Method and apparatus for detecting electron beam source filament wear
AssigneeArcam AB
InventorsCalle Hellestam, Mattias Fager
Life of this patent
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Abstract
A method for detecting electron beam filament wear in an electron beam source, the method comprising the steps of: enlarging a beam spot emanating from the electron beam source on a work table to a predetermined minimum size, capturing an image of the beam spot on the work table by a camera, comparing the captured image of the beam spot with a reference image, and detecting filament wear if the captured image is deviating more than a predetermined value from the reference image.
Claims20
A method for detecting electron beam filament wear in an electron beam source, the method comprising the steps of:
- fixing the electron beam source in a reference condition,
- moving a focus plane of electron beams emanating from the electron beam source a predetermined distance from a target surface for reproducing electron emission of the filament onto the target surface,
- capturing an image of the reproduced electron emission of the filament onto the target surface by a camera,
- comparing the captured image with a reference image of the reproduced electron emission of the filament onto the target surface, and
- detecting filament wear if a luminous flux in the captured image is deviating more than a predetermined value from the reference image.
An apparatus for detecting electron beam filament wear in an electron beam source, the apparatus comprising:
- means for fixing the electron beam source in a reference condition,
- means for moving a focus plane of electron beams emanating from the electron beam source a predetermined distance from a target surface for reproducing electron emission of the filament onto the target surface,
- a camera for capturing an image of the reproduced electron emission of the filament onto the target surface, and
- a processor configured for:
- comparing the captured image with a reference image, and
- detecting filament wear if a luminous flux in the captured image is deviating more than a predetermined value from the reference image.
A computer program product comprising at least one non-transitory computer-readable storage medium having computer-readable program code portions embodied therein, the computer-readable program code portions comprising one or more executable portions configured for:
- fixing the electron beam source in a reference condition,
- moving a focus plane of electron beams emanating from the electron beam source a predetermined distance from a target surface for reproducing electron emission of the filament onto the target surface,
- capturing an image of the reproduced electron emission of the filament onto the target surface by a camera,
- comparing the captured image with a reference image, and
- detecting filament wear if a luminous flux in the captured image is deviating more than a predetermined value from the reference image.
Dependencies are inferred from the claim text.