Optical Filter Switch Module Hybrid Housing Thermal Stability
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Solution Overview
Problem
Current IR-cut filter modules made of plastic expand with rising room temperature, causing lens focus issues and resulting in blurred images due to 'front focus' state, where the lens cannot accurately focus on the image sensor.
Innovation Solution
An optical filter switch module with a housing assembly comprising a metal first housing and a plastic second housing, where the thermal expansion coefficient of the first housing is lower than that of the second housing, reducing focus shift and ensuring accurate lens focusing on the image sensor. The module includes fitting grooves and bumps for stable embedding and a moving mechanism with a motor and rotating arm for optical filter alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the housing assembly is made of plastic for ease of manufacture and cost reduction, then manufacturing cost is reduced, but thermal expansion occurs at higher temperatures causing focus shift and blurred images
Solution Approach 1:
The patent applies composite materials by combining metal (first housing) and plastic (second housing) in a hybrid structure. The metal first housing provides thermal stability with low expansion coefficient to maintain focus accuracy, while the plastic second housing reduces manufacturing cost and enables insert molding integration. This composite approach resolves the contradiction between cost reduction and focus reliability.
Solution Approach 2:
The patent applies local quality by assigning different material properties to different parts of the housing assembly. The first housing (metal) is positioned where thermal stability is critical for focus maintenance, while the second housing (plastic) is used in areas where cost reduction is prioritized. This localized material selection allows the system to achieve both low cost and high reliability simultaneously.
2Reliability
If the thermal expansion coefficient of the housing is reduced to maintain focus accuracy, then focus stability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent segments the housing assembly into two distinct parts: the first housing (metal) and the second housing (plastic). This segmentation allows each part to be manufactured separately using optimal materials and processes, then assembled together. The metal first housing ensures focus stability while the plastic second housing maintains manufacturing simplicity through insert molding, avoiding the need for complex single-material manufacturing.
Solution Approach 2:
The patent applies nesting by placing the plastic second housing inside the metal first housing. The second housing is embedded within the first housing structure, creating a nested configuration. This nesting approach allows the plastic component to be manufactured via insert molding directly within the metal housing, simplifying the overall manufacturing process while maintaining the thermal stability benefits of the metal outer structure.
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 focus shift at higher temperatures, ensuring accurate focusing on the image sensor and maintaining high image resolution, while also reducing manufacturing costs through insert molding and preventing light reflection.
Implementation Method 1
A thermal expansion coefficient of the first housing in the direction along the axis is smaller than a thermal expansion coefficient of the second housing in the direction along the axis
Data Source
AI summary
An optical filter switch module including a housing assembly and an optical filter switch is provided. The housing assembly includes a first housing and a second housing. The first housing has a first through hole extending along an axis. The second housing is disposed in the first housing along the axis and partially embedded in the first housing. The second housing has a second through hole corresponding to the first through hole. A thermal expansion coefficient of the first housing in the direction along the axis is smaller than a thermal expansion coefficient of the second housing in the direction along the axis. The optical filter switch is disposed on the second housing and partially corresponds to the position of the second through hole. A lens assembly having the optical filter switch module is further provided.