Six-Lens Optical Assembly with Cemented Elements for Compact Design
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Solution Overview
Problem
Conventional six-piece lens assemblies face challenges in achieving miniaturization, large aperture, and resistance to ambient temperature variations while maintaining optical performance.
Innovation Solution
A lens assembly design comprising specific refractive power lenses, including a meniscus, biconcave, and biconvex lenses, with optimized focal lengths and refractive indices, and aspheric surfaces, which are cemented together to achieve a short total lens length, small F-number, high resolution, and resistance to temperature variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a conventional six-piece lens assembly is used, then the optical performance can be maintained, but the total lens length becomes longer
Solution Approach 1:
The patent applies parameter changes by optimizing the focal lengths, refractive indices, and curvature radii of the six lens elements to achieve a compact design. Specific ratios are defined (e.g., 0.34/f4 for fourth lens focal length, 2.11/f1 for first lens focal length) to control the overall lens length while maintaining optical performance. The aspherical surfaces and cemented lens combinations further enable parameter optimization for miniaturization.
Solution Approach 2:
The patent uses composite material principles by combining different glass types with specific refractive indices and Abbe numbers for each lens element. The fourth and fifth lenses are cemented together to form a compound lens, allowing for better control of optical parameters and reduction of total lens length while correcting chromatic and spherical aberrations.
2Length of moving object
If the lens assembly is miniaturized, then the total lens length is reduced, but the aperture becomes smaller
Solution Approach 1:
The patent optimizes the F-number parameter to achieve a small F-number (large aperture) while maintaining a compact lens length. The aperture diameter and focal length ratios are carefully controlled through the defined parameters (e.g., focal length ratios of individual lenses to effective focal length) to maximize light gathering capability within a short total lens length.
3Length of moving object
If the lens assembly is miniaturized, then the total lens length is reduced, but the resolution decreases
Solution Approach 1:
The patent employs aspherical surfaces on several lens elements (first, third, fourth, and sixth lenses) to correct spherical aberration and improve resolution. The aspherical coefficients are optimized to maintain high image quality and resolution despite the reduced total lens length, allowing better control of light rays across the entire field of view.
Solution Approach 2:
The cemented combination of fourth and fifth lenses with different refractive indices and Abbe numbers creates a compound lens system that effectively corrects chromatic and spherical aberrations, thereby improving resolution. The specific glass material selections (with defined Nd and Vd values) enable better color correction and sharpness in the compact design.
4Length of moving object
If the lens assembly is miniaturized, then the total lens length is reduced, but the resistance to temperature variations worsens
Solution Approach 1:
The patent defines specific parameter ranges and ratios (focal length ratios, refractive indices, Abbe numbers) that are optimized to minimize thermal sensitivity. The cemented lens design with carefully selected glass materials helps compensate for thermal expansion and refractive index changes with temperature, maintaining optical performance stability in a compact configuration.
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 design results in a lens assembly with improved optical performance, corrected aberrations, increased resolution, and enhanced resistance to environmental temperature changes, balancing manufacturability and image quality.
Implementation Method 1
a first lens L11 with positive refractive power, an object side surface of the fourth lens is convex... a second lens L12 with negative refractive power... a third lens L13 with positive refractive power... a fourth lens L14 with positive refractive power... a fifth lens L15 with negative refractive power... a sixth lens L16 with positive refractive power
Data Source
AI summary
A lens assembly comprises sequentially from an object side to an image side along an optical axis a first lens, a second lens, a third lens, a stop, a fourth lens, a fifth lens and a sixth lens. The first lens is a meniscus with refractive power and includes a convex surface facing an object side and a concave surface facing an image side. The second lens is with negative refractive power and includes a concave surface facing the object side. The third lens is with positive refractive power and includes a convex surface facing the image side. The fourth lens is with positive refractive power and includes a convex surface facing the image side. The fifth lens is a biconcave lens with negative refractive power. The sixth lens is with positive refractive power and includes a convex surface facing the object side.