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CORONA CHARGING DEVICE WITH DIELECTRIC-COATED END SUPPORT BLOCKS

IP.com Disclosure Number: IPCOM000023911D
Original Publication Date: 1979-Apr-30
Included in the Prior Art Database: 2004-Apr-01
Document File: 2 page(s) / 394K

Publishing Venue

Xerox Disclosure Journal

Abstract

This proposal relates to an improved corona generating device of the type used in the field of xerography and more particularly, relates to improved end support blocks for the support of a corona discharge electrode. In corona charging devices of the type generally used in xerographic reproduction systems, a corona electrode or wire is supported on insulated blocks in such a manner as to prevent the corona wire from vibrating which would cause damage to the wire. In U.S. Patent 3,483,372, the corona wire is stretched between and attached to two blocks of suitable insulating material which are arranged between side walls at opposite ends thereof, and the corona wire is attached to the blocks by screws extending through the walls into the blocks. In U.S. Patent 4,086,650, the corona wire may be supported in conventional fashion at the ends thereof by insulating end blocks mounted within the ends of a shield structure. These end blocks or support blocks are subject to strong electric fields from the corona discharge. This frequently leads to early failure of the end blocks.

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XEROX DISCLOSURE JOURNAL

CORONA CHARGING DEVICE WITH Proposed Classification DIELECTRIC~COATEDEND SUPPORT U.S. CL 250/324 BLOCKS Int. CI. Halt 19/04 Charles G. Scouten

This proposal relates to an improved corona generating device of the type used in the field of xerography and more particularly, relates to improved end support blocks for the support of a corona discharge electrode. In corona charging devices of the type generally used in xerographic reproduction systems, a corona electrode or wire is supported on insulated blocks in such a manner as to prevent the corona wire from vibrating which would cause damage to the wire. In U.S. Patent 3,483,372, the corona wire is stretched between and attached to two blocks of suitable insulating material which are arranged between side walls at opposite ends thereof, and the corona wire is attached to the blocks by screws extending through the walls into the blocks. In U.S. Patent 4,086,650, the corona wire may be supported in conventional fashion at the ends thereof by insulating end blocks mounted within the ends of a shield structure. These end blocks or support blocks are subject to strong electric fields from the corona discharge. This frequently leads to early failure of the end blocks.

In accordance with the present proposal, the end or support blocks are coated with a dielectric material to extend the life of the end or support blocks. Films of dielectric material are applied to the end or support blocks by using a plasma of varying current density, The coating is applied in such a way that it has a graduation of dielectric constants, the dielectric constant being lower nearer the corotron wire and higher toward the support block. This reduces the field intensity and prolongs the life of the end or support block.

The...