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US 4,628,325 AGranted
Electromagnetic interference suppresion for electrical discharge printers
AssigneeBurroughs Corporation
InventorFlavius A. Mathamel
Life of this patent
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AssigneeBurroughs Corporation
InventorFlavius A. Mathamel
Estimating the term…
Disclosed is a system and method for reducing the level of electromagnetic emission radiated by electrical discharge type printers. Such printers utilize one or more styluses which are scanned across the width of a roll of electrosensitive paper and are selectively energized to vaporize small areas on the paper's coating to thereby form characters. When the coating vaporizes, a spark is produced which generates a broad band of electromagnetic energy which is conducted into the environment due to the conductive coating of the previously printed paper acting as an antenna. In order to reduce the effective antenna length and/or propagation capability to thereby reduce the energy radiated, the present system creates isolation bands at preset intervals as the printing occurs. The isolation bands are produced by continuously energizing all styluses as they scan across the full width of the paper, thereby causing an entire band of the paper's conductive coating to be burned off across the entire width of the paper. Each isolation band severs the conductive surface of the paper, thereby reducing the effective length and/or propagation capability of the antenna created by the printed paper and lowering the level of radiated energy.
A method of operating an electrical discharge type printer in order to reduce the level of radiated electromagnetic emissions, said method comprising the steps of:
The method in accordance with claim l further including the step of longitudinally incrementing said length of paper after printing each one of said sequences and each one of said isolation bands.
In combination with an electrical discharge printing apparatus of the type utilizing a spark mechanism to accomplish printing of images on an electrosensitive paper, including at least one stylus, means for moving said at least one stylus across the width of said paper, means for selectively applying a voltage between said paper and said at least one stylus, and means for feeding said paper past said at least one stylus to position said paper to print a next line, the improvement which comprises:
A method of operating an electrical discharge printing apparatus of the type utilizing a spark mechanism to accomplish printing on a length of coated electrosensitive paper, said apparatus including at least one stylus, said method including the steps of feeding said paper longitudinally past said at least one stylus, moving said at least one stylus across the entire width of said paper and selectively applying a voltage between said paper and said at least one stylus, the improvement comprising the additional step of periodically continuously applying said voltage between said at least one stylus and said paper as said at least one stylus is noved across the entire width of said paper, whereby a line of the coating across the entire width of said paper is removed.
A method of operation an electrical discharge type printing apparatus, said printing apparatus including a plurality of styluses which scan across the width of a length of electrosensitive paper, each one of a subset of said plurality of styluses energized with a voltage each time an image is to be printed on the paper at a point corresponding to the respective location of said each one of a subset of said plurality of styluses, wherein at least one of said plurality of styluses is constantly energized as it scans across the width of said paper, whereby an isolation band is printed across the width of the paper adjacent to each one of said images printed.
A method of operating an electrical discharge type printer comprising the steps of:
Dependencies are inferred from the claim text.