Disk Recording Medium Sync Pattern Shift for Crosstalk Reduction
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Solution Overview
Problem
Current techniques face challenges in recording data with high density and robustly reproducing it, particularly due to crosstalk issues between adjacent tracks on disk-type recording media.
Innovation Solution
A disk-type recording medium and apparatus that record synchronization patterns with a shift in the track direction to prevent overlapping positions, allowing for independent equalization and robust reproduction signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If data is recorded with high density on disk-type recording medium, then storage capacity increases, but crosstalk between adjacent tracks increases causing reproduction errors
Solution Approach 1:
The synchronization pattern is divided into multiple segments recorded in different tracks (land track and groove track). By segmenting the sync pattern across adjacent tracks with positional shifts, the system achieves high-density recording while the segmentation itself helps isolate crosstalk effects, as each segment can be independently processed and synchronized.
Solution Approach 2:
Different synchronization patterns are recorded in different local regions (land and groove tracks) with different positional offsets. This local quality variation allows the system to maintain high recording density while creating distinct signal characteristics in different areas that can be differentiated during reproduction, reducing the impact of crosstalk.
2Measurement precision
If synchronization patterns are recorded in adjacent tracks at the same position, then tracking accuracy improves, but crosstalk between tracks increases
Solution Approach 1:
The synchronization patterns in adjacent tracks are recorded with asymmetric positional offsets relative to each other. The land track sync pattern and groove track sync pattern are deliberately misaligned in the track direction, creating an asymmetric configuration that maintains tracking accuracy through positional reference while reducing symmetric crosstalk interference between tracks.
Solution Approach 2:
The solution moves from a one-dimensional alignment problem to a two-dimensional configuration by utilizing both the radial direction (for track positioning) and the circumferential direction (for positional offsets). By introducing positional offsets in the track direction while maintaining radial adjacency, the system achieves accurate tracking through multi-dimensional geometric arrangement that inherently separates signal paths and reduces crosstalk.
3Reliability
If equalization is performed on reproduction signals from adjacent tracks, then signal quality improves, but processing complexity increases
Solution Approach 1:
Synchronization patterns are recorded in advance with predetermined positional offsets and known structures. During reproduction, these pre-configured patterns serve as reference signals that simplify equalization processing, as the system can use the known positions and characteristics of these pre-recorded sync patterns to establish initial equalization parameters without requiring complex real-time analysis.
Solution Approach 2:
The synchronization patterns provide feedback reference signals that enable adaptive equalization. By comparing the reproduced sync patterns against their known original configurations, the system can adjust equalization parameters dynamically, improving signal quality while keeping processing manageable through iterative refinement rather than exhaustive computation.
Data Source
AI summary
There is provided a disk-type recording medium, a recording apparatus, a recording method, a reproducing apparatus, and a reproducing method, which are capable of recording, for example, data with high density and reproducing data recorded with high density robustly. In the disk-type recording medium, synchronization patterns for synchronization are recorded in two adjacent tracks with a shift in a track direction so that positions in the track direction do not overlap. The present technology can be applied to, for example, optical discs, other disk-type recording mediums, and the like.