Lens Unit O-Ring Elastic Member Rattle Prevention
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Solution Overview
Problem
The existing lens units experience rattling issues due to lifting of the caulking portion at the end part of the lens barrel, which compromises the contact between the lens and the caulking portion, leading to instability and potential misalignment.
Innovation Solution
Incorporating an elastic member, such as an O-ring, between the first and second lenses in the optical axis direction, with a lens barrel design featuring an annular caulking portion bent from the object side to the inner peripheral side, and a stepped portion with a seating surface that maintains contact and applies an urging force to prevent rattling and load transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a caulking portion is formed by bending the end part of the lens barrel to contact the first lens, then the first lens is fixed in position, but the caulking portion may lift due to repulsion from the lens side, causing rattling
Solution Approach 1:
A light shielding sheet is introduced as an intermediary component between the first lens and the lens barrel. This sheet is pressed against the first lens by the elastic member, and its outer peripheral surface contacts the inner peripheral surface of the lens barrel, creating a stable mechanical linkage that prevents rattling without relying solely on the caulking portion
Solution Approach 2:
The elastic member changes the mechanical parameters of the system by providing continuous elastic pressure. This ensures that the light shielding sheet maintains constant contact with both the first lens and the lens barrel, compensating for any lifting of the caulking portion and maintaining stable positioning
2Device complexity
If the caulking portion is formed by bending the end part of the lens barrel, then the structure is simple, but load applied to the first lens is transmitted to the second lens side, causing potential misalignment
Solution Approach 1:
The light shielding sheet acts as a load-blocking intermediary. It is positioned between the first lens and the second lens, and when pressed by the elastic member, it prevents load transmitted from the first lens from reaching the second lens, thereby maintaining alignment precision while keeping the overall structure relatively simple
Solution Approach 2:
The positioning and load-bearing functions are segmented into separate components: the caulking portion provides initial positioning, the light shielding sheet provides load blocking, and the elastic member provides continuous pressure. This segmentation allows each component to perform its specific function effectively, preventing load transmission to the second lens
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The elastic member ensures continuous contact between the lens and the caulking portion, preventing rattling and maintaining lens stability, even when the caulking portion lifts, thereby ensuring precise alignment and reducing the transmission of loads to adjacent lenses.
Implementation Method 1
an elastic member which is compressed in the optical axis direction at a position adjacent to the inner peripheral-surface portion in the radial direction and which exerts an urging force
Data Source
AI summary
A lens unit includes a lens, a lens, a second O-ring disposed between the lens and the lens in an optical axis direction, and a second lens barrel that accommodates them. The second lens barrel includes an annular caulking portion which is brought into contact with an outer peripheral-edge portion of the lens from the object side and includes an object-side stepped portion on an inner peripheral surface. The lens is located between the caulking portion and the seating surface of the object-side stepped portion. The second O-ring is compressed in the optical axis direction at a position adjacent to an annular wall surface of the object-side stepped portion in a radial direction. The second O-ring exerts an urging force to urge the lens toward the object side and to urge the lens toward the image side.