Lens Mount Screw Mechanism Eliminates Play
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bayonet-type lens mounts experience play issues with larger interchangeable lenses due to spring deformation, leading to image quality degradation.
Innovation Solution
A lens mount design incorporating a fixed and movable mount part with screw portions that engage to eliminate play by ensuring precise alignment and contact between the lens and camera body, using a bayonet-lug portion and screw mechanism for secure attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a spring member is used to urge the lens into the image pickup apparatus body, then the lens can be held in place, but play occurs corresponding to the spring deformation amount
Solution Approach 1:
The lens mount is divided into a fixed mount part and a movable mount part. The fixed mount part includes a first screw portion that is fixed to the interchangeable lens, while the movable mount part includes a second screw portion that cooperates with the first screw portion. This segmentation allows the movable mount part to move toward the fixing portion during rotation, bringing the lug portion into engagement with the bayonet-lug portion without spring deformation play.
Solution Approach 2:
The conventional spring member urging mechanism is replaced with a screw mechanism. The first screw portion and second screw portion cooperate to convert rotational motion into linear motion, causing the movable mount part to move toward the fixing portion during rotation. This mechanical substitution eliminates the play caused by spring deformation while maintaining the holding function.
2Adaptability or versatility
If a bayonet-type lens mount is used for interchangeable lenses, then attachment and removal are enabled, but larger lenses experience increased play due to spring deformation
Solution Approach 1:
The movable mount part is designed to dynamically move during the attachment rotation process. As the interchangeable lens and image pickup apparatus body are rotated, the movable mount part moves toward the fixing portion through the screw mechanism, ensuring that the lug portion engages precisely with the bayonet-lug portion. This dynamic adjustment eliminates play for lenses of various sizes while maintaining interchangeability.
3Strength
If the lug portion is engaged with the bayonet-lug portion using spring urging, then the lens is held securely, but image quality degrades due to play in the coupling portion
Solution Approach 1:
The spring urging mechanism is replaced with a screw-based mechanical system. The first screw portion and second screw portion cooperate to provide precise positional control during attachment, eliminating the play that occurs with spring deformation. This substitution maintains the holding force through precise engagement while improving coupling precision to prevent image quality degradation.
Data Source
AI summary
A lens mount capable of suppressing play of an interchangeable lens against a camera body. The lens mount of the interchangeable lens includes a fixed mount part having a female screw portion, a movable mount part having a male screw portion, and an arm part protruding from the movable mount part. When the movable mount part is rotated about an optical axis by turning the arm part about the optical axis from a state where a mount surface of the camera body and a lens-side mount surface of the fixed mount part are in contact and a bayonet-lug portion of the camera body and a lug portion of the movable mount part do not overlap on an optical axis projection, the movable mount part moves toward the fixing portion in the optical axis direction, as the male screw portion is screwed with the female screw portion.