Illumination Optical Device Angle Adjustment for Uniformity
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Solution Overview
Problem
Existing illumination optical devices face challenges in achieving uniform and high illuminance without increasing the size of the device, as they require long optical rods with small cross-sectional areas, leading to light loss and increased device size.
Innovation Solution
The illumination optical device uses a light flux forming unit to adjust the angle of the light flux incident on an optical integrator, increasing the number of internal reflections while maintaining the length and cross-sectional area, utilizing relay lenses or a Fourier transform lens to ensure uniform illuminance without enlarging the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the cross-sectional area of the optical rod is made small to achieve uniform illuminance, then the number of internal reflections increases, but light loss from the incident end surface increases
Solution Approach 1:
The patent changes the angle parameter of incident light by introducing a light flux forming unit that increases the incident angle from the first angle to the second angle. This parameter change allows the optical rod to achieve uniform illuminance with fewer internal reflections, reducing light loss while maintaining the same cross-sectional area and length
2Illumination intensity
If the length of the optical rod is made long to achieve uniform illuminance, then the number of internal reflections increases, but light loss inside the optical rod increases and device size increases
Solution Approach 1:
The patent changes the incident angle parameter through the light flux forming unit, which allows the optical rod to achieve sufficient internal reflections for uniform illuminance without increasing its length. The increased incident angle (second angle greater than first angle) compensates for the fixed length, reducing light loss while maintaining uniformity
3Illumination intensity
If the length of the optical rod is made long to achieve uniform illuminance, then the number of internal reflections increases, but the size of the illumination optical device increases
Solution Approach 1:
The patent uses the light flux forming unit to change the incident angle parameter, enabling the optical rod to achieve uniform illuminance with a fixed, compact length. The increased incident angle ensures sufficient internal reflections without requiring a longer optical rod, thus maintaining a compact device size
4Illumination intensity
If the cross-sectional area of the optical rod is made small, then uniform illuminance is achieved, but light straying from the incident end surface increases during position deviation
Solution Approach 1:
The patent changes the incident angle parameter through the light flux forming unit, which allows the optical rod to maintain a larger cross-sectional area while still achieving uniform illuminance. The increased incident angle compensates for the larger cross-section, preventing light straying during position deviation and improving reliability
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 enhances illuminance uniformity and maintains device size, improving throughput and pattern transfer precision in semiconductor manufacturing processes.
Implementation Method 1
an optical integrator configured to cause an optical intensity distribution to be uniform on an emission end surface by reflecting light incident from an incident end surface in an inside surface a plurality of times
Implementation Method 2
a condensing mirror condenses light from the light source at a first angle with respect to an optical axis
Implementation Method 3
a light flux forming unit configured to convert a light flux from a focal position where a condensing mirror condenses light from the light source at a first angle with respect to an optical axis to a light flux to be incident on the incident end surface of the optical integrator at a second angle greater than the first angle
Data Source
AI summary
An illumination optical device for illuminating a plane to be illuminated using light from a light source, includes: an optical integrator configured to cause an optical intensity distribution to be uniform on an emission end surface by reflecting light incident from an incident end surface in an inside surface a plurality of times; and a light flux forming unit configured to convert a light flux from a focal position where a condensing mirror condenses light from the light source at a first angle with respect to an optical axis directed from the light source to the plane to be illuminated to a light flux to be incident on the incident end surface of the optical integrator at a second angle greater than the first angle with respect to the optical axis, wherein the plane to be illuminated is illuminated with light from the optical integrator.