Lens Barrel Air-Hole Layout for Accurate Seal Airtightness Testing

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Solution Overview

Problem

The close contact between the image side lens and the flange portion in lens units makes it difficult to accurately measure airtightness, especially when the seal member is damaged, not attached, or mispositioned, leading to unintended air leakage and difficulty in performing airtightness tests.

Innovation Solution

A lens unit design with an annular flange portion and air holes on the lens barrel allows air to fill the barrel even if the image side lens is in close contact, enabling precise airtightness measurement by introducing air through these holes, and a gap is formed between the optical filter and the air hole to release adhesive outgas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a lens unit with multiple lens elements is used to achieve high image quality, then image quality is improved, but the number of parts increases and the structure becomes complex

Engineering Contradiction:
Improveimage qualityVSAvoidnumber of parts
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple lens elements (first lens element, second lens element, third lens element) into a single integrated lens unit structure. The lens elements are arranged in sequence along the optical axis and work together as a unified optical system, reducing the need for separate mounting and adjustment mechanisms while maintaining high image quality through optimized optical design

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lens unit is designed to perform multiple optical functions simultaneously - the first lens element provides primary focusing, the second lens element corrects aberrations, and the third lens element fine-tunes the optical path. This multi-functional integration allows a single lens unit to replace what would otherwise require multiple separate optical components

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If lens elements are arranged in sequence along the optical axis to achieve focusing, then focusing function is improved, but the length of the lens unit increases

Engineering Contradiction:
Improvefocusing functionVSAvoidlength of lens unit
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent transitions from a traditional linear arrangement where lens elements are spaced far apart along the optical axis to a more compact configuration where lens elements are closely integrated. The supporting plate structure enables vertical stacking or close proximity arrangement, effectively utilizing the vertical dimension and reducing the horizontal length required for focusing operation

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Stability of the object's composition

If a supporting plate structure is used to support lens elements, then structural stability is improved, but the number of parts increases

Engineering Contradiction:
Improvestructural stabilityVSAvoidnumber of parts
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The supporting plate integrates multiple support functions into a single structural component. It simultaneously supports the first lens element, second lens element, and third lens element, providing structural stability while reducing the need for multiple separate mounting brackets, screws, and adjustment mechanisms that would otherwise be required

Inventive Principle:
Principle #5Merging (Combining)

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

Enables accurate airtightness testing of the seal member by allowing air to flow through the air holes, ensuring reliable airtightness assessment and preventing adhesive fogging on the optical filter.

Implementation Method 1

a first lens element, a second lens element and a third lens element which are arranged in sequence along an optical axis

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3623855B1Lens unit
Publication Date: 2026.04.15 MAXELL LTD
  • EP3623855B1 patent drawingFigure 1
  • EP3623855B1 patent drawingFigure 2
  • EP3623855B1 patent drawingFigure 3

AI summary

Provided is a lens unit capable of exactly checking the airtightness of a seal member provided between an object side lens and an inner circumferential surface of a lens barrel. A part of an end portion of an air hole (including a flange portion and provided in the barrel 11) on the object side is opened radially inward from the inner circumferential surface of the lens barrel 11, and at least part of the end portion of the air hole 40 on the image side is also opened. In this way, even if the image side lens 16 is in close contact with the lens installation surface 35a of the flange portion 35, the air can still be introduced to exactly fill the lens barrel 11 through the air hole 40. Therefore, even if the seal member 37 provided between the object side lens 12 and the inner circumferential surface of the lens barrel 11 is damaged or it is not attached to a predetermined position from the beginning, it is still possible to exactly measure an air leakage, thus rendering it possible to exactly check the airtightness of the seal member 37.