JPH0785584A - Disk motor controller - Google Patents

Abstract

PURPOSE:To rotate a disk at high speed in a range allowable by a memory so as to attain the high speed of a system. CONSTITUTION:A stored amt. of the memory 9 is monitored by a monitor circuit 11, and the disk 1 is rotated at high speed until the stored amt. becomes a prescribed value. When the stored amt. of the memory 9 reaches the prescribed value, the disk 1 is rotated at low speed in accordance with an output of the monitor circuit 11 to prevent the memory 9 from overflowing. Consequently, the burden on a pickup is lightened, and the current consumption is reduced.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a CD-DA and a CD-R.
The present invention relates to a disc motor drive device of a disc player for reproducing a CD type disc such as OM, and more particularly to a disc motor control device for variably controlling the rotation speed of a disc motor.

[0002]

2. Description of the Related Art CD-DA disc for audio only and CD-used as read-only memory for digital information
A disc based on the CD system such as a ROM disc is known. Since data is recorded on the disc at CLV (constant linear velocity), when the disc player is used for reproduction, the disc motor is controlled so that the disc rotates at CLV to pick up the data. It is carried out.

[0003]

By the way, especially CD-
The data transfer rate is important in ROM disks. In order to increase the data transfer rate, it is sufficient to rotate the disk motor at a speed higher than the rated speed and increase the amount of data read from the disk. However, if the rotation speed of the disk motor is increased blindly, various problems will occur. For example, the data read from a disc is
It is temporarily stored in memory, but if that amount overflows, the pickup will be in a paused state. This pose state puts a heavy burden on the pickup. Further, an excessive increase in the number of rotations causes an increase in current consumption, which is not preferable.

[0004]

The present invention has been made in view of the above points, and a servo circuit for CAV controlling a disk motor, and a demodulation circuit for demodulating data recorded on the disk, A memory for storing data demodulated by the demodulation circuit and a storage amount of the memory are monitored, a first control signal is generated while the storage amount of the memory is small, and the storage amount is a predetermined value. And a rotation control means for rotating the disk motor at a high speed in response to the first control signal and for rotating the disk motor at a low speed in response to the second control signal. Is characterized by.

[0005]

According to the present invention, the storage amount is monitored by the monitoring means. While the memory reserve is low, the monitoring means generates the first control signal to rotate the disk motor at a high speed. Therefore, the data transfer rate becomes high. When the stockpiling amount reaches a predetermined value, a second output signal is generated from the monitoring means, and the rotation speed of the disk motor is switched to a low speed accordingly. Therefore, the memory overflow can be delayed, and the load on the pickup and the current consumption can be reduced.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit block diagram of a CD system compatible disc player showing an embodiment of the present invention. In the figure, 1 is a CD-ROM disk, 2 is a disk motor for rotating the disk 1, 3 is a motor servo circuit for controlling the rotation of the disk motor 2, and 4 is a disk 1 traced by a light beam. A pickup for reading the signal from the RF amplifier 5 is an RF amplifier for amplifying the RF signal (high frequency signal) read by the pickup 4 to shape the waveform, and 6 is an RF obtained from the RF amplifier 5.
The pickup 4 is driven according to a signal to perform focusing control for focusing the light beam on the signal surface of the disc 1 and tracking control for causing the light beam to follow the signal track of the disc 1, and the pickup 4 is moved to the disc 1 It is a pickup servo circuit that controls the feed in the radial direction. Reference numeral 7 is an E of the disk 1 whose waveform is shaped by the RF amplifier 5 and output as a digital signal.
A synchronization detection / EFM demodulation circuit that detects a frame synchronization signal indicating the beginning of a frame from the FM-modulated recording signal and performs EFM demodulation, and 8 is configured by a PLL circuit. A clock regenerating circuit for regenerating a bit clock synchronized with the bits included in the memory 9; a memory 9 for storing the output signal of the demodulating circuit 7;
Reference numeral 1 is a monitoring circuit for monitoring the write address of the memory 9, and 12 is switched according to the first or second control signal generated from the monitoring circuit 11, and the motor servo circuit 3
It is a switching circuit that supplies a reference voltage for rotation to.

Next, the operation of the circuit shown in FIG. 1 will be described. When a start switch (not shown) is turned on, the disc motor 2 is driven and the disc 1 starts rotating. The disk motor 2 is CAV by the motor servo circuit 3.
Since it is controlled (constant angular velocity), in a stable state,
The disk 1 is in a constant rotation state. The pickup 4 is
Trace the disk by projecting a light beam,
The signal recorded on the disc 1 is picked up.

The RF signal (high frequency signal) read by the pickup 4 is supplied to the RF amplifier 5. The RF signal is amplified by the RF amplifier 5, waveform-shaped, and supplied to the demodulation circuit 7 as an EFM digital signal. The demodulation circuit 7 performs EFM demodulation on the input digital signal, and thereafter performs various data extraction and decoding processes, as well as main data (CD-DA data and C-data).
D-ROM data) error detection and error correction processing is performed, and missing main data is interpolated. Further, the demodulation circuit 7 separates the sub-code signal, and the Q in it is separated.
Perform code demodulation. The demodulated Q code is supplied to the system control circuit (not shown) in the subsequent stage, and the system control circuit operates according to the Q code. When an output signal is generated from the RF amplifier 5, the clock recovery circuit 8
Is to reproduce a bit clock serving as an operation clock of the demodulation circuit 7 from the output signal, and the demodulation circuit 7 demodulates the EFM signal using the bit clock reproduced by the clock reproduction circuit.

The memory 9 serves to temporarily store the signal demodulated by the demodulation circuit 7. The writing of data to the memory 9 is performed by the addressing circuit 10 designating the address of the memory 9. The addressing circuit 10 sequentially specifies addresses FF to FF of the memory 9 in accordance with the reproduction clock obtained from the clock reproduction circuit 8 and writes data. Further, the addressing circuit 10 sequentially designates the address of the memory 9 according to a read command from a main system (not shown), and sequentially reads out the data stored in the memory 9 according to the reproduction clock. The monitoring circuit 11 monitors the designated address of the written character. While the designated address is small, the monitoring circuit 11 continues to generate the first control signal. When writing to the memory 9 progresses and a predetermined address is designated, the monitoring circuit 11 detects it and the output changes from the first control signal to the second control signal. For example, it may be set so that the output of the monitoring circuit 11 changes when the writing to 1/3 of the memory 9 is completed.

If the output of the monitoring circuit 11 is the first control signal, the switching circuit 12 generates the first output, and the motor servo circuit 3 controls the disk motor 2 to rotate at high speed. The storage amount in the memory 9 increases, and the monitoring circuit 11
When the output of the control signal becomes the second control signal, the switching circuit 12 also generates the second output, and the motor servo circuit 3 controls the disk motor 2 to rotate at a low speed.

When the addressing circuit 10 is brought into the read state by the read command, a reset signal is generated from the addressing circuit 10 and the output of the monitoring circuit 11 returns to the first control signal, so that the disk motor 2 is driven at high speed again. It becomes a rotation. When the rotation speed of the disk 1 is set to 4 times the normal speed in order to increase the data transfer rate, the writing of data to the memory 9 becomes faster and the memory 9 overflows, causing various problems as described above. But,
As in the present invention, by monitoring the storage amount of the memory 9 and rotating the disk 1 accordingly, it is possible to increase the data transfer rate when necessary and prevent the memory 9 from overflowing. Also, no read command is generated,
Even if the memory 9 overflows, the rotation speed of the disk motor 2 is reduced, so that the current consumption can be reduced. Furthermore, when the memory 9 is read frequently, the disk motor can always be rotated at high speed, and high-speed processing of the entire system can be achieved.

[0012]

As described above, according to the present invention, the disk motor is driven by CAV control, and the rotation speed of the disk motor is switched by monitoring the amount of storage in the memory. It is possible to achieve both of prevention of memory overflow, reduction of load on the pickup, and reduction of current consumption.

[Brief description of drawings]

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

[Explanation of symbols]

 2 disk motor 3 motor servo circuit 4 pickup 7 demodulation circuit 8 clock reproduction circuit 9 memory 10 addressing circuit 11 monitoring circuit 12 switching circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Ikeda 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Shinichiro Tomizawa 2-18, Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Within the corporation

Claims (2)

[Claims] 1. A disc motor control device for a disc player for reproducing a disc, comprising a servo circuit for CAV controlling the disc motor, a demodulation circuit for demodulating data recorded on the disc, and the demodulation circuit. And a memory for storing the data demodulated in step S1, and monitor the stockpiling amount of the memory, generate a first control signal while the stockpiling amount of the memory is small, and the stockpiling amount becomes a predetermined value or more. And a rotation control means for rotating the disk motor at high speed in response to the first control signal and for rotating at low speed in response to the second control signal. Disc motor control device. 2. The disk according to claim 1, wherein the monitoring means includes a detection circuit for detecting a write address of the memory, and generates a second control signal when the detection circuit detects a predetermined address. Motor control device.