Spectrally Adjustable LED Light Source for High-Intensity Spectroscopy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source devices for spectroscopy are large, expensive, and produce low light output due to inefficient use of white light sources and low transparency of gratings, necessitating additional light sources and modulation techniques for effective wavelength analysis.
Innovation Solution
A light source device utilizing an array of LED units emitting different wavelength ranges, where LED pairs are selectively brought into the optical axis and switched on, with a linearly movable filter used to fine-tune the wavelength range, eliminating the need for diffractive elements and mechanical modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If white light sources (halogen or xenon lamps) are collimated and split by a monochromator to provide adjustable wavelength light, then wavelength selectivity is achieved, but light output is reduced to very small levels due to masking and grating transparency limitations
Solution Approach 1:
The continuous white light source is segmented into multiple discrete wavelength components using an LED array, where each LED emits light in a specific wavelength range. This segmentation allows direct generation of monochromatic light without the need for wavelength splitting, thereby maintaining high light output while achieving wavelength selectivity.
Solution Approach 2:
The invention extracts only the necessary wavelength-selective function from the traditional monochromator system by using an LED array that directly emits discrete wavelengths. This eliminates the need for gratings and masks that cause light loss, achieving both wavelength selectivity and high light output.
2Measurement precision
If gratings with less than 30% transparency are used for wavelength selection, then wavelength resolution is achieved, but further performance is lost due to low light transmission
Solution Approach 1:
The invention removes the grating component entirely from the optical path by using an LED array that directly emits discrete wavelengths. This eliminates the 70%+ light loss associated with grating transmission, achieving both wavelength resolution and high light transmission efficiency.
Solution Approach 2:
The mechanical grating-based wavelength selection system is replaced with an electrical control system that selectively activates specific LEDs based on desired wavelength. This substitution eliminates the inherent light loss of mechanical gratings while maintaining precise wavelength control.
3Measurement precision
If mechanical chopper wheels and synchronous measurement are used to detect photocurrent, then wavelength-specific detection is achieved, but device complexity and cost increase
Solution Approach 1:
The mechanical chopper wheel and synchronous measurement system is replaced with direct electrical modulation of LED current. This allows wavelength-specific detection through simple current modulation and measurement without requiring mechanical moving parts or complex synchronous detection circuits.
Solution Approach 2:
Instead of mechanical chopping, the invention uses periodic electrical current modulation of the LED to achieve wavelength-specific emission. This periodic electrical action simplifies the detection system by enabling direct correlation between modulation frequency and wavelength selection.
4Measurement precision
If additional unfiltered light sources are used to generate realistic bias, then measurement accuracy is improved, but device complexity and power consumption increase
Solution Approach 1:
The LED array serves multiple functions: it provides both the measurement light source and the bias generation capability through selective activation of different LEDs. This eliminates the need for separate unfiltered light sources, reducing both power consumption and device complexity while maintaining measurement accuracy.
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 achieves a higher intensity of monochromatic light with reduced color admixture, enabling more economical power usage and eliminating the need for lock-in technology, while allowing for compact design and flexible modulation frequencies.
Implementation Method 1
an array of LED units emitting light of different wavelength ranges
Implementation Method 2
the linearly movable filter shifted in such a way that light with a smaller wavelength range passes through from the light impinging on the filter
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a method and a light source device for supplying light to illuminate an object. A light array comprising LED units that are arranged adjacently to one another and emit light of different wavelength ranges is linearly shifted such that said LED units are selected one after another, each selected LED unit is switched on, the light emitted by each switched-on LED unit is focussed on a linearly shiftable filter, and said linearly shiftable filter is shifted such that, out of the light incident on the filter, it is light with a smaller wavelength range that passes through.