Field Emitter Structure for Guard Electrode Alignment
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Solution Overview
Problem
Field emission devices face issues with axis misalignment and tolerance-related problems during the operation of a movable body, which can prevent the electron generator from appropriately approaching or contacting the guard electrode, leading to failures in field emission and electron beam dispersion.
Innovation Solution
The field emission device incorporates a movable body with an emitter formed by film formation processing on its tip, featuring a stepped outer peripheral part that aligns with a stepped inner peripheral part of the guard electrode, allowing precise movement and contact between the electron generator and the guard electrode, thereby facilitating intended field emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a movable body is used to adjust the position of the emitter, then the electron generator can be brought close to the guard electrode for field emission, but axis misalignment and tolerance-related problems occur preventing proper contact
Solution Approach 1:
The device is divided into a movable body portion (holding the emitter) and a fixed body portion (holding the guard electrode), allowing independent positioning and adjustment of each segment to achieve proper alignment despite manufacturing tolerances
Solution Approach 2:
The movable body is designed to be movable relative to the fixed body, enabling dynamic adjustment of the emitter position to compensate for alignment issues and ensure proper contact with the guard electrode
2Adaptability or versatility
If the emitter is mounted on a movable body supported by a bellows member, then the emitter can be moved in the both-end direction, but tolerances cause axis misalignment between the emitter and guard electrode
Solution Approach 1:
The structure is segmented into movable and fixed portions, each capable of independent positioning, which allows the system to adapt to tolerance variations while maintaining axis alignment between the emitter and guard electrode
Solution Approach 2:
The position parameters of the emitter (mounted on movable body) can be changed relative to the guard electrode (mounted on fixed body), allowing adjustment to compensate for manufacturing tolerances and achieve proper alignment
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 eliminates axis misalignment issues, ensures proper contact between the emitter and guard electrode, stabilizes electron generation, and enhances the focus and convergence of the electron beam, improving the operational reliability and radioscopic resolution of X-ray devices.
Implementation Method 1
The emitter is structured to emit an electron beam due to electric field emission (i.e., generation and emission of electrons) therein, in response to application of a voltage between the emitter and the target
Implementation Method 2
a bellows member expandable in a both-end direction that is a direction of the first and second ends
Data Source
AI summary
A vacuum container is configured so that an opening on one side and an opening on another side in the longitudinal direction of a cylindrical insulating body are sealed with an emitter unit and a target unit respectively; and a vacuum chamber is provided on the inner peripheral side of the insulating body. The emitter unit is provided with: a moving body located on the one side in the longitudinal direction in the vacuum chamber and supported so as to be movable in the longitudinal direction via a bellows; and a guard electrode located on the outer peripheral side of the moving body. An emitter section having an electron generating section is formed at a tip section of the moving body on the other side in the longitudinal direction by subjecting the surface of the tip section to film formation processing.