Optical Disc Defect Management Area Segmentation
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Solution Overview
Problem
Conventional optical discs rapidly consume temporary defect management areas when defective clusters are detected during data recording, requiring re-recording of all defective area lists in subsequent clusters, which limits flexibility and efficiency.
Innovation Solution
A write-once optical disc design that allows for the recording of defective area lists in a predetermined order, using a temporary defect management area with sections for successfully written, retry-written, and last-cluster-including structure information, enabling discrete arrangement of lists and reducing area consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If defective area lists are arranged sequentially in ascending order of addresses in the temporary defect management area, then the firmware can process the lists normally, but the temporary defect management area is consumed rapidly when defective clusters are detected
Solution Approach 1:
The patent segments the temporary defect management area into multiple discrete sections, each capable of storing defective area lists independently. Instead of requiring contiguous sequential storage, the system divides the management area into separate segments that can be distributed across different clusters, allowing parallel storage of multiple defective area lists without requiring all clusters to be contiguous.
Solution Approach 2:
The patent transitions from a one-dimensional sequential arrangement of defective area lists to a multi-dimensional structure where lists can be arranged across multiple clusters in a tree-like hierarchy. The defective area lists are organized with parent-child relationships, allowing navigation through multiple levels rather than requiring linear sequential storage, thereby utilizing the two-dimensional space of cluster addresses more efficiently.
2Reliability
If all defective area lists are re-recorded in subsequent clusters when a defective cluster is detected, then data integrity is maintained, but the update time increases and productivity decreases
Solution Approach 1:
The patent extracts only the necessary defective area lists for re-recording when a defective cluster is detected, rather than requiring re-recording of all lists. The system identifies and isolates only those lists that are affected by the defective cluster, allowing selective updates that maintain data integrity while minimizing the scope of re-recording operations.
Solution Approach 2:
The patent performs preliminary organization of defective area lists into a hierarchical structure with parent-child relationships before finalization. This preliminary arrangement allows the system to quickly identify which lists need updating when defects are detected, rather than having to process all lists from scratch, thereby reducing update time and improving recording efficiency.
3Device complexity
If defective area lists are arranged in ascending order of addresses, then the firmware processing is simplified, but the flexibility in arranging lists is reduced
Solution Approach 1:
The patent implements a dynamic arrangement system where defective area lists can be organized in different configurations based on requirements. The hierarchical structure with parent-child relationships allows the system to adapt the arrangement dynamically - lists can be ordered by address when firmware processing is prioritized, or arranged in tree structures when flexibility and space utilization are prioritized, providing adaptability without increasing firmware complexity.
Data Source
AI summary
An optical disc 1 includes a defect management area (DMA). A plurality of defective area lists (TDFLs) and structure information (TDDS) are recorded in a temporary defect management area (TDMS) of the defect management area (DMA). The defective area lists (TDFLs) indicate at least one defective area which was detected during an access to the optical disc 1. The structure information (TDDS) includes a plurality of pieces of position information that indicate positions of the defective area lists (TDFLs). The plurality of pieces of position information, corresponding one-to-one to the defective area lists, are arranged in the structure information (TDDS) in an order in which the defective area lists (TDFLs) corresponding thereto are read out.