JP2000173166A - Disk rotation controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally stop a disk with an inexpensive motor having no Hall element, etc., with less fluctuation in detective precision, without depending on hardware and without complicated control for speed detection in a disk rotation controller rotating the disk by servo drive of a constant linear velocity. SOLUTION: A brake amount is obtained considering a rotational speed difference between the inner periphery and the outer periphery of the disk from the beforehand obtained brake amount Bin for stopping the rotation when a servo is applied in the innermost periphery of the disk, the brake amount Bout for stopping the rotation when the servo is applied in the outermost periphery and a present position X where the servo is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk rotation control device for a disk player which reads out a signal recorded on an optical disk such as a CD-ROM as an information recording medium and reproduces information, and more particularly to a rotating disk. This is related to stop control.

[0002]

2. Description of the Related Art Conventionally, in this type of CD player, when information is recorded on or read from an optical disk,
Constant velocity linear velocity (CLV; Constant Liner Velocit)
Many perform y) servo drive. To stop the rotation of a disk driven at a constant linear velocity in this way, a brake pulse is given to the rotary drive system in response to a stop operation command. , The number of rotations of the disk differs according to the diameter of the reproduction position of the disk, and the braking time for stopping the rotation of the disk differs. For this reason, a motor for driving the disk is provided with a hall element or the like for speed detection, and the brake is stopped until the FG signal output from the hall element reaches a certain fixed width that can be regarded as a motor stop.

Further, there is a disk player in which a rated speed is detected by speed detecting means during the stop operation of the disk, and a deceleration signal is generated starting from the detection of the rated speed (for example, see Japanese Patent Application Laid-Open No. 5-234243). ). In addition, the time from when the stop operation starts to when it is detected that the rotation of the disk has fallen below the predetermined linear velocity is measured, and the time for applying the brake pulse is controlled in accordance with the measured time. There is a control device (for example,
Japanese Patent No. 2645886, JP-A-64-69278
Reference).

However, when a motor having a hall element or the like is used as described above, the motor, which is hardware, becomes expensive, and a disk player as disclosed in Japanese Patent Laid-Open No. Hei 5-234243 requires a speed detection. Control becomes complicated, and Patent No. 26458
No. 86 discloses a disk rotation control device,
There are many unstable elements, and there is a problem that a stop error increases due to a variation in detection accuracy.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is directed to a method of rotating a disk by a servo drive at a constant linear velocity.
It is possible to stop the disk normally without relying on hardware, that is, using an inexpensive motor without a hall element, etc., without the need for complicated control for speed detection, and with little variation in detection accuracy. It is an object to provide a possible disk rotation control device.

[0006]

In order to achieve the above object, the present invention is directed to a rotating means for rotating a disk as an information recording medium, and a reading means for reading at least information from the disk. And a control means for servo-controlling the rotating means so that the disk rotates at a constant linear speed with respect to the reading means. A brake amount adjusting means for adjusting a brake amount applied to the rotating means, wherein the brake amount adjusting means stops the rotation when a servo is applied on the innermost circumference of the disk determined in advance. From the amount of braking to perform, the amount of braking to stop rotation when servo is applied at the outermost circumference, and the current position where the servo is applied. And requests the over air amount.

According to the first aspect of the present invention, the brake amount required at the innermost circumference of the disk and the brake amount required at the outermost circumference of the disk are determined in advance, and the current brake position and the current position where the servo is applied are determined. The brake amount can be determined from the above, the brake amount can be adjusted in consideration of the rotational speed difference between the inner circumference and the outer circumference of the disk, and the disk can be stopped normally.

According to a second aspect of the present invention, in the disk rotation control device according to the first aspect, the brake amount adjusting means stops rotation when a servo is applied to an innermost circumference of the disk determined in advance. Brake amount to perform
in, the brake amount for stopping rotation when servo is applied at the outermost periphery is Bout, the radius at the current position where the servo is applied is X, the innermost radius is Rin, and the outermost radius is Rout. , The brake amount for stopping the rotation at the current position is represented by ｛(Bout−Bin) / (Rou
t-Rin)｝ × (X-Rin) + Bin or ｛(B
in-Bout) / (Rout-Rin)｝ × (Rou
This is set to a predetermined application time of the reverse rotation drive voltage, which is obtained by the formula of (t−X) + Bout. By calculating the brake amount in this manner, the brake can be easily and accurately applied.

According to a third aspect of the present invention, in the device according to the first or second aspect, the current position is obtained from time information recorded on a disk read by the reading means. Thereby, the current position can be easily known.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a disk drive system including a CD-ROM disk rotation control device. The disk drive device is a CD-
C for reading (reproducing) data from the ROM disk 1
The D-ROM drive 2 has a core configuration, and the CD-RO
The M drive 2 is connected to a host computer or a personal computer 5 (hereinafter, referred to as a personal computer) that controls the entire system through an interface 3 and executes predetermined arithmetic processing. On the personal computer 5,
A display 6 such as a liquid crystal and a hard disk 7 storing various data are connected.

The CD-ROM drive 2 has a CPU 10 for transferring data and reading data from the CD-ROM in accordance with instructions from the personal computer 5. Also, CD-
The ROM drive 2 includes a motor 11 (rotating means) for rotating the table of the CD-ROM disk 1 and a motor driving circuit 12 (control means) for servo-controlling the motor 1.
An optical head 13 (reading means) including an optical pickup; a processing unit 14 for processing a reproduction signal from the optical head 13; a processing unit 15 for processing a recording signal for the optical head 13; and controlling the optical head 13. A focus servo circuit and a tracking servo circuit 16 are included. Also,
The CPU 10 is connected to a RAM 17 for storing various information, a ROM 18 for storing programs, and the like.

The CD-ROM drive 2 is controlled by a command input to the personal computer 5 from an operation unit (not shown) and a program corresponding to the command, and performs a reproducing operation. Also, C
The PU 10 is arranged such that the CD-ROM disk 1 has a constant linear velocity (CLV) with respect to the optical head 13.
The servo control of the motor 1 is performed via the motor drive circuit 12 so that the motor 1 rotates. Further, when a stop signal is output from the personal computer 5, when the CD-ROM disk 1 is changed from the state of being driven to the state of rotation to the state of being stopped, the brake amount applied to the motor 1 is adjusted (brake amount adjusting means). .
Here, since the linear velocity constant control is performed, the CD-
There is a disc rotation speed difference between the inner and outer peripheral sides of the ROM disk 1, and it is necessary to adjust the brake amount. The brake amount is determined in advance when the servo is applied on the innermost circumference of the CD-ROM disk 1, the brake amount when the servo is applied on the outermost circumference, and the current time when the servo is applied. Determined from the position (details will be described later)

FIG. 2 shows a CD-ROM disc 1.
A lead-in area is provided on the inner circumference side, and TOC (Table of Contents) information including a track number, a track start time, etc. is recorded as session information, and an applicable recording speed (standard double speed, 2 ×
Double speed, quadruple speed, etc.) and the optimum laser power are encoded as ATIP information. Further, the intermediate area has a program area (also called a user data area), a plurality of tracks are formed, various data are recorded in session units, and a sub-Q code in the sub-Q code records current position information. I have. There is a lead-out area indicating the end of the session on the outer peripheral side. CD-ROM
The innermost radius of the disk 1 is Rin, and the outermost radius is Rou.
Let t be the radius at the current position where the servo is applied.

FIG. 3 is a diagram for explaining a method of calculating a brake amount when the CD-ROM disc 1 is stopped from being driven to rotate at a constant linear velocity. The amount of brake for stopping rotation when servo is applied on the innermost circumference of the disk is Bin, and the amount of brake for stopping rotation when servo is applied on the outermost circumference is B.
Out, the innermost radius is Rin, and the outermost radius is Rout, and these values are stored in the RAM 18. When the radius at the current position where the servo is applied is X, the brake amount for stopping the rotation at the current position is:

１ (Bout−Bin) / (Rout−Ri)
n)｝ × (X-Rin) + Bin or ｛(Bin-
Bout) / (Rout-Rin)｝ × (Rout-
X) + Bout

It is determined by the following equation. This braking amount may be set to a predetermined reverse rotation driving voltage application time. The current position can be obtained by detecting the current position in the CPU 10 from the time information in the subcode Q recorded on the CD-ROM disc 1 read by the optical head 13. By calculating the amount of brake in this way, it is possible to apply the brake easily and accurately from the rotational state of the CD-ROM disk 1 to stop. By applying the brake in this way, it is possible to treat the disk rotation as stopped without actually detecting the stop of the disk rotation.

It should be noted that the present invention is not limited to the configuration of the above embodiment, and various modifications are possible.
-Although the ROM drive 2 has been described, the present invention can be applied to other drive devices, for example, a DVD drive device. The stop signal is also generated by opening the cover of the apparatus or ejecting the disk. In the above description, the brake amount is obtained by the calculation formula. However, the brake amount may be obtained by holding it in a table and referring to it.

[0017]

As described above, according to the disk rotation control device of the present invention, the disk rotation is controlled by the servo drive at a constant linear velocity. Since the braking amount is calculated from the braking amount at the time and the current position where the servo is applied, an inexpensive motor without a hall element etc. is used, without relying on hardware, and complicated for speed detection. Without any control, the brake can be applied in consideration of the difference in rotation speed between the inner circumference and the outer circumference of the disk, and the disk can be stopped normally.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a disk drive system including a disk rotation control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a CD-ROM disc.

FIG. 3 is a diagram for explaining a method of calculating a brake amount for stopping disk rotation in the disk rotation control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CD-ROM disk (disk) 2 CD-ROM drive (disk rotation control device) 5 Personal computer 10 CPU (brake amount adjustment means) 11 Motor (rotation means) 12 Motor drive circuit (control means) 13 Optical head (read means) )

Claims (3)

[Claims] A rotating means for rotating a disk serving as an information recording medium; a reading means for reading at least information from the disk; and a rotating means for rotating the disk at a constant linear speed with respect to the reading means. A disk rotation control device comprising: a control unit that servo-controls the rotation unit; and a brake amount that adjusts a brake amount to be applied to the rotation unit when the disk is changed from a rotationally driven state to a stopped state. The brake amount adjusting means includes a brake amount for stopping rotation when a servo is applied on the innermost circumference of the disk and a rotation stop when the servo is applied on the outermost circumference. A disk rotation control device characterized in that a brake amount is obtained from a brake amount for performing the servo control and a current position where the servo is applied. 2. The brake amount adjusting means sets a brake amount for stopping rotation when a servo is applied on the innermost circumference of the disk, and a rotation amount when the servo is applied on the outermost circumference. When the brake amount for stopping is Bout, the radius at the current position where the servo is applied is X, the innermost radius is Rin, and the outermost radius is Rout, the brake amount for stopping the rotation at the current position. To
{(Bout-Bin) / (Rout-Rin)} ×
(X-Rin) + Bin or ｛(Bin-Bout)
/ (Rout-Rin)｝ × (Rout-X) + Bou
2. The disk rotation control device according to claim 1, wherein the time is set to a predetermined reverse rotation drive voltage application time obtained by the expression of t. 3. The disk rotation control device according to claim 1, wherein the current position is obtained from time information recorded on the disk read by the reading unit.