Information Recording Apparatus Marker Recognition
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Solution Overview
Problem
In information recording media, such as DVDs, the presence of multiple intermediate markers after format processes complicates the recognition of the true end edge of recorded user data, leading to difficulties in maintaining accurate recording and reproduction operations, especially when read-only systems detect these markers as lead-out areas.
Innovation Solution
An information recording apparatus and method that utilize a flag bit set to a first value to distinguish user data from intermediate markers, ensuring the markers are recognized correctly and preventing misunderstandings with buffer areas, thereby maintaining operational integrity even with multiple markers present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a quick format process is performed multiple times to delete user data, then the user data can be logically deleted and reused, but multiple intermediate markers remain on the information recording medium causing confusion about the true end edge of recorded data
Solution Approach 1:
The intermediate marker is segmented into multiple unit blocks (e.g., 32 ECC blocks), each containing unit sectors. This segmentation allows the system to identify and process marker portions individually, enabling accurate recognition of the true end edge even when multiple markers exist from repeated format operations.
Solution Approach 2:
Different attributes are applied to different portions of the marker structure. The marker has a data area attribute added to indicate it occupies user data area, and specific flag bits are set in different unit sectors to indicate marker presence. This local differentiation allows read-only systems to distinguish markers from actual user data while preserving marker functionality.
2Measurement precision
If intermediate markers are recorded with lead-out area attribute to enable boundary detection, then seek operations can recognize data edges, but read-only systems mistakenly interpret markers as lead-out areas preventing proper user data access
Solution Approach 1:
The marker is given a data area attribute rather than a lead-out area attribute, creating a local quality distinction. Additionally, specific flag bits are set within the marker structure to indicate its true nature. This allows boundary detection functionality while preventing misinterpretation by read-only systems.
Solution Approach 2:
The flag bit acts as an intermediary indicator within the marker structure that provides additional information about the marker's true identity. This intermediary element allows the marker to serve its boundary detection function while simultaneously signaling to reading systems that it should not be interpreted as a lead-out area.
3Adaptability or versatility
If multiple intermediate markers exist on the information recording medium after repeated format processes, then format flexibility is maintained, but it becomes difficult or impossible to judge whether a detected marker represents the true end edge of recorded user data
Solution Approach 1:
The marker is divided into multiple unit blocks with identifiable portions. By examining specific unit sectors and their flag bits, the system can determine which marker portion represents the true end edge, even when multiple markers exist from repeated formatting operations.
Solution Approach 2:
The flag bit provides feedback information within the marker structure itself, indicating whether a particular unit sector contains marker data. This internal feedback mechanism allows the system to validate and identify the true end edge marker among multiple candidates without requiring deletion of previous markers.
Data Source
AI summary
An information recording apparatus (200) is provided with: a first recording device (354) for recording user data into a user data area (105, 115) provided for an information recording medium (100), with a data area attribute added; and a second recording device (354) for recording a marker (108) following an end edge portion of the recorded user data, with a predetermined flag bit set to a first value and with the data area attribute added, the flag bit indicating at least whether or not the marker is recorded.