Optical Element Diffracting Structure for Multi-Wavelength Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical disc drives face challenges in supporting multiple optical disc types due to limited design freedom for diffracting structures, which leads to compromised optical performance and increased manufacturing errors, making it difficult to correct spherical aberrations caused by wavelength shifts and environmental changes.
Innovation Solution
A method for designing an optical element with a single diffracting structure that incorporates multiple optical path difference functions to maximize diffraction efficiencies at different wavelengths, allowing for the formation of a diffracting structure with various functions on a single surface, enabling support for multiple optical disc types while minimizing manufacturing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single diffracting structure is used to support multiple optical disc types, then device complexity is reduced, but manufacturing precision deteriorates due to limited design freedom
Solution Approach 1:
The patent divides the diffracting structure into multiple independent optical path difference functions, each optimized for specific wavelength ranges. This segmentation allows each function to be designed and manufactured with high precision for its specific purpose, while the combination achieves multi-wavelength support.
Solution Approach 2:
The patent creates a universal diffracting structure that performs multiple functions: supporting different optical disc types (CD, DVD, Blu-ray), correcting spherical aberration, and compensating for wavelength shifts. By integrating these functions into a single structure with multiple optical path difference functions, the patent achieves multi-functionality without sacrificing precision.
2Adaptability or versatility
If diffracting structures are designed to support two types of optical discs, then adaptability is improved, but the ability to correct spherical aberration for wavelength shifts deteriorates
Solution Approach 1:
The patent segments the aberration correction function into multiple optical path difference functions, where some functions are optimized for specific wavelength ranges. This allows the structure to maintain adaptability for multiple disc types while ensuring reliable spherical aberration correction for each wavelength range through dedicated functions.
Solution Approach 2:
The patent changes the optical path difference parameters across different regions of the diffracting structure to optimize for different wavelengths. By varying these parameters, the structure can simultaneously support multiple optical disc types and provide accurate spherical aberration correction for wavelength shifts within each optimized range.
3Manufacturing precision
If multiple diffracting structures are used to achieve high optical performance, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple optical path difference functions into a single diffracting structure. Instead of using separate structures for different functions, the patent combines them in one integrated design, achieving high optical performance through the synergistic interaction of the merged functions while avoiding the complexity of multiple separate structures.
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 enhances the optical disc drive's ability to accurately converge light beams for multiple optical disc types, correcting spherical aberrations and wavelength shifts, thereby improving compatibility and reducing manufacturing complexities.
Implementation Method 1
a diffracting structure on one of surfaces of optical elements (e.g., an objective lens) in the optical system so that the light beam is suitably converged on a recording surface of each optical disc
Implementation Method 2
an optical system for an optical disc drive is required to correct a spherical aberration which varies depending on the thickness of a cover layer of an optical disc being used
Data Source
AI summary
A method of designing an optical element to be used for an optical system in which each of a plurality of light beams having different design wavelengths passes through the optical element is provided. The method includes determining at least two types of optical path difference functions including first and second optical path difference functions in such a manner that proportion, brought by the first optical path difference function, between diffraction orders at which diffraction efficiencies of the plurality of light beams are maximized is different from proportion, brought by the second optical path difference function, between diffraction orders at which diffraction efficiencies of the plurality of light beams are maximized, and obtaining a shape defined by combining the at least two types of optical path difference functions so as to apply the obtained shape to at least one surface of surfaces of the optical element.