Seven-Element Lens Assembly for Compact Off-Axis Imaging

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Solution Overview

Problem

Conventional optical lens modules face difficulties in simultaneously achieving a large aperture and short total track length, which limits their ability to enhance imaging functionality, especially in off-axis regions, making them unsuitable for portable electronic devices.

Innovation Solution

An image capturing lens assembly with seven lens elements, featuring specific refractive powers and surface shapes, including aspheric surfaces, is designed to balance refractive power distribution and correct aberrations, ensuring a large field of view and short total track length, while maintaining a compact size and improved brightness in off-axis regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the aperture size is increased to enhance imaging functionality in off-axis regions, then the imaging quality in off-axis regions is improved, but the total track length increases

Engineering Contradiction:

Improveimaging quality in off-axis regionVSAvoidtotal track length

Core Design Contradiction:

Measurement precisionVSLength of stationary object

Solution Approach 1:

The lens assembly is divided into seven distinct lens elements with different refractive powers and surface configurations. Each lens element contributes specifically to correcting certain types of aberrations, allowing the system to achieve high off-axis imaging quality without requiring a large aperture and long track length.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different lens elements have locally optimized surface shapes (convex, concave, aspheric) and refractive powers tailored to correct specific aberrations in different regions of the optical path. For example, the seventh lens element has an aspheric image-side surface specifically designed to correct off-axis aberrations, while the fifth lens element has a positive refractive power with specific surface curvatures to control light convergence.

Inventive Principle:

Principle #3Local quality

2Length of stationary object

If the total track length is reduced for compact device design, then the device size is reduced, but the imaging functionality in off-axis regions deteriorates

Engineering Contradiction:

Improvetotal track lengthVSAvoidimaging quality in off-axis region

Core Design Contradiction:

Length of stationary objectVSMeasurement precision

Solution Approach 1:

The lens assembly incorporates aspheric surfaces on multiple lens elements (first, second, third, sixth, and seventh lens elements) to replace traditional spherical surfaces. These aspheric surfaces provide better control over light ray paths, enabling effective aberration correction in a more compact configuration, thus maintaining high off-axis imaging quality with a reduced total track length.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent employs precise control of optical parameters including refractive indices (1.5 < n < 1.9), specific surface curvature ratios, and axial distance proportions between lens elements. These parameter optimizations allow the system to achieve high imaging performance in off-axis regions while maintaining a compact total track length suitable for portable devices.

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 effectively enhances imaging functionality in off-axis regions with a large aperture and short total track length, making the lens assembly suitable for portable electronic devices by optimizing refractive power distribution and surface shapes.

Implementation Method 1

an image capturing lens assembly includes seven lens elements, which are, 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

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS11782248B2Image capturing lens assembly, imaging apparatus and electronic device

Publication Date: 2023.10.10 LARGAN PRECISION

AI summary

An image capturing lens assembly includes seven lens elements, which are, 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 fifth lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The sixth lens element has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. The seventh lens element has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, and the image-side surface thereof includes at least one convex shape in an off-axis region thereof.