Plastic Lens Spacer Assembly for Humidity-Stable Optical Gaps
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Solution Overview
Problem
Plastic lenses in camera modules are vulnerable to environmental changes due to differing expansion rates, leading to optical performance deterioration.
Innovation Solution
A lens assembly design featuring a spacer made of a plastic material with a higher hygroscopic expansion coefficient than the lenses, coupled with protrusions to counteract deformation caused by temperature and humidity changes, maintaining consistent lens gaps and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a plastic lens with high refractive index is used, then optical performance is improved, but the lens becomes vulnerable to temperature and humidity changes causing optical performance deterioration
Solution Approach 1:
The patent changes the material parameter (coefficient of hygroscopic expansion) of the spacer to be higher than that of the plastic lens. This parameter mismatch creates a compensatory effect where the spacer's expansion counteracts the lens's deformation under humidity changes, maintaining optical performance while using high-refractive-index plastic material.
Solution Approach 2:
The patent converts the harmful effect of differential expansion between lens and spacer into a beneficial compensatory mechanism. By intentionally selecting a spacer material with higher expansion coefficient, the spacer's deformation under humidity/temperature changes counterbalances the lens's deformation, thereby stabilizing the optical system.
2Measurement precision
If lenses with different expansion rates are combined, then optical performance can be optimized, but interference with surrounding structures occurs due to differential expansion
Solution Approach 1:
The spacer acts as an intermediary element between the plastic lens and the lens barrel (surrounding structure). It absorbs and compensates for the differential expansion forces, preventing direct interference between the expanding lens and the rigid lens barrel, thereby allowing optimization of lens material properties without causing structural interference.
3Productivity
If environmental changes occur rapidly, then camera module operation continues, but optical performance deteriorates due to material expansion differences
Solution Approach 1:
The patent implements preliminary anti-action by pre-designing the spacer-lens material combination to anticipate and counteract environmental changes. The spacer material is specifically selected with higher expansion coefficient to proactively compensate for lens deformation before optical performance deteriorates, enabling continuous operation under rapid environmental changes.
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
Stabilizes optical performance by compensating for environmental changes, ensuring consistent lens spacing and alignment, thereby improving product reliability.
Implementation Method 1
the first spacer is formed of a same material as the first plastic material, or is formed of a second plastic material which has a higher coefficient of hygroscopic expansion (CHE) than a coefficient of hygroscopic expansion of the first plastic material
Data Source
AI summary
A lens assembly is provided. The lens assembly includes a lens barrel; a plurality of lenses arranged in an optical axis direction and disposed in the lens barrel; and a first spacer disposed between a (N)th lens and a (N+1)th lens, which are adjacent among the plurality of lenses, wherein the (N)th lens may be formed of a first plastic material, and the first spacer may be formed of a same material as the first plastic material, or may be formed of a second plastic material which has a higher coefficient of hygroscopic expansion than a coefficient of hygroscopic expansion of the first plastic, and wherein N is a natural number of two or more.