Four-Lens Projection Assembly for Miniaturization and Aberration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional projection lens assemblies face challenges in miniaturization and achieving high imaging quality due to increased lens count, which leads to larger size and distortion issues, particularly when trying to match with defractive optical elements for accurate beam redistribution.
Innovation Solution
A projection lens assembly comprising four lenses with specific refractive powers, surface types, and axial spacings, including a first lens with positive refractive power, a second lens with negative refractive power and concave surfaces, a third lens with positive or negative refractive power, and a fourth lens with positive refractive power and a convex image-side surface, optimized to achieve telecentricity, reduce aberrations, and enhance light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of lenses is increased to eliminate aberrations and enhance resolution, then imaging quality is improved, but the total track length increases, which is not conductive to miniaturization
Solution Approach 1:
The patent applies parameter changes by carefully controlling the focal lengths, spacing distances, and curvature radii of the four lenses to achieve optimal imaging quality with a compact total track length. The conditional expressions define specific parameter ranges that balance aberration correction with miniaturization requirements
Solution Approach 2:
The patent uses a composite lens system combining four different lens elements with varying refractive powers and surface curvatures. This composite structure allows each lens to contribute differently to aberration correction while maintaining a compact overall design
2Area of stationary object
If the field-of-view is enlarged, then coverage area is improved, but distortion increases and imaging quality deteriorates
Solution Approach 1:
The patent applies local quality by designing each lens with specific surface curvatures and refractive powers tailored to correct aberrations in different regions of the field. The conditional expressions ensure that each lens element contributes to correcting distortion and maintaining imaging quality across the entire enlarged field-of-view
3Manufacturing precision
If the number of lenses is increased to eliminate aberrations, then resolution is enhanced, but device complexity increases
Solution Approach 1:
The patent uses a composite lens system with four elements that work together to correct aberrations and enhance resolution. The structured arrangement with defined spacing and focal length relationships achieves high resolution while controlling overall system complexity
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 enables miniaturization while maintaining high imaging quality and large aperture, with improved light transmittance and reduced distortion, effectively addressing the limitations of conventional lens assemblies.
Implementation Method 1
a first lens having a positive refractive power
Implementation Method 2
a second lens having a negative refractive power
Implementation Method 3
a third lens having a positive refractive power or a negative refractive power
Implementation Method 4
a fourth lens having a positive refractive power, where an image-side surface of the fourth lens may be a convex surface
Data Source
AI summary
A projection lens assembly is provided. The projection lens assembly includes, sequentially along an optical axis from a source-side to an image side, a first lens having a positive refractive power; a second lens having a negative refractive power, where a source-side surface and an image-side surface of the second lens are concave surfaces; a third lens having a positive refractive power or a negative refractive power; and a fourth lens having a positive refractive power, where an image-side surface of the fourth lens is a convex surface. A total effective focal length f of the projection lens assembly and an effective focal length f1 of the first lens satisfy: 2.0<f/f1<3.5.