Optical Disc Device Spherical Aberration Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical disc devices face challenges in accurately adjusting the spherical aberration, focus balance, and lens tilt due to low levels of reproduction signals during initial test writing, making it difficult to optimize these parameters effectively.
Innovation Solution
The optical disc device employs a controller that performs adjustment-use recording in unrecorded regions of the optical disc, adjusts the collimator lens position based on reproduction signal levels, and performs re-adjustment when the signal level falls below a specific threshold to maximize the reproduction signal, ensuring accurate adjustment of spherical aberration, focus balance, and lens tilt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If test writing data is written in an initial state without spherical aberration adjustment, then the adjustment process can be initiated, but the reproduction signal level becomes insufficient making accurate adjustment impossible
Solution Approach 1:
The patent applies preliminary action by performing a first adjustment-use recording before the spherical aberration adjustment process. This preliminary recording creates test data that can be reproduced with sufficient signal level, enabling the subsequent adjustment to proceed accurately. The controller records adjustment-use data, reproduces it to measure signal level, and only proceeds with adjustment when the signal exceeds the threshold, thus preparing the system in advance for successful adjustment.
2Measurement precision
If the reproduction signal level is low during initial test writing, then the adjustment process can start, but the measurement precision required for accurate adjustment cannot be achieved
Solution Approach 1:
The patent implements feedback by continuously monitoring the reproduction signal level during adjustment-use recording and comparing it against a predetermined threshold. The controller measures the signal level after each recording attempt and uses this feedback to determine whether to proceed with the adjustment process. When the signal level is insufficient, the system performs additional adjustment-use recordings to improve the signal level before attempting adjustment, ensuring measurement precision is achieved.
3Measurement precision
If multiple adjustment-use recordings are performed to increase signal level, then measurement precision improves, but the time required for adjustment increases
Solution Approach 1:
The patent applies partial or excessive action by performing adjustment-use recordings only when necessary to achieve the signal level threshold. Rather than always performing multiple recordings, the system records once, checks the signal level, and only performs additional recordings if the threshold is not met. This approach performs slightly more recordings than the absolute minimum in some cases, but avoids unnecessary recordings when the first attempt suffices, thus balancing measurement precision with time efficiency.
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 allows for precise adjustment of the optical pickup's parameters, improving the accuracy and reliability of spherical aberration, focus balance, and lens tilt adjustments, even with new or blank optical discs, by increasing the reproduction signal level to a target threshold, thereby enhancing the overall performance of the optical disc device.
Implementation Method 1
an optical pickup that emits light at an optical disc and detects light reflected by the optical disc
Data Source
Figure 1~2
Figure 3~5
Figure 6
AI summary
An optical disc device includes an optical pickup and a controller. The optical pickup is configured to emit light to an optical disc and detect the light reflected on the optical disc. The controller is configured to perform adjustment of at least one of spherical aberration, focus balance and lens tilt of the optical pickup based on a reproduction signal corresponding to the light detected by the optical pickup. The controller is further configured to perform the adjustment based on a level of the reproduction signal of adjustment-use recording. The controller is further configured to perform re-adjustment after performing subsequent adjustment-use recording in response to the level of the reproduction signal of the adjustment-use recording being at or below a specific threshold after the adjustment.