (4) and a reference clock signal from the reference clock generation unit (6) F based on the CLV control circuit (5) for generating the CLV control signal, the FG signal from the spindle motor (2) and the reference clock signal from the reference clock generation unit (6).
The FG control unit (7) for generating the G control signal, the motor drive unit (10), and the FG control signal at the time of startup are CLV.
At the time of control, a selector (8) for switching the CLV control signal to each of them and supplying it to the motor drive unit, and a reference clock of the reference clock generation unit corresponding to the rotation speed for the normal speed and the rotation speed for the N-fold speed A spindle motor control circuit for an optical disk recording / reproducing apparatus, comprising: means (9) for variably controlling a signal frequency.