Camera Lens Flange Calibration via Processor Compensation
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Solution Overview
Problem
Existing camera systems face challenges in automatically compensating for flange focal distance errors due to manufacturing tolerances, which can lead to focusing errors and impact performance, especially when swapping different lenses.
Innovation Solution
A camera apparatus that measures and stores the flange focal distance error during commissioning, allowing the processor to generate lens control signals to automatically adjust the lens position or optical power to compensate for the error, regardless of the type of lens used, using a combination of sensor and lens memory data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If factory calibration is performed for a specific lens-sensor combination, then focusing accuracy is improved, but lens interchangeability deteriorates
Solution Approach 1:
The system performs preliminary measurement of the flange focal distance during factory calibration and stores this measurement data in memory. This preliminary action allows the system to automatically compensate for manufacturing tolerances when different lenses are swapped, maintaining focusing accuracy without requiring recalibration for each lens-sensor combination.
Solution Approach 2:
The system uses stored flange focal distance measurement data as feedback to automatically adjust focus settings when lenses are interchangeably mounted. The processor retrieves the pre-measured error data and applies compensation, enabling both high focusing accuracy and lens interchangeability through automated feedback-based correction.
2Measurement precision
If mechanical adjustment mechanism is added to compensate for flange focal distance error, then focusing accuracy is improved, but device complexity increases
Solution Approach 1:
The system replaces complex mechanical adjustment mechanisms with an automated software-based solution. The processor uses stored flange focal distance measurement data to calculate and apply the necessary focus compensation, eliminating the need for manual mechanical adjustments while maintaining focusing accuracy.
Solution Approach 2:
The system performs self-calibration by automatically retrieving stored flange focal distance error data and applying compensation without requiring external mechanical adjustment mechanisms. The processor autonomously adjusts focus settings based on pre-measured data, reducing system complexity while maintaining accuracy.
3Measurement precision
If commissioning procedure with calibration target is implemented, then flange focal distance error is compensated, but productivity decreases
Solution Approach 1:
The flange focal distance measurement is performed as a preliminary action during factory calibration and the results are stored in memory. This eliminates the need for time-consuming commissioning procedures with calibration targets at the customer site, significantly improving productivity while maintaining error compensation accuracy.
Solution Approach 2:
The system skips the lengthy commissioning procedure with calibration targets by using pre-measured flange focal distance data stored in memory. The processor directly applies compensation based on this preliminary measurement, rushing through what would otherwise be a time-consuming setup process and thereby improving system deployment productivity.
Data Source
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AI summary
A method and camera assembly for use in a machine vision system, the assembly comprising a support structure forming a mounting flange that is configured for coupling with any of a plurality of exchangeable electrically controllable adjustable focal length lens assemblies, a two dimensional image sensor supported by the support structure and forming a sensor plane spaced from the mounting flange by a flange focal distance and a processor programmed with a flange focal distance error and to use the flange focal distance error to generate lens control signals to compensate for the flange focal distance error when a lens is mounted to the mounting flange.