Retro Focus Optical System Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Retro focus lens systems face challenges in correcting chromatic aberration and other aberrations due to the asymmetrical placement of negative and positive refractive power elements, leading to issues like negative distortion and chromatic aberration, especially when the optical system length is reduced, and materials with high dispersion are sensitive to temperature changes.
Innovation Solution
A retro focus optical system using a refractive optical element made from a solid material with specific Abbe number and partial dispersion ratio conditions, where the refractive power increases towards the periphery, and the thickness distribution is optimized to correct chromatic aberration across a wide wavelength range, incorporating materials like UV curable resin and TiO2 particles in a synthetic resin to satisfy these conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a lens component with negative refractive power is disposed in the front to provide wide angle, then wide viewing angle is achieved, but negative distortion (barrel distortion) occurs due to asymmetrical refractive power placement
Solution Approach 1:
The patent applies local quality by forming the negative lens with non-uniform refractive power distribution. Specifically, the negative lens has higher refractive power at the periphery and lower refractive power at the center, creating a gradient refractive index profile. This local variation in refractive power compensates for the asymmetrical placement while maintaining wide angle coverage and reducing barrel distortion.
2Shape
If a material of high index of refraction is used to reduce negative distortion, then distortion is reduced, but negative chromatic aberration of magnification occurs due to high dispersion
Solution Approach 1:
The patent changes the refractive index parameter by forming the negative lens with a gradient refractive index profile rather than a uniform index. The refractive index increases from the center toward the periphery, creating an optimized optical path that reduces both distortion and chromatic aberration simultaneously, avoiding the need for high dispersion materials.
3Length of stationary object
If the total optical length is reduced to make the system compact, then device size is reduced, but chromatic aberration increases significantly
Solution Approach 1:
The patent applies local quality by creating a gradient refractive index profile within the negative lens, where the refractive index varies from the center to the periphery. This internal structure allows the lens to compensate for chromatic aberration effects that would normally require increased optical length, enabling compact system design while maintaining aberration control.
4Object-generated harmful factors
If low dispersion material such as fluorite is used to correct chromatic aberration, then chromatic aberration is reduced, but the material has large Abbe number which limits correction effectiveness when optical length is reduced
Solution Approach 1:
The patent changes the refractive index parameter by forming the negative lens with a gradient refractive index profile. This approach allows effective chromatic aberration correction without relying on materials with extremely high Abbe numbers like fluorite, achieving a balance between material properties and optical performance for compact system design.
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
The solution effectively corrects and reduces chromatic aberration and other aberrations, providing improved optical performance and resistance to temperature changes, while maintaining a compact optical system design.
Implementation Method 1
a refractive optical element composed of a solid material having a refractive index Nd and a partial dispersion ratio θgF, wherein the refractive power of the refractive optical element increases towards the periphery from the optical axis
Data Source
AI summary
At least one exemplary embodiment is directed to A retro focus optical system that is capable of sufficiently correcting and/or reducing various aberrations including the chromatic aberration. The optical system includes a refractive optical element including a solid material. The Abbe number νd and the partial dispersion ratio θgF of the solid material along with a shape of the refractive optical element can reduce various aberrations.