KR100247594B1 - Damage defection circuit for optical disk player - Google Patents

Abstract

The damage detection circuit of the disclosed optical disc reproducing apparatus detects a disc damage state by using a sub beam output from an optical pickup and a disc damage state by using a main beam output from an optical pickup. It is about making it possible.

The apparatus of the present invention is an optical disc reproducing apparatus for reproducing and outputting a signal recorded on an optical disc while the optical disc mounted on the deck is moved from the inner circumference to the outer circumferential direction. And a disk damage detector for outputting a signal for detecting an optical disk damage state, and a signal processor for outputting a tracking hold signal to the motor driver in response to the optical disk damage state detection signal input from the disk damage detector.

Accordingly, the present invention enables the detection of damage state of the optical disc, which has not been detected only by the sub-beams, by using the main beam, which enables the detection of minute damage state of the optical disc, and provides the effect of adjusting the detection sensitivity and detection band. have.

Description

Damage Detection Circuit of Optical Disc Player

The present invention relates to a damage detection circuit of an optical disc reproducing apparatus, and more particularly to detecting a disc damage state by using a sub beam output from an optical pickup and a disc damage state using a main beam output from an optical pickup. As a result, the present invention relates to a damage detection circuit of an optical disc reproducing apparatus that can detect minute damage of an optical disc.

In general, optical discs such as compact discs (CDs), laser discs (LDs), and video compact discs (VCDs), etc., are robust as storage media that are designed to allow data such as audio and video to be recorded in a defined effective area and reproduced therefrom. In addition, since the recorded data is not easily damaged and has the advantage of being reproduced cleanly without noise using a light beam, its use is gradually increasing.

FIG. 1 is a schematic block diagram for explaining the structure of a damage detection circuit of an optical disc player according to the prior art. As shown in FIG.

The disc motor 10 rotates the optical disc 20 mounted on the deck to be reproduced.

The optical disc 20 is roughly divided into three area signal areas, that is, a lead area, a program area, and a lead-out area. Each signal area is separated from the center of the optical disc. It has data in the form of a projection called a pit along a track spiraling outward.

The lead-in area is often a table of contents (TOC), such as the type of optical disc, the number and size of programs stored on the optical disc, the address of each program, i.e. the location on the optical disc, the start time of each track, the total playback time of the optical disc, and so on. It has data called.

The program area contains actual program data, and the lead-out area has data indicating the end of the program.

The objective lens 30 focuses the light beam on one surface of the optical disk 20 and receives the reflected light beam.

The optical pickup 40 converts a light beam incident by the objective lens 30 into an RF signal and outputs the RF signal.

The disk damage detector 50 adds the sub beams E and F input from the optical pickup 40 and outputs a signal SBAD for detecting an optical disk damage state.

The RF amplifier 60 amplifies and waveforms an RF signal input from the optical pickup 40 to a predetermined level, and responds to an optical disk damage detection signal DS in response to a signal SBAD input from the disk damage detector 50. )

The signal processor 70 converts the RF signal input from the RF amplifier 60 into a digital signal, outputs an image signal and an audio signal, and responds to the optical disk damage detection signal DS input from the RF amplifier 60. To output the signal TH for holding tracking.

The motor driver 80 outputs the drive control signal TM so that the motor 90 is not driven by the tracking hold signal TH input from the signal processor 70.

FIG. 2 is a detailed block diagram illustrating a disk damage detector applied to FIG. 1.

As shown, a first low pass filter 51 for filtering into the damage detection band for one sub beam E, F output from the optical pickup 40 and another output from the optical pickup 40. Disc damage is detected by adding the second low pass filter 52 for filtering the sub beam F into the damage detection band and the two sub beams input from the first and second low pass filters 51 and 52. It consists of a signal summer 53 for outputting a signal (SBAD) for.

Referring to the operation of the damage detection circuit of the optical disc player having the above-described configuration, the sub beams disposed on both sides of the main beam M for reading out the signal recorded on the optical disc 20 by the optical pickup 40 E) (F) is used to detect disk damage.

At this time, the three beams form an image on the photodiode PD of the optical pickup 40 which detects the returning light since the lines connecting the centers are arranged to have a certain offset angle with respect to the track direction. After outputting to the first low pass filter 51 and the second low pass filter 52 to filter the signal band for detecting whether the optical disk is damaged or not, the two signals filtered by the signal summer 53 are summed and finalized. Outputs the signal SBAD shown in FIG.

Then, the RF amplifier 60 outputs the disk damage signal DS shown in FIG. 3B, and the signal processor 70 responds to the disk damage signal DS input from the RF amplifier 60. And outputs the tracking hold signal TH.

However, in the above-described optical disc reproducing apparatus, there is a problem in that disc damage caused by interruption or scratch cannot be completely detected by detecting whether the optical disc is damaged by summing two signals generated by the sub-beams. there was.

Accordingly, an object of the present invention is to detect the disk damage state by using the sub-beam output from the optical pickup to detect the disk damage state by using the main beam output from the optical pickup to solve the above-described problems, It is an object of the present invention to provide a damage detection circuit of an optical disc reproducing apparatus that can detect damage.

1 is a schematic block diagram for explaining the structure of a damage detection circuit of an optical disc player according to the prior art;

2 is a detailed block diagram of a disk damage detection unit applied to FIG.

3 is a view of each sub waveform of FIG.

4 is a schematic block diagram for explaining a configuration of a damage detection circuit of an optical disc player according to the present invention;

FIG. 5 is a detailed block diagram of the disk damage detection unit applied to FIG.

6 is an output waveform diagram of the low pass filter and the high pass filter of FIG.

<Explanation of symbols on main parts of the drawing>

400: optical pickup PD: photodiode

500: disk damage detection unit 510: low pass filter

520 high pass filter

In the optical disc reproducing apparatus according to the present invention for achieving the above object, the apparatus of the present invention reproduces and outputs a signal recorded on the optical disc while moving the optical pickup mounted on the deck from the inner circumference to the outer circumferential direction A reproducing apparatus, comprising: a disc damage detector for outputting a signal for detecting an optical disc damage state by combining and filtering the main beams input from the optical pickup, and a motor drive unit in response to the optical disc damage state detection signal input from the disc damage detector; And a signal processor for outputting a tracking hold signal.

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

4 is a schematic block diagram for explaining the configuration of a damage detection circuit of an optical disc reproducing apparatus according to the present invention. As shown in FIG.

The disk motor 100, the optical disk 200, the objective lens 300, the optical pickup 400, the RF amplifier 600, the signal processor 700, the motor driver 800, and the motor 900 are conventional The same description as that in the configuration is omitted.

The disk damage detector 500 adds the main beams A, B, C, and D input from the optical pickup 400 to output a signal 4D for detecting an optical disk damage state.

FIG. 5 is a detailed block diagram illustrating a disk damage detector applied to FIG. 4.

As illustrated, the disk damage detector 500 filters the main beams A, B, C, and D input from the optical pickup 400 to the optical disk damage detection band to output a damage detection signal. And a high pass filter 520 that increases a gain for a specific band of the damage detection signal filtered by the low pass filter 510 and outputs a damage detection signal.

In this case, the above-mentioned disk damage detection unit 500 detects whether the disk is damaged by using the main beams A, B, C, and D. The reason for tracking the tracking servo in the case of using the sub beam as in the related art is as follows. This is because a large disc is not able to detect fine disc damage, and as described above, when the main beams A, B, C, and D are detected, the amount of beams formed on the photodiode of the optical pickup 400 is increased. This wide distribution makes it easy to detect even very fine disc damage.

The operation of the optical disc player according to the present invention configured as described above will be described in more detail with reference to the accompanying drawings.

When the optical pickup 400 outputs the main beams A, B, C, and D, which read the signals recorded on the optical disc 200, to the low pass filter 510 of the disc damage detection unit 500, the low pass filter. In operation 510, the signal in which the main beam for detecting the disk damage output from the disk damage detection unit 500 is combined is filtered into the damage detection band as shown in "A" of FIG. 6.

The signal filtered by the low pass filter 510 is output after the gain of only a specific band is increased through the high pass filter 520 as shown in "B" of FIG. 6. Detect.

Then, the RF amplifier 60 outputs the disk damage signal to the signal processing unit 700 in response to the damage state detection signal 4D output from the disk damage detection unit 500, and the signal processing unit 70 is a motor driving unit ( 80) to output the tracking hold signal.

Therefore, as described above, the present invention can detect the signal according to the damaged state of the optical disc, which has not been detected only by the sub beam, by using the main beam, and provides the effect of adjusting the detection sensitivity and the detection band.

Claims (1)

In an optical disc reproducing apparatus that reproduces and outputs a signal recorded on an optical disc while the optical disc mounted on the deck is moved from the inner circumference to the outer circumferential direction, the main beam input from the optical pickup is filtered by the optical disc damage detection band to detect damage. And a disk damage detector comprising a low pass filter for outputting a signal and a high pass filter for increasing a gain for a specific band of the damage detection signal filtered by the low pass filter and outputting a damage detection signal. Damage detection circuit of regeneration equipment.

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