Folded Tele Camera Zoom Structure for Thin Dual-Camera Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dual-aperture zoom cameras face challenges with large F numbers, bulky actuators, slow operation, and high costs due to the structural requirements of their lens assemblies, particularly when incorporating a Tele lens with a long effective focal length for high zooming effects, which complicates miniaturization for use in compact devices.
Innovation Solution
A dual-camera system with a Wide and folded Tele lens configuration, featuring movable lens element groups G1 and G3 relative to the Tele sensor, and a stationary G2, achieving a Tele lens effective focal length change from EFLT,min to EFLT,max while maintaining a small Tele lens f-number and total track length, using voice coil motors and ball-guided mechanisms for precise movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a Tele lens with long effective focal length is used to achieve high zooming effect, then zoom capability is improved, but device thickness and overall dimensions increase
Solution Approach 1:
The patent employs an optical path folding element (prism) to fold the optical path at 45 degrees, changing the dimensional arrangement from a straight linear path to a folded configuration. This allows the Tele lens to achieve long effective focal length while keeping the physical thickness of the device minimal by utilizing the lateral dimension for optical path length.
Solution Approach 2:
The patent integrates the optical path folding element within the lens module structure, nesting the prism inside the Tele lens assembly. This nested configuration allows the folding element to be incorporated without significantly increasing the overall device dimensions, enabling compact integration of the zoom functionality.
2Reliability
If traditional lens assembly structures are used, then optical performance is maintained, but F number becomes large and device size increases
Solution Approach 1:
The patent divides the Tele lens into multiple lens element groups (first group, second group, third group) that can move independently relative to each other. This segmentation allows each group to be optimized for specific functions (zooming and focusing) while maintaining overall optical performance, and enables compact configuration through independent movement of smaller groups rather than moving the entire lens assembly.
Solution Approach 2:
The patent implements dynamic movement of lens element groups during zooming and focusing operations. The first and third lens element groups move relative to the second group and the image sensor, enabling variable focal length and focus adjustment. This dynamic configuration allows the lens to maintain optimal optical performance across different zoom states while keeping the device compact.
3Manufacturing precision
If bulky actuators are used for lens movement, then positioning precision is achieved, but device size and weight increase
Solution Approach 1:
The patent replaces traditional bulky mechanical actuators with voice coil motors for moving the lens element groups. Voice coil motors provide precise positioning control through electromagnetic force while maintaining a compact and lightweight structure, thereby achieving accurate lens positioning without increasing device size and weight.
4Adaptability or versatility
If multiple lens element groups are made movable for zooming, then zoom range is extended, but device complexity and cost increase
Solution Approach 1:
The patent segments the Tele lens into three distinct lens element groups with different movement characteristics. The first and third groups move relative to the second group and image sensor for zooming, while the second group remains stationary during zooming but can move for focusing. This segmentation enables extended zoom range through coordinated movement of specific groups while keeping the overall structure manageable and cost-effective.
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 system provides a compact dual-camera with improved zoom capabilities, reduced F number, and efficient actuation, addressing the limitations of existing designs by maintaining a small form factor and enhancing operational speed and reliability.
Implementation Method 1
using voice coil motors and ball-guided mechanisms for precise movement
Implementation Method 2
using voice coil motors and ball-guided mechanisms for precise movement
Implementation Method 3
a reflecting element (also referred to as optical path folding element or 'OPFE') that folds light arriving from an object or scene along a first optical path to a second optical path toward the Tele image sensor
Data Source
AI summary
Multi-cameras and in particular dual-cameras comprising a Wide camera comprising a Wide lens and a Wide image sensor, the Wide lens having a Wide effective focal length EFLW and a folded Tele camera comprising a Tele lens with a first optical axis, a Tele image sensor and an OPFE, wherein the Tele lens includes, from an object side to an image side, a first lens element group G1, a second lens element group G2 and a third lens element group G3, wherein at least two of the lens element groups are movable relative to the image sensor along the first optical axis to bring the Tele lens to two zoom states, wherein an effective focal length (EFL) of the Tele lens is changed from EFLT,min in one zoom state to EFLT,max in the other zoom state, wherein EFLTmin>1.5×EFLW and wherein EFLTmax>1.5×EFLTmin.