Stop Mechanism Light-Blocking Projection for Compact Lens Aperture
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Solution Overview
Problem
Existing stop mechanisms in lens apparatuses face challenges in minimizing size while maintaining a simple configuration and high degree of freedom in arrangement, often resulting in increased complexity, cost, and limited size reduction due to overlapping components and complex structures.
Innovation Solution
A stop mechanism featuring stop blades with arc portions and light-blocking projections that are received in a reception member, where the interlocking arm allows the light-blocking projections to move inward as the aperture diameter is reduced, preventing light leakage without increasing the mechanism's diameter and allowing for flexible arrangement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the operation lever is moved on the outer peripheral side of the stop blades to prevent interference, then the stop blades and operation lever do not interfere with each other, but the diameter of the stop mechanism increases
Solution Approach 1:
The operation lever is projected in the optical axis direction (depth dimension) rather than radially outward, allowing it to be positioned above the stop blades without increasing the stop mechanism's diameter. This dimensional repositioning resolves the interference issue while maintaining compact size.
2Object-affected harmful factors
If light-blocking projection portions are projected outward from the sleeve to prevent light leakage, then light leakage is prevented, but the size of the stop mechanism increases and arrangement flexibility is reduced
Solution Approach 1:
The light-blocking projection portions are positioned to extend in the optical axis direction above the stop blades rather than radially outward, preventing light leakage while maintaining a compact stop mechanism diameter and preserving arrangement flexibility.
Solution Approach 2:
The light-blocking function is integrated into the stop blades themselves through the light-blocking projection portions, eliminating the need for separate light-blocking components and simplifying the overall structure.
3Object-affected harmful factors
If a first diaphragm group and second diaphragm group are used to define stop effective diameter and prevent light leakage, then light leakage is prevented, but the structure becomes complicated and costs increase
Solution Approach 1:
The light-blocking function is integrated into the stop blades themselves through the light-blocking projection portions, eliminating the need for separate light-blocking components and simplifying the overall structure.
Solution Approach 2:
The stop blades serve dual functions: defining the stop effective diameter through their arc portions and preventing light leakage through their light-blocking projection portions, reducing the need for additional specialized components.
Data Source
AI summary
A stop mechanism, including: diaphragms; a reception receiving the diaphragms; a cam rotating the diaphragms to change an aperture diameter; and an interlocking arm interlocking with rotation of the cam and arranged on a radially outer side of the cam to rotate the cam from an outside of the stop mechanism. The diaphragms each include: an arc portion defining the aperture diameter and being received in the reception at maximum aperture; and a light-blocking projection formed on the arc portion to block light outside the aperture diameter. The reception includes cutouts for allowing the light-blocking projection to project outside at the maximum aperture. The interlocking arm is located at a position where the light-blocking projection does not overlap in a circumferential direction, and the light-blocking projection moves into the reception while the interlocking arm moves in the circumferential direction in which the aperture diameter is reduced.