Deformable Mirror Carrier for Piezoelectric Pointing Accuracy
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Solution Overview
Problem
Piezoelectric pointing devices face limitations in achieving high angular travel with minimal size and cost, while also experiencing wave front errors due to mirror deformations caused by rigid mirror carriers and differential expansion between materials.
Innovation Solution
A piezoelectric device with a deformable mirror carrier featuring multiple support points that can move independently via elastic deformation, reducing stress on the mirror and incorporating flexible links and torsional connections to enhance angular travel and vibration resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rigid mirror carrier is used to support the mirror, then the mechanical stability is improved, but wave front errors occur due to mirror deformation from differential expansion
Solution Approach 1:
The patent changes the rigidity parameter of the mirror carrier by introducing a deformable mounting plate with controlled flexibility. This allows the mounting plate to deform elastically under thermal expansion differences between the mirror and carrier materials, accommodating dimensional changes without transmitting stress to the mirror, thereby preventing wave front errors while maintaining overall structural stability.
Solution Approach 2:
The patent explicitly addresses thermal expansion by designing the mounting plate with material properties and geometric characteristics that allow it to expand and contract in response to temperature variations. The deformable mounting plate absorbs thermal expansion differences between the mirror (glass) and mirror carrier (metal), preventing stress buildup that would cause mirror deformation and wave front errors.
2Length of moving object
If larger piezoelectric actuators are used to achieve greater angular travel, then the angular travel is improved, but the device size and cost increase
Solution Approach 1:
The patent introduces a deformable mounting plate that dynamically adapts its rigidity based on operational requirements. The mounting plate provides flexibility during thermal cycling to prevent deformation, while maintaining sufficient rigidity during actuation to transmit piezoelectric forces effectively. This dynamic behavior allows smaller actuators to achieve the required angular travel without compromising performance.
Solution Approach 2:
The patent employs a thin, deformable mounting plate that acts as a flexible intermediate structure between the rigid mirror carrier and the piezoelectric actuators. This flexible element amplifies the displacement effect of small actuators while accommodating thermal expansion, enabling greater angular travel with smaller, more cost-effective piezoelectric actuators.
3Ease of operation
If four piezoelectric actuators are used in push-pull mode, then the angular travel control is improved, but the device complexity increases
Solution Approach 1:
The deformable mounting plate serves multiple functions simultaneously: it acts as a thermal expansion compensation mechanism, a mechanical linkage for actuator forces, and a structural support for the mirror. This multi-functionality reduces the need for additional components to manage thermal effects, simplifying the overall device complexity while maintaining precise angular travel control with the four-actuator push-pull configuration.
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
The solution effectively reduces wave front errors, increases angular travel, and minimizes the size and weight of the device, while maintaining mechanical integrity and efficiency, even under temperature variations.
Implementation Method 1
piezoelectric actuators fixed to a fixed frame (1), said piezoelectric actuators being able to deform independently from one another
Implementation Method 2
at least one of said at least three support points being a support point mounted movable independently from the other support points in a first direction by elastic deformation of the mirror carrier
Data Source
AI summary
A piezoelectric device comprises a fixed frame and a mirror carrier defining several support points securing a mirror. The mirror carrier is mounted rotatable. Several piezoelectric actuators are fixed to the support and deform independently in translation in a first direction. Each piezoelectric actuator moves the support area of the mirror carrier. The mirror carrier defines several attachment points. Each attachment point connects the mirror carrier mechanically with a piezoelectric actuator. The support points and attachment points are distinct from one another. The mirror carrier defines a plurality of flexion areas. The support points are movable with respect to one another. The piezoelectric actuators supplied in push-pull mode drive the support points making the mirror rotate perpendicularly to the first direction.