Optical Disc Recording Power Control via Land/Groove Switch Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical disc recording methods face challenges in accurately determining the land/groove track switch points, leading to increased bit error rates due to inconsistent recording power across alternating land and groove tracks, especially under noisy conditions or high rotation speeds.
Innovation Solution
A predictive mechanism using counters and a Land/Groove switch predict machine to determine the track type and adjust recording power based on physical identification numbers (PID), allowing for accurate prediction of land/groove switch points even without sector type information, thereby maintaining consistent recording power across tracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same power level is used for recording data on land and groove tracks, then the recording process is simplified, but bit error rate increases due to different recording conditions on land and groove tracks
Solution Approach 1:
The patent applies local quality by using different recording power levels for different track types. Specifically, a first recording power level is used for groove tracks and a second recording power level is used for land tracks, optimizing recording conditions for each track type's specific characteristics rather than using a uniform power level across all tracks
2Ease of operation
If conventional methods using PID information are used to determine land/groove track switch points, then track type identification is straightforward, but accuracy decreases under high noise or high rotation speed conditions
Solution Approach 1:
The patent implements feedback by continuously monitoring the reproduced signal during recording and detecting zero-crossing points. The system uses the relationship between write clock cycles and zero-crossing points to dynamically identify land/groove track switch points, providing real-time feedback that maintains accuracy even under high noise or high rotation speed conditions where conventional PID-based methods fail
Data Source
AI summary
A system controlling recording on an optical disc is provided. A first counter performs a bit count according to provided channel bit clock signals. A second counter performs a sector count responsive to the bit count obtained by the first counter. The Land/Groove switch predicts machine uses the result of bit count and sector count to predict the land/groove switch point. The processor uses the physical ID (PID) to determine the track type of a sector at which a recording operation initiates. The power controller determines a recording power for the recording operation according to the Land/Groove switch predict machine.