TILT CALIBRATION APPARATUS AND METHOD CAPABLE OF ADJUSTING INCLUDED ANGLE BETWEEN OPTICAL PICK-UP HEAD AND OPTICAL DISC ACCORDING TO WOBBLE SIGNAL

• US 20070133365A1
• Filed: 12/12/2005
• Published: 06/14/2007
• Est. Priority Date: 12/12/2005
• Status: Abandoned Application

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Huang, Ying-Feng, Ko, Shih-Hao, Lee, Chi-Jui
• Application Number:
  US11/164,962
• Publication Number:
  US 20070133365A1
• Time in Patent Office: Days
• US Class Current: 369/44.320
• CPC Class Codes: G11B 19/20 Driving; Starting; Stopping; Control thereof
• CPC Class Codes: G11B 7/0956 to compensate for tilt, skew, warp or inclination of the disc, i.e. maintain the optical axis at right angles to the disc
• CPC Class Codes: G11B 7/24082 Meandering

Abstract

A tilt calibrating apparatus and method capable of adjusting an included angle between an optical disc and an optical pick-up head are disclosed. The tilt calibrating apparatus includes a photo detector, in the optical pick-up head, for detecting a signal reflected from a wobble groove on the optical disc, a wobble processor, electrically connected to the photo detector, for generating a wobble signal according to the signal reflected from a wobble groove on the optical disc, and an driver, electrically connected to the wobble processor, for controlling the included angle by rotating the optical pick-up head or the optical disc according to the wobble signal.

Claims

1. A tilt calibrating apparatus for adjusting an included angle between an optical disc and an optical pick-up head, the tilt calibrating apparatus comprising:

a photo detector, in the optical pick-up head, for detecting a signal reflected from a wobble groove on the optical disc;

a wobble processor, electrically connected to the photo detector, for generating a wobble signal according to the signal reflected from the wobble groove; and

an driver, electrically connected to the wobble processor, for controlling the included angle by rotating the optical pick-up head or the optical disc according to the wobble signal.

2. The tilt calibrating apparatus of claim 1, further comprising:

a controlling unit, electrically connected between the wobble processor and the driver, for generating a control signal according to the wobble signal to control the driver;

wherein the driver rotates the optical pick-up head according to the control signal in order to decreases the included angle between the optical disc and the optical pick-up head.

3. The tilt calibrating apparatus of claim 2, wherein the driver rotates the optical pick-up head until the amplitude of the wobble signal is substantially maximum.

4. The tilt calibrating apparatus of claim 3, wherein if the amplitude of the wobble signal is increased after the driver rotates the optical pick-up head along a first direction according to a control signal, the controlling unit outputs the control signal to control the driver to keep rotating the optical pick-up head along the first direction;

and if the amplitude of the wobble signal is decreased after the driver rotates the optical pick-up head along the first direction, the controlling unit outputs the control signal to stop the driver from rotating the optical pick-up head.

5. The tilt calibrating apparatus of claim 4, wherein if the amplitude of the wobble signal is decreased after the driver rotates the optical pick-up head along the first direction according to the control signal, the controlling unit outputs the control signal to control the driver to rotate the optical pick-up head along a second direction opposite to the first direction;

and if the amplitude of the wobble signal is decreased after the driver rotates the optical pick-up head along the second direction, the controlling unit outputs the control signal to stop the driver from rotating the optical pick-up head.

6. The tilt calibrating apparatus of claim 3, wherein the wobble signal carries a predetermined data.

7. The tilt calibration apparatus of claim 6, wherein if the error rate of the predetermined data is decreased after the driver rotates the optical pick-up head along a first direction according to a control signal, the controlling unit outputs the control signal to control the driver to continue rotating the optical pick-up head along the first direction;

and if the error rate of the predetermined data is increased after the driver rotates the optical pick-up head along the first direction, the controlling unit outputs the control signal to stop the driver from rotating the optical pick-up head.

8. The tilt calibration apparatus of claim 6, wherein if the error rate of the predetermined data is increased after the driver rotates the optical pick-up head along the first direction according to the control signal, the controlling unit outputs the control signal to control the driver to rotate the optical pick-up head along a second direction opposite to the first direction;

and if the error rate of the predetermined data is increased after the driver rotates the optical pick-up head along the second direction, the controlling unit outputs the control signal to stop the driver from rotating the optical pick-up head.

9. The tilt calibrating apparatus of claim 2, wherein the controlling unit generates the control signal according to an inner wobble signal and an outer wobble signal generated from the wobble processor, the inner wobble signal corresponds to an inner side of the optical pick-up head, the outer wobble signal corresponds an outer side of the pick-up head, the controlling unit outputs the control signal to drive the driver to rotate the optical pick-up head to make the inner side approach the optical disc when the amplitude of the inner wobble signal is less than the amplitude of the outer wobble signal, and the controlling unit outputs the control signal to drive the driver to rotate the optical pick-up head to make the outer side approach the optical disc when the amplitude of the inner wobble signal is greater than the amplitude of the outer wobble signal.

10. A tilt calibrating method for adjusting an included angle between an optical disc and an optical pick-up head, the tilt calibrating method comprising:

detecting a signal reflected from a wobble groove on the optical disc;

generating a wobble signal according to the signal reflected from the wobble groove; and

controlling the included angle by rotating the optical disc or the optical pick-up head according to the wobble signal.

11. The tilt calibrating method of claim 10, further comprising:

generating a control signal according to the wobble signal; and

the step of controlling the included angle comprising;

rotating the optical pick-up head according to the control signal to adjust the included angle.

12. The tilt calibrating method of claim 11, wherein the step of rotating the optical pick-up head comprises:

rotating the optical pick-up head according to an axis parallel to a radial direction of the optical disc until the amplitude of the wobble signal is substantially maximum.

13. The tilt calibrating method of claim 12, wherein the step of generating the control signal comprises:

if the amplitude of the wobble signal increases after rotating the optical pick-up head along a first direction according to a control signal, updating the control signal to keep rotating the optical pick-up head along the first direction; and

if the amplitude of the wobble signal decreases after rotating the optical pick-up head along the first direction, updating the control signal to stop rotating the optical pick-up head.

14. The tilt calibrating method of claim 13, wherein the step of generating the control signal further comprises:

if the amplitude of the wobble signal decreases after rotating the optical pick-up head along the first direction according to the control signal, updating the control signal to rotate the optical pick-up head along a second direction opposite to the first direction; and

if the amplitude of the wobble signal decreases after rotating the optical pick-up head along the second direction, updating the control signal to stop rotating the optical pick-up head.

15. The tilt calibrating apparatus of claim 12, wherein the wobble signal carries a predetermined data.

16. The tilt calibrating method of claim 15, wherein the step of generating the control signal comprises:

if the error rate of the wobble signal decreases after rotating the optical pick-up head along a first direction according to a control signal, updating the control signal to keep rotating the optical pick-up head along the first direction; and

if the error rate of the wobble signal increases after rotating the optical pick-up head along the first direction, updating the control signal to stop rotating the optical pick-up head.

17. The tilt calibrating method of claim 16, wherein the step of generating the control signal further comprises:

if the error rate of the wobble signal increases after the rotating the optical pick-up head along the first direction according to the control signal, updating the control signal to rotate the optical pick-up head along a second direction opposite to the first direction; and

if the error rate of the wobble signal increases after the rotating the optical pick-up head along the second direction, outputting the control signal to stop rotating the optical pick-up head.

18. The tilt calibrating method of claim 11, wherein the step of generating the control signal comprises:

generating the control signal according to an inner wobble signal and an outer wobble signal according to the signal reflected from the wobble groove, the inner wobble signal corresponds to an inner side of the optical pick-up head, the outer wobble signal corresponds an outer side of the pick-up head.

19. The tilt calibrating method of claim 18, wherein the step of generating the control signal further comprises:

updating the control signal corresponding to rotating the optical pick-up head to make the inner side approach the optical disc when the amplitude of the inner wobble signal is less than the amplitude of the outer wobble signal; and

updating the control signal corresponding to rotating the optical pick-up head to make the outer side approach the optical disc when the amplitude of the inner wobble signal is greater than the amplitude of the outer wobble signal.