Four-Lens Optical Assembly with Aspheric Inflection Points

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Solution Overview

Problem

Conventional optical image capturing assemblies in portable electronic products face challenges in achieving high-quality images due to limitations in compactness and manufacturing complexity, particularly with three-element and four-element lens structures that fail to provide optimal image quality and are difficult to manufacture.

Innovation Solution

An optical image capturing assembly comprising a specific arrangement of four lens elements with positive and negative refractive powers, including aspheric surfaces and inflection points, optimized to reduce total track length and correct aberrations, allowing for a compact and high-quality imaging solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a three-element lens structure is used, then the assembly is compact, but image quality is poor

Engineering Contradiction:

Improveassembly sizeVSAvoidimage quality

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The lens assembly is divided into four distinct lens elements with specific refractive powers and surface curvatures, allowing each element to contribute differently to aberration correction while maintaining a compact overall structure. The segmentation of optical functions across multiple elements enables high image quality without sacrificing compactness.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If a four-element lens structure with glass spherical lenses is used, then chromatic aberration is eliminated, but total track length increases and manufacturing becomes difficult

Engineering Contradiction:

Improveaberration correctionVSAvoidtotal track length

Core Design Contradiction:

Manufacturing precisionVSLength of stationary object

Solution Approach 1:

The patent employs aspheric surfaces on multiple lens elements instead of simple spherical surfaces. These aspheric surfaces provide additional degrees of freedom for correcting aberrations including chromatic aberration, while allowing for a more compact optical path. The inflection points on the aspheric surfaces enable precise control of light rays to achieve aberration correction with reduced total track length.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent specifies precise parameter relationships including focal length ratios (f3/f within 0.8-1.2, f4/f within -1.0 to -0.5), curvature radius ratios (R1/R2 within -2.0 to 0.5, R3/R4 within -0.5 to -2.0), and inflection point positions on the aspheric surfaces. These controlled parameter changes enable optimal aberration correction while maintaining compact dimensions.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If glass spherical lenses are attached together, then chromatic aberration is corrected, but manufacturing process becomes difficult

Engineering Contradiction:

Improvechromatic aberration correctionVSAvoidmanufacturing process

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

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 the production of compact optical image capturing assemblies with improved image quality, reduced total track length, and simplified manufacturing, suitable for lightweight and portable electronic products.

Implementation Method 1

a first lens element (110), a second lens element (120), a third lens element (130) and a fourth lens element (140) The first lens element with positive refractive power has a convex object-side surface. The second lens element with negative refractive power has a concave object-side surface and a convex image-side surface.

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS8670189B2Optical image capturing assembly

Publication Date: 2014.03.11 LARGAN PRECISION

AI summary

An optical image capturing assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element with negative refractive power has a concave object-side surface and a convex image-side surface. The third lens element with positive refractive power is made of plastic material, and has a convex object-side surface and a convex image-side surface. The fourth lens element with negative refractive power is made of plastic material, and has a convex object-side surface and a concave image-side surface. The object-side surfaces and the image-side surfaces of the third lens element and the fourth lens element are aspheric. The fourth lens element has at least one inflection point formed on at least one surface thereof.