Multilayer Optical Disc Address Offset for Layer Shift Compensation
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Solution Overview
Problem
In multilayer information recording media, such as dual-layer optical discs, the relative shift between recording layers can cause deviations in track pitch and radial position, leading to inefficient recording and reproduction due to the need for complex recording control and potential waste of recording area.
Innovation Solution
The solution involves defining a predetermined position relationship between the first and second recording layers, allowing for continuous recording in opposite or parallel directions without significant changes in laser irradiation position, thereby minimizing waste and optimizing recording area usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the L0 layer and L1 layer are formed by different stampas and laminated, then the recording capacity is increased, but eccentricity and dimensional errors occur causing shift in radial position
Solution Approach 1:
The patent applies preliminary action by pre-defining the position relationship between corresponding points in L0 and L1 layers before recording. The radial position of the second point in L1 is determined in advance based on the first point in L0, considering dimensional errors and eccentric amounts. This allows the recording apparatus to pre-calculate address offset values and compensation amounts, enabling accurate recording without real-time detection of relative shifts between layers.
2Manufacturing precision
If recording control is performed to satisfy recording order through detection, then recording accuracy is improved, but device complexity and control complexity increase
Solution Approach 1:
The patent extracts the complex real-time detection and control process by replacing it with a predetermined position relationship approach. Instead of detecting relative shifts between L0 and L1 layers during recording and adjusting accordingly, the invention removes this complexity by pre-defining position relationships and using fixed address offset values based on predetermined dimensional errors and eccentric amounts.
3Manufacturing precision
If address offset value is determined to reduce influence of relative shift on one side, then recording order is satisfied on that side, but recording area is wasted on the other side
Solution Approach 1:
The patent applies local quality by defining different position relationships for different regions. The predetermined position relationship between first and second points is established separately for inner circumferential side and outer circumferential side, allowing each region to have optimized address offset values that satisfy recording order locally without excessive waste of recording area.
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 efficient recording and reproduction by minimizing the impact of relative shifts, allowing for uninterrupted recording and reducing the need for complex control processes, thus optimizing the use of the recording area.
Implementation Method 1
laser light for recording is focused or condensed on a recording layer located on the front
Implementation Method 2
record information into the L0 layer in an irreversible change recording method by heat
Implementation Method 3
the laser light is focused or condensed on a recording layer located on the rear of the L0 layer, through the L0 layer
Data Source
AI summary
An information recording medium (100) includes (i) a first recording layer (L0 layer) having a first track and (ii) a second recording layer (L1 layer) having a spiral or coaxial second track sharing the rotation center with the first track. (iii) The first recording layer has a first point (point Bx) indicated by a first address. (iv) The second recording layer has a second point (point Dx) which can be defined according to a predetermined positional relationship (allowable area: 10) with respect to the first point (point Bx).