Rotatable Aperture Wheel for Oblique Incident Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microscope illumination systems for oblique incident illumination are mechanically complex, require user training, and have limited reproducibility and variability in incident light angle, making them difficult to use effectively for visualizing surface structures with high contrast and three-dimensional appearance.
Innovation Solution
A microscope illumination system featuring a rotatable aperture wheel with apertures of varying sizes, allowing for central or off-center positioning relative to the optical axis, enabling easy and reproducible adjustment of incident light angle and aperture size, coupled with a control unit for optimizing camera images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mechanically complex aperture stop device with variable size and pivoting movement is used to achieve oblique incident illumination, then the incident light angle can be varied, but the device complexity increases and reproducibility is limited
Solution Approach 1:
The aperture stop device is segmented into multiple discrete aperture stops with different aperture sizes, arranged in a circular pattern. Each aperture stop corresponds to a specific incident light angle, allowing selection without continuous mechanical adjustment. This segmentation transforms a continuous adjustment problem into a discrete selection problem, reducing mechanical complexity while maintaining adaptability.
Solution Approach 2:
The different aperture stops are pre-positioned at specific radial distances from the optical axis during manufacturing. Each pre-positioned aperture stop is designed to produce a specific incident light angle when activated. This preliminary positioning eliminates the need for complex real-time mechanical adjustment mechanisms, as the desired incident light angle is achieved by simply selecting the pre-configured aperture stop.
2Adaptability or versatility
If an aperture stop device with pivoting movement is used to vary incident light angle, then illumination can be adjusted, but ease of operation decreases due to required user training
Solution Approach 1:
The system dynamically switches between different aperture stops based on the desired incident light angle. Instead of requiring manual pivoting and positioning, the selected aperture stop is automatically activated through a simple selection mechanism. This dynamic switching approach maintains the adaptability to achieve various incident light angles while dramatically simplifying user operation to a simple selection process.
Solution Approach 2:
The complex mechanical pivoting system is replaced with an optical selection system where aperture stops are positioned in a plane conjugate to the aperture stop plane. The desired incident light angle is achieved by optically selecting the appropriate pre-positioned aperture stop rather than mechanically pivoting a single aperture stop, thereby simplifying user interaction.
3Adaptability or versatility
If a rotationally adjustable aperture stop is used to continuously vary incident light angle, then illumination flexibility increases, but manufacturing precision requirements increase
Solution Approach 1:
The continuous adjustment requirement is segmented into discrete aperture stops at predetermined radial positions. Each aperture stop is manufactured at a specific radial distance corresponding to a desired incident light angle. This segmentation allows for standardized manufacturing of each aperture stop position, reducing the cumulative precision errors that would accumulate in a continuously adjustable system.
Solution Approach 2:
Multiple aperture stops serve different functions (different incident light angles) within a single unified device structure. The circular arrangement of aperture stops allows the same device to provide multiple fixed incident light angles, achieving versatility without requiring high-precision continuous adjustment mechanisms. Each aperture stop is a universal component that can be precisely manufactured and positioned independently.
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 system provides a technically simple, easy-to-use, and reproducible method for variable oblique incident illumination, enhancing contrast and resolution, particularly in the ultraviolet spectrum, allowing effective visualization of both north-south and east-west oriented surface structures without the need for complex rotary stages.
Implementation Method 1
oblique incident illumination of objects to be examined is used, for example, in wafer inspection to image surface structures of a specimen with high contrast and three-dimensional appearance using the diffraction effects produced at said surface structures
Implementation Method 2
image surface structures of a specimen with high contrast and three-dimensional appearance using the diffraction effects produced at said surface structures
Data Source
AI summary
A microscope illumination system includes a first light source configured to provide light along an optical axis and an aperture device including an aperture wheel that is rotatable about an axis of rotation. The aperture wheel includes a plurality of apertures of varying size disposed circumferentially on the aperture wheel. The aperture wheel is rotatable so as to dispose each of the apertures in a position that is centered on the optical axis so as to generate an illumination beam path that extends in a centered relationship with respect to the optical axis, and so as to dispose each of the apertures in a position that is off-center from the optical axis and that is within a defined region around the optical axis so as to generate an illumination beam path that extends off-center from the optical axis for oblique incident illumination.