Planar Filament Mounting With Collector Plates for X-Ray Tube Alignment
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Solution Overview
Problem
Existing x-ray tubes face challenges in consistently aligning planar filaments within cathode cups, leading to undesirable variance in x-ray spot location, twisting or warping of filaments, improper electron emission, and potential overheating or damage due to improper welding, resulting in early failure of the x-ray tubes.
Innovation Solution
A filament assembly comprising a planar filament supported by a pair of collector plates that provide alignment and reduce twisting or warping, with a specific electrical coupling and welding design that allows for visual inspection and easier manufacturing, and blocks undesirable electron emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a planar filament is used in x-ray tubes, then electron beam focusing to a circular spot is improved, but consistent alignment within the cathode cup becomes difficult
Solution Approach 1:
The patent introduces collector plates as intermediary components between the filament and the cathode cup. These plates provide a stable mounting structure that facilitates precise and consistent filament alignment during manufacturing, eliminating the difficulty of directly placing the filament within the cathode cup while maintaining the electron beam focusing benefits of the planar filament design
2Reliability
If welding is used to attach the filament to electrodes, then electrical connection is achieved, but overheating and damage to the filament can occur
Solution Approach 1:
The collector plates serve as intermediary components between the filament and the electrodes. This intermediate structure allows for electrical connection without direct welding to the filament, thereby achieving stable electrical connection while avoiding the overheating and damage that would result from direct welding of the filament to the electrodes
3Ease of manufacture
If the filament is freely mounted, then installation is simple, but twisting or warping occurs which adversely affects electron beam shape
Solution Approach 1:
The collector plates act as intermediary mounting structures that provide mechanical support and stabilization to the filament. This intermediate structure enables simple installation while preventing twisting or warping of the filament, thereby maintaining the desired electron beam shape and focusing characteristics
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 filament assembly ensures consistent alignment and reduced variation between x-ray tubes, preventing overheating and misshaped electron spots, thereby enhancing the reliability and performance of x-ray tubes.
Implementation Method 1
A large voltage between a cathode and an anode of the x-ray tube, and a heated filament at the cathode, can cause electrons to emit from the filament to the anode
Implementation Method 2
The anode can include a target. The target can generate x-rays in response to impinging electrons from the cathode
Data Source
AI summary
A filament assembly 10 for an x-ray tube 20 can include a planar filament 11 electrically-coupled between and substantially-encircled by a pair of collector plates C1 and C2. The pair of collector plates C1 and C2 can support the planar filament 11 so that it does not twist or warp and align the filament assembly 10 within a cathode cup 33. The pair of collector plates C1 and C2 can block electrons emitted from a back side of the filament. Without the collector plates C1 and C2, back side electrons can change direction by about 180°, hit the target, and distort a target electron spot. Each collector plate C1 or C2 can include holes H1 and H2. These holes H1 and H2 can aid in alignment of the collector plates C1 and C2 with electrodes 31 and electrode 32, can allow welding at a lower temperature, and can facilitate weld inspection.