JPH07176173A - Track accessing device in optical disk player - Google Patents

Abstract

PURPOSE:To reduce a truck moving error by providing an arithmetic part increasing or decreasing the residual number of track counts by one track in accordance with the moving direction of an actuator at the point of the time of one peripheral revolution according to the revolution of a spindle motor. CONSTITUTION:Both circuits 11, 12 constitute a correction value supplying circuit and are constituted as to perform correction with respect to a counter. Then, the counter 6 receives the correction value and increases or decreases the present number of counted tracks by '1' in accordance with the rotational direction of the spiral direction of a disk 1 and an access direction with the correction value. For example, when the actuator is moving to outer peripherals in a state tracking to the disk and the actuator is made to access to an inner peripheral direction, the present number of counted tracks is added by '1'. Thus, the track moving error is reduced by performing the correction of the counted value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track access device for an optical disc player.

[0002]

2. Description of the Related Art A conventional access device of this type has the structure shown in FIG. 2, in which 1 is a disk having spirally formed tracks, 2 is a motor for rotating the disk 1, 3 is an actuator capable of detecting information from a track on the disk 1, 4 is a track pulse generation circuit which outputs a pulse every time the actuator 3 crosses one track, and 5 is a drive circuit for accessing the actuator 3. , 6 are counters that store the number of remaining count tracks that must be moved with respect to the target track.

Reference numeral 7 is a table memory in which the relationship between the number of tracks accessed by the actuator and the track movement error in the rotation of the disk obtained from the time required for the access is stored in advance. 8 is the current track position of the actuator. To the target track position, the input unit for instructing the number of count tracks to be accessed and the direction of the access, 9 should actually access the numerical value (count track number) given from the input unit 8 by referring to the table memory 7. An arithmetic unit 10 for giving the number of count tracks, an actuator 10 for the drive circuit 5 according to the number of count tracks from the arithmetic unit 9, the access direction given by the input unit 8 and the state of the actuator 3 from the drive circuit 5, and the count number of the counter 6. To drive 3 A control unit for performing instructions.

The operation of the track access device configured as described above will be described below. First, when the number of tracks to be accessed and the direction of access are given in the input unit 8, it is necessary to calculate the count error corresponding to the number of tracks by the arithmetic unit 9 by referring to the function of the table memory 7 and actually count. A certain number of tracks is required.

While the access is being executed, the track pulse generating circuit 4 generates a track pulse according to the tracking error signal from the actuator 3. The counter 6 counts it and obtains the number of crossed tracks at the present time.

In the control unit 10, the number of actually counted tracks obtained by the calculation unit 9 and the direction of access,
A signal is output from the counter 6 to the drive circuit 5 according to the current count track number, and the actuator 3 is actually driven to access the target track position.

[0007]

However, in the above-mentioned conventional example, since the function given by the table memory 7 is given with a constant access time, when the access time is not so accurate in practice, The target track location cannot be reached and track error in rotation occurs.

[0008]

The present invention has been invented in view of the above-mentioned drawbacks of the prior art, and optically reads the information on the track from a disk having spirally formed tracks. A track pulse generation circuit that outputs a pulse each time the actuator crosses a track in the one that moves the actuator in the radial direction while counting the number of tracks to access a predetermined track position, and the actuator when an access command is received. Target track position setting means for setting the number of count tracks from the current track position to the target track position, and the pulse from the track pulse generating circuit preset by the count track number set by the target track position setting means. Each time you receive A counter for count down, the disk is to provide a track access device in an optical disc player, characterized in that a correction value supplying means for providing a correction value to the counter at a timing of one rotation.

The present invention also provides a track access device in an optical disk player, wherein the correction value supply means is composed of a circuit for outputting a pulse each time one rotation of a spindle motor for rotating the disk is detected. .

Further, the present invention provides a track access device in an optical disk player, wherein the correction value supply means is composed of a timer circuit which gives a correction value at the timing of one rotation of the disk.

[0011]

Therefore, according to the present invention, when the target track position is accessed, the count track number of the counter is corrected by the correction value every time the disk makes one revolution, and the target track position can be accurately detected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block-like electric circuit diagram showing an embodiment of the present invention. For convenience of explanation, the same parts as those in the conventional art will be designated by the same reference numerals.

Reference numeral 1 is a disk having spirally formed tracks, 2 is a motor for rotating the disk 1, 3 is an actuator capable of detecting information of a track on the disk, and 4 is tracking from the actuator 3. It is a track pulse generation circuit that outputs a pulse when it crosses one track according to an error signal.

Reference numeral 5 is a drive circuit for accessing the actuator 3, 6 is a counter for storing the number of remaining count tracks that must be moved with respect to a target track position, and 8 is an access to a key input device (not shown). An input unit for instructing the number of count tracks to be counted from the current track position of the actuator 3 to the target track position and the access direction,
Is a rotation pulse generating circuit that outputs a pulse each time the disk 2 is detected by the motor 2 to rotate once, 10 is the count track number from the input section 8 and the access direction, and the state of the actuator 3 from the drive circuit 5, and A control unit for instructing the drive circuit 5 to drive the actuator 3 according to the count number of the counter 6, 12
Is a timer circuit and is configured to generate pulses at a time interval required for one rotation of the disk 1. This pulse generating operation continuously generates pulses regardless of the rotating operation of the disk 1.

The counter 6 is preset with the number of count tracks set by the input section 8, and each time the pulse from the track pulse generating circuit 4 is received, the counter 6 counts down the preset count tracks. Rotation pulse generation circuit 11 or timer circuit 1
Each time the pulse from 2 is received, the count number is set to “1” according to the spiral direction, rotation direction and access direction of the disk 1.
Only increase or decrease.

That is, the circuits 11 and 12 together constitute a correction value supply circuit, and are configured to supply the pulse as a correction value to the counter 6. And
The counter 6 receives the correction value, and increases or decreases the correction value by "1" from the current count track number according to the rotation direction of the spiral direction of the disk 1 and the access direction. For example, when the actuator moves to the outer circumference while the disk is being tracked and the inner circumference is accessed, only "1" is added.

The track access device according to the present invention is constructed as described above, and its operation will be described below. First, according to the key input from the key input device, the input section 8 instructs the number of count tracks and the access direction. In accordance with this, the control unit 1 is attached to the counter 6.
The count track number is preset by the control of 0.

At a timing at which the count track number is preset in the counter 6, the actuator 3 starts moving on the rotating disk 1 from the current track position toward the target track position. In accordance with the movement of the actuator 3, the track pulse generation circuit 4 detects the tracking error signal from the actuator 3 and outputs one pulse each time the beam spot crosses the track, and supplies it to the counter 6.

Each time the counter 6 receives this pulse, the counter 6 counts down the number of count tracks and receives a correction value from the rotation pulse generation circuit 11 or the timer circuit 12 for each rotation of the disk 1 to correct the count value. . The control unit 9 moves the actuator 3 to the target track position through the drive circuit 5 according to the count value of the counter 6.

[0020]

According to the present invention, in a device for accessing a spiral track on a rotating disk while driving an actuator in the radial direction to count the number of tracks, the spiral track on the rotating disk is changed according to the rotation of a spindle motor (disk).
By providing a calculation unit that increases or decreases the remaining track count number by one track in accordance with the moving direction of the actuator after one rotation, it is possible to reduce the track movement error in the rotation of the disk during access.

[Brief description of drawings]

FIG. 1 is a block-like electric circuit diagram showing an embodiment of a track access device in an optical disc player according to the present invention.

FIG. 2 is a block-like electric circuit diagram showing a conventional track access device.

[Explanation of symbols]

 1 disk 2 spindle motor 3 actuator 4 track pulse generation circuit 5 drive circuit 6 counter 7 table memory 8 input unit 9 arithmetic unit 10 control unit 11 rotation pulse generation circuit 12 timer circuit

Claims (3)

[Claims] 1. A disc having spirally formed tracks, wherein an actuator for optically reading information on the tracks is moved in the radial direction while counting the number of tracks to access a predetermined track position. A track pulse generating circuit for outputting a pulse each time the actuator crosses a track, and a target track position setting means for setting a count track number from the current track position of the actuator to a target track position when an access command is received. The counter is preset with the count track number set by the target track position setting means, counts down the count track number each time a pulse from the track pulse generating circuit is received, and the counter is rotated at one rotation of the disk. Mosquito Track access device in an optical disc player, characterized in that a correction value supplying means for providing a correction value to the pointer. 2. The correction value supply means comprises a circuit for outputting a pulse each time one rotation of a spindle motor for rotating the disk is detected.
A track access device for an optical disc player described in 1. 3. The track access device in an optical disk player according to claim 1, wherein the correction value supplying means is constituted by a timer circuit which gives a correction value at the timing of one rotation of the disk.