Temperature-Compensated Spacer for Optical Alignment Stability

Solution Overview

Problem

Optical elements experience stress and deformation due to mismatched thermal expansion coefficients between materials, leading to alignment issues and undesirable vibration in systems exposed to temperature variations.

Innovation Solution

A temperature-compensated spacer with a frame and crossbar made of materials with differing thermal expansion coefficients, designed to deform in a way that compensates for temperature changes, maintaining alignment and rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If rigid mounting structures are used to maintain alignment, then alignment precision is improved, but thermal stress and deformation increase due to mismatched thermal expansion coefficients

Engineering Contradiction:

Improvealignment precisionVSAvoidthermal stress

Core Design Contradiction:

Measurement precisionVSStress or pressure

Solution Approach 1:

The patent changes the physical parameters of the mounting structure by using a compliant mechanism that can change its stiffness or dimensional parameters in response to temperature changes. The structure transitions from a purely rigid mounting to one that incorporates controlled flexibility, allowing it to adapt its parameters (such as gap width or mounting position) to compensate for thermal expansion differences between the optical element and support structure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic characteristics to the mounting structure by enabling it to adapt its configuration in response to temperature variations. Rather than being statically rigid, the structure incorporates movable or deformable elements that can dynamically adjust their position or shape to maintain proper alignment while accommodating thermal expansion, effectively making the mounting system responsive to environmental changes.

Inventive Principle:

Principle #15Dynamics

2Stress or pressure

If flexible elements are used to accommodate thermal expansion, then thermal stress is reduced, but vibration and instability increase

Engineering Contradiction:

Improvethermal stressVSAvoidvibration resistance

Core Design Contradiction:

Stress or pressureVSStability of the object's composition

Solution Approach 1:

The patent introduces dynamic characteristics to the mounting structure by enabling it to adapt its configuration in response to temperature variations. Rather than being statically rigid, the structure incorporates movable or deformable elements that can dynamically adjust their position or shape to maintain proper alignment while accommodating thermal expansion, effectively making the mounting system responsive to environmental changes.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent divides the mounting structure into separate functional segments: rigid portions that provide structural support and alignment reference, and compliant portions that specifically handle thermal expansion accommodation. This segmentation allows different parts of the structure to perform specialized functions - the rigid segments maintain stability and alignment precision while the compliant segments absorb thermal stresses through controlled deformation.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If the gap width is fixed to maintain alignment, then alignment precision is improved, but the structure cannot accommodate temperature variations

Engineering Contradiction:

Improvealignment precisionVSAvoidtemperature adaptability

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the physical parameters of the mounting structure by using a compliant mechanism that can change its stiffness or dimensional parameters in response to temperature changes. The structure transitions from a purely rigid mounting to one that incorporates controlled flexibility, allowing it to adapt its parameters (such as gap width or mounting position) to compensate for thermal expansion differences between the optical element and support structure.

Inventive Principle:

Principle #35Parameter 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

Effectively compensates for thermal expansion, maintaining alignment and reducing vibration in optical systems by using a spacer with a frame and crossbar that deforms to accommodate temperature variations.

Implementation Method 1

the frame is formed from a first material having a first coefficient of thermal expansion and the crossbar is formed from a second material having a second coefficient of thermal expansion, the first and second coefficients of thermal expansion differing such that variation in temperature causes deformation of the frame

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS12411305B2Temperature compensated spacer

Publication Date: 2025.09.09 RAFAEL ADVANCED DEFENSE SYST LTD

AI summary

A temperature compensated spacer includes first and second anchoring configurations for anchoring the spacer relative to first and second elements, and a frame providing a mechanical connection between the anchoring configurations. The frame has a polygonal opening with a first diagonal extending across the width of a gap between the elements and a second diagonal extending transversely to the first diagonal. A crossbar is associated with the polygonal opening so as to span the second diagonal. The frame and the crossbar are formed from materials having differing coefficients of thermal expansion. The crossbar is deployed so as to determine a length of the second diagonal such that variation in temperature causes deformation of the frame, thereby varying a length of the first diagonal.