Lens-less Foucault TEM Mode Switching Control
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Solution Overview
Problem
The lens-less Foucault method in ordinary general use type transmission electron microscopes, which do not mount a magnetism shielding lens, faces restrictions in switching between sample image and diffraction pattern observation modes, increasing the burden on the electron microscope operator due to the need for repeated adjustments of the optical system.
Innovation Solution
A control method that fixes the irradiating lens condition after confirming the observation mode, ensuring the lens condition coincides with the final observation mode, thereby preventing erroneous operations and simplifying the switching process between image and diffraction pattern observation modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the lens-less Foucault method is used in ordinary transmission electron microscopes without magnetism shielding lenses, then the device complexity is reduced, but the ease of operation deteriorates due to repeated adjustments needed when switching between observation modes
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the irradiating lens condition to match the final observation mode before switching occurs. The control method determines the target observation mode (image or diffraction pattern) and proactively sets the irradiating lens parameters in advance, so that when mode switching is triggered, the optical system is already in the correct state, eliminating the need for repeated adjustments during operation
Solution Approach 2:
The patent implements feedback by continuously monitoring the current observation mode and comparing it with the target mode, then automatically adjusting the irradiating lens condition based on this feedback loop. The control method uses the state of the optical system to determine appropriate lens parameters and applies them dynamically, creating a closed-loop control system that maintains optimal operation during mode transitions
2Adaptability or versatility
If repeated adjustments of the optical system are performed when switching between observation modes, then the adaptability is improved, but the loss of time increases due to the burden on the operator
Solution Approach 1:
The control method determines the target observation mode in advance and pre-calculates the appropriate irradiating lens condition, so that when switching is needed, the parameters are already prepared. This eliminates the time-consuming trial-and-adjustment process that would otherwise be required to achieve the correct observation state
Solution Approach 2:
The system performs self-adjustment by automatically changing the irradiating lens condition based on the determined target observation mode, without requiring manual intervention from the operator. The control method enables the optical system to self-correct and self-configure, reducing both the time and skill burden on the operator while maintaining full adaptability across different observation modes
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 approach reduces the time and labor required for adjusting the optical system, improves the accuracy and reproducibility of experiments, and enhances the reliability of experimental data by simplifying the execution of the lens-less Foucault method, allowing for efficient observation of both Foucault images and small angle diffraction patterns.
Implementation Method 1
an irradiating optical system focuses a crossover at a selected area aperture position
Implementation Method 2
A Lorenz microscope method has been developed as a method of observing a behavior of deflecting an electron beam transmitting a magnetic material by receiving a Lorenz force
Data Source
AI summary
The present invention relates to a lens-less Foucault method wherein a transmission electron microscope objective lens (5) is turned off, an electron beam crossover (11, 13) is matched with a selected area aperture (65), and the focal distance of a first imaging lens (61) can be changed to enable switching between a sample image observation mode and a sample diffraction pattern observation mode, characterized in that a deflector (81) is disposed in a stage following the first imaging lens (61), and conditions for an irradiating optical system (4) can be fixed after conditions for the imaging optical system have been determined. This allows a lens-less Foucault method to be implemented in a common general-use transmission electron microscope with no magnetic shielding lens equipped, without burdening the operator.