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SUPPORTED DICOROTRON

IP.com Disclosure Number: IPCOM000024201D
Original Publication Date: 1979-Dec-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 63K

Publishing Venue

Xerox Disclosure Journal

Abstract

Dicorotron devices have been used to perform negative charging functions in an electrophotographic environment. A corona wire is coated with a dielectric material and excited by an AC voltage capacitively coupled to the air across the dielectric sheath. A net DC current to the surface to be charged is obtained by applying a DC bias to the surrounding corona shield. The only dielectric coating found to date capable of withstanding the corrosive attack of the corona products is glass. Glass is so brittle, however, in a thin coating on a flexible wire that it requires a means of firm support to keep it from cracking in shipment and in use. One approach has been to cement the dicorotron wire to the edge of a glass slide.

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(EROX DISCLOSURE JOURNAL

SUPPORTED DICOROTRON
L. Bean
J. Ewing

Proposed Classification
U.S. C1. 355/3CH

Int. C1. G03g 15/00

Dicorotron devices have been used to perform negative charging functions in an electrophotographic environment. A corona wire is coated with a dielectric material and excited by an AC voltage capacitively coupled to the air across the dielectric sheath. A net DC current to the surface to be charged is obtained by applying a DC bias to the surrounding corona shield. The only dielectric coating found to date capable of withstanding the corrosive attack of the corona products is glass. Glass is so brittle, however, in a thin coating on a flexible wire that it requires a means of firm support to keep it from cracking in shipment and in use. One approach has been to cement the dicorotron wire to the edge of a glass slide.

This method is sensitive to the shape of the meniscus of the cement joining the wire and glass slide and so far has not demonstrated the uniformity of the unsupported dicorotron. An improved design uses a partly evaporated structure starting with ten to forty mil glass plates commercially available and evaporating a thin line of chromium or other metal near one edge. Two such plates sandwiched together by cementing or fusion form the device. Depending on line width and spacing, corona may initiate at the sides of the glass support and so avoid the non- uniformity problems associated with edges. Evaporation of a suitable metal on...