Optical Disc Recording Position Displacement Correction
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Solution Overview
Problem
Conventional optical disc recording devices face challenges in maintaining high-precision recording position control, especially when connecting new data to existing data, leading to potential discontinuities, data interruptions, or overwriting issues, due to unstable recording clock frequencies and deteriorated S/N ratios caused by light intensity modulation during recording.
Innovation Solution
An optical disc recording device that includes a reproduction signal extractor, clock reproducer, signal processor, recording signal generator, recorder, and dummy data controller to correct recording position displacement by modulating light intensity and adjusting dummy data lengths based on detected position discrepancies, ensuring accurate synchronization with pre-recorded concave-convex marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If light intensity is modulated during recording to encode data, then information can be recorded on the optical disc, but the S/N ratio deteriorates and recording clock frequency becomes unstable
Solution Approach 1:
The patent segments the recording process into distinct phases: a reproduction phase where the light beam reads concave-convex marks to generate a stable clock signal, and a recording phase where light intensity is modulated to encode data. By separating these functions temporally and spatially, the system maintains frequency stability during reproduction while enabling information recording during the recording phase, thus resolving the contradiction between information recording capability and reliability.
Solution Approach 2:
The patent introduces an intermediary mechanism - the concave-convex marks pre-formed on the optical disc - that serves as a reference for generating the recording clock signal. This intermediary structure allows the system to derive a stable frequency reference from the physical geometry of the disc features, independent of the modulated light intensity used for data encoding, thereby maintaining reliability while enabling information recording.
2Manufacturing precision
If recording position control is tightened to prevent data interruption or overwriting, then data integrity is improved, but recording speed and productivity decrease
Solution Approach 1:
The patent applies preliminary action by pre-forming concave-convex marks on the optical disc before the recording operation. These pre-formed features serve as advance reference points that enable the system to establish accurate positional reference and generate stable clock signals before actual data recording begins. This preliminary structuring allows high-speed recording to proceed with maintained precision, as the positional reference is already in place rather than requiring real-time adjustment.
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 solution enables stable and rapid recording of new information by correcting position displacements and maintaining data integrity, preventing discontinuities and overwriting, while enhancing the S/N ratio and frequency stability during the recording process.
Implementation Method 1
a reproduction signal extractor for extracting a reproduction signal, based on reflected light from the concave-convex mark irradiated with a light beam
Implementation Method 2
a recorder for recording the second information in synchronism with the concave-convex mark by modulating a light intensity of the light beam in accordance with the recording signal generated by the recording signal generator, and by irradiating the light beam of the modulated light intensity onto a reflection film formed on the concave-convex mark of the optical disc for changing an optical characteristic of the reflection film
Data Source
AI summary
Provided are an optical disc recording device and a recording signal generating device which enable to correct displacement between a reproducing position of a reproduction signal from a concave-convex mark preformed in an optical disc, and a recording position of second information to be recorded in synchronism with the reproduction signal, and stably and speedily record the second information. A digital signal processor (202) specifies a reproducing position in the concave-convex mark, using a reproduction signal and a channel clock. A recording signal generator (211) generates a recording signal alternately including a plurality of additionally recordable data, each of which includes second information and has a predetermined length, and a plurality of dummy data. A recording position controller (110) detects a recording position displacement amount representing a displacement amount between the reproducing position and a recording position of the additionally recordable data, using the reproducing position and the reading signal. A recording length adjustor (208) increases or decreases the recording length of dummy data in accordance with the recording position displacement amount.