Adjustable Optical Mounting Stage for Zero-Backlash Alignment
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Solution Overview
Problem
Existing optical mounts suffer from cross-coupling between adjustment inputs, leading to undesired displacements and misalignments, and lack compactness, economy, and serviceability for precision optical systems.
Innovation Solution
A compact 4, 5, and/or 6-axis alignment stage with a virtual center pivot and minimal cross-coupling, utilizing a stationary base, first and second moving members, and adjustable screws acting independently via preloaded springs to achieve zero backlash relative movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If commercially available stages and mounts are used to achieve precise alignment, then alignment precision is improved, but cross-coupling between adjustments occurs causing undesired displacements
Solution Approach 1:
The adjustment mechanism is divided into independent adjustment inputs, each controlling a specific degree of freedom. The spherical interface separates the mounting function from the adjustment function, allowing independent control of position and orientation without cross-coupling between adjustments.
Solution Approach 2:
A spherical interface acts as an intermediary between the mounting mechanism and the optical component. This sphere provides a virtual center of rotation that decouples the adjustment inputs from each other, allowing tilt adjustments without causing lateral or axial displacements.
2Ease of operation
If prior art adjustment mechanisms are used, then alignment adjustments can be made, but multiple iterative adjustments are required due to cross-coupling
Solution Approach 1:
The adjustment system is segmented into independent controls for each degree of freedom. This allows direct adjustment of tilt, position, and rotation without affecting other parameters, eliminating the need for iterative adjustments and reducing alignment time.
3Measurement precision
If gimbal-style mount designs are used to enable angular adjustment about center, then angular adjustment precision is improved, but device size increases significantly
Solution Approach 1:
The use of a spherical interface provides a virtual center of rotation that enables precise angular adjustment about the aperture center. This spherical geometry allows compact design compared to traditional gimbal mechanisms, achieving the same angular precision in a smaller volume.
4Ease of manufacture
If manufacturing tolerances of mounts and housings are relaxed, then ease of manufacture is improved, but alignment precision deteriorates
Solution Approach 1:
The alignment precision function is extracted from the mechanical mounting structure. Instead of relying on tight manufacturing tolerances of the mount housing, the precision is achieved through the spherical interface mechanism and adjustment inputs, allowing relaxed manufacturing tolerances while maintaining high alignment precision.
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 precise, independent adjustments in multiple degrees of freedom without backlash, improving alignment accuracy and reducing the need for iterative corrections in optical systems.
Implementation Method 1
The first moving member is attached to the stationary base using two spherical interfaces, each spherical interface comprising two spheres each in tangential contact with a pair of cylindrical pins thereby allowing rotary displacement about a first axis defined between the centers of the two spheres and linear displacement along the same first axis
Implementation Method 2
Linear and tilt adjustments of the first moving member with respect to the stationary base are performed by actuating first axis linear and tilt adjustment screws against two preloaded springs
Data Source
AI summary
The presently claimed and described technology provides an apparatus (500, 1000A, 1000B) configured to adjustably position a focal location (14) of a first instrument (12) of a first body (10, 20, 60) with respect to a target location (44, 54) of a second instrument (42, 42H, 42U, 52) of a second body (40, 50). The apparatus further includes a third body (30), a first joint (210), and a second joint (310). The first joint is configured to adjustably linearly position the first body with respect to the third body along a first axis (A2) and thereby perform a first adjustment and is further configured to adjustably rotatably position the first body with respect to the third body about the first axis (A2) and thereby perform a second adjustment. The second joint is configured to adjustably linearly position the second body with respect to the third body along a second axis (A3) and thereby perform a third adjustment and further configured to adjustably rotatably position the second body with respect to the third body about the second axis (A3) and thereby perform a fourth adjustment. Each of the first, second, third, and/or fourth adjustments are performed independently of each other and may have zero backlash. Additional third axis (A1, A1A, A1B) linear and/or rotational adjustment mechanism(s) may be added. In certain embodiments, the first, second, and/or third axes intersect each other at a point (P).