Blur-Calibration System for Electro-Optical Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current imaging systems face challenges in accurately and efficiently calibrating image blur due to optics and components, especially in cryo-vacuum conditions, where conventional methods are time-consuming, expensive, and limited in accuracy, and suffer from sign ambiguity in Zernike coefficient calculations.
Innovation Solution
A blur-calibration system using a moving multi-focal multi-target constellation with point-like objects at fixed relative positions and varying focus positions, allowing for efficient data collection without changing the test equipment's focus adjustment, and processing this data to generate high-resolution composite images and Zernike coefficients that characterize the optical system's aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional blur-calibration methods are used in cryo-vacuum conditions, then calibration can be performed, but the process is time-consuming and expensive
Solution Approach 1:
The patent applies preliminary action by pre-positioning multiple point targets at different focus positions along the optical axis before calibration begins. These targets are arranged in a constellation pattern with known relative positions, allowing the system to immediately begin capturing images at multiple focus planes without requiring time-consuming focus adjustment during the calibration process itself.
Solution Approach 2:
The patent segments the calibration process by dividing the target pattern into multiple discrete point targets (e.g., 7-13 points) arranged in a constellation, each at different focus positions. This segmentation allows parallel measurement of multiple focus planes simultaneously, transforming a sequential calibration process into a parallel one that dramatically reduces total calibration time.
2Measurement precision
If Zernike coefficients are calculated from fitted images, then optical aberrations can be characterized, but sign ambiguity remains in the coefficients
Solution Approach 1:
The patent introduces feedback by capturing images of the same point targets at multiple focus positions and using the focus variation to disambiguate the signs of Zernike coefficients. The known focus positions provide a reference that feeds back into the coefficient calculation, allowing the system to determine the absolute signs by comparing how the aberrations change with focus position.
Solution Approach 2:
The patent applies preliminary action by pre-arranging point targets at multiple known focus positions before measurement begins. This preliminary positioning creates a reference framework where the focus position is known a priori, allowing the system to use this known information to resolve the sign ambiguity in the Zernike coefficients during the calibration process.
3Measurement precision
If focus adjustment stage is repositioned to acquire data at different focus positions, then calibration accuracy improves, but the test equipment focus adjustment becomes dependent on exact return to zero
Solution Approach 1:
The patent applies preliminary action by pre-positioning the point targets at different focus positions along the optical axis before the calibration measurement begins. This eliminates the need to reposition the focus adjustment stage during data collection, as all required focus positions are already occupied by targets in the constellation. The focus adjustment stage remains fixed at its calibrated zero position throughout the entire measurement process.
Solution Approach 2:
The patent introduces an intermediary approach by using the point target constellation as a mediator that encodes multiple focus positions in space rather than using mechanical focus adjustment as the intermediary. The targets act as stationary markers at known focus positions, replacing the need for dynamic focus positioning and eliminating the reliability issues associated with focus adjustment stage return-to-zero dependency.
4Measurement precision
If multiple focus positions are measured to remove ambiguity, then Zernike coefficient accuracy improves, but calibration cost and time increase
Solution Approach 1:
The patent segments the measurement task by distributing multiple point targets at different focus positions across the field of view, allowing simultaneous capture of multiple focus planes in a single measurement sequence. This segmentation transforms the calibration from a sequential process requiring multiple separate measurements into a parallel process that collects all necessary data at once, dramatically improving productivity while maintaining coefficient accuracy.
Solution Approach 2:
The patent merges multiple measurement functions into a single calibration sequence by capturing images of the point target constellation at multiple focus positions simultaneously. Instead of performing separate calibration measurements at different focus positions, the system combines all necessary focus plane data collection into one integrated measurement, reducing total calibration time and cost while maintaining the accuracy benefits of multi-focus measurement.
Data Source
AI summary
Blur-calibration of an imaging system using a moving multi-focal multi-target constellation is described herein. The target has a known target pattern of a plurality of point-like objects with fixed relative positions in which at least one point-like object has a different focus position. In some embodiments, blur-calibration of an imaging sensor includes moving a known target pattern across the field-of view (FOV) of the imaging sensor to present the target pattern across different frames at different pixel phases. Frames of images of the moving target pattern as seen in the FOV of the imaging sensor are captured to sample point-like objects at different focus positions and generate a multi-focal image data output. The multi-focal image data output may be subsequently processed to generate data products at different focus positions from a high-resolution composite image generated from the captured frames.