Lens Unit Sealing Structure for Dew Condensation Prevention

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Solution Overview

Problem

Existing lens units are prone to dew condensation and fogging due to temperature differences between the exposed first lens and the lens barrel, leading to moisture accumulation and lens fogging.

Innovation Solution

A lens unit design incorporating first and second seal members to separate the space between lenses from the lens barrel, with a communication passage connected to an outer peripheral groove, allowing air flow and easy assembly, while using adhesive to fix lenses securely and prevent adhesive leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lens barrel is sealed tightly to prevent moisture entry, then reliability is improved, but manufacturing difficulty increases due to the need for precise positioning structures

Engineering Contradiction:

Improvedew condensation preventionVSAvoidassembly difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The internal space of the lens barrel is divided into multiple sealed compartments using seal members positioned between adjacent lenses. Each compartment can be independently sealed, allowing moisture prevention without requiring the entire lens barrel to be tightly sealed, thus simplifying manufacturing while maintaining reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Seal members are introduced as intermediary elements between the lenses and the lens barrel structure. These seal members create the necessary sealing function without requiring direct contact or precise positioning between the lenses and the lens barrel, thereby improving ease of manufacture while maintaining dew condensation prevention.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If seal members are added to prevent dew condensation, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improvefogging preventionVSAvoidsealing structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The seal members utilize flexible sealing structures that can conform to the existing lens and lens barrel geometry. This approach adds the necessary sealing function without requiring complex rigid sealing structures, thereby improving reliability while minimizing the increase in device complexity.

Inventive Principle:

Principle #30Flexible shells and thin films

3Manufacturing precision

If lenses are fixed securely to the lens barrel, then positional accuracy is improved, but adhesive leakage occurs

Engineering Contradiction:

Improvelens positional accuracyVSAvoidadhesive leakage

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The seal members serve as intermediary elements between the adhesive and the external environment. They contain the adhesive within the lens barrel interior, allowing secure lens fixation with high positional accuracy while preventing adhesive leakage to the exterior.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12436446B2Lens unit

Publication Date: 2025.10.07 SANKYO SEIKI MFG CO LTD

AI summary

An O-ring seals between a first lens and a lens barrel. Further, between the second lens and the lens barrel is also sealed by a first adhesive layer. The lens barrel, in a state before manufacturing of the lens unit, is provided with a communication passage that communicates an inside of the lens barrel with an outer peripheral groove (outside of the lens barrel. The communication passage, in the state of FIG. 1 after manufacturing, is sealed by a second adhesive layer (third seal member) made of an adhesive.