Five-Lens Optical System Aberration Control via Thickness Ratios
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Solution Overview
Problem
Conventional optical lenses face a challenge in balancing length and optical performance, as increasing the number of lenses to reduce aberration and achieve high resolution leads to excessive length, while decreasing the number of lenses compromises image quality.
Innovation Solution
An optical lens design comprising a sequence of five lenses with specific refractive powers and thickness ratios, including a biconvex first lens, a negative second lens, a positive third lens, a negative fourth lens, and a negative fifth lens, arranged along an optical axis, with conditions such as 0.52<(TH1+TH2+TH3)/EFL<1.0 and 0.5<(TH3+TH4+TH5)/EFL<0.65 to maintain short length and high optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of lenses is increased to reduce aberration and achieve high resolution, then optical performance is improved, but the total length of the optical lens becomes too long
Solution Approach 1:
The patent applies parameter changes by establishing specific mathematical relationships between lens parameters (focal lengths, thicknesses, and spacing). The conditions (1) through (5) define precise parameter ranges that optimize both optical performance and compactness. For example, the third lens has a positive focal length with specific constraints (0.05EFL < f3 < 0.15EFL) that differ from conventional designs, enabling aberration correction in a shorter configuration.
Solution Approach 2:
The patent uses composite lens structures where the optical system combines five different lens elements with alternating positive and negative refractive powers. This composite approach allows each lens to contribute differently to aberration correction, achieving superior optical performance with fewer total elements than conventional designs would require.
2Manufacturing precision
If the number of lenses is increased to correct aberration, then image quality is improved, but the complexity of the optical system increases
Solution Approach 1:
The patent reduces system complexity by changing the parameter configuration to use only five lenses with a specific alternating pattern of positive and negative refractive powers. The mathematical conditions (1) through (5) constrain the parameters to ranges that achieve effective aberration correction with minimal elements, avoiding the need for more complex multi-element designs.
Solution Approach 2:
The optical system is segmented into five distinct lens elements, each with a specific function in the aberration correction sequence. The segmentation follows a deliberate pattern (positive, negative, positive, negative, negative) where each element addresses specific aberration types, achieving comprehensive correction without requiring a larger number of elements.
3Length of stationary object
If the number of lenses is decreased to reduce length, then the total length is reduced, but optical performance deteriorates
Solution Approach 1:
The patent achieves compact length while maintaining optical performance through parameter changes in the lens design. The fifth lens has a negative focal length with specific constraints (0.1EFL < |f5| < 0.3EFL) that enable effective aberration correction in a short configuration. The thickness ratios and spacing parameters are optimized to maximize optical efficiency within a compact form factor.
Solution Approach 2:
The patent employs aspheric surfaces on multiple lens elements to enhance optical performance in a compact design. The aspheric profiles allow for better control of light rays and aberration correction without requiring additional lens elements, enabling high-resolution imaging in a shortened optical path.
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 effectively reduces aberration, achieves high resolution, and allows for a short total length while being easily manufacturable, ensuring good imaging quality and cost-effectiveness.
Implementation Method 1
The optical lens includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially along an optical axis from an object side to an image side, wherein the first lens has a positive refractive power, the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power and the fifth lens has a negative refractive power
Data Source
AI summary
An optical lens includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially along an optical axis from an magnified side to a minified side. A center thickness of the first lens is TH1, a center thickness of the second lens is TH2, a center thickness of the third lens is TH3, a center thickness of the fourth lens is TH4, a center thickness of the fifth lens is TH5, and an effective focal length of the optical lens is EFL, wherein the optical lens fits at least one of the following conditions: (1) 0.52<(TH1+TH2+TH3)/EFL<1.0; (2) 0.5<(TH3+TH4+TH5)/EFL<0.65; and (3) (TH1+TH2+TH3)/(TH3+TH4+TH5)>1.20. The optical lens can reduce aberration and has high resolution.