The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1977
Filed:
Oct. 06, 1975
James Lydell Bacon, Boulder, CO (US);
Jesse Wayne Spears, Boulder, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A corona and associated electrical drive as shown herein, neutralize the static charges on non-conductive sheets or webs. The neutralization of static charge is accomplished by passing the material to be neutralized under a double wire corona. Both wires in the corona are connected to an AC signal. The AC signal drives both wires with a signal that alternates in polarity at frequency f. The wires are spaced apart a predetermined distance calculated from a function dependent upon the frequency of the AC signal and the speed of the paper moving under the corona wires. The predetermined distance is such that a given area of the paper will pass under one wire at a first polarity and under the second wire at the opposite polarity. Further enhancement of neutralization can be accomplished by using a second double wire corona out of phase with the first double wire corona. In addition the sheet or web as it passes under the corona wires is supported to prevent static charge on the support from balancing a static charge on the sheet or web. Accordingly, the only static charge present as the sheet or web moves under the corona is that charge carried by the sheet or web. The corona wires will neutralize that charge either by discharging it with oppositely charged ions or depositing oppositely charged ions to balance the charge already on the sheet or web. Thus as the sheet or web moves away from the neutralizing station the sheet or web has a net charge which is substantially zero.