Seven-Lens Optical Assembly with Aspheric Surfaces for Compact Camera Design

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Solution Overview

Problem

Conventional optical systems for portable electronic devices fail to simultaneously achieve high image quality and compact size due to limitations in lens element arrangements and refractive power distribution, which are insufficient for modern high-end camera applications.

Innovation Solution

A photographing optical lens assembly comprising seven single and non-cemented lens elements, with specific refractive powers and surface shapes, including aspheric surfaces, is designed to optimize image quality and compactness by controlling refractive power distribution and reducing the total track length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional optical systems use traditional lens element arrangements, then wide field of view and sufficient incident light are achieved, but compact size requirement cannot be satisfied

Engineering Contradiction:

Improvefield of viewVSAvoidtotal track length

Core Design Contradiction:

Area of stationary objectVSLength of stationary object

Solution Approach 1:

The patent employs aspheric surfaces on multiple lens elements (first, third, fourth, fifth, and sixth lens elements) to replace traditional spherical surfaces. This curvature optimization enables better control of light paths, achieving wide field of view with reduced distortion while minimizing the total track length of the optical system, thus resolving the contradiction between field of view and compact size.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent optimizes specific parameter ratios including focal length to total track length (f/TL ≥ 0.50), curvature radii ratios (R1/|R2| ≥ 0.45, |R3|/R4 ≤ 1.50), and air gap distributions between lens elements. These parameter changes enable the optical system to achieve both wide field of view and compact dimensions by carefully balancing optical performance with physical constraints.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If more lens elements are added to improve image quality, then resolution and image quality increase, but device complexity and size increase

Engineering Contradiction:

Improveimage qualityVSAvoidlens element arrangement

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent assigns different aspheric coefficients and refractive indices to specific lens elements based on their local optical functions. The first lens element has positive refractive power with aspheric object-side surface, while the third lens element has negative refractive power with aspheric image-side surface. This localized optimization of quality parameters achieves high image quality without uniformly increasing complexity across all elements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Multiple lens elements in the patent serve multiple functions simultaneously. For example, the aspheric surfaces correct various aberrations (spherical, coma, astigmatism) while also controlling the overall field of view and focal length. The fourth lens element with positive refractive power both focuses light and corrects field curvature. This multi-functionality reduces the need for additional specialized elements, maintaining manageable complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Length of stationary object

If lens elements are cemented together to reduce air gaps, then total track length decreases, but manufacturing precision and alignment difficulty increase

Engineering Contradiction:

Improvetotal track lengthVSAvoidlens element alignment

Core Design Contradiction:

Length of stationary objectVSManufacturing precision

Solution Approach 1:

The patent divides the optical system into seven separate lens elements with specific air gaps between them, rather than cementing them together. This segmentation allows each element to be manufactured and aligned independently, reducing cumulative alignment errors while maintaining a compact total track length through optimized air gap distances and aspheric surface designs.

Inventive Principle:

Principle #1Segmentation

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 provides a compact optical system with improved image quality, wide field of view, and reduced sensitivity, effectively addressing the limitations of conventional systems by satisfying the requirements of high image quality and compact size for modern camera applications.

Implementation Method 1

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS9606328B2Photographing optical lens assembly, image capturing unit and electronic device

Publication Date: 2017.03.28 LARGAN PRECISION

AI summary

A photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The second lens element has positive refractive power. The sixth lens element has both of an object-side surface and an image-side surface being aspheric. The seventh lens element has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface of the seventh lens element has at least one convex shape in an off-axis region thereof, and both of an object-side surface and the image-side surface are aspheric.