Light Source Device Far-Red Phosphor Green Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source devices lack sufficient emission intensity over the entire visible range, particularly in the green range from 490 nm to 580 nm, and have insufficient emission components in the far-red range, which limits their application in illumination and sensing applications.
Innovation Solution
A light source device incorporating a light emitting element with emission peaks in specific wavelength ranges and phosphors that emit light in different peak wavelength ranges, including far-red phosphors with peak wavelengths of 680 nm or more, to achieve a uniform emission spectrum from 400 nm to 750 nm, ensuring high emission intensity across the visible range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a light source device uses conventional phosphors with emission peaks in yellow, green, or red ranges, then output performance is improved, but emission intensity in the green range (490-580 nm) remains insufficient
Solution Approach 1:
The patent segments the emission spectrum into multiple distinct wavelength ranges by employing multiple phosphors with different peak emission wavelengths. Specifically, it uses a first phosphor (480-560 nm), second phosphor (560-680 nm), and third phosphor (680-780 nm) to cover different portions of the visible spectrum, ensuring sufficient emission intensity in the green range while maintaining overall output performance.
Solution Approach 2:
The patent employs a composite phosphor system combining multiple phosphor materials with complementary emission characteristics. This composite approach integrates phosphors emitting in blue-green (first phosphor), yellow-red (second phosphor), and far-red (third phosphor) ranges, creating a synergistic effect that achieves comprehensive spectral coverage with enhanced green range emission.
2Reliability
If a light source device uses standard照明 phosphors, then color rendering is improved, but emission components in the far-red range are insufficient
Solution Approach 1:
The patent segments the red spectrum into two distinct regions by employing a second phosphor (560-680 nm) for conventional red emission and a third phosphor (680-780 nm) specifically for far-red emission. This segmentation ensures that color rendering properties are maintained through the second phosphor while far-red emission components are sufficiently provided by the third phosphor.
Solution Approach 2:
The patent extends the emission spectrum into the far-red range (680-780 nm) by introducing a third phosphor with peak emission wavelength in this range. This parameter change in the emission spectrum adds far-red components without compromising the color rendering properties provided by the first and second phosphors in the visible range.
3Loss of energy
If a light source device uses narrow-band LED emission, then efficiency is improved, but emission intensity decreases in wavelength ranges away from the peak
Solution Approach 1:
The patent introduces phosphors as intermediary materials that convert the narrow-band LED emission into broad-spectrum light. The phosphors absorb the efficient narrow-band LED light and re-emit it across wider wavelength ranges, maintaining energy efficiency while achieving sufficient emission intensity across the visible and far-red spectrum.
Solution Approach 2:
The patent transforms the emission spectrum from narrow-band to broad-band by utilizing phosphor down-conversion. This parameter change in the spectral distribution allows the light source to maintain high energy efficiency (inherited from the efficient LED) while achieving sufficient emission intensity across a wide wavelength range through the phosphors' emission characteristics.
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 provides a light source device with enhanced color rendering properties and improved sensing capabilities by ensuring sufficient emission intensity across the visible spectrum, addressing the limitations of existing devices in illumination and sensing applications.
Implementation Method 1
a light source device including a light emitting element (e.g., an LED (Light Emitting Diode))
Implementation Method 2
Primary light emitted from the light emitting element generally has a peak emission wavelength in the near-ultraviolet to blue range
Implementation Method 3
a phosphor that is excited by output light from the light emitting element and emits light having a peak in a wavelength range different from the wavelength range of the light emitted from the light emitting element
Data Source
AI summary
Provided is a light source device including: at least one light emitting element of at least one type; at least one far-red phosphor that, when excited by output light from the light emitting element, emits light having a peak in a wavelength range of 680 nm or more to less than 780 nm; and at least one phosphor that, when excited by the output light from the light emitting element, emits light having a peak in a wavelength range different from the wavelength range of the light emitted from the far-red phosphor. The spectrum of light emitted from the light source device has characteristic A below. This light source device has sufficient emission intensity over the entire visible range, i.e., over a wavelength range of from 400 nm to 750 nm inclusive.Characteristic A: The ratio of a minimum emission intensity to a maximum emission intensity in a wavelength range of from 400 nm to 750 nm inclusive is 20% or more.