JPH06203499A - Optical disk device - Google Patents

Abstract

PURPOSE:To reduce the load of a CPU by simplifying the control preventing that an optical head is moved to a further outer periphery or a further inner periphery from an outermost periphery or an innermost periphery, in an optical disk device using an optical disk having a spiral-shaped track. CONSTITUTION:The output of a frequency divider circuit 3 generating an index pulse once per one revolution of a spindle motor 1 is counted, and the count value is compared with the value of a latch circuit 6 set by the CPU 5 by a comparator circuit 7. Thus, the fact that the optical head is placed on the outermost periphery or the innermost periphery of the disk is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device,
Especially for monitoring the track on the disc where the optical head is located

2. Description of the Related Art Tracks of an optical disk device are formed in a spiral shape unlike magnetic disks. Therefore, the optical head moves along the track toward the outer circumference or the inner circumference to reach the end of the track. Therefore, in the conventional optical disk device, the CPU of the device
Had to constantly read and monitor the ID on the medium.

[0002]

In the above-mentioned conventional optical disk device, the CPU of the device always has the ID of the track of the medium.
Must be monitored. However, when the ID is being read, the access from the host device cannot be received, so that the access time with the host device is apparently delayed.

[0003]

An optical disk apparatus according to the present invention divides a spindle motor that rotates a disk and an encoder pulse that is output with the rotation of the spindle motor into one pulse for one rotation. Circuit,
A counter for counting the number of pulses per cycle of the frequency dividing circuit, a CPU for controlling the device, a latch circuit for setting an arbitrary value from the CPU, and an output of the counter and an output of the latch circuit are compared. , A comparison circuit for notifying the CPU of the comparison result.

[0004]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

The spindle motor 1 outputs an encoder pulse A while rotating the optical disc 2. The frequency dividing circuit 3 frequency-divides the encoder pulse A and outputs an index pulse B which is output once per one rotation of the disk 2.
The counter 4 counts the index pulse B and outputs the count value. The CPU 5 sets an initial value or an updated value in the counter 4 and an arbitrary value in the latch circuit 6. The latch circuit 6 is set by the CPU 5 to an arbitrary value. The comparison circuit 7 compares the value held by the latch circuit 6 with the count value of the counter 4, and notifies the CPU 5 when the count value matches the value of the latch circuit 6.

Next, the operation will be described. CPU5
The maximum track value is set in the latch circuit 6 in advance. When the seek operation is completed, the CPU 5 sets the value of the track at that time in the counter 4. After that, when the spindle motor 1 makes one rotation, that is, one track of the disk 2, the frequency dividing circuit 3 outputs the index pulse B and the counter 4 counts up by one. That is, the counter 4 is incremented each time one track of the disc 2 is advanced. When the maximum track is reached, the comparison circuit 7 detects that the counter 4 and the latch circuit 6 match each other, and notifies the CPU 5 of this. The CPU 5 seeks to the smaller track and updates the value of the counter 4 again after the seek is completed.

As described above, the CPU 5 only seeks when the maximum track is reached, and at other times, it becomes free and can always access the host device.

[0009]

As described above, the present invention has the counter for counting the rotation of the spindle motor, so that the CPU of the apparatus does not have to constantly monitor the ID of the CPU.
Has reached the maximum track, the upper device can always access the optical disc device, and has an effect that the access time becomes shorter than that of the conventional device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 Spindle motor 2 DISK 3 Dividing circuit 4 Counter 5 CPU 6 Latch circuit 7 Comparison circuit A Encoder pulse B Index pulse

Claims (1)

[Claims] 1. A spindle motor for rotating a disk, a frequency dividing circuit for frequency-dividing an encoder pulse output in accordance with the rotation of the spindle motor, and frequency-dividing the pulse once per one cycle, and the frequency dividing circuit. Counter that counts the pulse once per revolution of the CPU and CPU that controls the device
And a latch circuit that can set an arbitrary value from the CPU, and a comparator circuit that compares the output of the counter and the output of the latch circuit and notifies the CPU of the comparison result of the value of the counter and the value of the latch circuit. An optical disk device comprising: