De-icing Multilayer Optical Discs via Partial Dummy Data Writing
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Solution Overview
Problem
Current methods for formatting multilayer optical record carriers are time-consuming and can cause compatibility issues with read-only players when blank areas are not properly de-iced, leading to potential errors in data access.
Innovation Solution
A method for formatting multilayer record carriers that prioritizes de-icing the second layer by writing dummy data adjacent to the user data area on the first layer, ensuring compatibility with read-only players by maintaining a fixed starting position for dummy data writing and alternating sequences across layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional de-icing method is used on multilayer record carriers, then all layers are fully de-iced, but the formatting process takes a considerable amount of time
Solution Approach 1:
The patent applies partial de-icing by writing dummy data only on specific layers (second layer and further layers) rather than all layers. This partial action is sufficient to prevent read-only players from scanning blank areas while significantly reducing the total formatting time compared to complete de-icing of all layers.
Solution Approach 2:
The de-icing process is segmented by layer, treating the first layer differently from the second and further layers. The first layer is de-iced only if user data will be recorded there, while other layers are de-iced unconditionally. This segmentation allows optimization of formatting time while maintaining compatibility.
2Reliability
If dummy data is written on all layers, then read-only players can access data without errors, but the device complexity and processing overhead increase
Solution Approach 1:
Instead of writing dummy data on all layers, the patent writes dummy data only where necessary - on the second layer and further layers unconditionally, and on the first layer only when user data will be recorded there. This partial approach maintains data access reliability while reducing processing complexity.
Solution Approach 2:
The de-icing strategy applies different qualities to different layers based on their specific roles. The second layer and further layers receive full de-icing treatment, while the first layer receives conditional de-icing. This local differentiation optimizes both reliability and complexity.
Data Source
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AI summary
A device for recording information on a record carrier (11) is arranged for formatting a multilayer record carrier. The device has formatting means (16) for formatting the record carrier according which formatting includes de-icing by, in the event that locations in the user data area have not yet been recorded, writing dummy data (60) on the locations. The formatting means (16) determine a first radial position (50) and a first layer (40), which first radial position is indicative of a location on the first layer on which user data will be recorded first according to a predefined recording format. Subsequently said de-icing is started by writing of dummy data on a second layer (41) of the record carrier at the first radial position, opposite the location of the first user data (55). Hence a de-iced area (58) is created opposite the user data (55).