APPARATUS AND RELATED METHOD FOR GENERATING A TRACKING ERROR SIGNAL IN AN OPTICAL DISC DRIVE

• US 20060023580A1
• Filed: 10/19/2005
• Published: 02/02/2006
• Est. Priority Date: 07/08/2004
• Status: Active Grant

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Yen, Kuang-Yu, He, Wei-Hung
• Granted Patent: US 7,583,569 B2
• Time in Patent Office: Days
• US Class Current: 369/44.270
• CPC Class Codes: G11B 7/0906 Differential phase difference systems

Abstract

The present invention discloses an apparatus for generating a tracking error signal in an optical disc drive. The disclosed apparatus includes: an analog-to-digital conversion module for receiving a plurality of analog signals generated by accessing an optical disc and for converting the plurality of analog signals into a plurality of digital signals with a sampling rate; a frequency control module coupled to the analog-to-digital conversion module for adjusting the sampling rate according to the plurality of digital signals; and a signal generation module coupled to the analog-to-digital conversion module for generating the tracking error signal according to the plurality of digital signals.

Claims

1. An apparatus for generating a tracking error signal comprising:

an analog-to-digital conversion module for receiving a plurality of analog signals generated by accessing an optical disc and converting the plurality of analog signals to a plurality of digital signals according to a sampling rate;

a frequency control module coupled to the analog-to-digital conversion module for adjusting the sampling rate according to the plurality of digital signals; and

a signal generation module coupled to the analog-to-digital conversion module for generating the tracking error signal according to the plurality of digital signals.

2. The apparatus of claim 1, wherein the frequency control module comprises:

at least a detection module coupled to the analog-to-digital conversion module for generating at least a detection value according to the plurality of digital signals and a plurality of delay signals, wherein the plurality of delay signals are generated according to the plurality of digital signals; and

a frequency control unit coupled to the detection module for adjusting the sampling rate according to the detection value.

3. The apparatus of claim 2, wherein the detection value comprises a first detection value and a second detection value, and the frequency control unit increases and decreases the sampling rate by comparing the first and second detection value.

4. The apparatus of claim 2, wherein the detection module comprises:

a digital logic module coupled to the analog-to-digital conversion module for generating a plurality of control signals according to the plurality of digital signals and the plurality of delay signals; and

an envelope generation unit coupled to the digital logic module for generating the detection value according to the plurality of control signals.

5. The apparatus of claim 4, wherein the digital logic module is utilized for determining values of the plurality of control signals according to a truth table.

6. The apparatus of claim 1, wherein the signal generation module comprises:

a delay module coupled to the analog-to-digital conversion module for delaying the plurality of digital signals to generate the plurality of delay signals;

a digital logic module coupled to the analog-to-digital conversion module and the delay module for generating at least one increasing signal and at least one decreasing signal according to the plurality of digital signals and the plurality of delay signals; and

an output unit coupled to the digital logic module for generating the tracking error signal according to the increasing signal and the decreasing signal.

7. The apparatus of claim 6, wherein the digital logic module is utilized to determine values of the increasing and decreasing signals according to a truth table.

8. The apparatus of claim 1 further comprising:

a frequency conversion module coupled to the frequency control module for converting a frequency of an external clock to the sampling rate according to the plurality of digital signals.

9. A method for generating a tracking error signal, the method comprising:

receiving a plurality of analog signals generated by accessing an optical disc and converting the plurality of analog signals to a plurality of digital signals according to a sampling rate;

adjusting the sampling rate according to the plurality of digital signals; and

generating the tracking error signal according to the plurality of digital signals.

10. The method of claim 9, wherein the step of adjusting the sampling rate further comprises:

generating a plurality of delay signal according to the plurality of digital signals;

generating a plurality of detection values according to the plurality of digital signals and the plurality of delay signals; and

adjusting the sampling rate by comparing the plurality of detection values.

11. The method of claim 9, wherein the step of generating the tracking error signal further comprises:

generating a plurality of delay signals according to the plurality of digital signals;

generating at least one increasing signal and at least one decreasing signal according to the plurality of digital signals and the plurality of delay signals; and

generating the tracking error signal according to the increasing signal and the decreasing signal.

12. The method of claim 11, wherein the step of generating the increasing signal and the decreasing signal further comprises determining values of the increasing and decreasing signals according to a truth table.

13. An apparatus for generating a tracking error signal comprising:

an analog-to-digital conversion module for receiving a plurality of analog signals generated by accessing an optical disc and converting the plurality of analog signals to a plurality of digital signals according to a sampling rate;

a frequency control module coupled to the analog-to-digital conversion module for adjusting the sampling rate according to the plurality of digital signals;

a signal generation module coupled to the analog-to-digital conversion module for generating an error signal according to the plurality of digital signals;

a quality detection module coupled to the signal generation module for generating a quality detection signal according to the error signal; and

a signal mix module coupled to the signal generation module and the quality detection module for generating the tracking error signal according to the error signal and the quality detection signal.

14. The apparatus of claim 13, wherein the frequency control module comprises:

a detection module coupled to the analog-to-digital conversion module for generating a detection value according to the plurality of digital signals and a plurality of delay signals, wherein the plurality of delay signals are generated according to the plurality of digital signals; and

a frequency control unit coupled to the detection module for adjusting the sampling rate according to the detection value.

15. The apparatus of claim 14, wherein the detection value comprises a first detection value and a second detection value, and the frequency control unit is utilized to increase and decrease the sampling rate by comparing the first and second detection values.

16. The apparatus of claim 14, wherein the detection module comprises:

a digital logic module coupled to the analog-to-digital conversion module for generating a plurality of control signals according to the plurality of digital signals and the plurality of delay signals; and

an envelope generation unit coupled to the digital logic module for generating the detection value according to the plurality of control signals.

17. The apparatus of claim 16, wherein the digital logic module is utilized to determine values of the plurality of control signals according to a truth table.

18. The apparatus of claim 13, wherein the error signal comprises a first error signal and a second error signal, the quality detection signal comprises a first quality detection signal and a second quality detection signal, and the signal mix module is utilized to output a combination of the first error signal and second error signals the tracking error signal according to the first and second quality detection signals.

19. The apparatus of claim 13, wherein the error signal comprises a first error signal, the quality detection signal comprises a first quality detection signal and a second quality detection signal, and the signal mix module is utilized to output the first error signal as the tracking error signal according to the first and second quality detection signals.