JP2002183981A - Disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the futile power consumption generated at the time of slide control of a disk player and the tracking deviation of a slide motor after the access operation. SOLUTION: The drivable level of a slide mechanical part is detected, and the input voltage of a slide driving circuit is compared with the drivable level so that the power is not supplied to the slide motor when it is lower than the drivable level. Also, the initial delay time is set after the access operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus provided with a slide drive for driving a pickup when reproducing information recorded on a disc.

[0002]

2. Description of the Related Art As a slide motor used for a slide drive unit for driving a pickup in a disk radial direction, D is used.
A C brush motor or a stepping motor is used. When a stepping motor is used, the pickup can be moved a predetermined distance, but the drive circuit becomes complicated and the board area must be increased, so that the slide drive unit becomes expensive. On the other hand, a DC brushless motor has a simple drive circuit configuration, requires a small substrate area, and is inexpensive. When a DC brush motor is used, the slide drive unit is controlled based on a tracking error signal obtained from a pickup. The tracking error signal passes through a low-pass filter of a servo signal generation circuit to remove noise unnecessary for thread servo control for driving the motor. This signal is input to the signal processing circuit and processed by the tracking servo phase compensation circuit. The signal at the output stage of the tracking servo phase assurance circuit is branched and input, and input to the thread servo phase compensation circuit. The signal processed by the thread servo phase compensation circuit is input to the slide motor drive circuit, and while the track servo is ON, the rotation of the DC brushless motor is controlled, and the thread servo is applied.

A DC brushless motor, which is a slide motor, supplies a drive voltage corresponding to the amount of displacement of the tracking actuator via a phase compensation filter based on a tracking error signal obtained by movement of the tracking actuator in the disk radial direction. A method of applying voltage is used. Unless a torque of a certain level or more is applied to the DC brushless motor, the DC brushless motor cannot be driven by the frictional force of the slide mechanism. In order to eliminate the influence of the friction of the slide mechanism, a method of applying a pulse-like voltage to the DC brushless motor with a control ON time and a control OFF time is used.

[0004]

When a pulse-like voltage is applied by turning on and off the thread servo control, if the driving voltage value is small, the slide motor is affected by the frictional force of the slide mechanism and the like, and the slide motor is driven. It cannot be driven and wasteful power is consumed.

After the access control, displacement of the tracking actuator is likely to occur. That is, since the lens of the tracking actuator vibrates after the access control, the position of the lens becomes uncertain. For this reason, if a step-like voltage corresponding to the tracking error signal is applied in a state where the lens is largely displaced, the driving amount of the slide motor (DC brushless motor) becomes too large and a phenomenon occurs in which tracking is lost.

An object of the present invention is to solve the above-mentioned problems and to provide a disk reproducing apparatus in which useless power consumed by a slide motor is reduced. Another object of the present invention is to provide a disk reproducing apparatus capable of controlling a slide motor as much as possible.

[0007]

When a voltage value at which the slide motor can be driven is set in advance, and control is to be performed with a drive voltage lower than the set voltage value, the control is performed by turning off the control of the slide motor. Reduce power.
In addition, when a step-like drive voltage is generated in a situation in which the displacement of the tracking actuator is likely to occur after access control or the like, an initial delay time before thread servo control is started is provided.

According to the present invention, the disc reproducing apparatus provides a slide motor for driving a slide section on which a pickup is mounted in a radial direction of the disc, a slide motor driving circuit for driving the slide motor, and supplying a drive pulse to the slide motor. A thread servo control circuit and a microcomputer are provided, and after the access operation for driving the slide portion in the disk radial direction by the slide motor is completed, a delay time is provided until the slide motor is driven to perform access again. . When the voltage is equal to or higher than a predetermined voltage, the thread servo control circuit outputs a drive voltage. These are achieved by controlling the thread servo control circuit by the microcomputer.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings using examples. FIG. 3 is a block diagram showing one embodiment of the disk reproducing apparatus according to the present invention. As shown in the figure, the disc reproducing apparatus includes a slide mechanism 303 on which a pickup 302 is mounted. When reproducing the disc 301, the pickup 30
2, a tracking error signal is detected and input to the tracking error generation circuit 307. The tracking error signal is amplified by the tracking error generation circuit 307, unnecessary noise is removed by a low-pass filter of the tracking error generation circuit 307, and is input to the tracking servo control circuit 308 inside the signal processing circuit 311. The signal processed by the tracking servo control circuit 308 is output to the outside of the signal processing circuit 311 and is input to the tracking actuator drive circuit 306. The tracking actuator drive circuit 306 drives a tracking actuator inside the pickup 302 to perform feedback control.

On the other hand, the track servo control circuit 3
The signal generated at 08 is branched and input to the thread servo control circuit 309. After the input signal is processed by the thread servo control circuit 309,
The signal is output from the signal processing circuit 311 and input to the slide motor drive circuit 305. Slide motor drive circuit 30
Numeral 5 drives the slide motor 304 to perform feedback control.

A microcomputer 310 is connected to the thread servo control circuit 309. The microcomputer 310 has a timer, and the timer is used to control the output of the thread servo control circuit 309 on and off. When the slide motor is driven by the output of the thread servo control circuit 309, the friction of the slide mechanism and the slide motor 3
The drive distance varies due to the influence of the torque of No. 04 and the like. In order to eliminate the influence of the frictional force of the slide mechanism 303, which is the largest cause of the variation, a pulse drive voltage is generated at the output of the thread servo control circuit using the timer of the microcomputer 310, and the pulse voltage is slid. It is supplied to a motor drive circuit 305 to drive the slide motor 304 intermittently. By intermittently driving, a torque larger than the static friction force of the slide mechanism 303 can be generated in the slide motor 304, and the slide mechanism 303 can be driven.

When the torque generated in the slide motor 304 is larger than the static friction force of the slide mechanism 303,
The electric power output from the slide motor drive circuit 305 when the slide motor 304 is driven is consumed by the slide motor 304. However, the thread servo control circuit 30
If the voltage output from the motor 9 is small, the slide motor 3
04 cannot be supplied with sufficient power to drive it, and is consumed as invalid power. The microcomputer 310 has means for detecting a voltage value output from the thread servo control circuit 309, and
0 has an output permission voltage for permitting driving as a fixed value. The microcomputer 310 detects the voltage output from the thread servo control circuit 309, and outputs a voltage from the thread servo control circuit 309 when the output voltage exceeds the output permission voltage set in the microcomputer 310. When the output voltage of the circuit 309 is lower than the set output permission voltage, the output from the thread servo control circuit 309 is set to 0 so that no current flows to the slide motor 304.

Next, control by the microcomputer 310 after the end of the access operation will be described.
When seeking a relatively short distance, the tracking actuator drive circuit 308 is controlled by performing speed control.
In the case of realizing high-speed access, the access is completed within several tens of ms, and during this period, the slide motor 304 is driven to apply thread servo. After the access ends and the slide motor 304 stops, the amount of tilt of the lens in the tracking direction varies. In such a state, when the motor is driven by a pulsed voltage for performing intermittent control and reaches a predetermined position by several accesses, the slide motor 30 is driven.
There is a case where the next access operation is started before 4 stops. In order to minimize the influence on the speed control at the time of the next access control, it is preferable that the thread servo is applied during the access and the thread servo is not operated between the access and the next access.

The input / output waveforms of the thread servo control circuit of the disk reproducing apparatus according to the present invention will be described below with reference to FIG. FIG. 1 is a diagram showing operation waveforms of a disk reproducing apparatus according to the present invention. FIG. 1 (a) shows an input waveform of a thread servo control circuit, and FIG. 1 (b) shows a thread servo on / off controlled by the present invention. FIG. 1C is a diagram illustrating an output waveform of the control circuit, and FIG. 1C is a diagram illustrating an output waveform of the thread servo control circuit when the output permission voltage is determined on the output waveform of FIG.
In the figure, T1 is a period during which an access operation is being performed. T2 is a period of the reproduction state after the end of the access control. In the figure, 1 is an input waveform of the thread servo control circuit 309, 2 is a pulse-like output waveform of the thread servo control circuit 309, and 3 is an output waveform 2 that extracts only a voltage higher than a preset voltage value. 11 shows an output waveform of the thread servo control circuit 309 when the operation is performed.

First, the microcomputer 310 makes settings for control. That is, the initial delay time A, the ON time B, the OFF time C, and the output permission voltage D
1, D2 (normally D1 = D2) is set. (Figure 1
(See (b) and (c)). As shown in FIG.
Is a period of the access operation, and the pull-in of the tracking servo is completed at the time when T1 changes to T2. In the period T2, when the slide motor 304 is driven again to perform access, an initial delay period A is provided, and during this period, no voltage is generated at the output of the sled servo control circuit 309. When the access is performed again, when the initial delay period A elapses, the pulse is turned on for the time B and the thread servo control circuit 3 is turned on.
09 outputs a pulse voltage. Thereafter, no voltage is generated during time C. Further, the microcomputer 310 controls the thread servo control circuit 309 so that the pulse voltage is not output from the sled servo control circuit 309 unless the pulse voltage becomes a predetermined voltage D1 or more in the plus or minus direction with respect to the reference voltage. Therefore, the pulse voltage shown in FIG. 1C is output to the output of the thread servo control circuit 309.

FIG. 2 is a flow chart for explaining the operation of the disk reproducing apparatus according to the present invention. The microcomputer 310 determines at the end of T1, that is, from T1 to T2.
Confirm that the tracking servo has been pulled in at the point when it changes to. During the period of T2, the playback state is entered,
Further, the access operation may be started. When starting the access operation, an initial delay time A is provided, during which the pulse ON time B does not occur. After the start, in step 201, it is determined whether or not the set initial delay time A has elapsed. If the initial delay time A has not elapsed, the flow shifts to step 207 to set the output voltage of the sled servo control circuit 309 to zero. The initial delay time A estimates and sets the time from the detection of the disk reproduction position to the transition to the next access operation. To enter the access state, step 20
When the initial delay time A has elapsed at step 1, the process proceeds to step 202, where the output voltage of the thread servo control circuit 309 is input to the slide motor drive circuit 305 to drive the slide motor 304 until the set ON time B has elapsed. During the ON period B, the process proceeds to step 204, where the output voltage of the thread servo control circuit 309 is compared with the set output permission voltage. If the output voltage of the thread servo control circuit 309 is lower than the output permission voltage, the process proceeds to step 205, where the output voltage of the thread servo control circuit 309 is set to zero. Here, output voltage 0
Is an output voltage at which no current flows through the slide motor 304. When the ON time B ends, the process proceeds to step 203, and the thread servo control circuit 309 is executed in step 206 until the set OFF time C elapses.
Is set to 0, and the drive of the slide motor is stopped. When the OFF time C ends, the operation moves to the ON time
The slide motor 304 is driven by a pulsed voltage by repeating the / OFF operation.

As described above, by providing the initial delay time, the thread servo control can be performed by the same method regardless of whether the access operation is started after the access is completed or in the reproduction state.

Further, by using the output voltage of the sled servo control circuit as a pulse voltage and outputting a pulse having a voltage higher than a predetermined voltage, wasteful power can be reduced.

[0019]

As described above, according to the present invention, power consumption during reproduction can be reduced in controlling the slide mechanism with high accuracy.

Further, even if a large displacement occurs in the tracking actuator after the access operation, the slide mechanism can be stably controlled.

[Brief description of the drawings]

FIG. 1 is a diagram showing operation waveforms of a disk reproducing apparatus according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the disc reproducing apparatus according to the present invention.

FIG. 3 is a block diagram showing one embodiment of a disk reproducing apparatus according to the present invention.

[Explanation of symbols]

301: disk, 302: pickup, 303: slide mechanism, 304: slide motor, 305: slide motor drive circuit, 306: tracking actuator drive circuit, 307: tracking error generation circuit,
308: tracking servo control circuit, 309
... Sled servo control circuit, 310 ... Microcomputer, 311 ... Signal processing circuit.

Continued on the front page F term (reference) 5D088 RR10 UU10 5D096 UU07 UU10 5D117 FF28 FF30 5D118 AA13 BF12 BF13 BF17 CA07 CA15

Claims (3)

[Claims] 1. A slide motor for driving a slide section on which a pickup is mounted in a radial direction of a disc, wherein a delay time is provided between the end of access and the start of driving when the slide motor is driven. Disk playback device. 2. A slide motor for driving a slide portion on which a pickup is mounted in a radial direction of a disk. When the slide motor is driven, a current is not supplied to the slide motor until a drivable voltage is generated. A disk reproducing apparatus for controlling an input voltage of a circuit. 3. A slide motor for driving a slide section on which a pickup is mounted in a radial direction of a disk, a slide motor drive circuit for driving the slide motor, a thread servo control circuit for supplying a drive pulse to the slide motor, A delay time between the end of an access operation for driving the slide section in the disk radial direction by the slide motor and the access to the slide motor to perform access again, and a predetermined voltage. A disk reproducing apparatus characterized in that the microcomputer controls the sled servo control circuit so as to output a drive voltage from the sled servo control circuit in the above case.