KR0155750B1 - Apparatus and method of rotation controlling optical disc - Google Patents

Abstract

The present invention is a rotation control method of an optical disc which rotates an optical disc in a stopped state and stops in order of acceleration mode, phase control mode, automatic mode, deceleration mode, and stop mode, wherein it is determined whether or not it is an abnormal rotation state in the automatic mode state. Making; Determining a current rotation direction when it is determined that the abnormal rotation state is at the determination step; Performing the deceleration mode when the determined rotation direction is the forward direction; and performing the acceleration mode when the determined rotation direction is the reverse direction; And performing a stop mode after the acceleration / deceleration mode, and then performing an acceleration mode during normal rotation control, so that when an abnormal phenomenon occurs in the automatic mode, it can automatically recover to a normal state again. do.

Accordingly, the present invention can automatically return to normal operation when an abnormal rotation condition occurs in the unlocking state of the spindle servo system.

Description

Rotation control method and device of optical disc

1 is a flowchart showing a rotation control method of a conventional optical disc.

2 is a block diagram of a general optical disc player.

3 is a flowchart showing an optical disk rotation control method according to an embodiment of the present invention.

4 is a block diagram showing an optical disk rotation control apparatus according to an embodiment of the present invention.

5 is a detailed circuit diagram of the abnormal rotation detector of FIG.

6 is a detailed circuit diagram of the comparison means of FIG.

The present invention relates to a rotation control method and apparatus for an optical disk, and more particularly, to a rotation control method and apparatus for preventing an abnormal rotation of an optical disk.

In general, such an optical disc is rotated in accordance with the rotation control method shown in FIG. 1 in order to control the rotation at a constant linear speed (speed at which the track passes over the laser beam at the time of tracking) within a fast time during play. . That is, when the play mode is designated (step 1000), in the initial stop state, a large torque is required to rotate the optical disk that is stopped in the forward direction, so that the drive mode is driven in an acceleration mode in which the spindle motor is strongly rotated. (Step 1010). If the optical disk starts to rotate to some extent, the motor is driven in a phase control mode that roughly controls the rotation of the optical disk because the optical disk has not yet undergone accurate phase synchronization. Then, it checks whether phase synchronization is performed (step 1030), and drives by phase and speed control during phase locking (step 1040) and by phase control when phase unlocking (step 1050). In this way, if the stop mode is specified during rotation control (step 1060), the motor operates in deceleration mode to apply reverse torque to the spindle motor rotating in the forward direction in order to stop in a short time when the motor stops (step 1070). In operation 1080, a stop mode is performed such that no torque is applied.

However, since the conventional rotation control method is a phase control method, when an abnormal phenomenon deviates from the normal operation, for example, when it rotates in the reverse direction due to an abnormal phenomenon, there is a problem in that it cannot recover to the normal state because the phase synchronization is to be reversed. In addition, there may be a case where the disc rotation control is not performed in the phase unlocking state without the phase locking state even when rotating in the forward direction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotation control method and apparatus for an optical disk capable of normal recovery even in the reverse rotation caused by an abnormal phenomenon in order to solve the problems of the prior art.

In order to achieve the above object, the present invention provides a rotation control method of an optical disc in which an optical disc is rotated in a stopped state and stopped again in the order of an acceleration mode, a phase control mode, an automatic mode, a deceleration mode, and a stop mode. Determining whether or not the abnormal rotation state; Determining a current rotation direction when it is determined that the abnormal rotation state is at the determination step; Performing the deceleration mode when the determined rotation direction is the forward direction; and performing the acceleration mode when the determined rotation direction is the reverse direction; And performing a stop mode after the acceleration / deceleration mode, and then performing an acceleration mode during normal rotation control, so that when an abnormal phenomenon occurs in the automatic mode, it can automatically recover to a normal state again. do.

The apparatus of the present invention to achieve the above object is the speed of phase locking when the phase comparison signal obtained by inputting the first phase comparison signal and the phase comparison signal and the speed detection signal obtained by inputting the speed comparison signal are summed and outputted; A phase control unit; A schematic phase controller for inputting a second phase comparison signal to generate a phase comparison signal by comparing the phase with the second reference signal; A first selector for selecting outputs of the speed and phase controller and the coarse phase controller by detection signals in response to a phase locking / unlocking state; An abnormal rotation control unit which detects the pulse width of the EFM signal by inputting the EFM signal, and determines whether the detected pulse width is equal to or greater than a predetermined value, and generates a deceleration signal when the current state is accelerated and generates an acceleration signal when the decelerated state; Selection signal generating means for inputting said detection signal to check an unlocking detection period and to generate a selection signal depending on whether or not it is longer than a predetermined time; And a second selector configured to select and output an output of the first selector and an output of the abnormal rotation controller in response to the selection signal.

The above and other objects and novel features of the present invention will become more apparent from the following description of the provided embodiments and the appended claims when taken in conjunction with the accompanying drawings.

A more detailed description of the embodiments illustrating the invention with reference to the accompanying drawings is as follows.

2 shows a block diagram of a typical magneto-optical disc player. In FIG. 2, the magneto-optical disk 1 is driven to rotate in a predetermined direction by the spindle motor 2. At the time of recording, the audio signal is recorded in the data area of the magneto-optical disk 1 through the magnetic head 3, the magnetic head control section 5, the data processing section 8 and the analog-digital converter 9. The digitally converted audio signal is compressed and coded in the data processing section 8, and modulated into EFM (8-to-14 modulation) to form recording data. The recording data is supplied to the magnetic head control section 5 to supply the magnetic head 3. Modulate the magnetic field At the time of reproduction, the audio signal is reproduced and output through the optical head 4, the high frequency amplifier 6, the data processor 8 and the digital analog converter 10. A light beam is irradiated to the data area of the disk 1 from the optical head 4 and photoelectrically converted into the light reflected thereon, and the weak high frequency signal obtained is amplified through the high frequency amplifier 6 and then supplied to the data processing unit 8. . The data processor 8 EFM demodulates the high frequency signal, expands the compressed signal, and outputs the digital audio signal. The digital audio signal is output as an analog audio signal via the digital analog converter 10. On the other hand, in the optical head 4, the focusing and tracking of the optical head 4 is controlled by the focusing and tracking control unit 7 by the detection signal obtained by the photodetector. The wobble signal among the detection signals is provided to the address demodulator 12 through the band filter 11. The address demodulator 12 inputs a wobble signal to restore the data by FM demodulation. The recovered data is bi-phase demodulated and the demodulated address information is supplied to the system controller 13 after error detection. At this time, when a demodulation error is detected, a demodulation error signal is generated. The system control unit 13 decodes the operation command generated by the operation unit 14 to control each unit of the system and displays the input address information on the display unit 15. On the other hand, the wobble signal is supplied to the rotation controller 16, and the rotation controller 16 generates the rotation control method 'signal by comparing the phase of the wobble signal and the reference signal. The spindle composition unit 17 inputs a rotation control signal to drive the spindle motor at a constant linear speed.

In the case of an optical disk without a pregroove, for example, a CD (Compack Disk), the high frequency signal picked up through the optical head 4 is supplied to the data processing unit 8 via the high frequency amplifier 6 and the EFM demodulation is performed in the data processing unit 8. After the address information is obtained from the subcoat among the obtained signals, the address information is supplied from the system control unit 13 to control the spindle servo.

The present invention relates to a rotation control method and apparatus for the spindle motor. 3 is a flowchart of a preferred embodiment of the rotation control method according to the present invention. The same steps as in the flowchart of the conventional method shown in Fig. 1 are denoted by the same reference numerals.

As shown in FIG. 3, the rotation control method of the present invention can be largely divided into four steps, an acceleration mode (step 1010), a phase control mode (step 1020), an automatic mode (steps 1030-1060), and a deceleration mode. In step (1070) and the stop mode (step 1080), the optical disc rotation control method of rotating the optical disc in the stopped state and stopping again, determining whether or not the abnormal rotation state in the automatic mode state (1090-1094) And determining the current rotation acceleration / deceleration ratio if the abnormal rotation state is determined in the determination step (1096, 1098), and performing the deceleration mode if the acceleration state is accelerated by the determined rotation acceleration / deceleration ratio, and performing the acceleration mode if the deceleration state. (1100, 1102), and performing the stop mode after the acceleration / deceleration mode and performing the acceleration mode in the normal rotation control again (1104), when an abnormal phenomenon occurs in the automatic mode state. Exodus by features that can be automatically restored to the normal state.

The abnormal rotation state determination step (1090-1094) checks whether or not the time that is unlocked at the phase locking check of the automatic mode has exceeded a predetermined time n seconds (step 1090) and the phase so that the n seconds have passed. If the unlocking state is continued, the pulse width of the reproduced EFM signal is detected. If the pulse width is larger or smaller than the predetermined pulse width, it is determined that an abnormal rotation state is generated (steps 1092 and 1094). Perform phase control mode.

The pulse width detection of the EFM signal is performed by counting every half cycle period as a reference clock (T = 1/4321800 sec) having a fundamental frequency of the EFM signal in synchronization with the edge of the reproduced EFM signal, and inputting the count value. Generating the first and second pulse width detection signals by decoding the counted first coefficient value 11T and the second coefficient value 12T, which is counted one clock more than the first coefficient value; Generating a first sampling signal synchronized to the front end of each cycle of the reference signal and a second sampling signal synchronized to the front end of the predetermined period, that is, four cycles, and the first and second pulses by the first sampling signal. Checking the presence or absence of the width detection signal and determining acceleration or deceleration according to the check result for the four periods by the second sampling signal, and maintaining the acceleration or deceleration control state for the next four periods according to the determination result. do.

In the determining of the acceleration / deceleration ratio, the current acceleration / deceleration state is determined by checking the ratio of the acceleration and deceleration sections, and in response to the ratio, the deceleration mode is performed in the acceleration state, and the acceleration mode is performed in the deceleration state.

4 shows a block diagram of a rotation control device suitable for carrying out the method of one embodiment of the present invention. Referring to FIG. 4, the rotation control apparatus according to an embodiment receives a first phase comparator signal S1 and compares the phase with a first reference signal to generate a phase comparison signal and a speed comparison signal. Speed and phase locking when the phase detector consisting of a speed detector 120 for generating a speed detection signal by inputting (S2), and an adder (130) for adding the output of the first phase comparator 110 and the speed detector 120 and outputs the sum; A phase control unit 200 comprising a phase control unit 100 and a second phase comparator 210 for inputting a second phase comparison signal S3 to generate a phase comparison signal in phase comparison with a second reference signal; And a first selector 300 for selecting outputs of the speed and phase control unit 100 and the schematic phase control unit 200 by a detection signal DS in response to the phase locking / unlocking state, and an EFM signal. The pulse width of the EFM signal is detected and the detected pulse width is equal to or greater than a predetermined value. If it is determined that the current state is an acceleration state, a deceleration signal is generated, and if the deceleration state is an abnormal rotation control unit 400 and the detection signal is inputted, the unlocking detection period is checked and selected according to whether or not it is longer than a predetermined time. A selection signal generator 500 for generating a signal, and a second selector 600 for selecting and outputting the output of the first selector 300 and the output of the abnormal rotation control unit 400 in response to the selection signal; Equipped.

The abnormal rotation control unit 400 detects the pulse width of the EFM signal and compares the ratio between the abnormal rotation detector 410 which generates the acceleration / deceleration control signal and the acceleration / deceleration control signal according to the detection result, and the acceleration is decelerated. Comparing means 420 is generated.

The abnormal rotation detector 410 includes a pulse width detector 412, a sampling pulse generator 414, and an acceleration / deceleration determination unit 416. Referring to FIG. 5, the pulse width detector 412 includes an edge detector 412a, a counter 412b, and a decoder 412c, and the sampling pulse generator 414 includes a first sampling signal (SAMS) generating means ( 414a) and a second sampling signal (SAML) generating means (414b), the first sampling signal generating means (414a) is composed of D-type flip-flops (D1, D2) and OR gate (G1), the second sampling The signal generating means 414b includes a divider DIV, D-type flip flops D3 and D4, and an OR gate G2. Further, the acceleration / deceleration determination means 416 includes an acceleration determination means 416a and a reduction determination means 416b, and the acceleration determination means 416a includes the multiplexers MUX1 to MUX3 and the D-type flip-flops D5 to D7. The deceleration determination means (416b) has a multiplexer (MUX4 ~ MUX6) and D-type flip-flops (D8 ~ D10). Here, MUX1 and MUX4, MUX2 and MUX5, and MUX3 and MUX6 multiplex their inputs according to the control signals and output them as shown in the following table.

Referring to FIG. 6, the comparison means 420 includes an exclusive logic circuit 422 for exclusively logically summing the deceleration control signal ZSCLVR and the acceleration control signal ZFCLVR, which are outputs of the abnormal rotation detector 410, and a clock signal. A divider 424 for dividing XCLK), an AND circuit 426 for gated the divided clock signal by the output of the exclusive logic circuit 422, and an up / down mode are generated by the deceleration control signal. And a counter 428 that clocks and outputs the output of the AND circuit 426 up / down coefficients. The counter 428 is in the up count mode because the deceleration control signal remains high in the non-active state. The counter 428 is counted up since the divided clock signal is clocked in the active state of the acceleration control signal. Since the state is kept low, the unit enters the down count mode, and the divided clock signal is inputted to the down count mode. Thus, the counter 428 generates a sine value that varies according to the up counted value and the magnitude of the up counted value as the acceleration / deceleration signal. As described above, in the present invention, the acceleration / deceleration signal is supplied to the spindle motor during the rotation control of the optical disc and controlled by the phase control. Therefore, even when the state of the phase control system is impossible to return from the unlocking state, it is detected and returned to normal. You can do it.

Claims (3)

Acceleration mode to strongly rotate the spindle motor to rotate the optical disk stationary in the forward direction, phase control mode to roughly control the rotation of the optical disk in the absence of accurate phase synchronization, phase to determine whether the phase synchronization is achieved And rotating the optical disc in the stopped state in the following order: automatic mode driven by speed control or driven by phase control, deceleration mode for slowing down the speed of the spindle motor rotating in the forward direction, and stop mode for stopping the rotating spindle motor. A rotation control method of an optical disk for stopping and restarting, comprising: a rotation state determination step of determining whether an abnormal rotation state is checked by checking a stock price of a reproduced EFM signal when a phase unlocking period is detected in the automatic mode state for a predetermined period or more; A rotation direction determination step of determining a current rotation direction by checking an acceleration / deceleration ratio of the phase control mode when it is determined that the abnormal rotation state is in the determination step; Performing the deceleration mode when the determined rotation direction is the forward direction; and performing the acceleration mode when the determined rotation direction is the reverse direction; And performing a stop mode after the acceleration / deceleration mode and performing an acceleration mode in normal rotation control again, and when an abnormal phenomenon occurs in the automatic mode, it can automatically recover to a normal state again. Rotation control method for an optical disc. The method of claim 1, wherein the determining of the rotation direction maintains the acceleration mode or the deceleration mode for the next n periods in response to a result of determining the rotation direction. Phase and phase comparison in phase locking for outputting a phase comparison between the first phase comparison signal and the first reference signal, and adding the phase comparison signal corresponding to the phase comparison result and the speed detection signal obtained by inputting a predetermined speed comparison signal. Control unit; A schematic phase controller configured to compare a phase comparison of the second phase comparison signal with a second reference signal and output the phase comparison result as an approximate phase comparison signal; A first selector for selecting outputs of the speed and phase controller and the coarse phase controller by detection signals in response to a phase locking / unlocking state; Determine whether the pulse width of the EFM signal is greater than or equal to a predetermined value to determine the rotation state, and generate an acceleration / deceleration control signal in response to the determined result, and determine the rotation direction by determining the ratio of the acceleration / deceleration control signal. An abnormal rotation control section for controlling the rotation of the optical disk by generating an acceleration / deceleration signal in response to the result; Selection signal generating means for inputting the detection signal to check an unlocking detection period, and generating a selection signal depending on whether or not the checked result is longer than a predetermined time; And a second selector configured to select and output an output of the first selector and an output of the abnormal rotation control unit in response to the selection signal.