Diaphragm Apparatus Dynamic Gap Control for Aperture Accuracy
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Solution Overview
Problem
Existing diaphragm apparatuses face issues with increased driving torque and size due to overlapping diaphragm blades in small aperture states and rattling in open aperture states, leading to suboptimal aperture accuracy and efficiency.
Innovation Solution
A diaphragm apparatus with a driving member featuring a protrusion that rotates around the optical axis, contacting a rail part on the base plate to adjust the gap between the driving member and the base plate, allowing the gap size to change with rotation, thereby optimizing aperture diameter adjustments without increasing size or torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the gap between the base plate and rotating member is widened in a small aperture state, then the warpage of diaphragm blades is prevented, but the driving torque increases
Solution Approach 1:
The gap between the base plate and rotating member is made dynamically adjustable rather than fixed. The gap width changes according to the aperture state: wider in small aperture states to prevent blade warpage, and narrower in open aperture states to reduce driving torque. This dynamic adjustment resolves the contradiction by adapting the gap width to the specific operational requirements of each aperture state.
2Stability of the object's composition
If the gap between the base plate and rotating member is narrowed in an open aperture state, then the rattling of diaphragm blades is prevented, but the driving torque increases due to overlapping blades
Solution Approach 1:
The gap between the base plate and rotating member is made dynamically adjustable rather than fixed. The gap width changes according to the aperture state: narrower in open aperture states to prevent blade rattling and maintain aperture accuracy, and wider in small aperture states to reduce driving torque. This dynamic adjustment resolves the contradiction by adapting the gap width to the specific operational requirements of each aperture state.
3Device complexity
If a fixed gap is maintained between the base plate and rotating member, then the structure is simple, but it cannot simultaneously prevent blade warpage and rattling across different aperture states
Solution Approach 1:
The gap between the base plate and rotating member is made dynamically adjustable based on the aperture state. This allows the system to optimize blade support conditions for both small aperture (preventing warpage) and open aperture (preventing rattling) states, thereby improving aperture control performance without requiring a completely complex fixed-gap structure for each state.
Solution Approach 2:
The gap width parameter is changed according to the aperture state. By varying this geometric parameter dynamically, the system achieves optimal performance across different operating conditions without requiring fundamentally different structural configurations, thus balancing simplicity and reliability.
Data Source
AI summary
According to an aspect of the invention, the diaphragm apparatus includes: a plurality of diaphragm blades which define an aperture diameter; a driving member which includes a protrusion protruding in an optical axis direction, rotates around an optical axis, and drives the diaphragm blades to change the aperture diameter; and a base plate which includes a rail part with which the protrusion contacts to be movable in a direction of a rotation of the driving member. The plurality of diaphragm blades are disposed in a gap between the driving member and the base plate, the gap being defined when the protrusion and the rail part contact with each other. A size of the gap changes in accordance with the rotation of the driving member in the optical axis direction.