JPH07334852A - Traverse mechanism of optical pickup - Google Patents

Abstract

PURPOSE:To prevent performance for moving an optical pickup from being changed by the fluctuation of a driving load. CONSTITUTION:A moving time deciding means 14 compares a moving time when an optical pickup 1 is moved from the outermost circumference position to the innermost circumference position with the preset reference moving time of the optical pickup 1 at the time when the operation of a device is normal to output a decision signal. A pulse rate setting means 15 makes a pulse rate change by a fixed value while making the pulse rate correspond to the decision signal and a driving circuit 9 makes a driving torque generated by a stepping motor 2 change while making a driving torque correspond to the pulse rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traverse mechanism of an optical pickup used in an optical recording / reproducing apparatus,
In particular, the present invention relates to a traverse mechanism of an optical pickup equipped with a means for preventing the occurrence of malfunction.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing an optical disk drive device having a conventional traverse mechanism. A is a disk which is a disk-shaped recording medium, 1 is an optical pickup, and 2 is an optical pickup.
Is a stepping motor, 3 is a lead screw, 4 is a bearing, 5 is a feed screw nut, 6 is a guide shaft, 7 is a guide shaft retainer, 8 is a housing, 9 is a traverse drive driver, 9a is pulse generation means, and 9b is a drive circuit. Is. The optical pickup 1 is for reproducing information spirally recorded on the disc A, or for recording information spirally on the disc A, and the traverse mechanism stores the optical pickup 1 in the radial direction of the disc A. It is a mechanism to move to.

The traverse mechanism includes a stepping motor 2 fixed to a housing 8 and a stepping motor 2
It has a lead screw 3 which is an output shaft, a bearing 4 which is fixed to the housing 8 and supports the lead screw 3, and a gear portion which is fastened to the optical pickup 1 and meshes with the lead screw 3. The feed screw nut 5, a guide shaft 6 that supports the optical pickup 1 and restrains the moving direction in the radial direction of the disk A, and a guide shaft retainer 7 that fixes the guide shaft 6 to the housing 8. The traverse drive driver 9 is a circuit for driving the stepping motor 2 in the traverse mechanism, and determines the pulse generation means 9a for generating a pulse signal and the excitation order of each phase of the stepping motor to control the power supply. And a drive circuit 9b.

Next, the operation of the above traverse mechanism in the optical disk drive will be described. The traverse drive driver 9 generates a pulse signal by the pulse generation means 9a when the drive command signal is input. The drive circuit 9b determines the excitation order of each phase of the stepping motor 2 in accordance with the pulse signal, and controls the power supplied to the stepping motor 2. As a result, the stepping motor 2 is driven to generate rotational thrust. The rotational thrust of the stepping motor 2 is transmitted to the gear portion of the feed screw nut 5 by the lead screw 3. The feed screw nut 5 converts the rotational thrust of the lead screw 3 into a linear motion thrust of the lead screw 3 and moves the optical pickup 1 in the radial direction of the disc A along the guide shaft 6.

[0005]

However, in the traverse mechanism as described above, a mechanism portion for generating and transmitting thrust is generated due to a large change in the operating environment temperature or deterioration of the components of the mechanism portion over time. Since the drive load of (1) changes from the initial design value, there arises a problem that the optical pickup cannot be moved or the moving time to the target position on the disk A changes. This problem can be solved, for example, by changing the drive torque generated by the stepping motor 2 in accordance with the drive load. However, in the conventional traverse mechanism,
Since the stepping motor 2 is always drive-controlled at the same pulse rate, the driving torque from the stepping motor 2 is always constant and the above problems cannot be solved.

In order to solve the above problems, it is an object of the present invention to provide a traverse mechanism for an optical pickup which is provided with a means for preventing the performance of moving the optical pickup from changing due to a change in driving load. .

[0007]

In order to solve the above problems, the present invention detects the moving time by moving the optical pickup by a preset distance in addition to the structure of the traverse mechanism of the conventional optical pickup. A moving time detecting means, a moving time judging means for comparing the moving time and a reference moving time to output a judgment signal, and a pulse rate of a pulse signal generated by the pulse generating means in correspondence with the judging signal. And a pulse rate setting means for changing the pulse rate.

[0008]

According to the above means, the pulse rate is changed in accordance with the actual moving time of the optical pickup to move a certain distance, and the driving torque generated by the stepping motor is set, so that the temperature change and the lapse of time can be prevented. Even if the drive load of the drive unit changes due to deterioration, an appropriate drive torque is supplied, and stable operation performance can always be ensured.

[0009]

1 is a block diagram showing an optical disk drive device having a traverse mechanism according to the present invention. Members corresponding to the members described with reference to FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

Reference numeral 11 is an outermost peripheral position detecting switch, 12 is an innermost peripheral position detecting switch, 13 is a timer, 14 is a moving time determining means, and 15 is a pulse rate setting means.

Next, the operation of the traverse mechanism of this embodiment in the optical disk drive will be described. Similar to the conventional traverse mechanism, the traverse drive driver 9 receives the drive command signal to generate the pulse generating means 9a.
Generates a pulse signal. The drive circuit 9b determines the excitation order of each phase of the stepping motor 2 in accordance with the pulse signal, and controls the power supplied to the stepping motor 2. As a result, the stepping motor 2
Drive to generate rotational thrust. The rotational thrust of the stepping motor 2 is transmitted to the gear portion of the feed screw nut 5 by the lead screw 3. The feed screw nut 5 converts the rotational thrust of the lead screw 3 into a linear motion thrust of the lead screw 3 and moves the optical pickup 1 in the radial direction of the disc A along the guide shaft 6.

FIG. 2 is a flow chart for explaining a pulse rate setting method in the traverse mechanism of this embodiment. As described above, when the stepping motor 2 is driven at the same pulse rate, the driving torque generated by the stepping motor 2 becomes constant. Therefore, if the driving load increases due to temperature change or deterioration of the mechanical unit, the stepping during driving is increased. A phenomenon occurs in which the motor 2 is out of synchronization, the optical pickup 1 does not move, or the moving time of the optical pickup 1 to a target position increases. Therefore, in the traverse mechanism of this embodiment,
The pulse rate is set according to the flow of FIG. 2 during non-recording and reproduction, and the stepping motor 2 is driven during recording and reproduction based on the set pulse rate.

The traverse drive driver 9 sets the pulse rate in the pulse generating means 9a to an initial value (step S1), and applies a peripheral drive signal corresponding to the pulse rate of the initial value to the stepping motor 2 by the drive circuit 9b. (Step S2), the optical pickup 1 is moved in the outer peripheral direction. If the outermost circumference position detection switch 11 detects that the optical pickup 1 has reached the outermost circumference position (YES in step S3), the movement time determination means 14 starts the timer 13 (step S4), and at the same time. The traverse drive driver 9 applies an inner peripheral direction drive signal corresponding to the pulse rate of the initial value to the stepping motor 2 by the drive circuit 9b (step S5) to move the optical pickup 1 in the inner peripheral direction.

If the innermost circumference position detection switch 12 detects that the optical pickup 1 has reached the innermost circumference position (YES in step S6), the moving time determination means 14 causes the timer 13 to operate. Stop (step S7),
The moving time when the optical pickup 1 moves from the outermost peripheral position to the innermost peripheral position is read from the timer 13 which constitutes the moving time detecting means together with the position detecting switches 11 and 12. The movement time determination means 14 compares the actual movement time of the optical pickup 1 read from the timer 13 with a reference movement time of the optical pickup 1 when the preset operation of the device is normal (step S8). ), If the movement time is longer than the reference movement time (No in step S8), "0" is output as a determination signal, and if the movement time is less than or equal to the reference movement time (Yes in step S8), "1" is output. Is output.

The moving time determining means 14 determines whether the optical pickup 1 has not reached the outermost position and the outermost position detection switch 11 has not detected the optical pickup 1 (NO in step S3), or the optical pickup. Even when 1 does not reach the innermost circumference position and the innermost circumference position detection switch 12 does not detect the optical pickup 1 (NO in step S6), "0" is output as a determination signal.

When the judgment signal output from the moving time judging means 14 is "0", the pulse rate setting means 15 lowers the pulse rate by a constant value (step S9). And
The processing for setting the pulse rate returns to step S2, and the processing from step S2 to step S9 is repeated until the output of the determination signal from the movement time determination means 14 is inverted to "1", and the movement time determination means When the output of the determination signal of 14 becomes "1", the pulse rate setting process is ended.

As described above, according to the traverse mechanism of the present embodiment, even when the driving load is changed due to the influence of the change of the temperature environment and the deterioration of the parts constituting the mechanism portion with time,
By changing the pulse rate for controlling the driving of the stepping motor 2 and setting the driving torque, the fluctuation of the driving load can be absorbed and the performance of moving the optical pickup 1 can always be kept constant.

[0018]

As described above, according to the traverse mechanism of the optical pickup described in the claims of the present invention, the driving load is affected by the influence of the temperature change and the deterioration of the parts constituting the mechanism portion over time. Even if it fluctuates, the fluctuation of the driving load can be absorbed, and the performance of moving the optical pickup can always be kept constant.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an optical disk drive device having a traverse mechanism of the present invention.

FIG. 2 is a flowchart illustrating a method of setting a pulse rate in the traverse mechanism of this embodiment.

FIG. 3 is a configuration diagram showing a disk drive device including a conventional traverse mechanism.

[Explanation of symbols]

1 ... Optical pickup, 2 ... Stepping motor,
3 ... Lead screw, 4 ... Bearing, 5 ... Feed screw nut, 6 ... Guide shaft, 7 ... Guide shaft retainer, 8 ... Housing, 9 ... Traverse drive driver,
9a ... Pulse generating means, 9b ... Drive circuit, 11 ... Outermost position detection switch, 12 ... Innermost position detection switch,
13 ... Timer, 14 ... Movement time judging means, 15 ... Pulse rate setting means, A ... Disc.

Claims (1)

[Claims] 1. A mechanism portion for moving a stepping motor and an optical pickup for recording or reproducing information on a recording medium by a driving force of the stepping motor, and a pulse signal for controlling driving of the stepping motor. Pulse generating means for generating, a drive circuit for receiving the pulse signal and outputting a drive signal for driving a stepping motor, a moving time detecting means for moving the optical pickup by a preset distance, and detecting a moving time, Moving time judging means for comparing the moving time and the reference moving time to output a judgment signal, and pulse rate setting means for changing the pulse rate of the pulse signal generated by the pulse generating means in correspondence with the judging signal. A traverse mechanism for an optical pickup, which is provided with.