Zoom Lens Light Splitting and Aperture Design

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Solution Overview

Problem

Existing zoom lenses face challenges in adapting to complex scenarios due to short back focal lengths, small apertures, and poor photosensitivity, limiting their ability to effectively split light and provide high-resolution imaging, especially in low luminance conditions.

Innovation Solution

A zoom lens design comprising multiple lens groups with specific refractive powers and a splitting unit using prisms to split light into different wavelengths, ensuring large apertures and target planes, and high resolution, with movable lens groups to adjust focal lengths and improve adaptability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If existing zoom lenses use short back focal length design, then the lens structure is compact, but the ability to split light is insufficient

Engineering Contradiction:
Improveback focal lengthVSAvoidlight splitting capability
Core Design Contradiction:
Length of stationary objectVSAdaptability or versatility

Solution Approach 1:

The zoom lens is divided into five distinct lens groups (G1-G5) with different functions. The first lens group (G1) with negative refractive power is specifically designed to handle light splitting, while the other groups handle focusing and image formation. This segmentation allows the lens to achieve both compact size and effective light splitting capability.

Inventive Principle:
Principle #1Segmentation

2Area of stationary object

If existing zoom lenses use small aperture design, then the lens size is reduced, but photosensitivity deteriorates

Engineering Contradiction:
Improveaperture sizeVSAvoidphotosensitivity
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The zoom lens design incorporates multiple lens groups that serve multiple functions simultaneously. The first lens group (G1) with negative refractive power contributes to both aperture control and light gathering, while the subsequent groups (G2-G5) with positive refractive power enhance both the aperture effect and photosensitivity. This multi-functional design allows the lens to achieve large aperture and high photosensitivity together.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If existing zoom lenses use fixed lens groups, then the structure is simple, but adaptability to different scenarios is limited

Engineering Contradiction:
Improvelens group structureVSAvoidscenario adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The zoom lens incorporates movable lens groups (G2, G3, G4, G5) that can be positioned at different locations along the optical axis to achieve different focal lengths and adapt to various imaging scenarios. The first lens group (G1) remains fixed to maintain the light splitting function, while the other groups are dynamically adjustable. This dynamic design enables the lens to adapt to different scenarios while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #15Dynamics

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 achieves high imaging performance under low luminance and diverse environmental conditions, enhancing adaptability and image quality in applications like video surveillance and intelligent traffic monitoring.

Implementation Method 1

a splitting unit; wherein the splitting unit may include at least two prisms, wherein two adjacent surfaces of the at least two prisms are covered by materials configured to split different wavelengths of light

Methodology Applied
Scientific EffectLight splitting: Prism

Implementation Method 2

a first lens having negative refractive power; a second lens having positive refractive power

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3948388B1Zoom lens and optical device having the same
Publication Date: 2024.10.09 ZHEJIANG DAHUA TECH CO LTD
  • EP3948388B1 patent drawingFigure 1
  • EP3948388B1 patent drawingFigure 2
  • EP3948388B1 patent drawingFigure 3

AI summary

Provided are a zoom lens and an optical device using the same. The zoom lens may include in order from an object side to an image side: a first lens group (G1), a second lens group (G2), a third lens group (G3), a fourth lens group (G4); and a fifth lens group (G5). The zoom lens may satisfy the following conditions: -2.28≤f 2/f w '≤-1.08, and 0.15≤TTL/ (BFL *f w ')≤0.45, wherein f 2 denotes a focal length of the second lens group, f w 'denotes a focal length of the zoom lens at a wide angle end, TTL denotes a total track length of the zoom lens, and BFL denotes a back focal length of the zoom lens.