Quantcast

METHOD FOR DETECTING SERVO ERROR, APPARATUS THEREFOR, DISK WHICH MAINTAINS QUALITY OF SERVO ERROR SIGNAL, METHOD OF CONTROLLING SERVO OF DISK RECORDING/REPRODUCING APPARATUS, METHOD OF DETECTING TRACKING ERROR, AND METHOD OF DETECTING TILT ERROR

Imported: 23 Feb '17 | Published: 22 Oct '02

Seong-sin Joo, In-sik Park, Byung-in Ma, Chong-sam Chung, Jang-hoon Yoo, Jung-wan Ko, Kyung-geun Lee, Joong-eon Seo

USPTO - Utility Patents

Abstract

A method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus. The apparatus for recording data on and reproducing data from the disk in which a recording area is divided into sectors, each sector has a header for indicating an address, each header has a first header and a second header which are recorded to deviate from the center of the track in opposite directions, and the first header and the second header have address areas in which the addresses of sectors are recorded and synchronous signal areas in which synchronous signals for detecting the address signals recorded in the address area are recorded, includes a reproducing signal generator for generating a reproducing signal including sum signals V

1 and V

2 of radial pairs, a sum signal RF_sum, and a push-pull signal RF_pp from an optical signal reflected from the disk, a header area detector for generating a header area signal including a header area from the reproducing signal received from the reproducing signal generator, a first synchronous signal level detector for receiving the output of the reproducing signal generator and detecting a magnitude Ivfo

1 of a first synchronous signal in the first header by being synchronized with the header area signal received from the header area detector, a second synchronous signal level detector for receiving the output of the reproducing signal generator and detecting a magnitude Ivfo

3 of a second synchronous signal in the second header by being synchronized with the header area signal received from the header area detector, and a balance calculator for calculating the balance of the magnitude Ivfo

1 of the first synchronous signal detected by the first synchronous signal level detector and the magnitude Ivfo

3 of the second synchronous signal detected by the second synchronous signal level detector. As a result, it is possible for the recording/reproducing apparatus to stably control a servo therein and maintain an optimal recording/reproducing state since the apparatus for detecting the servo error correctly detects the servo error state of the disk.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above object and advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings, in which:

FIG. 1A shows the physical shape of a land track;

FIG. 1B shows the waveform of a push-pull signal in the land track;

FIG. 2A shows the physical shape of a groove track;

FIG. 2B shows the waveform of a push-pull signal in the groove track;

FIG. 3 shows an enlarged header area shown in FIGS. 1A and 2A;

FIGS. 4A and 4B show a push-pull signal and a sum signal which are obtained when a laser spot passes through the header area of the groove track in FIG. 3;

FIG. 5 shows the structure of an apparatus for obtaining the reproducing signal shown in FIG. 4;

FIG. 6 is a block diagram showing a structure of an apparatus for detecting a servo error according to an embodiment of the present invention;

FIGS. 7A through 7E show waveforms generated during the operation of the apparatus shown in FIG. 6;

FIG. 8 is a block diagram showing a structure of an apparatus for detecting the servo error according to another embodiment of the present invention;

FIGS. 9A through 9B show waveforms generated during the operation of the apparatus shown in FIG. 8;

FIG. 10 shows a conventional technology for correcting tilt;

FIG. 11 is a graph showing the relationship between radial tilt and a balance value K in the method and apparatus according to the present invention; and

FIG. 12 is a graph showing the relationship between detrack and the balance value K in the method and apparatus according to the present invention.

Claims

1. A disk, comprising:

2. The disk of claim 1, wherein the magnitude ratio is no more than ±0.1.

3. The disk of claim 2, wherein the first and second magnitudes Ivfo

1 and Ivfo

3 are detected by a photodetector having radial pairs of detecting elements, from a subtraction signal RF_pp of the radial pairs of the detecting elements.

4. The disk of claim 2, wherein the first and second magnitudes Ivfo

1 and Ivfo

3 are detected by a photodetector having radial pairs of detecting elements, from a sum signal RF_sum of the radial pairs of the detecting elements.

5. The disk of claim 1, wherein the magnitude ratio is determined to be (Ivfo

1-Ivfo

3)/Io, wherein Io is a magnitude of a mirror signal.

6. The disk of claim 5, wherein the first and second magnitudes Ivfo

1 and Ivfo

3 are detected by a photodetector having radial pairs of detecting elements, from a subtraction signal RF_pp of the radial pairs of the detecting elements.

7. The disk of claim 5, wherein the first and second magnitudes Ivfo

1 and Ivfo

3 are detected by a photodetector having radial pairs of detecting elements, from a sum signal RF_sum of the radial pairs of detecting elements.

8. A disk, comprising:

9. The disk of claim 8, wherein the first magnitude I

1 of a first synchronous clock signal is detected from the first header.

10. The disk of claim 8, wherein the second magnitude I

2 of a second synchronous clock signal is detected from the second header.

11. The disk of claim 8, wherein the magnitude ratio is no more than ±0.1.

12. The disk of claim 8, wherein the magnitude ratio is determined to be (I

1-I

2)/Io, where Io is a magnitude of a mirror signal.

13. A disk, comprising:

14. The disk of claim 13, wherein the magnitude ratio is determined to be (I

1-I

2)/Io, where Io is a magnitude of a mirror signal.

15. The disk of claim 13, wherein the first and second magnitudes I

1 and I

2 are detected by a photodetector having radial pairs of detecting elements, from a subtraction signal RF_pp of the radial pairs of the detecting elements.

16. The disk of claim 13, wherein the first and second magnitudes I

1 and I

2 are detected by a photodetector having radial pairs of detecting elements, from a sum signal RF_sum of the radial pairs of the detecting elements.

17. A disk, comprising:

18. The disk of claim 17, wherein the magnitude ratio is determined to be (I

1-I

2)/Io, where Io is a magnitude of a mirror signal.

19. The disk of claim 17, wherein the first and second magnitudes I

1 and I

2 are detected by a photodetector having radial pairs of detecting elements, from a subtraction signal RF_pp of the radial pairs of the detecting elements.

20. The disk of claim 17, wherein the first and second magnitudes I

1 and I

2 are detected by a photodetector having radial pairs of detecting elements, from a sum signal RF_sum of the radial pairs of the detecting elements.