Retractable Zoom Lens Layout for Thin Folded Camera Modules

Solution Overview

Problem

Existing camera devices in mobile apparatuses face challenges in miniaturizing and thinning zoom lenses, leading to increased size and weight due to the need for multiple camera devices and sensors, which are costly and cumbersome.

Innovation Solution

A retractable zoom lens system with a first lens group having negative refractive power and a reflective optical element in the second lens group that moves along the optical axis during retraction, allowing the first lens group to be accommodated into the space created by the second lens group's movement, combined with a reflective optical element to bend the optical axis and minimize thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple camera devices with different field angles are arranged side by side to achieve wide-angle and zoom functionality, then the imaging capability is improved, but the volume and weight of the device increase

Engineering Contradiction:

Improveimaging capabilityVSAvoiddevice volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines multiple lens groups (first lens group with negative refractive power, second lens group with positive refractive power, and third lens group with positive refractive power) into a single integrated zoom lens system that provides both wide-angle and telephoto imaging capabilities, eliminating the need for multiple separate camera devices

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The first lens group is retractable and can be nested within the space created by the movement of the second lens group during retraction, allowing compact arrangement of optical components and reducing overall device volume

Inventive Principle:

Principle #7Nested doll (Nesting)

2Adaptability or versatility

If multiple camera devices with different field angles are arranged side by side to achieve wide-angle and zoom functionality, then the imaging capability is improved, but the weight of the device increases

Engineering Contradiction:

Improveimaging capabilityVSAvoiddevice weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

The patent combines multiple lens groups (first lens group with negative refractive power, second lens group with positive refractive power, and third lens group with positive refractive power) into a single integrated zoom lens system that provides both wide-angle and telephoto imaging capabilities, eliminating the need for multiple separate camera devices

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The first lens group is retractable and can be nested within the space created by the movement of the second lens group during retraction, allowing compact arrangement of optical components and reducing overall device volume

Inventive Principle:

Principle #7Nested doll (Nesting)

3Volume of moving object

If a retractable zoom lens is designed to achieve miniaturization, then the volume is reduced, but the optical performance may deteriorate

Engineering Contradiction:

Improvelens volumeVSAvoidoptical performance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent specifies precise refractive power relationships between lens groups (first lens group with negative refractive power, second and third lens groups with positive refractive power) and defines specific movement relationships during retraction and zooming to maintain optical performance while achieving miniaturization

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic movement of lens groups during retraction and zooming operations, where the first lens group moves to be retracted into the space generated by the second lens group's movement, and the P-lens group moves to reduce spacing with the second lens group, maintaining optical performance across different states

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 solution enables a wide-angle configuration while achieving significant miniaturization and thinning of the camera device by optimizing the balance between lens groups' movements and optical path bending, reducing mechanical parts and maintaining high performance.

Implementation Method 1

the second lens group has a reflective optical element bending the optical axis

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

the first lens group has a negative refractive power

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS12596241B2Zoom lens and camera device with zoom lens

Publication Date: 2026.04.07 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

AI summary

A zoom lens is retractable and includes a first lens group, a second lens group and a P-lens group from an object side to an image side along an optical axis, the first lens group has a negative refractive power, and the second lens group has a reflective optical element bending an optical axis. During retraction, the second lens group moves along the optical axis to an image side, and at least a part of the first lens group is retracted into a space generated by the movement of the second lens group.