Folded Camera Optical Stabilization via Coupled Lens and OPFE Motion

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Solution Overview

Problem

Existing folded cameras face challenges in providing effective focus and optical image stabilization due to limitations in the movement and alignment of optical path folding elements and lenses, particularly in dual-folded cameras integrated in mobile devices.

Innovation Solution

A dual-folded camera design incorporating a first and second optical path folding element (OPFE) with a lens that moves in parallel and perpendicular directions to provide focus and compensate for camera tilts, utilizing a combined motion of the lens and second OPFE to achieve three degrees of freedom for optical image stabilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a dual-folded camera design is used to reduce device thickness, then the compactness is improved, but the complexity of achieving focus and optical image stabilization increases

Engineering Contradiction:
Improvedevice thicknessVSAvoidoptical path folding element movement complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent combines the focus adjustment function and optical image stabilization function into a single integrated mechanism. The lens and second OPFE are coupled such that their combined motion provides both focus adjustment (by moving the lens along the optical axis) and OIS (by moving the second OPFE to shift the optical path laterally), reducing the need for separate actuation systems and simplifying the overall device structure despite the dual-folded compact design

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The second OPFE serves multiple functions: it folds the optical path in the dual-folded camera design, enables optical image stabilization through lateral motion, and works in conjunction with the lens to provide focus adjustment. This multi-functionality reduces the number of separate components needed, addressing the complexity issue while maintaining the compact form factor

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

2Reliability

If the lens and second OPFE are coupled to move together, then the optical image stabilization is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveoptical image stabilization effectivenessVSAvoidalignment precision between lens and second OPFE
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The lens and second OPFE are merged into a single movable assembly that acts as one integrated unit for OIS purposes. This coupling ensures that both elements move together in a coordinated manner, maintaining proper alignment during stabilization operations. The unified design reduces the need for extremely precise separate positioning mechanisms, as the relative alignment is maintained through the shared movement structure

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a coupling mechanism that acts as an intermediary between the lens and second OPFE. This intermediary structure ensures synchronized movement of both elements while accommodating minor manufacturing variations. The coupling mechanism translates the actuator's motion into coordinated displacement of both the lens and second OPFE, reducing the impact of manufacturing precision limitations

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If three degrees of freedom are implemented for focus and stabilization, then the optical performance is improved, but the device complexity increases

Engineering Contradiction:
Improvefocus and tilt compensation precisionVSAvoidactuation mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the three degrees of freedom (focus adjustment, lateral stabilization, and longitudinal stabilization) into a unified actuation system. The lens and second OPFE are coupled to move together, allowing a single actuator to control all three degrees of freedom through coordinated motion. This integration reduces the number of separate actuators and control systems needed, simplifying the device while maintaining precise focus and stabilization capabilities

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coupled lens-OPFE assembly serves multiple functions simultaneously: it provides focus adjustment through axial motion, lateral stabilization through lateral motion, and works within the dual-folded optical path. This multi-functionality allows three degrees of freedom to be achieved with a single integrated mechanism rather than three separate systems, reducing overall device complexity

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

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 enables simultaneous focus adjustment and compensation for camera tilts in two directions, enhancing the optical image stabilization capabilities of folded cameras, particularly in mobile devices.

Implementation Method 1

a first OPFE for folding light arriving from an object in a first optical path to a second optical path

Methodology Applied
Scientific EffectLight folding: Reflection

Implementation Method 2

a first OPFE for folding light arriving from an object in a first optical path to a second optical path

Methodology Applied
Scientific EffectLight folding: Refraction

Implementation Method 3

a second OPFE for folding light from the second optical path to a third optical path

Methodology Applied
Scientific EffectLight folding: Reflection

Implementation Method 4

a second OPFE for folding light from the second optical path to a third optical path

Methodology Applied
Scientific EffectLight folding: Refraction

Implementation Method 5

The lens forms an image on the sensor

Methodology Applied
Scientific EffectLight focusing: Lens

Data Source

PatentEP4439169B1Folded camera with optical image stabilization
Publication Date: 2025.08.13 COREPHOTONICS
  • EP4439169B1 patent drawingFigure 1A~1B
  • EP4439169B1 patent drawingFigure 1C~2A
  • EP4439169B1 patent drawingFigure 2B~2C

AI summary

Folded digital camera comprising a lens having a lens optical axis, an image sensor and first and second optical path folding elements (OPFEs), in which the second OPFE is closest to the image sensor, wherein the lens is operative to move in a first direction substantially parallel to the lens optical axis and in a second direction substantially perpendicular to first and second optical paths, wherein the second OPFE is operative to move in the first direction, and wherein the combined motion of the lens and of the second OPFE is operative to provide focus and to compensate for tilts of the camera around the first and second directions.