Calibrating Independent X and Y Stages Using Virtual Position Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing calibration techniques for positioning systems with separate X and Y stages are not applicable, leading to increased costs and complexity when aligning two objects on six-axis systems, as they rely on the relationship between XYθ-stage movements and camera displacements, which cannot be read within the camera's field of view when both stages move independently.
Innovation Solution
An image processing apparatus that performs positional calibration between a stage coordinate system and a camera coordinate system by calculating positional calibration parameters using reference and displaced positions of marks on the stages, allowing for accurate alignment even when the stages' movements cannot be read within the camera's field of view, using a processing unit that captures images of marks on separate stages and calculates virtual positions based on mechanical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a six-axis XYθ-stage system is used to align two objects, then positioning precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent divides the positioning system into two independent stages: an Xθ-stage for one object and a Y-stage for another object. Each stage is calibrated separately using its own imaging device, avoiding the need for a complex six-axis system while maintaining positioning precision through independent calibration of each stage's coordinate system.
Solution Approach 2:
The patent introduces imaging devices as intermediaries to establish coordinate transformations between the independent Xθ-stage and Y-stage. By using image processing to calculate positional relationships, the system avoids direct mechanical coupling of multiple stages, reducing complexity while preserving alignment accuracy.
2Device complexity
If separate X and Y stages are used to avoid six-axis system, then device complexity is reduced, but calibration becomes impossible using existing techniques
Solution Approach 1:
The patent uses imaging devices as intermediaries to perform calibration between independent stages. The imaging devices capture positions of marks on each stage, and image processing calculates the coordinate transformation parameters, enabling calibration without requiring traditional XYθ-stage configurations.
Solution Approach 2:
The patent replaces mechanical calibration methods with optical/image-based calibration. Instead of using mechanical references and physical measurements, the system uses imaging devices to detect mark positions and computationally determines calibration parameters, making calibration feasible for independent stage configurations.
3Adaptability or versatility
If both stages move independently, then positioning flexibility is improved, but measurement of stage movements becomes impossible within camera field of view
Solution Approach 1:
The patent introduces virtual position calculations as an intermediary method to resolve movement detection. Instead of directly observing both stage movements in a single camera view, the system calculates the combined effect of independent stage movements through coordinate transformation, enabling measurement flexibility without field of view constraints.
Solution Approach 2:
The patent transitions from direct spatial observation to computational coordinate space. By calculating virtual positions in a transformed coordinate system rather than directly observing physical movements, the system overcomes the limitation of camera field of view while maintaining positioning flexibility.
Data Source
AI summary
A positional calibration is enabled between an imaging device and a stage structure including X and Y stages that move independently of each other. An image processing apparatus performs the positional calibration of a camera coordinate system for an imaging device with a stage coordinate system using a reference position in a first image coordinate space indicating a position of a mark in an image captured when an X-stage is at a reference position, a displaced position in the first image coordinate space indicating a position of the mark in an image captured when the X-stage is at a first displaced position to which the X-stage moves in X-direction from the first reference position, and a virtual position in the first image coordinate space indicating a position of the mark in an image calculated using the characteristic value of a Y-stage.