Threaded Spacer with Offset Threads for Lens Backlash Reduction
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Solution Overview
Problem
Imaging devices face challenges with lens backlash, which affects image quality and adjustability, particularly due to tolerance issues in threaded components, leading to shifted focus and tilted optical axes, and existing solutions have limited success in reducing backlash without compromising adjustability.
Innovation Solution
A threaded spacer with an offset thread end point and a biasing element, such as a spring, is used to create a gap between the spacer and the carrier frame, applying a force to reduce backlash while allowing lens rotation for focus adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the lens is threaded into the carrier frame to allow focus adjustment, then the adjustability of the lens is improved, but backlash between the lens thread and carrier frame thread causes focus shift and optical axis tilting
Solution Approach 1:
A threaded spacer is introduced as an intermediary component between the lens and carrier frame. The spacer has a thread structure with an offset end point that does not align with the carrier frame thread start point, creating a gap that eliminates backlash. This mediator allows the lens to be adjusted while maintaining precise focus position.
Solution Approach 2:
The thread geometry parameters are modified by offsetting the thread end point of the spacer relative to the thread start point of the carrier frame. This parameter change creates a deliberate gap in the threaded connection that eliminates backlash while preserving adjustability.
2Manufacturing precision
If a helical spring is used to reduce backlash, then the backlash reduction is improved, but the lens adjustability is reduced due to changing spring force
Solution Approach 1:
The spring mechanism is completely removed from the system. Instead of using elastic deformation to reduce backlash, the invention uses a rigid threaded spacer with an offset geometry that eliminates backlash through precise mechanical positioning without requiring adjustable force.
3Manufacturing precision
If a retaining ring is used to apply force to the lens, then the backlash reduction is improved, but the lens cannot be adjusted without removing the retaining ring
Solution Approach 1:
The retaining ring is completely removed from the system. The threaded spacer with offset geometry provides backlash reduction through its inherent design, allowing the lens to be adjusted by simply threading it into the spacer without requiring removal or adjustment of any retaining mechanism.
4Stability of the object's composition
If rigid PCBs are used to support electronic devices, then the structural stability is improved, but the assembly complexity and housing size increase due to connectors and multiple boards
Solution Approach 1:
Multiple rigid PCBs and connectors are merged into a single rigid-flex PCB structure. The rigid portions provide structural stability while the flexible portion allows for simplified connections, eliminating the need for multiple connectors and reducing assembly complexity.
Solution Approach 2:
The rigid-flex PCB serves multiple functions simultaneously: it provides structural support like rigid PCBs, enables flexible routing connections, and reduces the need for separate connector components, thereby simplifying the overall assembly.
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 reduces lens backlash, maintaining image quality and adjustability by applying a consistent force to the lens, thereby minimizing focus shifts and tilting, even in harsh environments.
Implementation Method 1
The biasing element applies a force to the threaded spacer in the direction of the optical axis toward or away from the carrier frame, thereby reducing the backlash between the lens and the carrier frame
Implementation Method 2
A threaded spacer with an offset thread end point and a biasing element, such as a spring, is used to create a gap between the spacer and the carrier frame, applying a force to reduce backlash
Data Source
AI summary
An electronic device includes a threaded spacer and a biasing element to reduce backlash. The threaded spacer includes a thread end point that is offset from the thread start point of the carrier frame. The offset thread ending and starting points create a gap between the threaded spacer and the carrier frame. The biasing element applies a force to the threaded spacer, thereby reducing the backlash between the lens and the carrier frame, while at the same time allowing the lens to be rotated for focus adjustments.