Optical Disc Drive Data Writing with Tracking Error Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical disc technologies face challenges in achieving higher densification and larger capacity due to limitations in writing data into both land and groove tracks, particularly with narrow track pitches and multiple recording layers, which affect transmittance and tracking error signals.
Innovation Solution
A method for writing data into a write-once optical disc with multiple recording layers, where data is sequentially written into groove and land tracks using an optical disc drive with an optical pickup unit, employing a defect list to manage physical and virtual sector numbers, allowing for stable data writing by adjusting the laser spot based on tracking error signals and optimizing the writing order to minimize transmittance variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If data is written into both land and groove tracks to increase capacity, then recording capacity increases, but tracking error signal stability deteriorates
Solution Approach 1:
The patent applies preliminary action by writing data into groove tracks before land tracks. This sequencing ensures that the laser spot is stabilized on the groove track first, which has better tracking characteristics, before transitioning to land tracks. This preliminary stabilization prevents tracking error signal deterioration during the writing process while enabling high-density recording on both track types.
Solution Approach 2:
The patent employs dynamics by adjusting the laser spot position and writing parameters based on the track type (groove or land) being written. The system dynamically modifies writing conditions to maintain tracking stability when transitioning between groove and land tracks, thereby preserving reliability while achieving high recording capacity through dual-track utilization.
2Quantity of substance
If track pitch is narrowed to increase density, then recording capacity increases, but manufacturing precision requirements worsen
Solution Approach 1:
The patent utilizes feedback mechanisms by continuously monitoring tracking error signals during the writing process and adjusting the laser spot position accordingly. This real-time feedback compensates for manufacturing variations in narrow track pitches, maintaining writing accuracy without requiring extremely tight manufacturing tolerances, thereby enabling high-density recording with practical manufacturing precision.
3Quantity of substance
If multiple recording layers are stacked to increase capacity, then recording capacity increases, but transmittance variations worsen
Solution Approach 1:
The patent applies preliminary action by completing all writing operations on deeper recording layers before writing to shallower layers. This sequencing ensures that when the laser writes to upper layers, the transmittance characteristics are more stable because lower layers are already finalized. This approach reduces transmittance variations and improves writing stability in multi-layer discs.
4Ease of operation
If virtual sequential recording ranges are ensured in advance to manage writing, then data management improves, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the recording medium into multiple virtual sequential recording ranges (VSRRs) that can be independently managed. Each VSRR is assigned a unique identifier and can be filled sequentially, simplifying the management of large-capacity multi-layer discs. This segmentation approach organizes complex multi-layer writing operations into manageable units, improving ease of operation without requiring overly complex management systems.
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 stable and efficient data writing into optical discs with high density and larger capacity by stabilizing tracking error signals and optimizing the writing process across multiple layers, effectively overcoming previous limitations in data densification.
Implementation Method 1
an optical disc drive (102) including at least one optical pickup unit (OPU)
Implementation Method 2
stabilizing tracking error signals
Data Source
AI summary
On each of a plurality of recording layers of a write-once optical disc, two tracks constituted of adjacent land and groove are formed in a spiral shape. A writing method of data includes: a step of receiving data and a writing instruction of the data; and a step of recording management information, wherein the management information includes: virtual sequential recording range information that manages a last recorded address of the data as a virtual physical sector number; defect list that indicates a replacement correspondence relationship between the virtual physical sector number and an actually recorded physical sector number; and real next writable address information that indicates a real next writable address that is actually recordable subsequently to the physical sector number.