Laser Microscope Dynamic Range Expansion for PMT Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser microscopes face challenges in obtaining accurate brightness information due to saturation issues when dealing with strong light responses from specimens, leading to either saturation or noise burial, and they struggle to prevent photomultiplier tube degradation from excessive light exposure.
Innovation Solution
A laser microscope with a dynamic range expansion feature that allows for optional full-scale setting between normal and expanded modes, controlling laser power and high-voltage settings to prevent saturation and degradation, and utilizing conversion coefficients to process intensity signals into high-contrast brightness information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the full scale is set based on the brightness of light from a specimen that is not given a light stimulus, then the photomultiplier tube degradation is suppressed, but the brightness of light from a site where a strong response is obtained saturates
Solution Approach 1:
The patent applies dynamics by making the full scale setting changeable between normal and expanded modes. The system dynamically adjusts the full scale value based on the observation mode: using a smaller normal full scale for routine observations to protect the PMT, and switching to a larger expanded full scale when strong light responses are detected to prevent saturation and maintain measurement accuracy.
2Measurement precision
If the full scale is set on the basis of the brightness of light from a photoresponsive site on the specimen that is given a light stimulus, then saturation is prevented, but the brightness of extremely weak light from areas other than the photoresponsive site becomes buried in noise
Solution Approach 1:
The patent applies local quality by providing different full scale settings for different observation needs. The normal full scale setting is optimized for detecting weak light signals from non-photoresponsive areas, while the expanded full scale setting is optimized for measuring strong light responses from photoresponsive sites. This allows each region of the specimen to be measured with the appropriate sensitivity level.
3Reliability
If a low laser power or low high-voltage of the PMT is set so that the brightness does not saturate, then the photomultiplier tube degradation is suppressed, but the overall brightness becomes low and it becomes difficult to set conditions
Solution Approach 1:
The patent applies periodic action by implementing a two-stage observation approach. First, a preliminary observation is performed with normal full scale settings to identify photoresponsive sites and determine appropriate conditions. Then, a second observation is conducted with expanded full scale settings to capture the actual photoresponse without saturation. This periodic switching between observation modes allows for both PMT protection and optimal condition setting.
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
The solution effectively expands the dynamic range of intensity signals, preventing photomultiplier tube degradation and allowing for accurate, high-contrast brightness information capture from both weak and intense light sources without saturation or noise burial.
Implementation Method 1
a photomultiplier tube (PMT) serving as a detector that detects light and outputs an intensity signal of the detected light
Data Source
AI summary
A laser scanning microscope includes a light irradiating portion that irradiates a sample; a PMT that detects fluorescence from the sample and outputs an intensity signal; a data processing portion that converts the intensity signal to brightness information at each pixel; a full-scale setting portion that can set a normal full scale that is smaller than the intensity signal when a light stimulus is given and an expanded full scale that is larger than the normal full scale, as a maximum range of the intensity signal that can be converted to brightness information; and a control portion that determines whether to switch between a normal observation mode and a stimulation observation mode; wherein the full-scale switching portion sets the normal full scale in the normal observation mode and sets the expanded full scale in the stimulation observation mode.