Light Source Modulation for Scanning Microscope Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser scanning systems, such as confocal microscopes and Scanning Laser Ophthalmoscopes, face challenges in achieving uniform illumination across the scanning area due to varying scanning speeds, leading to non-uniform thermal and photochemical effects and reduced signal-to-noise ratio (SNR) due to excessive laser energy at the edges and insufficient energy at the center.
Innovation Solution
The system modulates the light source intensity based on the scanning velocity, using an external modulator or direct modulation to ensure uniform illumination across the scanning path, with the intensity adjusted according to the average scanning velocity and zero outside a specific window, correcting for sinusoidal motion distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the light source intensity is kept constant, then the laser safety is maintained by limiting the radiant flux to the maximum intensity, but the illumination becomes non-uniform with excessive energy at the edges and insufficient energy at the center
Solution Approach 1:
The patent applies dynamics by making the light source intensity time-dependent through modulation. The intensity is dynamically adjusted according to the scanning velocity at different positions, transitioning from constant intensity to variable intensity that compensates for the sinusoidal scanning motion characteristics.
Solution Approach 2:
The patent changes the intensity parameter of the light source as a function of time and scanning position. By modulating the intensity parameter according to the scanning velocity profile, the system achieves uniform illumination across the scanning area while maintaining safety limits.
2Measurement precision
If the light source intensity is increased to improve the signal-to-noise ratio at the center, then the signal quality improves, but the thermal and photochemical effects become non-uniform and may damage the specimen
Solution Approach 1:
The patent applies local quality by providing different intensity levels at different locations of the scanning area. The intensity is locally adjusted according to the scanning velocity at each position, ensuring uniform energy distribution across the entire scanning area rather than uniform intensity throughout.
Solution Approach 2:
The system dynamically modulates the light source intensity in sync with the scanning motion. The intensity is increased during slow scanning regions (center) and decreased during fast scanning regions (edges), creating a dynamic intensity profile that achieves uniform illumination and uniform thermal/photochemical effects.
3Productivity
If the scanning speed is increased to improve productivity, then the imaging speed improves, but the scanning velocity varies significantly across the scanning area leading to non-uniform illumination
Solution Approach 1:
The system uses feedback from the scanning velocity information to adjust the light source intensity. The intensity modulation is based on the known scanning velocity profile, creating a closed-loop control that ensures uniform illumination regardless of the scanning speed variations.
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 allows for reduced laser power usage while maintaining or improving the signal-to-noise ratio, achieving more uniform energy distribution and enhanced image quality by optimizing laser power delivery across the scanning field.
Implementation Method 1
a scanner to dynamically update positions of a laser spot on the specimen
Implementation Method 2
Laser confocal microscopes and Scanning Laser Ophthalmoscopes (SLO), obtain a two dimensional images of a specimen by employing two scanners to dynamically update positions of a laser spot
Implementation Method 3
The light reflected from the specimen is detected by a photo detector such as a Photo Multiplier Tube (PMT) or an Avalanche Photo Diode (APD)
Data Source
AI summary
Systems, method, and non-transitory computer readable medium for imaging an object. The system includes a scanner. The scanner positions a spot of light from a light source on the object along a scanning path. The scanning path includes a plurality of scan lines. The spot moves along the scanning path at a scanning velocity. The scanning velocity is not constant. The intensity of the spot of light is modulated as a function of the scanning velocity. The system includes a detector that is arranged to output data associated with positions along the scanning path. The system includes one or more processors that perform calculations. Pixels are calculated based on the output data. The image is constructed of the object based on the pixels.