Optical Disc Multi-Layer Test Write Zone Arrangement

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Solution Overview

Problem

Current optical disc technologies lack a comprehensive solution for determining appropriate writing conditions for optical discs with three or more information storage layers, particularly in terms of test write zone arrangement and recording power optimization.

Innovation Solution

The optical disc design incorporates multiple information storage layers with non-overlapping test write zones at different radial locations, allowing for independent determination of recording power for each layer, even under varying thermal environments, using test write zones to ensure optimal writing conditions across all layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple information storage layers are stacked to increase storage capacity, then storage capacity is improved, but determining appropriate recording power for each layer becomes more difficult

Engineering Contradiction:
Improvestorage capacityVSAvoidrecording power determination
Core Design Contradiction:
Quantity of substanceVSDifficulty of detecting and measuring

Solution Approach 1:

The patent divides the optical disc into multiple independent information storage layers, each with its own test write zone. This segmentation allows the recording power to be determined independently for each layer by using the test write zone specific to that layer, thereby solving the difficulty of determining recording power when multiple layers are stacked.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent incorporates test write zones in advance during the manufacturing process. These pre-provided test write zones enable the recording power to be determined before actual data writing occurs, allowing optimization of writing conditions for each layer without requiring trial-and-error during data writing operations.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If test write zones are provided for each information storage layer, then recording power can be optimized for each layer, but the structure and arrangement of these zones becomes more complex

Engineering Contradiction:
Improverecording power optimizationVSAvoidtest write zone arrangement
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent arranges test write zones at different radial positions corresponding to different information storage layers. By utilizing the radial dimension of the optical disc, the patent can provide separate test write zones for each layer without significant structural complexity, as the zones are distributed across the disc surface rather than concentrated in one location.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If information is written on deeper information storage layers, then storage capacity is increased, but the writing operation becomes more difficult due to thermal environment differences

Engineering Contradiction:
Improvestorage capacityVSAvoidwriting operation
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The patent provides separate test write zones for each information storage layer, allowing the recording power to be determined under the specific thermal environment of each layer. This local quality approach enables optimization of writing conditions for each layer individually, making writing operations on deeper layers as easy as those on upper layers.

Inventive Principle:
Principle #3Local quality

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 reliable and efficient writing operations on multiple layers by ensuring that each layer can be written with the best recording power, minimizing interference and maintaining data integrity across the disc.

Implementation Method 1

information can be written by being irradiated with a laser beam

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

information can be written by being irradiating with light that has been modulated so as to represent the information to write

Methodology Applied
Scientific EffectLight modulation: Phase Modulation

Implementation Method 3

a test write operation can still be performed on the target information storage layer using its test write zone under the operating environment of that layer

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 4

even if those information storage layers are irradiated with a laser beam at mutually different intensities or in respectively different thermal environments

Methodology Applied
Scientific EffectThermal environment: Heating

Data Source

PatentEP2264702B1Information recording medium, reading method and systems for reading and writing the medium
Publication Date: 2013.01.23 PANASONIC HOLDINGS CORP
  • EP2264702B1 patent drawingFigure 1
  • EP2264702B1 patent drawingFigure 2~3
  • EP2264702B1 patent drawingFigure 4(a)~4(c)

AI summary

An information storage medium according to the present invention has n information storage layers (where n is an integer and n≧3), on which data can be written with a laser beam and which are stacked one upon the other. Each of the n storage layers has a test write zone for determining the recording power of the laser beam. When those n layers are counted from the one that is located most distant from the surface of the medium on which the laser beam is incident, there is a bigger radial location difference between the outer peripheral end of the inner one of the test write zones of ith and (i+1)th information storage layers (where i is an integer that satisfies 2≦i≦n-1) and the inner peripheral end of the other outer test write zone than between the outer peripheral end of the inner one of the test write zones of jth and (j+1)th information storage layers (where j is an integer that satisfies 1≦j≦i-1) and the inner peripheral end of the other outer test write zone.