Two-Layer Optical Disc with Opposing Grooves and Pre-Recorded Buffer
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Solution Overview
Problem
Single-layer optical discs face challenges in determining the start position of the lead-out area, leading to inefficiencies in recording time due to the need for simultaneous recording of sync and address information, and the inability to reduce the lead-out area length effectively, requiring advanced control for variable-length lead-out areas.
Innovation Solution
A two-layer optical disc structure with opposing recording track paths and pre-recorded buffer areas on one edge, allowing for efficient layer switching and reduced finalize process time by omitting buffer data in the lead-out area, maintaining compatibility with standard DVD-ROM drives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the lead-out area is recorded simultaneously with sync and address information to maintain ROM disc compatibility, then compatibility is improved, but recording time is increased
Solution Approach 1:
The lead-out area is pre-formed as a pre-recorded area with embossed pits before the actual data recording process. This preliminary action allows the lead-out area to exist in advance, eliminating the need to record it during the finalize process while maintaining ROM disc compatibility.
Solution Approach 2:
The optical disc is divided into multiple recording layers (first recording layer and second recording layer), with the lead-out area specifically formed in the second recording layer. This segmentation allows different areas of the disc to serve different functions, with the lead-out area prepared in advance while data is recorded in other areas.
2Productivity
If the lead-out area length is reduced to improve recording efficiency, then productivity is improved, but compatibility with ROM disc standards deteriorates
Solution Approach 1:
The lead-out area is pre-formed with embossed pits in the second recording layer before data recording. This preliminary formation allows the lead-out area to meet ROM disc standards without requiring time-consuming recording operations during finalize, thus maintaining compatibility while improving productivity.
3Adaptability or versatility
If advanced control is implemented to enable variable-length lead-out areas, then adaptability is improved, but device complexity is increased
Solution Approach 1:
The lead-out area is pre-formed in the second recording layer before data recording begins. This preliminary action eliminates the need for advanced control during the finalize process to determine lead-out area length, as the area is already prepared with embossed pits, thereby reducing device complexity while maintaining adaptability.
4Productivity
If the start position of the lead-out area is determined in advance, then productivity is improved, but the ability to handle single-layer discs deteriorates
Solution Approach 1:
The optical disc is segmented into multiple recording layers, with the lead-out area specifically formed in the second recording layer. This segmentation allows the lead-out area start position to be determined in advance in the second layer without affecting single-layer disc operation, as single-layer discs can still function using the first recording layer.
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
The solution significantly reduces recording operation time and enhances user experience by enabling efficient data recording and reproduction across multiple layers with minimal additional buffer data, while maintaining compatibility with existing DVD-ROM technology.
Implementation Method 1
an optical pickup 352 for performing recording/reproduction with respect to the optical disc 100
Implementation Method 2
a first recording layer (L0 layer) in which a first recoding track path (groove: guidance groove) for recording at least record information, is formed
Data Source
AI summary
At least a first recording layer (L0 layer) and a second recording layer (l,1 layer) are provided. In the first recording layer, a first recording track path (a groove: a guiding groove) is formed for recording recording information. The second recording layer is arranged on the first recording layer and has a second recording track path (a groove: a guiding groove) formed in an opposite direction to the first recording track path for recording recording information. On an edge part on one side of the second recording layer, a first buffer area (103-1) is previously formed as a pre-recording area by an embossed pit (in the case of DVD-RW) or by a pit formed by recording laser irradiation (in the case of DVD-R).