Multilayer Optical Disc Management Area for Layer Type Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer optical discs with information layers conforming to different standards face challenges in quickly accessing and identifying the presence and type of other information layers, leading to increased access time when switching between them.
Innovation Solution
Incorporating a management area in the information layer with the highest recording density to record information about the presence and type of other information layers, allowing the optical disc device to efficiently identify and access them by pre-selecting the appropriate method for tracking error signal generation based on the layer type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a multilayer optical disc has information layers conforming to different optical disc standards, then the disc can accommodate multiple standards and increase user convenience, but it takes time to access other information layers when the need to reproduce or record information on another layer suddenly arises
Solution Approach 1:
The patent applies preliminary action by recording management information about other information layers (such as layer types, presence/absence, and track information) in advance in the management area. This allows the optical disc device to quickly access and identify target layers without time-consuming detection during actual layer switching operations.
Solution Approach 2:
The patent introduces a management area as an intermediary structure that stores information about other information layers. This management area acts as a mediator between the current information layer and other layers, enabling quick identification and access by providing pre-recorded management information without requiring direct detection of target layers.
2Device complexity
If the type of one information layer is not recorded on another layer, then the disc structure remains simple, but every time the device accesses a different information layer it must read the type of the layer to select a method of generating a tracking error signal adapted to the type
Solution Approach 1:
The patent applies preliminary action by pre-recording management information including layer types in the management area during disc manufacturing. This eliminates the need for time-consuming layer type detection during device operation, as all necessary information is prepared in advance.
Solution Approach 2:
The patent extracts the layer type information and management data from the actual information layers and places it in a separate management area. This separation allows the management information to be accessed independently without affecting the simplicity of the information layer structure while enabling quick identification.
3Loss of time
If information indicating the types of other information layers is recorded in the management area, then access time is reduced, but the management area requires additional information storage capacity
Solution Approach 1:
The patent applies partial action by recording only essential management information (layer types, presence/absence indicators, and basic track information) in the management area, rather than storing complete data from all layers. This provides sufficient information for quick access while minimizing the storage capacity required.
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 significantly reduces access time by enabling the optical disc device to quickly determine the type and presence of other information layers, allowing for faster switching and operation based on pre-set laser power and tracking error signal methods.
Implementation Method 1
a blue-violet laser light source 2a having a wavelength of about 405 nm... a beam 3a from the blue-violet laser light source 2a... a sensor lens 8 and a photodetector 9
Data Source
AI summary
In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.