Bi-telecentric Fluorescence Autofocus for Height Variation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current autofocus systems in macroscopic wide-field fluorescence imaging with angular illumination struggle to accurately maintain focus and alignment due to sample height changes, leading to positional shifting and reduced signal accuracy, especially when using differential scan imaging techniques.
Innovation Solution
A fluorescence imaging system employing laser scanning with angular illumination and a bi-telecentric optical configuration, coupled with a detector array and an intelligence module, continuously adjusts the sample platform or illumination beam to maintain focus and compensate for height variations, allowing simultaneous imaging of contiguous field points onto the detector array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If angular illumination is used to reduce optical background and increase sensitivity, then signal quality is improved, but the location of the imaged line on the sensor changes as sample height changes, requiring additional tracking complexity
Solution Approach 1:
A telecentric lens is introduced as an intermediary optical element that decouples the relationship between sample height changes and sensor position changes. The telecentric lens ensures that light rays from different object planes are parallel to the optical axis, making the imaged line position on the sensor independent of sample height variations. This mediator eliminates the need for complex tracking mechanisms while preserving the benefits of angular illumination.
2Adaptability or versatility
If sample height is allowed to vary, then adaptability to different samples is improved, but the detected signal 'walks off across the detection array' and measurement accuracy deteriorates
Solution Approach 1:
The telecentric lens acts as an intermediary that maintains constant magnification and fixed image position regardless of object distance variations. This allows the system to accommodate samples at different heights while keeping the detected signal position stable on the sensor array, preventing signal walk-off and maintaining measurement accuracy across varying sample conditions.
Solution Approach 2:
The system transitions from a static focusing approach (requiring fixed sample height) to a dynamic approach where the telecentric lens continuously maintains proper imaging conditions despite sample height changes. The telecentric optical design dynamically adapts to varying object distances while preserving image quality and position stability.
3Manufacturing precision
If traditional autofocus methods are used with angular illumination, then focus adjustment is possible, but additional steps to find x-y location are needed before focus determination, slowing down the process
Solution Approach 1:
The telecentric lens serves as an intermediary that eliminates the coupling between focus adjustment and x-y position determination. By ensuring that the imaged line position on the sensor is independent of sample height, the telecentric lens allows direct focus measurement from the sensor signal without requiring preliminary position-finding steps, thereby maintaining focus accuracy while significantly improving imaging speed.
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 significantly speeds up the focus determination process, maintains accurate alignment of fluorescence light origins, and ensures robust, quantitative imaging by compensating for sample height changes in real-time, eliminating the need for additional focus-dependent steps and reducing signal loss.
Implementation Method 1
an illumination system including a light source that emits excitation light in an absorption band of the fluorescent material, wherein the illumination system provides a beam of illumination that impinges on the fluorescent material at an angle
Implementation Method 2
an optical imaging system positioned between the sample platform and the light detector and configured to focus light emitted from field points on the sample platform onto the light detector
Data Source
Figure 1~2
Figure 3a~4
Figure 5~6b
AI summary
Quantitative fluorescence imaging systems and methods using angular illumination to obtain automatic focus information. Laser scanning (e.g., point or line scanning) with angular illumination in combination with an area imaging sensor, such as with a bi-telecentric scanner, is used to determine sample height (relative to a detection axis orthogonal to a platform holding the sample) and also correct for sample height in subsequent scans.