Diffractive Convex Lens for Vehicle Illumination Aberration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Illumination optical systems for vehicles suffer from chromatic aberrations causing color bleeding at the periphery and glare due to diffracted light, which existing systems with diffractive structures fail to adequately address while also deteriorating transmittance.
Innovation Solution
An illumination optical system featuring a convex lens with a diffractive structure, where the phase function is optimized to reduce glare and chromatic aberrations by controlling the coefficients and placement of the diffractive structure, ensuring the second derivative has extreme values and inflection points beyond 30% of the lens radius, and using a light source with a curved surface to correct field curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a diffractive structure is provided on the lens surface to correct chromatic aberrations, then chromatic aberrations are reduced, but glare is generated by diffracted light of unintended orders
Solution Approach 1:
The diffractive structure is provided only in the peripheral region (r ≥ 0.3R) of the lens surface rather than across the entire surface. This local placement corrects chromatic aberrations at the periphery where they are most problematic while avoiding the generation of glare from diffracted light in the central region where it would interfere with the main beam.
Solution Approach 2:
Instead of providing a diffractive structure across the entire lens surface, the invention applies the diffractive structure partially only to the peripheral region. This partial action is sufficient to correct chromatic aberrations while avoiding the excessive diffracted light that would cause glare if the full surface were used.
2Measurement precision
If a diffractive structure is provided on the lens surface to correct chromatic aberrations, then chromatic aberrations are reduced, but transmittance deteriorates
Solution Approach 1:
The diffractive structure is localized to the peripheral region of the lens where chromatic aberrations are most prominent. This local placement minimizes the total amount of light blocked or scattered by the diffractive structure, thereby maintaining high transmittance while still achieving effective chromatic aberration correction.
3Object-generated harmful factors
If the diffractive structure is provided in the peripheral region to reduce glare, then glare is reduced, but chromatic aberration correction effectiveness may be compromised
Solution Approach 1:
The invention strategically places the diffractive structure in the peripheral region (r ≥ 0.3R) where it can effectively correct chromatic aberrations without generating glare. The peripheral region is where chromatic aberrations are most problematic, and placing the diffractive structure there allows it to correct these aberrations while avoiding the central beam path where glare would be most problematic.
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 system effectively reduces chromatic aberrations and glare while maintaining high transmittance, achieving improved image quality and resolution by carefully designing the diffractive structure and light source configuration.
Implementation Method 1
a lens having a surface provided with a diffractive structure for correction of chromatic aberrations
Implementation Method 2
The phase function of the diffractive structure is represented by φ(r) = β2·r2/2 + β4·r4/4 + β6·r6/6 + β8·r8/8
Implementation Method 3
a single convex lens provided with a diffractive structure on a surface thereof
Data Source
AI summary
An illumination optical system having a light source and a single convex lens with a diffractive structure, wherein the phase function of the diffractive structure is represented byϕ(r)=∑i=1Nβ2ir2iwhere r represents distance from the central axis of the lens, the relationship|β2|·(0.3R)2<|β4|·(0.3R)4 is satisfied where R represents effective radius of the lens, the second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, and the area of a surface of the light source is equal to or greater than 3% of the area of the entrance pupil when the light source side of the lens is defined as the image side.