Recording Device Address Management for Write Once Media
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Solution Overview
Problem
The existing methods for rewriting data on write once type recording media, such as Blu-ray discs, face inefficiencies due to the inability to rewrite data at the recorded position, requiring logical overwrite and read modify write operations, which can lead to decreased response times and increased access times when reading and rewriting data, especially when read errors occur.
Innovation Solution
A recording apparatus and method that includes a write/read unit and control unit capable of generating write data by merging update data with read data from the recording medium, using replacement information and extended replacement information to associate addresses and track validity/invalidity of data, allowing for efficient rewriting even when read errors occur by checking alternative addresses and maintaining extended replacement information for past errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If read modify write operation is performed to rewrite data on write once type recording medium, then data rewriting capability is achieved, but access time increases and response time decreases
Solution Approach 1:
The system performs preliminary actions by pre-managing replacement information and extended replacement information that map original data addresses to alternative addresses. When rewriting is needed, the system has already prepared the replacement pathways, eliminating the need for time-consuming search operations during the actual rewrite process.
Solution Approach 2:
The patent introduces replacement information and extended replacement information as intermediary data structures that mediate between the original data addresses and alternative storage locations. These intermediaries enable efficient address translation and data retrieval without direct searching, reducing access time while maintaining rewriting capability.
2Adaptability or versatility
If replacement information is used to associate original address with new address, then rewriting is enabled, but device complexity increases
Solution Approach 1:
The address management system is segmented into multiple hierarchical levels: replacement information for primary address mapping and extended replacement information for alternative pathways. This segmentation divides the complex address translation task into manageable segments, reducing overall system complexity while maintaining full rewriting capability.
Solution Approach 2:
The patent adds an additional dimension to address management by introducing extended replacement information that provides alternative address pathways. This dimensional expansion transforms the address management from a single-level mapping to a multi-dimensional structure, enabling efficient rewriting without proportionally increasing complexity.
3Reliability
If read error occurs during RMW process, then data integrity is compromised, but extended replacement information enables error recovery
Solution Approach 1:
The system implements beforehand cushioning by pre-establishing extended replacement information that serves as a safety buffer against read errors. When errors occur, the pre-prepared alternative pathways in the extended replacement information enable recovery without compromising data integrity, while the error handling complexity is managed through this预先建立的 protection mechanism.
Data Source
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AI summary
In order to realize efficient access in the case of restoring read failure data by RMW at the time of data rewriting, a recording apparatus includes a write/read unit capable of performing data writing in a second data unit, in which a plurality of first data units of a predetermined amount of data are consecutive, and data reading in the first data unit with respect to a recording medium and a control unit. In response to a rewrite instruction of data, the control unit instructs the write/read unit to generate write data in the second data unit using update data relevant to the rewrite instruction and recorded data read out from the recording medium and to write the write data at a non-recording address on the recording medium, and generates or updates replacement information for associating an address at which the write data is written, as a replacement destination, with an address of a replacement source. In addition, the control unit generates extended replacement information including validity/invalidity information for each piece of data in the first data unit in the write data, as information linked to the replacement information, according to predetermined conditions.