KR19980040570A - Search control method in optical disk device - Google Patents

Abstract

The present invention relates to a reproduction control method in an optical disc device including a compact disc.

Existing optical disc players have a fatal disadvantage that the pickup may leave the program area on the disc due to overrun during track jump.

The present invention provides a method of determining a search mode in an optical disk device, and if the search mode is recognized in the step, calculating a target position and a current position to set a movement amount and determining whether the sled is turned on. In the step, if the sled-on condition is set, a timeout is set in the memory buffer, the sled-on subroutine is executed, and the movement amount and the count value are cleared. Determining whether it is satisfactory, determining whether the time limit is exceeded if the moving condition is not satisfied in the step, and if the time limit is exceeded, executing the step of determining whether the moving condition is satisfied again. If satisfied, the step of executing the search western routine after setting the movement time count in the memory buffer; In the disk reproduction control method.

Description

Search control method in optical disk device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for reproducing an A / V optical disc, which is in the limelight as a recording and reproducing medium of an audio signal and a video signal. In particular, a pickup device is moved by a feeder to read contents contained in the optical disc. The present invention relates to an optical disc control method for preventing a playback error due to overrun.

Looking at the characteristic configuration and operation relationship of the video signal and audio signal processing system in the optical disk device, first, when the optical disk control signal is input to the system control microcomputer from the selection key input unit for setting various functions of the optical disk device. This microcomputer outputs a control signal to the servo motor side of the spindle.

As a result, the turntable on the spindle motor on which the optical disk is placed rotates so that the optical disk placed thereon rotates. When the optical disk is rotated, the digital data recorded along the track on the surface of the disk is detected by the pickup device.

The picked-up digital signal is amplified to a constant level through a signal amplifier and applied to the focus and tracking controller. The focus and tracking controller provides position control information to an actuator side that determines and controls a transfer position of the pickup device based on an input digital signal, and also interchanges the read digital signal and control signal with the micom side. .

The microcomputer controls the digital reproduction signal on the optical disk to be picked up and amplified by the digital signal processor (DSP).

The signal processed by the digital signal processor is input to a digital analog converter (DAC) where the digital signal is converted into an analog signal and output.

The analog sound signal output from the digital to analog converter is amplified through an output amplifier and output to the speaker. After all, the optical disc device records audio (or video) signals on the disc using digital signals, reads these digital signals, converts them into analog signals, and outputs them.

The laser pickup device for digital signal pickup during optical disc reproduction starts from the inner circumference of the disk and proceeds toward the outer circumference. The rotation speed (500 rpm) in the inner circumference and the rotation speed (200 rpm) in the outer circumference are designed differently. It is becoming.

The reason why the rotational speed becomes slower toward the outer periphery of the optical disc is because it records in a linear speed constant manner in which the length of the track passing at a constant time is always constant when recording information on the CD.

In general, when the laser pickup device is to be moved a certain distance from the optical disk device, a method of directly driving the feeder is used for rapid movement. At this time, an overrun may occur due to external vibration.

If such an overrun occurs in the program area of the optical disc, it does not cause a big problem because it is required to immediately move back to the originally set moving distance.

However, if an overrun during the pick-up movement occurs outside the program area of the optical disc, a system error appears because there is no countermeasure for overrun.

SUMMARY OF THE INVENTION An object of the present invention is to move a pickup device by a feeder to read the contents of a disc in a system for playing an A / V optical disc or a compact disc, which is in the limelight as a recording-reproducing medium of an audio signal and a video signal. To provide an optical disk control method that can prevent the generation of playback errors due to overruns.

The present invention is characterized in that the microcomputer and the pick-up device for providing a control signal to the spindle servo unit for the spindle control and the focus / tracking servo unit for the pickup device control and the spindle servo unit and the focus / tracking servo unit provide the front and rear ends of the lead-in area. An optical disk device including a limit switch for sensing, comprising the steps of: determining whether a search mode is present; and when the search mode is recognized in the above step, calculating a target position and a current position to set a movement amount and determining whether the sled is on. And setting a timeout in the memory buffer, executing a sled on subroutine, clearing the shift amount and count value if the sled-on condition is in the step, and determining whether the sled state is in the sled-on determination step. Otherwise, determining whether the moving condition is satisfied; Determining whether the operation is terminated if it is exceeded, and if it is before exceeding, executing the step of determining whether the moving condition is satisfied again, and if the moving condition is satisfied in the above step, after setting the moving time count in the memory buffer, executing the search subroutine and ending. An optical disc reproduction control method comprising the steps of:

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a schematic circuit block diagram of an optical disc reproducing apparatus for optical disc reproducing control according to the present invention.

2 is a flowchart illustrating the present invention.

* Description of the symbols for the main parts of the drawings *

10: microcomputer 11: focus / tracking servo unit

12: spindle 13: spindle servo

14: pickup device 15: amplification unit

16: synchronization detection unit 17: PLL

18: digital signal processing unit 19: sub code detection unit

20: DAC 21: limit switch

1 is a block diagram of a system control circuit block of an optical disk apparatus to which a control method according to the present invention is applied.

As referred to herein, the position control and movement control signals of the focus / tracking servo unit 11 are connected to the laser pickup device 14 for reading digital signals recorded on the optical disk.

Accordingly, the laser optical pickup device 14 is focused / tracked and position controlled so as to read digital information on selected channels and tracks recorded on the lower surface side of the disc.

The digital signal picked up by the laser pickup device 14 is connected to the RF amplifier 15 so that the digital signal output from the amplifier 15 is synchronized with the synchronization detector 16 and the focus / tracking servo unit. (11) is connected to be applied.

Thus, the synchronization detection unit 16 detects a synchronization signal to be used for the spindle servo, and the focus / tracking servo unit 11 generates a control signal for positioning the pick-up device.

The synchronous detection unit 16 phase-controls the picked-up digital signal as the PLL 17 so that a part of the synchronous detection unit 16 is applied as a control signal of the spindle 12 for rotating the optical disk via the spindle servo unit 13. A part is connected to be applied to the digital signal processing unit 18.

The digital signal processor 18 is connected to the digital signal processor 18 output from the synchronization detector 16.

The digital signal processor 18 processes a digital sound signal, and the signal processed and output by the digital signal processor 18 passes left and right through a DAC 20 that converts and outputs a digital signal into an analog signal. It is connected to output audio signal of channel.

In addition, the signal output from the digital signal processor 18 is connected to the microcomputer 10 via the sub code detector 19 to provide a control signal source for determining the movement position of the optical pickup device.

The microcomputer 10 is connected to provide a detection signal of the limit switch 21 for limiting the movement position of the optical pickup device 14, and when the position shift excess information is inputted by the switch, the microcomputer 10 is focused / The pickup servo return control signal is output to the tracking servo section 11 side.

The operation of the present invention in such an optical disc control system will be described in detail with reference to FIG. 2 as follows.

First, the microcomputer 10 determines whether there is a search key input for performing a search function.

In the search mode, the target position and the current position are calculated to determine the movement amount, and then the step of determining whether the sled on start is performed.

If the sled on condition is determined in the step of determining whether the sled on starts, the time limit is set in the memory buffer, the sled on subroutine is executed to move the pickup, and the previously set movement amount data value and count data value are cleared. Run the step to end.

However, in the sled on start determination step, the microcomputer executes the step of determining whether the moving condition is satisfied when the start and the moving are not performed.

In the step of determining whether the movement condition is satisfied, it is determined whether the movement is performed as much as the track to be moved. If the movement is performed by the required setting value, the movement time count value is stored in the memory buffer to create a memory buffer RAM table for each mode, and After running the training, run the search subroutine and then exit.

On the other hand, if it is determined that the moving condition is not satisfied at the step of determining whether the moving condition is satisfied, the step of determining whether the time limit has elapsed is performed.

If the time limit has not yet reached at this stage, the process returns to the determination of whether the moving condition is satisfied. If the time limit is exceeded, the process ends.

Accordingly, when jumping from one track to another on an optical disc, the jump time for each time data of the corresponding setting condition is memorized and tabled, and then the jump time is set as the time limit for the jump. It is possible to reduce the amount of error when the scratch is severe on the surface of the jump or jump over the set distance due to disturbance or vibration.

As described above, the present invention can minimize the possibility of a failure to jump to the correct position due to defects in the surface state of the disk, disturbance or vibration during the search control of the optical disk device. The distinctive effect of maintaining this is shown.

Claims (1)

The microcomputer 10 and the pickup which provide control signals to the spindle 12 for controlling the spindle 12 and the focus / tracking servo 11 for controlling the pickup device 14 and the spindle servo and the focus / tracking servo. In the optical disk device, the apparatus includes a limit switch 14 for detecting the leading and trailing ends of the lead-in area, the method comprising: determining whether the search mode is selected; Calculating the amount of movement and determining whether the sled is on; setting a timeout in the memory buffer, executing a sled on subroutine, and clearing the amount of movement and count if the sled on condition is present; Determining whether the moving condition is satisfied if the sled state is not in the sled-on determination step; Determining whether the operation is terminated if it is exceeded, and if it is before exceeding, executing the step of determining whether the moving condition is satisfied again, and if the moving condition is satisfied in the above step, after setting the moving time count in the memory buffer, executing the search subroutine and ending. Optical disc playback control method comprising the steps of;