Optical Disc Write Pulse Control for High-Density Storage Compatibility
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Solution Overview
Problem
As storage density increases, the length of recording marks on optical discs approaches the detection system's resolution limit, leading to increased intersymbol interference and decreased signal-to-noise ratio (SNR), and existing methods struggle to efficiently store expanded read/write control information without compromising compatibility with lower-order media or older generations.
Innovation Solution
An information storage medium that uses a combination of reference and offset write pulse information, where the offset value is at least half the size of the reference value, to define write pulses for marks and spaces, allowing for high-density writing while maintaining compatibility with older systems by adjusting write waveforms based on retrieved control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If storage density is increased to approach the detection system's resolution limit, then storage capacity is improved, but intersymbol interference increases and signal-to-noise ratio decreases
Solution Approach 1:
The patent applies parameter changes by expanding the write pulse information parameters (such as pulse width, amplitude, and timing) to optimize the writing process for high-density storage. This allows the system to maintain reliable signal writing even when marks approach the detection resolution limit, thereby improving storage capacity while managing the degradation in signal-to-noise ratio through compensated writing parameters.
2Manufacturing precision
If read/write control information is expanded to cope with high-density storage, then writing precision is improved, but compatibility with lower-order media or older generations is compromised
Solution Approach 1:
The patent segments the write pulse information into multiple parts or fields within the control information structure. This segmentation allows older systems to read and ignore extended fields while newer systems can utilize the full expanded information set, thereby maintaining both writing precision for high-density storage and compatibility with lower-order media or older generations.
Solution Approach 2:
The control information structure is designed with universality by incorporating both traditional and extended parameters in a unified format. This multi-functional structure enables the same control information to serve both legacy systems (which use basic parameters) and advanced high-density systems (which utilize expanded parameters), ensuring broad adaptability without sacrificing writing precision.
3Manufacturing precision
If write pulse information is expanded to account for varying preceding and succeeding spaces, then mark length consistency is improved, but control information size increases
Solution Approach 1:
The patent applies local quality by providing different levels of write pulse information detail for different marking contexts. Instead of uniformly expanding all parameters, the system selectively applies detailed control information only where needed (e.g., for marks with varying preceding/succeeding spaces), thereby improving mark length consistency locally while minimizing the overall increase in control information size.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables high-density writing with improved SNR and compatibility with older systems, minimizing the need for new optical systems and ensuring reliable data storage across varying storage densities.
Implementation Method 1
marks are formed by irradiating the tracks with pulses of a laser beam
Data Source
AI summary
The present invention provides a measure for getting read/write control information stored within a space of a predetermined size in a format that ensures compatibility with media of a lower order or an older generation even if the size of the read/write control information increases significantly as the storage densities of information storage media rise in the near future. On an information storage medium, a data sequence is writable as a combination of marks and spaces. The medium has at least one information storage layer, which has an information storage area to store information and a control information area for use to perform a read/write operation on the at least one information storage layer. The control information area stores at least one set of control information, which includes a first kind of write pulse information including information to be used as a reference value and a second kind of write pulse information including information to be used as an offset value. The size of the offset value is at least a half as large as that of the reference value.