Camera System Thermal Expansion Matching

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Solution Overview

Problem

Camera systems used in precision measurement applications face issues such as measurement drift, hysteresis effects, and unpredictable errors due to thermal expansion differences between materials, mechanical instability, and complex manufacturing processes, which affect the accuracy and reliability of image acquisition.

Innovation Solution

A camera system design where the lens mount and printed circuit board are made from materials with thermal expansion coefficients that differ by less than 30%, and the connection between them is stabilized using thermally stable adhesives or screws made from materials with matching expansion coefficients, minimizing thermal stresses and mechanical errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the lens mount and printed circuit board are made from materials with different thermal expansion coefficients, then manufacturing flexibility is improved, but measurement precision deteriorates due to thermal expansion differences causing mechanical instability

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidmeasurement accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by carefully selecting materials for the lens mount and printed circuit board such that their thermal expansion coefficients differ by less than 30%. This parameter control ensures that thermal expansion differences remain within acceptable limits, preventing mechanical instability while allowing manufacturing flexibility. The specific parameter controlled is the thermal expansion coefficient difference between materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies homogeneity by ensuring that the materials used for the lens mount and printed circuit board have similar thermal expansion characteristics. By selecting materials with thermal expansion coefficients that differ by less than 30%, the system achieves homogeneous thermal behavior, reducing differential expansion and maintaining mechanical stability across temperature variations.

Inventive Principle:
Principle #33Homogeneity

2Measurement precision

If complex manufacturing processes are used to achieve high precision, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveimage acquisition accuracyVSAvoidmanufacturing process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-selecting materials with compatible thermal expansion coefficients before assembly. By ensuring that the lens mount and printed circuit board materials have thermal expansion coefficients differing by less than 30%, the system establishes thermal compatibility in advance, eliminating the need for complex compensation mechanisms or post-assembly adjustments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent controls the parameter of thermal expansion coefficient difference to be less than 30%, which simplifies the manufacturing process while maintaining high precision. This parameter control approach avoids complex manufacturing processes by addressing thermal compatibility at the material selection stage rather than through complex assembly or compensation mechanisms.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If materials with mismatched thermal expansion coefficients are used, then ease of manufacture is improved, but reliability deteriorates due to thermal stresses causing measurement drift

Engineering Contradiction:
Improvematerial selection flexibilityVSAvoidthermal stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the thermal expansion coefficient difference between lens mount and printed circuit board materials to be less than 30%. This parameter control prevents excessive thermal stresses while maintaining reasonable manufacturing flexibility. The specific parameter of thermal expansion coefficient is monitored and adjusted to achieve optimal reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of thermal expansion differences into a benefit by establishing a quantitative guideline (less than 30% difference). This approach transforms what could be a source of reliability problems into a controlled design parameter, allowing manufacturers to select from a range of materials while ensuring thermal compatibility and preventing measurement drift.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This design reduces measurement errors, enhances thermal stability, and simplifies manufacturing, resulting in a more reliable and accurate camera system for precision applications.

Implementation Method 1

the image sensor and lens are arranged in relation to one another or can be arranged in relation to one another in such a way that a sharp image can be reproduced on the image sensor

Methodology Applied
Scientific EffectLight: Light

Implementation Method 2

the lens mount and the printed circuit board are made of materials whose coefficients of thermal expansion differ by less than 30%

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3280127B1Camera system
Publication Date: 2020.07.22 HEXAGON TECH CENT GMBH
  • EP3280127B1 patent drawingFigure 1~2
  • EP3280127B1 patent drawingFigure 3~4
  • EP3280127B1 patent drawingFigure 5a~6b

AI summary

A camera system (10) is presented, comprising a lens (12), a lens carrier (16) supporting the lens (12), an image sensor (22), and a printed circuit board (20). The printed circuit board (20) and the image sensor (22) are electrically conductively connected to each other, and the image sensor (22) and lens (12) can be arranged relative to each other such that a sharp image can be projected onto the image sensor (22). The printed circuit board (20) has a circuit layer (42) made of electrically insulating material and a printed circuit board carrier (40). The printed circuit board carrier (40) is made of a material whose coefficient of thermal expansion aL differs by no more than 30% from the coefficient of thermal expansion aO of the material from which the lens carrier (16) is made.