KR19990041943A - Apparatus and method for adjusting servo gain of optical disc system - Google Patents

Abstract

The present invention relates to an apparatus and method for adjusting a servo gain of an optical disc system, wherein after recording and reproducing a laser beam onto a disc having a reflection amount measuring area on a signal surface, the amount of reflected light is detected, thereby recording and reproducing corresponding to the detected amount of reflected light. It is characterized by the ability to perform servo control with servo gain.

Description

Apparatus and method for adjusting servo gain of optical disc system

The present invention relates to an optical disc system capable of recording and reproducing, in particular, scanning a laser beam onto a disc before recording or reproducing data on the disc, and adjusting the servo gain adaptively to the amount of reflected light, A servo gain adjusting apparatus and method for performing regeneration.

In general, in an optical disk system capable of recording and reproducing, a method of scanning a laser beam of a certain power level to a disk when data is recorded on the disk or when the recorded data is played back is applied. For example, in the case of a phase change type disk, which is the most advanced disk storage medium, the focused laser beam is irradiated on the surface of the rotating disk, and the data is heated and cooled to record the data. After irradiating a laser beam of a predetermined level onto the recorded disc, the reflected light is converted into an electrical signal to reproduce the data recorded on the disc.

Here, substantially, the power level of the laser beam irradiated at the time of data recording and reproduction is different, for example, the power level of the laser beam at the time of data recording is slightly higher than the power level at the time of reproduction.

On the other hand, a servo control device can be cited as a constituent member which plays an important role in recording or reproducing data on a disc. In other words, in order to accurately record data on the disk or to accurately reproduce the recorded data, servo control is necessary. As is well known, servo control includes a focusing servo that controls the signal surface of the disk to be within the depth of focus of the laser beam, and a tracking servo that controls the laser beam to accurately track along the track of the disk. Etc.

Here, the focusing servo described above uses a focusing error signal that indicates the degree to which the signal plane of the disk deviates within the depth of focus of the laser beam, and the tracking servo uses a tracking error signal that indicates the degree to which the laser beam deviates from the track of the disk. As is well known, a servo error signal such as a focusing error signal and a tracking error signal is detected based on the deviation of the reflected light amount after irradiating a laser beam to the signal surface of the disc.

By the way, in the optical disk system capable of recording and reproducing, as described above, the laser beam power in the recording mode and the laser beam power in the reproducing mode are different, so that the amount of reflected light of the laser beam in the recording mode and the reproducing mode are different. The amount of light reflected by the laser beam is different. Therefore, in the related art, since the servo error signal detected for the servo control also changes in proportion to the reflected light amount, the servo gain of the servo control apparatus must be changed accordingly.

By the way, in the above-described prior art, only the servo gain set in accordance with whether the current mode is the recording mode or the reproducing mode does not take into account the state of each disc or the characteristic change of the optical disc system.

That is, in the case of the disc, even if the manufacturing process is constant, there are variations in the system characteristics due to process variations, for example, minute variations due to resin injection and curing, and aging of the optical disc system. Such a change in the state of the disk and the characteristics of the system immediately leads to a difference in the amount of reflected light. In the prior art, since only a fixed servo gain is applied, there is a problem that accurate servo control is not achieved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and by using a disk having a reflecting light measuring area for measuring the reflecting power of a laser powder in a predetermined area, the amount of reflected light is measured every time recording or reproducing is performed. It is an object of the present invention to provide an apparatus and method for adjusting a servo gain of an optical disk system that can be adjusted.

In order to achieve the above object, the present invention provides a method for adjusting a regenerative servo gain and a recording servo gain of a servo unit that performs servo control necessary to perform data reproduction and recording by using a disk having a reflectance measuring area on a signal surface. An apparatus for adjusting servo gain in an optical disk system, comprising: a laser beam generator for generating a recording laser beam for recording data on the disk and a reproduction laser beam for reproducing data recorded on the disk; A laser driver for recording / reproducing driving signals for driving the laser beam generator; An encoder for providing data to be recorded on the disc to the laser beam generator; An optical pickup unit which irradiates the laser beam generated by the laser beam generator to the reflected light measuring region of the disk and converts the reflected light into an electrical signal and outputs the electrical signal; A servo unit for performing servo control on the optical pickup unit based on a servo gain corresponding to a recording mode or a reproduction mode; An amplifier for amplifying and outputting an electrical signal provided from the optical pickup unit; A filter for removing noise of the signal amplified by the amplifier; The reflection amount of the recording laser beam irradiated to the reflectance measurement area of the disk, the recording servo gain corresponding to the reflection amount of the recording laser beam, the reflection amount of the reproduction laser beam irradiated to the reflection amount measurement area of the disc, and the reproduction laser beam The reproducing servo gain corresponding to the reflecting amount of the table is stored in the internal memory, and the laser driving unit is controlled in the recording or reproducing mode so that the laser beam is irradiated to the reflecting measuring region of the disc and inputted from the filter. A control unit for detecting the reflection amount of the laser beam from the signal and controlling the servo unit to perform servo control based on the recording or reproducing servo gain corresponding to the detected reflection amount based on the data stored in the internal memory. It is characterized by the configuration.

In addition, in the servo gain adjustment method of the optical disk system performing adjustment of the reproducing servo gain and the recording servo gain of the servo unit which performs the servo control necessary to perform data reproduction and recording by using the disk having a reflectance measuring area on the signal plane. A first step of determining whether a current mode is a recording mode or a reproduction mode when the disc is mounted on the optical disc system; A second step of detecting an amount of reflected light reflected after irradiating a recording laser beam to a reflection amount measurement area of said disk in a recording mode as a result of the determination of said first step; A third step of detecting a write servo gain corresponding to the reflected light amount of the second step and adjusting the gain of the servo unit to the detected write servo gain; A fourth step of detecting the amount of reflected light reflected after the reproduction laser beam is irradiated to the reflection amount measurement region of the disc in the reproducing mode as a result of the determination in the first step; And detecting a regenerative servo gain corresponding to the reflected light amount of the fourth stage, and adjusting a gain of the servo unit to the detected regenerative servo gain.

1 is a detailed configuration diagram showing an embodiment of the servo gain adjusting device of the present invention;

2 is a structural diagram of a disk applied to the present invention,

3 is a detailed flowchart showing an embodiment of the servo gain adjustment method of the present invention.

<Description of Symbols for Main Parts of Drawings>

100; Disk 110; Laser beam generator

120; Laser driver 130; Encoder

140; Optical pickup unit 150; Servo

160; Amplification unit 170; filter

180; Control

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

Fig. 1 is a detailed block diagram showing an embodiment of the servo gain adjusting device of the present invention. In FIG. 1, the servo gain adjusting device includes a disk 100 having a reflected light measuring area, a laser beam generator 110, a laser driver 120, an encoder 130, an optical pickup unit 140, and a servo unit 150. ), An amplifier 160, a filter 170, and a controller 180.

Generally, as shown in FIG. 2, the disc 100 includes a read-in area (a) in which information about a program is recorded as a table of contents (TOC), a program area (b) in which a program is stored, And a read out area c in which information on the end of the program is stored.

In this case, the disk 100 according to the present invention is characterized in that the reflection amount measurement region capable of measuring the reflection amount of the laser powder is allocated to a predetermined area, preferably a lead-in area (a) of the disk 100. can do.

The laser beam generator 110 generates a laser beam for recording data on the disk 100 or reproducing the data recorded on the disk 100, and the laser driver 120 generates the laser beam generator 110. Provides a recording / reproducing drive signal for driving a.

Meanwhile, the encoder 130 provides data to be recorded on the disk 100 to the laser beam generator 110, and the optical pickup unit 140 transmits the laser beam generated by the laser beam generator 110 to the disk 100. Data is recorded on the disk by irradiating the signal surface of the signal) or the light reflected from the disk 100 is converted into an electrical signal and provided to the amplifier 160.

The servo unit 150 is responsible for the servo of the optical pickup unit 140 based on the servo gain corresponding to the recording mode or the reproduction mode of the optical disc system.

The filter 170 removes the noise of the signal amplified by the amplifier 160 and provides it to the controller 180.

The controller 180 has a reflection amount of the laser beam irradiated from the optical pickup unit 140 to the reflection amount measurement area of the disk 100 in the recording mode, the recording servo gain corresponding to the reflection amount, and the optical pickup unit in the reproduction mode. The reflection amount of the laser beam irradiated to the reflection amount measurement area of the disk 100 at 140 and the reproducing servo gain corresponding to the reflection amount are tabulated and stored in the internal memory.

In addition, the controller 180 controls the laser driver 120 in the recording or reproducing mode so that the laser beam is irradiated to the reflectance measuring region of the disk 100, and then the amount of reflection of the laser beam from the signal input from the filter 170. And the servo unit 150 to perform servo control based on the recording or reproducing servo gain corresponding to the detected amount of reflection based on the data stored in the internal memory.

3 is a detailed flowchart illustrating an embodiment of the servo gain adjustment method of the present invention. Therefore, the operation and method of the servo gain adjusting apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1, 2, and 3.

First, when the disc 100 is loaded in the optical disc system (S1), the controller 190 determines the recording or reproducing mode (S2, S9). When the current mode is the recording mode (S2), the controller 180 controls the optical pickup unit 140 to move to the reflection amount measuring area of the disk 100 before recording data on the disk 100. The servo unit 150 transfers the optical pickup unit 140 to the reflection amount measuring region of the disk 100 under the control of the controller 180 (S3).

After the optical pickup unit 140 is transferred to the reflection amount measuring area of the disk 100, the controller 180 controls the laser driver 120 to control the laser beam of the recording power level.

The laser driver 120 provides a write drive signal to the laser beam generator 110 under the control of the controller 180, and the laser beam generator 110 is predetermined based on the write drive signal of the laser driver 120. Generates a laser level recording laser beam. The optical pickup unit 140 irradiates the recording laser beam generated by the laser beam generator 110 to the reflection amount measurement region of the disk 100 (S4), and then converts the amount of light reflected from the disk 100 into an electrical signal. To the amplifier 160.

The amplifier 160 amplifies an electrical signal corresponding to the amount of reflected light and provides it to the filter 170. The amplifier 160 removes noise by filtering the signal and provides it to the controller 180.

The controller 180 detects a reflection amount of the laser beam from the signal input from the filter 170 (S5). Then, the controller 180 determines the write servo gain corresponding to the reflection amount of the laser beam tabled in the internal memory (S6). When the recording servo gain is determined, the controller 180 adjusts the servo gain of the servo unit 150 to the recording servo gain determined in step S6. The servo unit 150 is adjusted to the recording servo gain by the control of the controller 180 (S7), and then the controller 180 controls the system to perform data recording (S8).

On the other hand, as a result of the determination in the process S2, S9, when the current mode is the playback mode (S9) before the control unit 180 plays the data on the disk 100, the optical pickup unit 140 measures the reflection amount of the disk 100 Control to move to the area. The servo unit 150 transfers the optical pickup unit 140 to the reflection amount measuring region of the disk 100 under the control of the controller 180 (S10).

After the optical pickup unit 140 is transferred to the reflection amount measuring area of the disk 100, the controller 180 controls the laser driver 120 to control the laser beam of the reproduction power level to be irradiated.

The laser driver 120 provides a reproduction drive signal to the laser beam generator 110 under the control of the controller 180, and the laser beam generator 110 is predetermined based on the reproduction drive signal of the laser driver 120. Generates a reproduction laser beam of the powder level. The optical pickup unit 140 irradiates the reproducing laser beam generated by the laser beam generating unit 110 to the reflection amount measuring region of the disk 100 (S11), and then converts the amount of light reflected from the disk 100 into an electrical signal. To the amplifier 160.

The amplifier 160 amplifies an electrical signal corresponding to the amount of reflected light and provides it to the filter 170. The amplifier 160 removes noise by filtering the signal and provides it to the controller 180.

The controller 180 detects the reflection amount of the laser beam from the signal input from the filter 170 (S12). Thereafter, the controller 180 determines the reproduction servo gain corresponding to the reflection amount of the laser beam tabled in the internal memory (S13). When the regenerative servo gain is determined, the controller 180 adjusts the servo gain of the servo unit 150 to the regenerative servo gain determined in step S13. The servo unit 150 is adjusted to the reproduction servo gain by the control of the controller 180 (S14), and then the controller 180 controls the system to perform data reproduction (S15).

As described above, according to the present invention, the servo gain is adaptively adjusted based on the amount of reflected light reflected after the recording laser beam or the reproduction laser beam is irradiated to the reflection amount measurement area of the disc, thereby changing the state of the disc and the characteristics of the system. Regardless of the effect, more accurate servo control can be performed.

Claims (2)

In a servo gain adjusting apparatus of an optical disc system for performing regulating servo gain and recording servo gain for performing servo control necessary for performing data reproduction and recording by using a disk having a reflectance measuring area on a signal plane: A laser beam generating unit (110) for generating a recording laser beam for recording data on the disk and a reproduction laser beam for reproducing the data recorded on the disk; A laser driver (120) for recording / reproducing driving signals for driving the laser beam generator (110); An encoder (130) for providing data to be recorded on the disc to the laser beam generator (110); An optical pickup unit (140) for irradiating the laser beam generated by the laser beam generator (110) to the reflected light measuring area of the disk and converting the reflected light into an electrical signal and outputting the electrical signal; A servo unit 150 for performing servo control on the optical pickup unit 140 based on a servo gain corresponding to a recording mode or a reproduction mode; An amplifier 160 which amplifies and outputs an electrical signal provided from the optical pickup unit 140; A filter 170 for removing noise of the signal amplified by the amplifier 160; The reflection amount of the recording laser beam irradiated to the reflectance measurement area of the disk, the recording servo gain corresponding to the reflection amount of the recording laser beam, the reflection amount of the reproduction laser beam irradiated to the reflection amount measurement area of the disc, and the reproduction laser beam The reproducing servo gain corresponding to the reflecting amount of the table is stored in the internal memory, and the laser driving unit 120 is controlled in the recording or reproducing mode so that the laser beam is irradiated to the reflecting measuring region of the disc. The servo unit 160 detects a reflection amount of the laser beam from a signal input from a filter and performs servo control based on a recording or reproducing servo gain corresponding to the detected reflection amount based on data stored in the internal memory. Servo gain adjusting device of an optical disk system having a control unit 180 for controlling the control. In the servo gain adjustment method of an optical disc system performing adjustment of the reproducing servo gain and the recording servo gain of the servo unit which performs the servo control necessary for performing data reproduction and recording by using a disc having a reflectance measuring area on the signal plane: A first step of determining whether the current mode is a recording mode or a reproduction mode when the disc is mounted in the optical disc system; A second step of detecting an amount of reflected light reflected after irradiating a recording laser beam to a reflection amount measurement area of said disk in a recording mode as a result of the determination of said first step; A third step of detecting a write servo gain corresponding to the reflected light amount of the second step and adjusting the gain of the servo unit to the detected write servo gain; A fourth step of detecting the amount of reflected light reflected after the reproduction laser beam is irradiated to the reflection amount measurement region of the disc in the reproducing mode as a result of the determination in the first step; And a fifth step of adjusting the gain of the servo unit to the detected reproducing servo gain after detecting the reproducing servo gain corresponding to the reflected light amount of the fourth step.