KR19980039974A - Disk Chucking Control Device of DVD System - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc chucking control apparatus for a DVDR system, comprising: an optical pickup unit for driving an optical disc capable of recording, erasing, and reproducing: an optical pickup unit for recording data on the optical disc or reading / erasing data on the optical disc; 110); A tracking error detector 120 for detecting a tracking error of the optical pickup unit 110 and outputting a tracking error signal corresponding thereto; A low pass filter 130 for low-pass filtering the tracking error signal; An A / D converter 140 for converting the output of the low pass filter 130 into digital; A disk loading unit 150 for chucking and chucking of the optical disk 100; The disk loading unit detects the output of the A / D converter 140 and determines that the chucking of the optical disc 100 is wrong when the output of the low pass filter 130 has a predetermined value. It is characterized by comprising a control unit 160 for controlling the 150.

Description

Disk Chucking Control Device of DVD System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc chucking control apparatus for controlling a chucking error of an optical disc in a DVDR (Digital Video Disc Recorder) system capable of recording, erasing, and playing back.

In general, optical discs are CD-only CDs, CD-ROMs, video discs, etc., which can be read only by the user. Information can be recorded once, and the recorded information can be read several times, but cannot be erased or rewritten. It can be divided into a recording type and an erased rewrite type that can repeatedly record, erase, and reproduce information.

Play-only type CD is already replacing the existing LP record board in the sound industry, CD-ROM which is a medium that can be searched when necessary by recording a large amount of information that needs to be widely spread such as encyclopedia, and recently in Korea Video discs and the like, which are rapidly expanding, have already been put into practical use and are in the dissemination stage. Additional recordable optical discs can be used for hospitals and large documents that need to store information such as X-rays, NMR-CTs, ultrasound tomography, and patient care cards. It is used for necessary public offices and mineral veins such as mines and oil fields.

The erasing rewritable optical disc has a magneto-optical type and a phase change type. The phase change type records using crystalline / amorphous reversible changes in the process of heating and cooling the micro part of the medium using a laser, and the information is reflected by the difference in reflectance between the two phases. I am using a method to read it.

1 and 2 show a diagram for explaining a recording, erasing, and reproducing method for such an erased rewritable optical disc.

First, recording is performed when the magnetic thin film oriented in one direction perpendicular to the thin film surface as shown in FIG. 1A is momentarily heated to near the Curie temperature by the laser focused light pulse as shown in FIG. The coercive force of the part is reduced. At this time, only the laser irradiation part heated by the weak magnetic field applied in the direction opposite to the medium magnetization direction is reversed. When the laser pulse is turned off and cooled to room temperature, only this part remains as a stable inverse magnetic field bit and information is recorded.

The erasing is performed by heating the portion where information is recorded as shown in FIG. 1B by means of a laser beam as shown in FIG. By doing so.

On the other hand, reading of the recorded information is performed by using a laser light and a polarizer which are weaker than at the time of recording as shown in FIG. 2C. When the linearly polarized light is reflected from the surface of the perpendicularly magnetized material, the polarization direction depends on the magnetization direction of the material. The magneto-optical Kerr effect which rotates left and right with respect to the polarization direction of this incident light is used (refer FIG. 1 (C)). That is, the polarization direction of the reflected light is rotated counterclockwise when the magnetization direction of the material is downward, and clockwise when it is upward, so that the reflected light passes through the two reflected beams with the analyzer set in advance in a direction that hardly passes the reflected polarization in the unrecorded portion. Then, the reflected light of the unrecorded part has a weak light quantity, and the reflected light of the recorded part passes through the analyzer and is converted into a strong signal of light, which is read by the digital signals '0' and '1' using a photodetector. Done.

As described above, a system for recording, erasing, and reproducing the erase rewritable optical disc is commonly referred to as a DVDR system.

On the other hand, when chucking such an erasing rewritable optical disc, if the chucking of the disc is not accurate, the eccentric amount is recorded with the basic eccentricity in recording the data on the pre-engraved groove.

In this case, since the eccentricity at the time of recording is accompanied when the recorded data is reproduced, jitter is affected during reproduction, resulting in a data error.

Accordingly, an object of the present invention is to provide a disk chucking control apparatus capable of detecting a chucking state before recording of an erasing re-entry optical disk, and retrying again if a chucking error occurs.

The present invention provides a DVDR system for driving an optical disc capable of recording, erasing, and reproducing in order to achieve the above object, comprising: an optical pickup unit for recording data on the optical disc or reading / erasing data on the optical disc; A tracking error detector for detecting a tracking error of the optical pickup unit and outputting a tracking error signal corresponding thereto; A low pass filter to low pass filter the tracking error signal; An A / D converter converting the output of the low pass filter into digital; A disk loading unit for chucking and chucking of the optical disk; A control unit for detecting the output of the A / D conversion unit 140 and controlling the disc loading unit to rechuck the optical disc by determining that the chucking of the optical disc is wrong when the output of the low pass filter has a predetermined value. It is characterized by the configuration.

1 and 2 are diagrams for explaining a recording, erasing, and reproducing method of an erased rewritable optical disc.

3 shows a disk chucking control device according to a preferred embodiment of the present invention.

4 is an output waveform diagram of a low pass filter in the component of FIG. 3; FIG.

<Description of the code | symbol about the principal part of drawing>

100: optical disk 110: optical pickup

120: tracking error detection unit 130: low pass filter

140: A / D conversion unit 150: disk loading unit

160: control unit

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

3 shows a disk chucking control device according to a preferred embodiment of the present invention.

In FIG. 3, the disc chucking control apparatus includes an optical disc 100, an optical pickup unit 110 for recording data on the optical disc 100 or reading / erasing data of the optical disc 100, and a tracking error of the optical pickup unit 110. tracking error detection unit 120 for detecting a tracking error and outputting a tracking error signal corresponding thereto, low pass filter 130 for low-pass filtering the tracking error signal, and A for converting the output of the low pass filter 130 to digital. / D (Analoge / Digital) converting unit 140, the disk loading unit 150 for performing chucking and chucking of the optical disc 100, if the chucking of the optical disc 100 is wrong, the disc so that the optical disc 100 is rechucked It is composed of a control unit 160 for controlling the loading unit 150.

An operation description of the disk chucking control device configured as described above is as follows.

In FIG. 3, the controller 160 controls the disc loading unit 150 to chuck the optical disc 100. When the optical disc 100 is chucked, the optical pickup unit 110 is driven and the optical disc 100 will rotate. When the optical pickup unit 110 is driven, a laser beam for optical pickup will be emitted to the signal surface of the optical disc 100, and the laser beam traces a track of the optical disc 100.

Meanwhile, as the laser beam of the optical pickup unit 110 traces the track of the optical disc 100, the tracking error detector 120 detects the tracking error signal and provides the tracking error signal to the low pass filter 130.

At this time, when the chucking of the optical disc 100 is performed correctly, the tracking error signal may have only a predetermined high frequency component as shown in FIG. 4A, but the tracking error signal when the chucking of the optical disc 100 is not properly illustrated in FIG. 4. As shown in (B), it will be a signal in which a high frequency component is added to a constant sine wave (a).

Thus, if a signal such as FIG. 4A is provided to the low pass filter 130, the output of the low pass filter 130 will be close to zero, and a signal such as FIG. 4B is provided to the low pass filter 130. The low pass filter 130 will only output a constant sinusoidal signal that is a low pass component as shown in FIG.

The A / D conversion unit 140 converts the output of the low pass filter 130 into digital and provides the control unit 160. The controller 160 detects a signal provided from the A / D converter 140 and recognizes that the chucking of the optical disc 100 is properly performed when the output of the low pass filter 130 is 0. The low pass filter 130 If the output of the predetermined value is recognized that the chucking of the optical disk 100 is not made properly.

Therefore, if the chucking of the optical disc 100 is not performed properly, the controller 160 controls the disc loading unit 150 to allow chucking to be released and rechucked.

The disc loading unit 150 releases the chucking of the optical disc 100 under the control of the controller 160 and then re-chucks it.

As described above, the present invention grasps the chucking state of the optical disc, so that if an error occurs in the chucking, the chucking is performed again, so that error-free chucking can be achieved.

Claims (1)

In DVDR systems driving optical discs capable of recording, erasing and playback: An optical pickup unit (110) for recording data on the optical disc or reading / erasing data on the optical disc; A tracking error detector 120 for detecting a tracking error of the optical pickup unit 110 and outputting a tracking error signal corresponding thereto; A low pass filter 130 for low-pass filtering the tracking error signal; An A / D converter 140 for converting the output of the low pass filter 130 into digital; A disk loading unit 150 for chucking and chucking of the optical disk 100; The disk loading unit detects the output of the A / D converter 140 and determines that the chucking of the optical disc 100 is wrong when the output of the low pass filter 130 has a predetermined value. A disk chucking control device for a DVDR system, comprising a control unit 160 for controlling 150.