Iris Diaphragm Aperture Shape Orientation Control
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Solution Overview
Problem
Prior iris diaphragms suffer from undesirable rotation of bokeh effect shape and orientation with aperture size changes, affecting image quality in photography and cinematography.
Innovation Solution
An iris diaphragm design featuring a fixed ring, blades that move in a plane perpendicular to the optical axis, and a control ring that rotates to adjust aperture size without altering the predetermined shape or orientation of the bokeh effect, utilizing guidance guideways and control pins to maintain shape consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If conventional iris diaphragm blades are rotated to adjust aperture size, then the aperture area changes, but the bokeh shape rotates and changes orientation
Solution Approach 1:
The iris diaphragm is divided into multiple independent blades (typically 8 or 9), each capable of individual movement control through separate control pins and guideways. This segmentation allows each blade to be positioned independently to maintain the overall aperture shape orientation while changing the aperture area.
Solution Approach 2:
Control guideways act as intermediary elements between the control ring and the blades. These guideways constrain the movement of control pins to specific paths, ensuring that when the control ring rotates, the blades move in a controlled manner that maintains aperture shape orientation while adjusting aperture area.
2Shape
If the number of blades is increased to improve bokeh circularity, then the bokeh shape quality improves, but the device complexity increases
Solution Approach 1:
The control ring serves multiple functions: it controls the aperture area adjustment and simultaneously maintains the aperture shape orientation through its integrated control guideways. This universal control mechanism eliminates the need for separate control systems for each blade, reducing overall device complexity despite having multiple blades.
Solution Approach 2:
The control guideways are integrated into the control ring structure, merging the control mechanism with the adjustment mechanism. This consolidation reduces the number of separate components and simplifies the overall device structure while maintaining precise control over multiple blades.
3Area of moving object
If traditional pivot connections are used for blade adjustment, then the aperture size can be changed, but the aperture shape rotates with the control ring
Solution Approach 1:
The control guideways are designed with asymmetric paths relative to the control ring rotation, where the guideway geometry is specifically shaped to convert rotational motion into linear blade movement along predetermined paths. This asymmetric design ensures that the aperture shape maintains its orientation while the aperture area changes.
Solution Approach 2:
The control mechanism transitions from simple rotational movement in one dimension to controlled movement in multiple dimensions through the guideway paths. The guideways constrain control pin movement to specific two-dimensional paths, transforming the control ring's rotational motion into precise linear blade adjustments that maintain aperture shape stability.
Data Source
AI summary
An iris diaphragm having an optical axis, includes a fixed ring, a plurality of [Formula (I)] blades defining a diaphragm aperture of predetermined shape, the blades being able to move in a plane perpendicular to the optical axis with respect to the fixed ring, each blade comprising a control pin, a control ring designed to rotate about the optical axis with respect to the fixed ring and comprising m control guideways, each control pin being able to move along a respective one of the control guideways by bearing along the respective control guideway, a rotation of the control ring about the optical axis giving rise, via the movement of the control pins in the control guideways, to the movement of the blades with respect to the fixed ring so as to modify the area of the aperture while maintaining the predetermined aperture shape, without causing a rotation of the predetermined shape with respect to the fixed ring.