Organic Dye Optical Disc Mark Distortion Control
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Solution Overview
Problem
Dual-layer recordable optical discs using organic dye materials exhibit poor recording characteristics, particularly at the recording layer close to the laser reception face, due to physical changes in the dye material during the recording process, leading to mark distortions and poor signal reproduction.
Innovation Solution
The use of an organic dye material with a specific property that minimizes physical changes (less than 10% modification) at the recording mark area, such as an azo metal complex with copper or nickel as the center metal, which avoids chemical changes and maintains the surface condition, ensuring good recording and reproducing performance for both single- and multi-layer discs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional organic dye material is used for recording, then the recording process can be completed, but mark distortions occur and recording characteristics deteriorate, particularly at the recording layer close to the laser reception face
Solution Approach 1:
The patent changes the chemical composition parameters of the organic dye material by introducing specific substituents (electron-withdrawing groups like -NO2, -CN, -CF3, or electron-donating groups like -OCH3, -OH) at positions 3 or 5 of the aromatic ring. This parameter change modifies the dye's physical properties to minimize expansion and mark distortion during laser recording, thereby improving recording characteristics and reducing mark distortion.
2Manufacturing precision
If the dye material undergoes physical changes during recording, then recording marks are formed, but signal reproduction quality deteriorates due to mark distortions
Solution Approach 1:
The patent modifies the molecular structure parameters of the dye by adding specific substituents at positions 3 or 5 of the aromatic ring. This parameter change controls the physical changes during recording to occur within acceptable limits (expansion ratio ≤ 10%), thereby forming clear recording marks while maintaining signal reproduction quality.
3Productivity
If a shorter wavelength laser (405 nm) is used to increase disc capacity, then recording density improves, but physical deformation of the dye material increases leading to poor recording performance
Solution Approach 1:
The patent changes the chemical structure parameters of the dye material by introducing specific substituents that modify the molecular stability and physical response to laser irradiation. This enables the use of 405 nm wavelength lasers to achieve high recording density while controlling physical deformation and expansion ratios to remain within acceptable limits.
Solution Approach 2:
The patent creates a composite dye structure by combining the base organic dye molecule with specific substituent groups at positions 3 or 5 of the aromatic ring. This composite structure provides both the necessary optical absorption properties for 405 nm laser recording and the structural stability to minimize physical deformation during the recording process.
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 results in improved recording and reproducing performance by reducing mark distortions and maintaining signal integrity, with an error rate of less than 1.0 e-04, and allows for the use of a shorter wavelength (405 nm) without significant physical deformation, enhancing the optical disc's capacity and reliability.
Implementation Method 1
The use of an organic dye material with a specific property that minimizes physical changes (less than 10% modification) at the recording mark area
Implementation Method 2
recording marks in which the reflectivity of the dye has been changed are formed by modulating the power of a laser light
Implementation Method 3
the information recording is performed utilizing the difference between the reflectivity of recording marks and that of unrecorded portions
Data Source
AI summary
According to one embodiment, a re-recordable write-once optical disc by which recording/reproducing can be properly done with a short-wavelength blue laser is provided. The disc has recording layers on which marks are recorded by the laser power of a modulated short wavelength, with a space formed between the recorded marks. The recording layer of the disc uses an organic dye material by which no physical modification or no physical change substantially occurs in an area of the recorded marks.