JPH0798930A - Optical disk device - Google Patents

Abstract

PURPOSE:To immediately stop a disk even when a stoppage instruction is issued before information is read out by supplying a driving voltage in an opposite direction to a spindle motor for a time calculated based on lapse time when the stoppage instruction is issued to the disk. CONSTITUTION:When the disk 1 is loaded on a disk reproducing device 100 and the spindle motor M is rotated, a control part 13 starts to count the lapse time after the disk 1 is started to rotate. When an instruction to stop the rotation of the disk 1 is issued before the rotating speed of the disk arrives at speed readable the information by the information pickup of the disk 1, the control part 13 stops the count of the lapse time. and stores the lapse time Ts up to this time. Furthermore, the controls part 13 calculates the time required for the stoppage of the spindle motor by multiplying the lapse time Ts by a constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device such as a compact disc (hereinafter referred to as a disc). .

[0002]

2. Description of the Related Art When information recorded on a disc is read by scanning a reading beam along a track, the synchronization signal contained in the recording information and a reference synchronization signal are phase-compared with each other so that the phase difference is zero. Rotate the disc as you would. The information recorded on the disc is recorded at a constant linear velocity, and the linear velocity is determined within the range of 1.2 m / s to 1.4 m / s regardless of the inner and outer peripheries of the disc. Further, the recorded information has a radius of 23 mm from the center of the disc.
Since it is recorded in the lead-in area up to 58 mm and the program area, the disk rotation speed is about 500 at the innermost circumference.
rpm, about 200 rpm at the outermost circumference.

The following two types are generally used to quickly bring a disk that rotates in a predetermined direction at a predetermined linear velocity into a stopped state. One is to divide the number of rotations of the disk into several types, preset the application time of the voltage required for stopping, and set the applied time according to the number of rotations of the disk at the time of receiving the disk stop command. Select
During that time, a negative voltage is applied.

The other is to apply a negative voltage to the spindle motor to stop the rotation of the disk when a disk stop command is received while the disk is rotating. After applying a negative voltage to the spindle motor, The elapsed time of is measured, and when it is detected that the rotation of the spindle motor has dropped to a state where the EFM signal has become longer than a certain length based on the channel clock of a certain period, it is based on the negative voltage application time up to this time. Then, the supply time of the additional negative voltage required for the disk to stop normally is calculated, and during this time, the negative voltage is further supplied to the spindle motor.

[0005]

However, in the above-mentioned conventional disk device, if there is a disk stop command from the start of rotation of the disk to the reading of the information recorded on the disk, the former method will cause the spindle motor to rotate. Since the rotation of the disk is not constant from the start of rotation to the reading of the information recorded on the disk, it cannot be handled. Further, the latter method has a problem in that the stop command cannot be dealt with because neither the EFM signal nor the channel clock can be detected until the information recorded on the disc is read out.

The present invention has been made in view of the above conventional problems, and promptly even if there is a disc stop command from the start of rotation of the disc to the reading of information recorded on the disc. The purpose is to make the disk stop.

[0007]

In order to solve the above-mentioned problems, the present invention relates to an optical disk device for reading information by rotating a disk in a predetermined direction at a predetermined linear velocity by a spindle motor, from the start of rotation of the disk. When there is a disc stop command from the start of rotation of the disc until the information recorded on the disc is read out, the spindle motor is driven to the predetermined direction based on the elapsed time. And a control means for supplying a drive voltage in the reverse direction to the spindle motor during the calculated time.

[0008]

According to the present invention, when there is a disk stop command until the time elapsed from the start of rotation of the disk is read and the information recorded on the disk is read, the spindle is read based on the time counted. The time for applying the drive voltage in the direction opposite to the predetermined direction to the motor is calculated, and the drive voltage in the reverse direction is applied to the spindle motor during the calculated time to stop the disk. Therefore, even if there is a disc stop command from the start of rotation of the disc until the information recorded on the disc is read, the disc can be stopped promptly.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. The control unit 13 controls each unit via the sub-control unit 131 according to an operation from the key operation unit 14. The sub-control unit 131 operates each servo circuit according to the command code generated by the control unit 13, and when the process for the command code is completed, a process completion code is generated. The control unit 13 detects the processing completion code to obtain the timing for outputting the next command code.

Reference numeral 1 denotes a disc on which information to be reproduced and index information necessary for reproduction thereof are recorded as a digital signal containing a synchronizing signal. The disc 1 is loaded and ejected at a reproducing position (on a turntable (not shown)) by a loading mechanism (not shown) according to an operation of a key operation unit. The motor M drives the loaded disk 1 at a predetermined rotation speed. The reproduced information and the index information recorded on the recording tracks of the disc 1 are optically read by the pickup 2. The signal read by the pickup 2 is sent to the signal conversion circuit 12 via the preamplifier 3 and is also input to the tracking servo circuit 9 and the disc signal level detection unit 11.

The tracking error detector 4 detects from the output signal of the pickup 2 that the focus position of the reading beam emitted from the pickup 2 is displaced inward or outward from the track on the information recording surface of the disk 1, and the tracking error detector 4 detects the focal point. The corresponding positive and negative analog signals are output to the tracking servo circuit 5. The tracking servo circuit 5 is controlled to operate or not operate by the output signal from the sub-control unit 131, and in the operating state, the reading beam follows the track on the disk 1 in response to the signal from the tracking error detection unit 4. A tracking actuator (not shown) is driven. Also, a large movement that cannot be followed by the tracking actuator is detected by the pickup feed servo circuit 1 according to the signal from the tracking error detection unit 4.
5 operates to move the pickup 2 to a predetermined position by a motor by a pickup transfer mechanism (not shown).

The focus error detection unit 6 detects from the output signal of the pickup 2 whether the focus position of the reading beam is above or below the information recording surface of the disc 1, and a positive and negative analog signal corresponding to each of them. Is output to the zero-cross detection unit 10 and the terminal X of the switch SW3.
If the focus position of the reading beam is on the recording surface of the disc, the output signal of the focus error detector 6 is zero. If the output signal of the focus error detection unit 6 is 0, the zero-cross detection unit 10 outputs an “H” signal to the sub control unit 131. From the output of the zero-cross detector 10, the sub controller 131 can determine whether or not the focus position of the reading beam of the pickup 2 is on the recording surface of the disc.

The scan signal generator 8 includes a sub controller 13
In response to the signal from 1, positive and negative analog signals are output to the terminal Y of the switch SW3. The switch SW3 connects the focus servo circuit 7 to one of the terminal X and the terminal Y in response to a signal from the sub control unit 131. The focus servo circuit 7 has a focusing actuator (not shown) provided with the objective lens (not shown) of the pickup 2 in the pickup 2 according to the output signal of the focus error detector 6 or the scan signal generator connected through the switch SW3. Up and down.

Here, if the switch SW3 is connected to the X side, the focus servo circuit 7 responds to the focus detection unit 6 to perform negative feedback control so that the focus of the reading beam is on the recording surface of the disk 1. Will be done. The disc signal level detector 11 shapes the signal from the pickup 2 and inputs it to the controller 13. The disk rotation servo circuit 9 controls the rotation speed of the motor M so that the frequency of the internal reference signal and the frequency of the synchronization signal included in the output signal of the pickup 2 match.
There are four operating states: a kick-up operation for driving the motor M at a predetermined rotation speed at the start of reproduction, a brake operation for driving in the opposite direction to the rotation to forcibly stop the rotation, and a non-operation. The operation state is switched by the sub control unit 131.

The signal conversion circuit 12 performs processing such as error correction and EFM demodulation on the signal from the pickup 2 to convert it into a digital audio signal, and outputs it to an analog system circuit via a digital analog converter (not shown). , A sub-code, which is control data recorded by being mixed with the digital audio signal, is extracted and output to the control unit 13. The subcode includes the address of the digital audio signal and the like.

The signal conversion circuit 12 outputs an error signal to the control unit 13 when the extracted subcode is abnormal due to scratches on the disk 1 or the like. 10 disc players
0 has the above configuration. In the present embodiment, the control unit 13 further measures the elapsed time from the start of the rotation of the disc 1, and also calculates the time for reverse rotation of the disc and controls the reverse rotation time of the disc. .

Next, the operation of this embodiment will be described. FIG. 2 is a flowchart showing the processing of the control unit 13 according to the present invention. The disc 1 is loaded in the disc reproducing apparatus 100, and the spindle motor M is used to reproduce the disc 1.
When is rotated (step 20), the control unit 13 starts counting the elapsed time Ts from the start of rotation of the disk 1 (step 21). Next, the pickup 2 is the disc 1
It is determined whether or not the information recorded in (1) is read (step 22), and then it is determined whether or not there is a rotation stop command for the disc 1 (step 23). If there is an instruction to stop the rotation of the disc 1 by operating the eject button or the like before the number of revolutions of the disc 1 becomes readable by the information pickup of the disc 1, the control unit 13 counts the time Ts. Is stopped (step 24), and the elapsed time Ts up to this point is stored. Further, based on the elapsed time Ts, the control unit 13 multiplies the elapsed time Ts by a constant k to calculate the time Tb required to stop the spindle motor M (step 2).
5). The constant k varies depending on the characteristics of the spindle motor M, the drive voltage value, etc. However, ideally, k = 1 is desirable when the forward and reverse rotations of the spindle motor M are performed at the same voltage value. Then, a constant voltage in the reverse direction is supplied to the spindle motor M for the time Tb calculated in step 25 (step 26).

If there is no stop command in step 23, the process returns to step 21 to continue measuring the elapsed time Ts. On the other hand, if it is determined in step 22 that the number of revolutions of the disc 1 is such that the information recorded on the disc 1 can be read by the pickup 2, the conventional reproducing process (step 40) is performed.

If there is a command to stop the disk 1 after the rotation of the disk 1 reaches the number of rotations at which the information of the disk 1 can be read in step 22, a negative voltage is applied to the spindle motor M as in the conventional case. Then, the rotation of the disk 1 is stopped, and when it is detected that the rotation of the spindle motor M has decreased until the pulse length of the reproduced EFM signal becomes equal to or longer than a predetermined value, based on the negative voltage application time up to this time. Then, the supply time of the further negative voltage required to normally stop the disk 1 is calculated, and during this time, the negative voltage is further supplied to the spindle motor M.

As described above, in the above-described embodiment, even if there is a disc stop command from the start of rotation of the disc 1 to the state where the information recorded on the disc 1 can be read, the disc 1 is promptly read. It is possible to stop the rotation.

[0021]

As described above, according to the present invention, the elapsed time from the start of rotation of the disk is measured, and the spindle motor is supplied with the drive voltage in the opposite direction to the predetermined direction based on the measured time. Since the drive voltage in the reverse direction is applied to the spindle motor during the calculated time, even if there is a disk stop command until the information recorded on the disk is read, the disk is promptly processed. Can be stopped.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a process of a control unit 13 according to this embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc 2 ... Pickup 12 ... Signal conversion circuit 13 ... Control unit 131 ... Sub control unit M ... Spindle motor 100 ... Disc playback device

Claims (1)

[Claims] 1. An optical disk device for reading information by rotating a disk in a predetermined direction at a predetermined linear velocity by a spindle motor, and a time measuring means for measuring an elapsed time from the start of rotation of the disk, and a start of rotation of the disk. If there is a disc stop command from the time until the information recorded on the disc is read,
Calculating means for calculating a time for supplying a drive voltage to the spindle motor in a direction opposite to the predetermined direction based on the elapsed time; and control means for supplying a drive voltage in the reverse direction to the spindle motor for the calculated time. An optical disc device comprising: