KR20040010981A - Tilt control method of optical disc - Google Patents

Abstract

PURPOSE: A tilt control method for an optical disc is provided to achieve the tilt control precisely for realizing the stable recording and playing data for an optical disc. CONSTITUTION: A tilt control method for an optical disc includes the steps of setting initial tilt reference values, and detecting real tilt amounts from inner and outer peripheral areas of the disc for correcting the initial tilt reference value. The tilt reference values are corrected for both of the inner and outer peripheral areas individually, wherein the corrected values are stored in a memory to be used in the real tilt control for corresponding areas. The real tilt amount detection is carried out by a uniform/ununiform interval along the inner and outer peripheral areas.

Description

Tilt control method of optical disc

The present invention relates to a tilt control method for a tube disk.

In recent years, as the optical disc system has been increased in density, precise servo control is required to record and reproduce the disc. In particular, the tracking servo and focusing servo have been controlled so as to accurately follow the track of the information recorded on the disc. However, with the recent increase in the density of discs, the space between tracks on which information is recorded becomes very narrow, and thus, the tracking servo and the focusing servo alone do not accurately follow the tracks of the disc.

Tilt servo is a control of the tilt component generated by the production process or use of the disc, and this tilt component may cause serious recording and playback quality, especially on high density discs with narrow track pitches. Accordingly, an optical disc drive that performs a tilt servo for high precision servo control has been increasing.

However, the conventional tilt control method uses a tilt sensor or a three-axis actuator. Recently, a method of controlling the tilt with reference to the signal quality reproduced in a specific region of a disc has been proposed.

However, the problem of the conventional method as described above had a problem of low control accuracy.

The present invention aims to provide a method for precise tilt control of a disc.

1 is a configuration diagram of an optical disc tilt control for explaining the tilt control method of the present invention.

2 is a flow chart showing the tilt control method of the present invention

The present invention has the following configuration to achieve the above object.

Setting an initial tilt control reference (Ref.) Value, detecting a tilt amount of the disc from the inner and outer peripheral regions of the disc, and correcting the tilt control reference value from the detected tilt amount. do.

In the detecting of the tilt amount, the tilt amount may be obtained a plurality of times by dividing the inner and outer circumferences of the disk at equal intervals.

In the detecting of the tilt amount, the inner and outer circumferences of the disk may be divided at a predetermined interval, and the tilt amount may be obtained a plurality of times including at least the inner and outer circumferences of the disk.

In the detecting of the tilt amount, the tilt adjustment is performed on the inner and outer circumferences of the disc, and then the validity of the tilt adjustment through linear correction is determined, and the tilt amount is determined by re-detecting the tilt amount in another region. It is characterized by.

Hereinafter, a detailed description of the present invention will be described with reference to FIGS. 1 and 2.

1 is an optical disk tilt control configuration for explaining the tilt control method of the present invention.

For optical disc tilt control, a tilt driving mechanism must be provided in the pickup mechanism. This is necessary to drive the pickup mechanism in the direction of canceling the tilt in accordance with the tilt control. There is a tilt error generating section for generating a tilt error amount from a signal in the disk detected from the pickup mechanism, wherein a tilt control section for generating a tilt control signal controlled from the generated tilt error amount is provided, and the pickup is made according to the tilt control value. A tilt drive for driving the mechanism is provided.

2 is an operation flowchart showing a tilt control method of the present invention.

When the optical disc is loaded first, the tilt driving mechanism of the pickup mechanism sets the initial tilt reference value. This can be set to an average median value of the tilt error amount while driving the tilt driving mechanism as a reference value for the tilt control. However, such tilt reference alone does not allow full tilt correction because there is a difference in tilt amount in the inner and outer circumferences of the disc. Therefore, when the initial tilt reference value is set, the actual tilt amount is detected in the inner and outer circumferential regions of the disc. The detected tilt amount corrects the initial tilt reference value. At this time, the correction of the tilt reference is performed separately by the inner and outer circumferences of the disk, and the corrected value is stored in the memory and used when the tilt control is actually performed in the corresponding area.

At this time, the present invention is to present three cases as a method of detecting the amount of tilt.

The first is to try to detect the tilt a plurality of times by dividing the inner and outer circumferences at equal intervals and to correct the tilt reference at each corresponding position.

The second is to divide the inner and outer circumferences at random intervals, not at equal intervals, and to attempt tilt detection a plurality of times, and to correct the tilt reference at each corresponding position. At this time, it is preferable that at least the inner and outer circumferential regions of the disc detect the tilt amount one or more times.

The third method is to adjust the tilt at the inner and outer circumferences of the disk, adjust again at an appropriate distance from the outer circumference, and perform linear correction to determine the validity of the tilt adjustment and then decide whether to adjust at another position. At this time, the tilt amount detection position is determined according to the disk state.

The present invention enables stable recording and reproducing of high density discs by performing precise tilt control.

Claims (4)

Setting an initial tilt control reference (Ref.) Value; Detecting the amount of tilt of the disk from the inner and outer peripheral regions of the disk; And tilting the tilt control reference value from the detected tilt amount. The tilt control method as claimed in claim 1, wherein the detecting of the tilt amount comprises: calculating the tilt amount by a plurality of times by dividing the inner and outer circumferences of the disc at equal intervals. The tilt control method of claim 1, wherein the detecting of the tilt amount comprises dividing the inner and outer circumferences of the disk at a predetermined interval, and obtaining the tilt amount by a plurality of times including at least the inner and outer circumferences of the disk. The method of claim 1, wherein the detecting of the tilt amount is performed by adjusting the tilt on the inner and outer circumferences of the disc, and then checking the validity of the tilt adjustment through linear correction and determining whether to redetect the tilt amount in another region. Tilt control method characterized by obtaining the amount.