Dual Error Correction Coding for Optical Disc Stability
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Solution Overview
Problem
High-density optical discs face challenges in stable data reproduction and efficient recording capacity due to increased bit errors caused by scratches or dust, which conventional error correction techniques struggle to address effectively.
Innovation Solution
An optical disc device employing dual error correction coding circuits, with a first format using Reed-Solomon product codes and a second format generating higher redundancy parity codes, allowing for stable data reproduction and efficient use of recording capacity by switching between formats based on error conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If recording density is increased to increase recording capacity, then space efficiency is improved, but the number of bit errors increases due to scratches or dust
Solution Approach 1:
The error correction functionality is segmented into two distinct circuits: a first error correction coding circuit using conventional Reed-Solomon product codes, and a second error correction coding circuit using enhanced codes with higher redundancy. This segmentation allows the system to handle different error scenarios with appropriately matched correction capabilities, resolving the contradiction between high-density recording and error stability.
Solution Approach 2:
The patent employs a composite error correction approach by combining two different error correction coding formats. The first format provides standard correction for typical errors, while the second format provides enhanced correction for severe errors caused by scratches or dust. This composite structure enables the system to maintain reliable data reproduction across varying disc conditions while preserving high recording capacity.
2Device complexity
If conventional error correction techniques are used on high-density optical discs, then device complexity is kept simple, but error correction capability is insufficient for continuous errors
Solution Approach 1:
The error correction system is made dynamic by enabling switching between two error correction coding formats based on the detected error conditions. When continuous errors are detected that exceed the correction capability of the first format, the system dynamically transitions to using the second format with higher redundancy. This dynamic adaptation resolves the contradiction by providing enhanced correction capability only when needed, rather than always using the more complex second format.
Solution Approach 2:
The patent changes the redundancy parameter of the error correction codes by providing two different coding formats with different redundancy levels. The first format uses standard redundancy appropriate for normal operation, while the second format increases the redundancy parameter to handle continuous errors. This parameter change allows the system to maintain simplicity during normal operation while achieving high reliability when errors occur.
3Reliability
If replacement tracks are provided for error correction, then data reliability is improved, but recording capacity efficiency decreases
Solution Approach 1:
Instead of providing complete replacement tracks for all data blocks, the patent applies partial action by using the enhanced second error correction format only for specific blocks that require it. The system selectively applies the second coding format based on error detection, rather than universally applying it to all data. This partial application reduces the impact on recording capacity while maintaining reliability where needed.
Solution Approach 2:
The patent implements local quality by applying different error correction formats to different data blocks based on their specific requirements. Blocks that are more susceptible to errors or that contain critical data can be assigned the second format with higher redundancy, while other blocks use the more efficient first format. This localized approach optimizes the balance between reliability and recording capacity.
Data Source
AI summary
An optical disc device includes a first error correction coding circuit that codes the recording data according to a first error correction coding format, a second error correction coding circuit that codes the recording data according to a second error correction coding format, and a recorder that converts the recording data into a recording signal and records it on an optical disc. The second error correction coding format is different in an arrangement of the recording data from the first error correction coding format. The second error correction coding format is configured to generate a second parity code with a higher degree of redundancy. The recorder records the recording data coded by the first error correction coding circuit and only the second parity code in the recording data coded by the second error correction coding circuit.