Optical Memory Device Write Strategy Correction for Mark Length Deviation
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Solution Overview
Problem
Existing optical memory devices face challenges in setting an optimal write strategy for various optical disks due to variations in physical characteristics, leading to improper recording and tracking issues, as manufacturers cannot prepare a proper strategy for all types of disks in the market.
Innovation Solution
An optical memory device and method that measure and adjust mark and land lengths using a reference write strategy, compute deviation values, and update the write strategy to minimize jitter and deviation, ensuring optimal recording parameters are set for each disk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a reference write strategy is used for recording, then the recording process is simple and fast, but the mark lengths deviate from theoretical values due to variations in optical disc physical characteristics
Solution Approach 1:
The patent applies preliminary action by measuring the actual mark lengths formed during recording and computing deviation values before finalizing the write strategy. This allows the system to pre-calculate correction values based on measured deviations, so that the optimal write parameters are prepared in advance, resolving the contradiction between fast recording and precise mark length control.
Solution Approach 2:
The patent implements feedback by measuring the actual mark lengths formed during recording, comparing them with theoretical values, and using the computed deviation values to update the write strategy. This closed-loop feedback mechanism ensures that mark length precision is maintained while keeping the recording process efficient, as the system automatically adjusts parameters based on measured performance.
2Manufacturing precision
If write parameters are optimized for one optical disc, then recording precision is high for that disc, but the same parameters are not suitable for other optical discs with different physical characteristics
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting write parameters based on measured mark length deviations. The system computes correction values specific to each optical disc's characteristics and updates the write strategy accordingly. This allows the system to maintain high recording precision across different optical disc types by adapting parameters to each disc's specific physical characteristics rather than using fixed parameters.
3Device complexity
If mark and land lengths are not uniformly controlled, then the recording process is simple, but tracking problems occur due to extended gaps
Solution Approach 1:
The patent uses feedback to measure actual mark and land lengths and compute deviation values from theoretical values. This measurement and correction mechanism ensures that extended gaps are prevented and tracking reliability is maintained. The system automatically adjusts write parameters based on measured deviations, providing reliable tracking without requiring complex manual control procedures.
Solution Approach 2:
The patent applies self-service by implementing an automated system that measures mark lengths, computes deviations, and updates write strategies without requiring complex external control. The optical recording device performs self-correction based on measured deviations, maintaining uniform mark and land lengths and ensuring tracking reliability through autonomous parameter adjustment rather than complex external intervention.
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
The solution enables accurate and efficient recording by setting an optimal write strategy that minimizes deviations and variations in mark and land lengths, improving recording quality across different optical disks.
Implementation Method 1
an optical pickup 2 for irradiating a laser beam to the optical information recording medium 1
Data Source
AI summary
An optical memory device records and reproduces information by forming marks and lands in an optical information recording medium. The optical memory device includes: a first measuring part for measuring a length of each of the marks when information is recorded in the optical information recording medium using a reference write strategy and a write strategy in which widths of a specific mark and a powered pulse with respect to the reference write strategy are varied; a first measuring value memorizing part for memorizing a result of the first measuring part; a theory length memorizing part for memorizing theoretical lengths of the respective marks and lands; a first deviation value computing part for computing deviation value of each of the marks by changing the write strategy on the basis of the lengths of the marks memorized in the first measuring value memorizing part and the lengths of the mark memorized in the theory length memorizing part; a first contractile rate computing part for computing inherent contractile rates of all marks from the computed deviation value and an existing probability of each of the marks; a first write strategy setting part for setting an optimal write strategy by computing a correction value for the reference write strategy on the basis of the computed inherent contractile rates of and the existing probability of all the marks such that the deviation values of all the marks are within the predetermined range; a variation computing means for computing variations in lengths of the lands before and after each of the marks on the basis of the existing probability of each of the marks when the widths of the specific mark and powered pulse are varied.