Aperture Blade Driver Mechanism for Compact Optical Systems

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Solution Overview

Problem

Existing light-quantity control apparatuses for optical devices, such as cameras, face challenges in achieving a compact size while maintaining a good aperture shape, often resulting in unnatural blur and ghost shapes due to non-circular aperture configurations.

Innovation Solution

A light-quantity control apparatus comprising a base member with a movable first aperture blade and a rotatable second aperture blade, driven by a driver with a protruding portion engaging the first blade and a rotation center for the second blade, allowing for miniaturization and formation of a circular-like aperture shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a driving ring is disposed around the aperture to rotate multiple aperture blades, then the aperture shape becomes closer to circular, but the circumferential size of the apparatus increases

Engineering Contradiction:
Improveaperture shapeVSAvoidcircumferential size
Core Design Contradiction:
ShapeVSArea of stationary object

Solution Approach 1:

The patent combines the driving functions for both linear movement and rotation into a single driving lever. The driving lever has a first engaging portion that engages with the linearly-movable aperture blade and a second engaging portion that engages with the rotatably-movable aperture blade, eliminating the need for separate driving rings and reducing circumferential size while maintaining circular aperture shape.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driving lever serves multiple functions: it acts as both a linear actuator for the first aperture blade and a rotational actuator for the second aperture blade. This multi-functionality is achieved through the specific geometry of the engaging portions, allowing one component to replace what would traditionally require separate driving mechanisms.

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

2Area of stationary object

If paired linearly-movable aperture blades and paired swingable aperture blades are used, then the apparatus width decreases, but the size cannot be sufficiently decreased due to the ring plate configuration

Engineering Contradiction:
Improveapparatus widthVSAvoidapparatus size
Core Design Contradiction:
Area of stationary objectVSVolume of stationary object

Solution Approach 1:

The patent merges the ring plate structure with the driving lever into a single integrated component. The driving lever is formed as a unitary structure that eliminates the need for a separate ring plate, thereby reducing both the width and overall volume of the apparatus while maintaining the paired blade configuration for compactness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and eliminates the separate ring plate component from the design. By integrating its functionality directly into the driving lever, the design removes unnecessary structural elements, reducing the overall apparatus size while preserving the essential driving function for both linear and rotational blade movements.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If multiple separate driving mechanisms are used for linear and rotational blade movement, then the aperture shape control is precise, but the device complexity increases

Engineering Contradiction:
Improveaperture shape controlVSAvoiddriving mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple driving mechanisms into a single driving lever with specifically designed engaging portions. The first engaging portion controls linear movement while the second engaging portion controls rotation, maintaining precise aperture shape control while significantly reducing device complexity by eliminating separate driving components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The driving lever is designed as a universal component that performs both linear actuation and rotational actuation functions. This multi-functionality is achieved through the geometric design of the engaging portions, which translate the lever's movement into both linear and rotational blade movements, simplifying the overall mechanism while preserving precision.

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

Data Source

PatentEP2610670B1Light amount adjustment device and optical equipment
Publication Date: 2020.05.06 CANON DENSHI KK
  • EP2610670B1 patent drawingFigure 1
  • EP2610670B1 patent drawingFigure 2~3
  • EP2610670B1 patent drawingFigure 4~5

AI summary

[Problem] It is necessary to provide a compact light-quantity control apparatus capable of forming an aperture having a good shape. [Solution] The light-quantity control apparatus includes a base member (2) provided with an opening (2b) allowing light to pass therethrough a first aperture blade (4, 7) movable with respect to the base member in a direction orthogonal to a light passing direction so as to increase and decrease its part overlapping the opening, a second aperture blade (5, 6, 8, 9) rotatable with respect to the base member in a surface orthogonal to the light passing direction so as to increase and decrease its part overlapping the opening, and a driver (1) attached to the base member and driving the first and second aperture blades. The base member is provided with a protruding portion (2d, 2e) engaging with a groove portion formed in the first aperture blade to guide the first aperture blade in its movable direction, and the second aperture blade is rotatable in the surface about the protruding portion.