Six-axis correction stage for simultaneous six-degree-of-freedom error correction

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Solution Overview

Problem

Existing error correction technologies for optical components in VR, AR, and XR systems require sequential measurements and corrections across different devices, leading to inefficient production, increased operation time, and potential for re-introduction of errors due to multiple transfers and large apparatus volume.

Innovation Solution

A six-degree-of-freedom error correction apparatus integrating auto-collimation, telecentric image, and confocal distance measurement devices on a single optical axis with a six-axis correction stage, allowing simultaneous measurements and corrections, reducing the need for device transfers and optimizing space usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple optical measurement devices are used for six-degree-of-freedom measurements, then measurement capability is improved, but apparatus volume increases and floor efficiency decreases

Engineering Contradiction:
Improvesix-degree-of-freedom measurement capabilityVSAvoidapparatus volume
Core Design Contradiction:
Measurement precisionVSVolume of stationary object

Solution Approach 1:

The patent combines auto-collimation, telecentric image, and confocal distance measurement devices into a single integrated apparatus sharing a common optical axis. Multiple measurement functions are merged into one compact system, enabling six-degree-of-freedom measurements without requiring separate devices, thus reducing apparatus volume while maintaining measurement capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The measurement apparatus is designed with multi-functionality, where a single optical axis supports multiple measurement devices that can measure different degrees of freedom. The system can perform auto-collimation measurement for rotation angles, telecentric image measurement for translation distances, and confocal distance measurement for surface heights, all through one integrated platform.

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

2Measurement precision

If sequential measurements are performed using multiple devices, then measurement capability is achieved, but operation time increases and productivity decreases

Engineering Contradiction:
Improvesix-degree-of-freedom measurement capabilityVSAvoidcorrection operation efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

By merging multiple measurement devices into one integrated system with a shared optical axis, the patent enables simultaneous measurement of all six degrees of freedom in a single operation. This eliminates the need for sequential measurements and multiple device transfers, significantly reducing operation time and improving productivity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated measurement system allows continuous measurement of all six degrees of freedom without interruption or device transfer. The correction stage can be adjusted based on real-time feedback from all measurement devices simultaneously, maintaining continuous useful action throughout the correction process.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If device transfers are performed on the correction stage, then measurements for different degrees of freedom are enabled, but error re-introduction occurs and correction accuracy decreases

Engineering Contradiction:
Improvedegree-of-freedom measurement coverageVSAvoidcorrection accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent merges multiple measurement capabilities into a single fixed apparatus, eliminating the need to transfer the device under test between different measurement devices. All six degrees of freedom are measured simultaneously from a fixed position, preventing error re-introduction during transfers and maintaining correction accuracy.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If multiple measurement devices are arranged side by side, then measurement functionality is achieved, but floor efficiency decreases and apparatus volume increases

Engineering Contradiction:
Improvemeasurement device functionalityVSAvoidfloor space occupation
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

Instead of arranging measurement devices side by side in a two-dimensional layout, the patent stacks them along a common optical axis in a one-dimensional configuration. This vertical stacking approach significantly reduces the horizontal footprint and floor space occupation while maintaining all measurement functionalities.

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

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 approach enhances accuracy and efficiency by enabling synchronous six-degree-of-freedom positioning corrections within a compact apparatus, reducing operation time and minimizing error re-introduction.

Implementation Method 1

a light splitter (5), which is arranged on the measurement optical axis and is interposed between the six-axis correction stage (2) and the auto-collimation measurement device (3)

Methodology Applied
Scientific EffectLight splitting: Reflection

Implementation Method 2

the optical component (8) is arranged on the measurement optical axis, is interposed between the six-axis correction stage (2) and the auto-collimation measurement device (3), and spectroscopically reflects or totally reflects a measurement light of the confocal distance measurement device (7) to the device under test (D) along the measurement optical axis

Methodology Applied
Scientific EffectSpectroscopic reflection: Reflection

Implementation Method 3

spectroscopically reflects or totally reflects a measurement light

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP4354187A1Six-degree-of-freedom error correction method and apparatus
Publication Date: 2024.04.17 CHROMA ATE INC
  • EP4354187A1 patent drawingFigure 1
  • EP4354187A1 patent drawingFigure 2A~2B
  • EP4354187A1 patent drawingFigure 3A~3B

AI summary

The present invention relates to six-degree-of-freedom error correction method and apparatus. The apparatus comprises a six-axis correction stage, an auto-collimation measurement device, a light splitter, a telecentric image measurement device, and a controller. The six-axis correction stage is used for carrying a device under test; the auto-collimation measurement device is arranged above the six-axis correction stage along a measurement optical axis; the light splitter is arranged on the measurement optical axis and is interposed between the six-axis correction stage and the auto-collimation measurement device; the telecentric image measurement device is arranged on one side of the measurement optical axis and corresponds to the light splitter. The method controls the six-axis correction stage to correct rotation errors in at least two degrees of freedom of the device under test according to a measurement result of the auto-collimation measurement device, and controls the six-axis correction stage to correct translation and yaw errors in at least three degrees of freedom of the device under test according to a measurement result of the telecentric image measurement device by means of the controller.