Optical Recording Device Cooling Pulse Width Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing techniques fail to ensure sufficient recording characteristics for write-once type optical information recording media using organic dyes with an absorption spectrum at 405 nm, as they suffer from thermal interference issues due to variations in space forming power and cooling pulse width.
Innovation Solution
An optical information recording apparatus that sets specific power levels for write marks and spaces, and optimizes the pulse width of the cooling pulse based on pre-measured favorable regions in rectangular coordinates, thereby minimizing thermal interference and enhancing recording quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the space forming power is increased to form spaces easily, then the space formation is improved, but thermal interference between consecutive recording marks increases
Solution Approach 1:
The patent applies periodic pulsed laser irradiation with specific pulse widths (0.1T to 2T) and power levels (0.1mW to 10mW) to create cooling pulses between write pulses. This periodic cooling action removes excess heat from the recording layer, preventing thermal interference between consecutive recording marks while still allowing adequate space formation. The cooling pulse timing and duration are critical to maintaining thermal balance.
Solution Approach 2:
The patent optimizes multiple parameters including space forming power (Ps), cooling pulse power (Pc), cooling pulse width (dTs), and write power (Pw) to achieve the desired balance. By adjusting these parameters within specific ranges and maintaining their relationships (e.g., Pc < Ps < Pw), the system achieves both easy space formation and minimal thermal interference. The favorable region in the plane of rectangular coordinates represents the optimized parameter space.
2Object-affected harmful factors
If the cooling pulse width is increased to reduce thermal interference, then thermal interference is reduced, but the recording speed decreases
Solution Approach 1:
The cooling pulse is implemented as a periodic pulsed action with optimized width (0.1T to 2T) between consecutive write pulses. This periodic cooling maintains thermal management without excessive duration that would slow recording. The pulse timing is synchronized with the recording process to provide just enough cooling to prevent thermal interference while maintaining high recording speed.
Solution Approach 2:
The patent optimizes the cooling pulse width parameter (dTs) within the range of 0.1T to 2T, where T is the clock cycle period. This parameter optimization balances thermal interference reduction with recording speed maintenance. The cooling pulse width is adjusted based on the relationship with write power and space forming power to achieve optimal performance.
3Object-affected harmful factors
If the space forming power is decreased to reduce thermal interference, then thermal interference is reduced, but space formation becomes difficult
Solution Approach 1:
The cooling pulse is applied as a preliminary action between write pulses to prepare the recording layer for the next write operation. By removing excess heat in advance, the cooling pulse prevents thermal interference from affecting subsequent space formation, allowing the use of lower space forming powers without compromising space formation quality.
Solution Approach 2:
The patent establishes specific parameter relationships where space forming power (Ps) is set to a value greater than cooling pulse power (Pc) but less than write power (Pw), and the ratio Ps/Pw is optimized. This parameter configuration allows adequate space formation while the cooling pulse effectively manages thermal interference. The favorable region in parameter space represents the optimal balance point.
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 ensures favorable recording characteristics by determining the optimal ratio of space forming power to write power and cooling pulse width, effectively addressing thermal interference and maintaining high data integrity.
Implementation Method 1
a recording layer, reflection layer and cover layer, if necessary, are formed on one surface of a optical penetrating disc substrate... By irradiating the recording laser beam onto a recording layer
Implementation Method 2
a cooling pulse whose pulse width dTs is provided, whereby the mark is easily formed... the influence of the thermal interference
Data Source
Figure 1~3
Figure 4~6
Figure 7~9
AI summary
In order to ensure a favorable recording characteristic for a write-once recording medium for a bluish-purple laser, whose recording layer is made of an organic dye having an absorption spectrum at a wavelength λ= 405 nm, this optical information recording apparatus includes means for setting a write power to form recording marks, a space forming power whose power value is less than the write power, to form spaces, and a pulse width of a cooling pulse whose power value is less than the space forming power and which should be output immediately after a last pulse when the recording mark is formed, and means for recording information onto the optical information recording medium according to the setting of the write power, the setting of the space forming power and the setting of the pulse width of the cooling pulse. At this time, the pulse width of the cooling pulse and a ratio whose numerator is the write power and whose denominator is the space forming power have a preferable region of the recording characteristic, and information is recorded onto the optical recording medium by using values in this range.