Compact Iris Mechanism Using SIDM Rotary Drive

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Solution Overview

Problem

Existing iris mechanisms for cameras, such as those used in information devices, are difficult to miniaturize due to their reliance on galvanometers, which are bulky and hard to shrink in size.

Innovation Solution

An iris mechanism utilizing a smooth impact drive mechanism (SIDM) to convert linear drive force into rotational force, combined with a rotational transfer portion and iris blades, allowing for compact design and rapid adjustment of light passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a galvanometer is used as the drive source to move the iris blade, then the iris mechanism can achieve stable and reliable operation, but the structure becomes bulky and difficult to miniaturize

Engineering Contradiction:
Improvestable and reliable operationVSAvoidsize of iris mechanism
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent replaces the traditional galvanometer (electromagnetic actuator) with a piezoelectric actuator that uses piezoelectric materials to generate mechanical displacement. This substitution enables miniaturization while maintaining reliable operation, as piezoelectric actuators can provide precise control and stable performance in a compact form factor.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental operating parameters of the drive source by transitioning from electromagnetic actuation to piezoelectric actuation. This parameter change allows the iris mechanism to achieve both miniaturization and reliable operation, as piezoelectric materials can generate sufficient force for iris blade movement in a much smaller volume.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If the iris mechanism is miniaturized for built-in cameras in information devices, then the device thickness can be reduced, but the drive source becomes more difficult to design and manufacture

Engineering Contradiction:
Improvesize of iris mechanismVSAvoiddifficulty of designing and manufacturing drive source
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent replaces complex electromagnetic drive sources with piezoelectric actuators that have simpler manufacturing processes. Piezoelectric components can be fabricated using standard semiconductor manufacturing techniques, making them easier to produce in miniaturized forms while maintaining the required drive force and control precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The piezoelectric actuator serves multiple functions within the miniaturized iris mechanism, including driving the iris blade, providing precise position control, and enabling rapid response. This multi-functionality simplifies the overall design by eliminating the need for separate components that would be required in a miniaturized galvanometer system.

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 mechanism achieves miniaturization, enabling thinner smart phones and applications in built-in cameras, including folding smartphones, while maintaining stable and efficient light control.

Implementation Method 1

a smooth impact drive mechanism (SIDM) as a drive source configured to extend and retract in a linear direction according to energization to generate a drive force in the linear direction

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the drive force in the linear direction of the output shaft is converted into the rotational drive force through contact between an outer circumferential face of the output shaft and the pair of clamping portions

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4715443A1Aperture mechanism
Publication Date: 2026.03.25 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4715443A1 patent drawingFigure 1
  • EP4715443A1 patent drawingFigure 2
  • EP4715443A1 patent drawingFigure 3

AI summary

The subject matter of the present disclosure is to provide an iris mechanism capable of being miniaturized. An iris mechanism A, including: a frame portion (1) formed around an optical axis; an iris blade (2) capable of moving relative to the frame portion (1) in a direction intersecting the optical axis and capable of changing an opening area of an opening in a direction of the optical axis along with a movement; and a drive portion 3 configured to drive the iris blade (2) to move. The drive portion (3) includes an SIDM (31) as a drive source configured to extend and retract in a linear direction according to energization to generate a drive force in the linear direction; a conversion portion (32) configured to convert the drive force in the linear direction of the SIDM (31) into a rotational drive force; and a rotational transfer portion (33) continuous with the conversion portion (32) and connected to the iris blade (2) for rotational movement based on a rotation center.