Optical Disk Recording Power Ratio Control for Multilayer Distortion
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Solution Overview
Problem
Conventional optical disk recording technologies face challenges in suppressing distortion of marks on multilayer disks and at varying linear velocities, leading to suboptimal recording quality due to differences in heat radiation conditions and linear velocity effects.
Innovation Solution
An optical disk recording device and method that uses a semiconductor integrated circuit to determine and adjust the ratio of recording powers for each recording layer and linear velocity, producing a recording pulse with leading, intermediate, and space pulses to maintain consistent mark formation across layers and velocities, thereby optimizing laser beam power and reducing distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional recording power conditions are used on multilayer disks, then recording can be performed on multiple layers, but mark distortion occurs due to differences in heat radiation conditions between layers
Solution Approach 1:
The patent applies local quality by setting different recording power conditions for different recording layers. Specifically, the ratio of second recording power to first recording power is determined separately for each recording layer based on its heat radiation characteristics. This allows each layer to receive optimized power conditions tailored to its local thermal environment, preventing mark distortion while maintaining high recording capacity across multiple layers.
2Speed
If conventional recording power conditions are used at varying linear velocities, then recording can be performed at different speeds, but mark distortion occurs due to linear velocity effects on heat radiation
Solution Approach 1:
The patent applies dynamics by making the recording power conditions variable according to linear velocity. The semiconductor integrated circuit dynamically adjusts the ratio of second recording power to first recording power based on the detected linear velocity. This dynamic adaptation allows the system to maintain optimal mark formation across a range of recording speeds by compensating for velocity-dependent heat radiation changes.
3Manufacturing precision
If a multi-pulse structure is used for mark formation, then mark shape can be controlled, but the rise rate of the laser beam must be extremely fast for high-speed recording
Solution Approach 1:
The patent applies parameter changes by modifying the recording power levels and pulse timing parameters to reduce the required laser beam rise rate. By optimizing the ratio of second recording power to first recording power and adjusting pulse widths, the system achieves accurate mark formation with more relaxed rise rate requirements, enabling high-speed recording without demanding extreme laser performance.
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 effectively suppresses mark distortion and enhances recording quality on multilayer disks and at different linear velocities, enabling higher capacity and speed in optical disk recording.
Implementation Method 1
The mark 904 is formed at a portion of the recording track 903 irradiated with the laser beam at a power level of at least a predetermined lower limit, and the space 905 is formed at a portion irradiated with the laser beam at a power level below the lower limit.
Data Source
AI summary
According to a method of the present invention for recording data on an optical disk, a recording pulse corresponding to a long mark includes a combination of a leading pulse and a subsequent intermediate pulse. Further, a level of the leading pulse indicates a first recording power, and a level of the intermediate pulse indicates a second recording power. When an optical disk includes a plurality of recording layers, a ratio of the second recording power to the first recording power is determined for each recording layer. When the recording speed is variable, the ratio of the second recording power to the first recording power is determined for each recording speed.