Exposure Light Source LED Layout for Thermal Wavelength Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of LED arrays in exposure apparatuses leads to wavelength unevenness due to temperature dependency, affecting illuminance uniformity and resolution, which existing techniques like Japanese Patent Laid-Open No. 2024-035053 fail to address effectively.
Innovation Solution
The arrangement of light emitting elements with different temperature characteristics in the element array, aligning peak wavelengths with temperature unevenness by positioning elements with longer peak wavelengths in cooler regions and shorter peak wavelengths in warmer regions, and using a coolant system to manage temperature transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a plurality of LEDs are arrayed to increase total light output, then the luminance and energy efficiency are improved, but temperature unevenness among LEDs causes wavelength unevenness
Solution Approach 1:
The patent applies local quality by arranging LEDs with different temperature characteristics in different spatial regions of the array. Specifically, LEDs with different peak wavelengths are positioned according to the temperature distribution pattern, so that LEDs experiencing higher temperatures are placed where their peak wavelengths naturally shift to longer wavelengths, compensating for the temperature-induced wavelength shift and maintaining overall wavelength uniformity across the array.
2Illumination intensity
If individual control of current values is applied to each LED, then illuminance uniformity can be adjusted, but temperature unevenness among LEDs increases causing wavelength variation
Solution Approach 1:
The patent addresses this contradiction by implementing local quality through spatial differentiation of LED characteristics. Instead of uniformly controlling all LEDs with the same current, the system assigns different current values to LEDs based on their positions and temperature characteristics. This localized control strategy allows each LED to operate at optimal conditions for its specific thermal environment, maintaining both illuminance uniformity and peak wavelength uniformity across the array.
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
Reduces wavelength unevenness among LEDs, ensuring consistent peak wavelengths and improved resolution and illuminance in the exposure apparatus.
Implementation Method 1
a plurality of light emitting elements are arrayed... each light emitting element has a temperature characteristic indicating a relationship between an element temperature and a peak wavelength
Implementation Method 2
using a coolant system to manage temperature transitions
Data Source
AI summary
A light source apparatus includes an element array in which a plurality of light emitting elements are arrayed, wherein the plurality of light emitting elements include a first light emitting element, and a second light emitting element having temperature characteristic, which indicates a relationship between an element temperature and a peak wavelength, different from a temperature characteristic of the first light emitting element, and the first light emitting element and the second light emitting element are arrayed in accordance with temperature unevenness in the element array.