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:
Nov. 23, 1999
Filed:
Jul. 07, 1997
John A Thompson, Boise, ID (US);
George B Clifton, Boise, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
In a color electrophotographic printing system using a transfer belt, residual toner remains on the surface of the transfer belt after the printing of a page. To prevent print defects from occurring, the residual toner on the surface of the transfer belt must be removed. A transfer belt charge roller driven by a high voltage power supply is used to positively charge the residual toner to permit electrostatic transfer of the residual toner from the surface of the transfer belt to the surface of a photoconductor drum for removal by a cleaning blade. By applying an AC waveform and a positive DC offset, the residual toner is effectively positively charged for electrostatic removal from the transfer belt.