Write-Once Disc Access Information Areas for Update Area Search

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Solution Overview

Problem

Write-once discs face inefficiencies in accessing updated information due to the need for large update areas and the time-consuming process of detecting updated data, especially when defect management information is updated, as existing methods require recording new information at empty locations, leading to prolonged search times for desired information.

Innovation Solution

Implementing a write-once disc with multiple update areas and access information areas (AIA) that include main and sub AI, where the main AI is repeatedly recorded in entire recording blocks, and AI includes location information and flags to quickly identify the final update area and location of updated information, reducing access time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a large update area is allocated to record defect management information on a write-once disc, then the disc can accommodate multiple updates, but the time to search for and detect finally updated information increases excessively

Engineering Contradiction:

Improveupdate countVSAvoidaccess time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The access information area is divided into multiple update areas (first update area, second update area, etc.) arranged in sequence. Each update area can store defect management information independently, allowing the system to segment the search space and quickly locate the relevant update area using access information rather than searching the entire data area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Access information is introduced as an intermediary element that stores location pointers to defect management information in the update areas. This access information acts as a mediator between the reading apparatus and the actual defect management information, enabling direct access without exhaustive searching of the entire update area.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If updated defect management information is recorded at empty locations on a write-once disc, then the information can be preserved, but the location of finally updated information becomes difficult to detect

Engineering Contradiction:

Improveinformation preservationVSAvoiddetection difficulty

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

Update area allocation information is recorded in advance in the access information area before actual defect management information is written to update areas. This preliminary recording of location information allows the reading apparatus to know in advance where to find the latest defect management information without having to search through multiple empty locations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The access information is updated with the latest update area location information each time defect management information is written to a new update area. This feedback mechanism ensures that the access information always points to the most recent defect management information, making detection straightforward.

Inventive Principle:

Principle #23Feedback

3Loss of information

If the entire update area is searched to detect finally updated information, then the information can be found, but the search process takes an excessive amount of time

Engineering Contradiction:

Improveinformation completenessVSAvoidsearch time

Core Design Contradiction:

Loss of informationVSLoss of time

Solution Approach 1:

Access information that contains location pointers to defect management information is extracted from the update areas and stored separately in the access information area. This extraction allows the reading apparatus to access location information directly without searching through the entire update area, significantly reducing search time while maintaining information completeness.

Inventive Principle:

Principle #2Taking out (Extraction)

4Device complexity

If access information is not repeatedly recorded, then the disc structure is simpler, but error correction capability and access reliability are reduced

Engineering Contradiction:

Improvedisc structureVSAvoidaccess reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Access information is repeatedly recorded throughout the disc structure at multiple locations. This repeated recording creates local redundancy, ensuring that even if some copies are damaged, the access information can still be retrieved from other locations, thereby enhancing access reliability without fundamentally changing the disc structure.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7944805B2Method of and apparatus for recording data on write-once disc and write-once disc therefor

Publication Date: 2011.05.17 SAMSUNG ELECTRONICS CO LTD

AI summary

A method of recording, and an apparatus to record, data on a write-once disc, and the write-once disc used with the method and apparatus. The write-once disc includes a plurality of update areas in which to record a predetermined type of updated information, at least one main access information area (AIA) in which to record main access information (AI), the main AI indicating a final update area in which finally updated information is recorded, among the plurality of update areas, and at least one sub AIA in which to record sub AI, the sub AI indicating a location of the finally updated information recorded in the final update area.