RF Equalizer Delay Control for Optical Disk Waveform Distortion
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Solution Overview
Problem
Existing optical disc drive devices face challenges in correcting waveform distortion caused by tangential tilt, which leads to playback data distortion, and current solutions like PRML techniques require high-cost, high-power processing circuits.
Innovation Solution
An optical disk drive device and method that utilize an RF equalizer to generate an equalized RF signal by controlling the frequency characteristic of the delay time of the RF signal based on a control input signal, extracted from the optical disk, to correct waveform distortion, thereby improving signal quality without the need for large-scale processing circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If PRML technique is used to correct tangential tilt, then waveform distortion correction is improved, but chip cost and power consumption increase due to large scale processing circuits
Solution Approach 1:
The patent extracts only the essential delay time adjustment function from the complex PRML processing system. By isolating and implementing just the delay control mechanism in the RF equalizer, the system achieves waveform distortion correction without requiring large-scale A/D converting circuits and Viterbi decoding circuits, thereby reducing chip cost and power consumption while maintaining correction effectiveness
Solution Approach 2:
The patent segments the waveform distortion correction function into a dedicated delay time control module within the RF equalizer. This segmentation allows the system to perform correction through focused delay adjustment rather than requiring complete PRML processing infrastructure, simplifying the overall system architecture and reducing resource requirements
2Manufacturing precision
If PRML technique is used to correct tangential tilt, then waveform distortion correction is improved, but power consumption increases due to high speed clock operation
Solution Approach 1:
The patent extracts only the essential delay time adjustment function from the complex PRML processing system. By isolating and implementing just the delay control mechanism in the RF equalizer, the system achieves waveform distortion correction without requiring large-scale A/D converting circuits and Viterbi decoding circuits, thereby reducing chip cost and power consumption while maintaining correction effectiveness
Solution Approach 2:
The patent applies partial action by implementing only the necessary delay time control function rather than the complete PRML processing chain. This partial implementation is sufficient to correct waveform distortion caused by tangential tilt, avoiding the excessive power consumption associated with full PRML processing while maintaining adequate correction performance
3Manufacturing precision
If pickup is designed without tangential tilt, then waveform distortion is avoided, but pickup margin and process yield worsen
Solution Approach 1:
The patent replaces the mechanical approach of physically eliminating tangential tilt in the pickup design with an electronic signal processing approach. By using the RF equalizer to adjust delay time and correct waveform distortion in the electrical domain, the system maintains playback data quality without requiring tighter mechanical tolerances, thereby improving pickup margin and manufacturing yield
Solution Approach 2:
The patent converts the harmful effect of tangential tilt into a correctable signal characteristic. Instead of preventing tilt mechanically, the system allows the tilt-induced waveform distortion to occur and then uses the RF equalizer's delay control to compensate for and correct the distortion, transforming a manufacturing challenge into a solvable signal processing problem that improves overall system robustness
Data Source
AI summary
An optical disk drive device has an RF equalizer configured to generate an equalized RF signal by controlling a frequency characteristic of a delay time of an RF signal read out from an optical disk based on a control input signal, a playback clock extractor configured to extract a playback clock for reproducing data recorded on the optical disk from the equalized RF signal, and an RF rate controller configured to generate the control input signal inputted to the RF equalizer, wherein the control input signal is a signal for correcting waveform distortion of the RF signal by controlling the delay time of the RF signal dependent on a frequency of the playback clock.