DMD Segmentation for Confocal Microscopy Back-Reflection Rejection
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Solution Overview
Problem
Confocal reflectance microscopy using a single DMD is hindered by camera saturation from DMD reflections, limiting its application to strongly reflecting objects, and requires precise optical alignment with dual DMDs, which is complex.
Innovation Solution
The optical layout separates the DMD into two areas for illumination and detection, using one area to generate light spots and the other to act as pinholes, with separate paths to avoid DMD reflections and simplify alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single DMD is used for both illumination and detection in confocal reflectance microscopy, then device complexity is reduced, but camera saturation from DMD reflections occurs and detection precision deteriorates
Solution Approach 1:
The patent divides the DMD device into two spatially separated functional areas: an illumination area that generates light spots and a detection area that acts as pinholes. This segmentation allows the illumination and detection paths to be separated, preventing back-reflections from the DMD from reaching the camera while maintaining the benefits of a single DMD device configuration.
2Measurement precision
If dual DMDs are used with separate illumination and detection paths, then detection precision improves by avoiding DMD reflections, but device complexity and alignment difficulty increase
Solution Approach 1:
The patent combines the functions of two separate DMDs into a single DMD device by allocating different functional areas within the same device. The illumination area and detection area coexist in one DMD, eliminating the need for precise alignment between two separate devices while still achieving separation of illumination and detection paths to avoid reflections.
3Measurement precision
If point-by-point scanning is used in confocal microscopy, then measurement precision is maintained, but imaging speed deteriorates
Solution Approach 1:
The patent uses a DMD to generate multiple illumination spots simultaneously across the sample, allowing parallel confocal measurements at multiple locations. This continuous multi-point illumination maintains optical sectioning quality while dramatically increasing imaging speed compared to sequential point-by-point scanning.
Solution Approach 2:
The patent employs a programmable DMD that can dynamically change the pattern and number of illumination spots. This dynamic control allows flexible adjustment of the imaging mode between single-point scanning and multi-point parallel imaging, optimizing both precision and speed based on the specific imaging requirements.
4Productivity
If Nipkow disk is used to create light spot array, then imaging speed improves through parallel scanning, but image quality deteriorates due to vibrations and fixed pinhole arrangement
Solution Approach 1:
The patent replaces the mechanical Nipkow disk system with a digitally controlled DMD. This substitution eliminates mechanical vibrations from spinning the disk while maintaining the ability to create arrays of light spots for parallel imaging. The digital control also allows flexible adjustment of pinhole size and spacing without mechanical constraints.
Solution Approach 2:
The patent uses a programmable DMD that can dynamically adjust the number, size, and spacing of virtual pinholes based on imaging requirements. Unlike the fixed mechanical arrangement in a Nipkow disk, the digital micromirror device can be reconfigured in real-time to optimize image quality and adapt to different sampling densities.
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 configuration allows efficient detection of weak reflections, especially in biological tissues, by rejecting DMD back-reflections and enabling flexible pinhole size and spacing, enhancing image quality and speed.
Implementation Method 1
when a light source, such as an LED, illuminates DMD, a part of that illumination is reflected to the LED by DMD micromirrors
Data Source
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AI summary
The present invention solves a problem of back-reflections from a digital micromirror device (DMD) and optical path allignment when a DMD device is used in confocal microscopy to generate multiple spots on a sample (sample), as well as to act as an array of pinholes for registering the light reflected from the sample (sample). The working area of a single DMD devixe is split into two separate parts of the DMD working surface area, which are independently controlled: one part (illumination part) is used to generate an array of spots, while the second part (detection part) is used to act as an array of pinholes directing the light reflected from the sample (sample) to the image registering device (camera). Such spatial separation of the two parts of the DMD prevents the back-reflection from DMD reaching a detector or the image registering device (camera). Furthermore, using a single DMD device (DMD) for both light beam paths allows perfect allignment of the optical layout and light beam paths, thereby, implementing the confocal microscopy function more simply and efficiently.