Prism-Based Tele-Lens Optical Path Folding for Compact Smartphone Imaging

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Solution Overview

Problem

Conventional zoom lenses are not suitable for smartphones due to their large size and the resulting dark images, prompting the need for a compact tele-lens solution that can provide a zooming effect without a lens driving system.

Innovation Solution

A tele-lens design featuring a first prism lens with a positive refractive index and an optical element that changes the light path, along with a lens unit, to achieve a reduced volume structure, satisfying the condition 0.9<TTL/EFL<1.5, allowing for a compact and efficient imaging device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional zoom lens with a lens driving system is used, then the zooming function is achieved, but the lens volume is enlarged and images become dark

Engineering Contradiction:

Improvezooming functionVSAvoidlens volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent replaces the mechanical lens driving system with an optical path folding mechanism using prisms. The telephoto lens achieves zooming effect through optical path manipulation rather than mechanical movement of lens elements, eliminating the need for a lens driving system and reducing overall lens volume.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces optical path folding using prisms to change the spatial arrangement of optical components. By folding the optical path in additional dimensions, the effective optical length is extended without increasing the physical length of the lens assembly, thereby reducing the volume occupied by the lens.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a conventional zoom lens with a lens driving system is used, then the zooming function is achieved, but the image brightness decreases

Engineering Contradiction:

Improvezooming functionVSAvoidimage brightness

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent replaces the mechanical lens driving system with an optical path folding mechanism using prisms. This substitution eliminates light loss associated with mechanical movement and complex lens element adjustments, maintaining better image brightness while achieving the zooming function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Volume of moving object

If a thin type telescopic lens is designed for dual camera, then the camera thickness is reduced, but the optical path length must be shortened

Engineering Contradiction:

Improvecamera thicknessVSAvoidoptical path length

Core Design Contradiction:

Volume of moving objectVSLength of stationary object

Solution Approach 1:

The patent employs optical path folding using prisms to extend the optical path length without increasing the physical thickness of the camera. By manipulating the light path through multiple reflections and folds, the effective optical distance is increased while maintaining a compact form factor suitable for thin cameras.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent divides the optical path into multiple segments using prisms and optical elements. This segmentation allows the light to traverse a longer total path length through multiple directional changes, achieving the required optical path length while keeping the overall camera thickness minimal.

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 tele-lens design achieves a compact form factor while maintaining effective optical performance, reducing the volume and length of the lens system, and enabling efficient image capture with a wide angle lens and telescopic lens combination in a dual camera setup.

Implementation Method 1

a first prism lens arranged to change a light path of light which is incident from an object side along a first optical axis, from the first optical axis to a second optical axis, the first prism lens having a positive refractive index

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

an optical element arranged to change the light path from the second optical axis to a third optical axis

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS10788651B2Tele-lens and imaging device

Publication Date: 2020.09.29 SAMSUNG ELECTRONICS CO LTD

AI summary

A tele-lens includes a first prism lens configured to change a light path of light, which is transmitted along a first optical axis, from an object side to a second optical axis, and an optical element configured to change the light path from the second optical axis to a third optical axis, wherein the tele-lens satisfies the following condition of 0.9<TTL/EFL<1.5, where EFL is an effective focusing distance of the tele-lens and TTL is an entire length of the tele-lens.