Fluorescence Observation Apparatus Illumination Light Filter
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Solution Overview
Problem
Conventional fluorescence observation apparatuses face challenges in balancing white light and excitation light intensities, leading to insufficient fluorescence luminance and signal saturation in white-light images due to the need to suppress excitation light to avoid bright white-light images.
Innovation Solution
A fluorescence observation apparatus with a light source unit that emits both white light and excitation light, featuring an illumination-light filter with higher transmittance in the excitation-light band than in the white-light band, ensuring that the intensity of excitation light is higher than white light, and a light guide that simultaneously irradiates these lights onto a specimen, along with a beam splitter to separate and acquire white-light and fluorescence images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If excitation light intensity is increased to improve fluorescence luminance, then fluorescence detection sensitivity is improved, but white-light image signal becomes saturated
Solution Approach 1:
The illumination light filter applies different transmittance characteristics to different wavelength bands: high transmittance for excitation light wavelengths and low transmittance for white light wavelengths. This local differentiation in optical properties allows the system to selectively enhance fluorescence excitation while suppressing white light transmission, resolving the contradiction between fluorescence sensitivity and white-light image quality
Solution Approach 2:
The filter's transmittance parameter is changed as a function of wavelength, creating a spectral selectivity that differentiates between excitation light and white light. By adjusting the transmittance characteristics across different wavelength ranges, the system achieves high fluorescence luminance without saturating the white-light image signal
2Illumination intensity
If white light intensity is increased to improve white-light image brightness, then white-light image quality is improved, but fluorescence luminance becomes insufficient
Solution Approach 1:
The illumination light filter creates local quality differences in the transmitted light by applying wavelength-dependent transmittance. The filter allows high transmission in the white light band for adequate image brightness while simultaneously providing high transmission in the excitation light band for sufficient fluorescence luminance, resolving the contradiction through spectral differentiation
3Device complexity
If a single light source is used to emit both white light and excitation light, then device complexity is reduced, but light intensity balance becomes difficult to control
Solution Approach 1:
The illumination light filter acts as an intermediary optical element that automatically balances the intensities of white light and excitation light. By positioning the filter in the optical path between the single light source and the specimen, the filter's wavelength-selective transmittance characteristics automatically regulate the light intensity distribution, eliminating the need for complex control mechanisms while maintaining proper intensity balance
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 for sufficient fluorescence luminance and prevents signal saturation in white-light images, ensuring a suitable dynamic range and detection sensitivity while maintaining a balanced light emission.
Implementation Method 1
the light source unit has an illumination-light filter that is disposed between the light-emitting portion and the light guide part, and that satisfies the following conditional expression, Pf(λw)＜Pf(λe) wherein Pf(λw) is a light transmittance of the illumination-light filter at a wavelength λw in a white-light band, and Pf(λe) is a light transmittance of the illumination-light filter at a wavelength λe in a excitation-light band
Implementation Method 2
a light guide part that guides the white light and the excitation light radiated from the light source unit and that simultaneously irradiates the white light and the excitation light onto a specimen
Implementation Method 3
a white-light-image acquisition unit that receives return light of the white light coming from the specimen and that acquires a white-light image; and a fluorescence-image acquisition unit that receives fluorescence excited in the specimen by the excitation light
Implementation Method 4
a fluorescence-image acquisition unit that receives fluorescence excited in the specimen by the excitation light and that acquires a fluorescence image
Data Source
AI summary
A fluorescence observation apparatus comprising a light source having a single light-emitting portion for emitting white light and excitation light simultaneously and radiates the white light and the excitation light; a light guide that guides the radiated white and excitation lights and simultaneously irradiates the white and excitation lights light onto a specimen; a white-light-image acquisition unit that receives return light of the white light coming from the specimen and acquires a white-light image; a fluorescence-image acquisition unit that receives fluorescence excited in the specimen by the excitation light and acquires a fluorescence image; an illumination-light filter that is disposed between the light-emitting portion and a radiation exit end of the light source, and satisfies the following conditional expression, Pf(λw)<Pf(λe), wherein Pf(λw) and Pf(λe) are transmittances of the illumination-light filter at a wavelength λw in a white-light band and a wavelength λe in a excitation-light band.