Optical Disc Laser Power Adjustment During Standby

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical disc devices face challenges in accurately adjusting recording laser power during recording operations due to changes in system state, leading to deviations from optimal values and complicating the processing sequence, which results in reduced precision and potential damage to the medium.

Innovation Solution

An optical disc device that records sample data during an intermittent standby period using reduced laser power, allowing for precise adjustment of recording laser power based on current recording characteristics derived from reproduction signals, thereby avoiding complications in the recording operation sequence and ensuring accurate power settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If recording laser power is adjusted during recording operation by monitoring reflection light intensity, then the recording laser power can be adjusted according to current system state, but the processing sequence during recording operation becomes complicated and the adjustment precision is reduced

Engineering Contradiction:

Improveadjustment of recording laser power according to current system stateVSAvoidprocessing sequence during recording operation

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent performs trial writing and modulation factor measurement before actual recording operations to determine optimal laser power. By conducting these measurements in advance during standby periods rather than during active recording, the system establishes the processing sequence that avoids complications while maintaining adaptability through periodic re-adjustment

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If recording laser power is adjusted during recording operation by monitoring reflection light intensity, then the recording laser power can be adjusted according to current system state, but the adjustment precision is reduced because the method does not monitor modulation factor of disc reflection light

Engineering Contradiction:

Improveadjustment of recording laser power according to current system stateVSAvoidadjustment precision of recording laser power

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where modulation factors of reflection light are measured during trial writing operations. These modulation factor measurements provide precise feedback about the recording characteristics, enabling accurate determination of optimal laser power settings while maintaining adaptability to changing system conditions

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If recording laser power is not adjusted according to current system state, then the processing sequence remains simple, but the recording laser power deviates from adequate value due to changes in system state

Engineering Contradiction:

Improveprocessing sequence during recording operationVSAvoidadequacy of recording laser power

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent adjusts recording laser power periodically during standby periods between recording operations. This periodic adjustment maintains adequate laser power settings without requiring continuous monitoring during recording, thus preserving processing sequence simplicity while ensuring reliability through regular updates to the laser power settings

Inventive Principle:

Principle #19Periodic action

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 precise adjustment of recording laser power without complicating the processing sequence, reducing the risk of overpower damage and ensuring smooth recording operations by reflecting the current system state, thus protecting the medium and recorded data.

Implementation Method 1

an optical disc device for recording and reproducing information on and from an optical disc by using laser beams

Methodology Applied

Scientific EffectLaser: Laser

Implementation Method 2

monitoring a reflection light intensity during recording operation (reflection light intensity from formed recording mark) based on a signal level from a photo detector

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS7428198B2Optical disc device

Publication Date: 2008.09.23 SANYO ELECTRIC CO LTD

AI summary

Provided is an optical disc device in which adjustment precision of recording laser power is improved without complication of a processing sequence during recording operation. In response to a recording start instruction, OPC is executed using an inner disc drive zone to set an initial value of recording laser power Pws. Then, when a first recording instruction REC(1) is detected, recording is successively performed from the head of a data area using the laser power Pws. After that, when an intermittent standby period is set, sample data is recorded to a next recording position and R-OPC is executed. Therefore, the recording laser power Pws is set again. Next, when a second recording instruction REC(2) is detected, recording is successively performed from a next recording position, that is, a position next to an end portion of the first recording instruction REC(1) using the reset laser power Pws. At this time, data corresponding to a head portion of the second recording instruction REC(2) is overwritten on sample data in the head of the recording position.