Eccentric Pin Mechanism for Stable Optical Axis Alignment
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Solution Overview
Problem
Existing optical devices face issues with unstable adjustment of optical axis inclination due to rattle between cam pins and cam grooves, leading to inconsistent optical axis alignment.
Innovation Solution
An optical device featuring a tubular member with first and second concave grooves and an eccentric pin that eccentrically rotates within these grooves, with specific dimensions and surface orientations to prevent rattle and ensure stable alignment, including a first outer surface guided in the first direction and a second outer surface guided in the second direction, and a screw for securing the eccentric pin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a cam pin is eccentrically rotated within a cam groove to adjust lens barrel inclination, then the optical axis alignment can be adjusted, but rattle occurs between the cam pin and cam groove leading to unstable adjustment
Solution Approach 1:
The invention divides the single cam groove into two separate grooves: a first cam groove formed on the outer circumferential surface of the tubular member and a second cam groove formed on the inner circumferential surface. The eccentric pin penetrates both grooves, creating a segmented constraint system that eliminates rattle while maintaining adjustment capability
Solution Approach 2:
The eccentric pin acts as an intermediary element that connects and coordinates the first and second cam grooves. By penetrating both grooves, it mediates between the outer and inner surfaces, ensuring synchronized movement and eliminating relative motion that causes rattle
2Reliability
If the first concave groove has greater length in the circumferential direction and the second concave groove has greater length in the optical axis direction, then rattle is suppressed, but the structure becomes more complex
Solution Approach 1:
The invention applies different geometric characteristics to different locations: the first cam groove has its long dimension in the circumferential direction to constrain radial movement, while the second cam groove has its long dimension in the optical axis direction to constrain axial movement. This local differentiation of groove orientations provides targeted constraint at each location
Solution Approach 2:
The first and second cam grooves are designed with asymmetric orientations relative to each other and to the eccentric pin. The first groove extends primarily in the circumferential direction while the second groove extends primarily in the optical axis direction, creating an asymmetric constraint system that effectively suppresses rattle in multiple directions
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 solution effectively suppresses rattle and ensures stable optical axis alignment, enhancing the optical performance of the lens barrel by allowing precise adjustment of the lens group positions.
Implementation Method 1
an eccentric pin penetrating through the first and second concave grooves, including one end attached to the holding frame, and eccentrically rotating against the first and second concave grooves in response to a force applied to the other end of the eccentric pin
Data Source
AI summary
An optical device includes: a holding frame holding an optical system; a tubular member provided at an outer circumferential surface with a first concave groove and at an inner circumferential surface with a second concave groove, and holding the holding frame; and an eccentric pin penetrating through the first and second concave grooves, including one end attached to the holding frame, and eccentrically rotating against the first and second concave grooves in response to a force applied to the other end of the eccentric pin. A length, in a first direction intersecting a penetrating direction through which the eccentric pin penetrates, of the first concave groove is greater than a length, in a second direction intersecting the first direction and the penetrating direction, of the first concave groove.