Optical Disc Edge Shift Correction via Signal Filtering
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Solution Overview
Problem
The estimation and adjustment of edge shifts in high-linear density optical discs are challenging due to interference components in the regenerative signal, making it difficult to accurately position recorded marks.
Innovation Solution
A recording adjustment device with a storage, filter processing, calculation, detection, and control portion that identifies impulse responses, calculates amplitude differences, detects step response slopes, and corrects edge positions to achieve precise recording compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-linear density recording is implemented to increase data storage capacity, then the linear density increases, but the regenerative signal contains many interference components between codes making edge shift estimation and adjustment difficult
Solution Approach 1:
The patent extracts and removes interference components from the regenerative signal through signal processing techniques. Specifically, it separates the desired mark edge information from unwanted intersymbol interference and other noise components, enabling accurate edge shift measurement even in high-linear density conditions where such interference would normally prevent precise measurement.
Solution Approach 2:
The patent introduces an intermediary processing stage between signal reproduction and edge shift measurement. This intermediary includes filtering operations and signal conditioning that prepare the regenerative signal for accurate analysis, acting as a mediator that transforms the noisy high-density signal into a form suitable for precise edge position detection.
2Quantity of substance
If mark and space lengths are reduced to increase linear density, then the linear density increases, but thermal interference causes position shift in recorded marks
Solution Approach 1:
The patent implements a feedback mechanism where the measured edge shift information is used to adjust and correct subsequent recording operations. By continuously monitoring actual mark positions through precise edge detection and comparing them with intended positions, the system feeds back correction information to compensate for thermal interference and other disturbances, maintaining position accuracy despite reduced mark and space lengths.
Solution Approach 2:
The patent adjusts recording parameters dynamically based on detected edge shifts and interference conditions. This includes modifying laser pulse characteristics, recording power levels, or timing parameters to compensate for thermal effects that become more significant at higher linear densities, thereby maintaining mark position precision.
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
Enables effective recording compensation for high-linear density optical discs, minimizing edge shifts and improving data reproduction accuracy.
Implementation Method 1
The intensity of a laser beam is modulated on the basis of a recording pattern, and the recording layer is irradiated with a recording pulse, thereby forming the mark.
Implementation Method 2
the laser beam is applied to the recording layer, and a regenerative signal as a change in light quantity of return light generated from the optical characteristics such as a difference in reflectivity between the mark and the space is obtained
Data Source
Figure 1A~1I
Figure 2
Figure 3
AI summary
The present technique relates to a recording adjustment device, a recording adjustment method, and a program of which enables recording compensation for an optical disc for a high-linear density to be realized. A recording adjustment device according to an embodiment of the present technique executes filter processing on the basis of a regenerative signal obtained by reproducing data recorded in a recording medium, and a recording pattern of marks and spaces of the data, identifies an impulse response of a system, calculates a difference in amplitude between an output from the filter processing after the identification of the impulse response and the regenerative signal every edge type, and detects a slope of a step response in the vicinity of an edge position. In addition, the recording adjustment device calculates a correction amount of the edge position for each edge type on the basis of the amplitude difference, and the slope of the step response, corrects the edge position in response to the correction amount, and repetitively executes predetermined processing of processing for recording date as a recording target in a recording medium. The present technique can be applied to a recording adjustment device which records data in an optical disc.