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:
Jan. 02, 1996
Filed:
Jan. 08, 1993
Gopal C Bhagat, Houston, TX (US);
Compaq Computer Corporation, Houston, TX (US);
Abstract
An electrophotographic printing system. Negatively charged toner is supplied to the surface of a first roller where the toner electrostatically adheres, either in a uniform layer or a variable layer, to the surface of the first roller. The negatively charged toner electrostatically adhered to the surface of the first roller is then transferred to the photoconductive surface and, from a photoconductive surface, to a sheet of paper positioned in proximity to the photoconductive surface. The apparatus may also include a second roller held at a positive charge relative to the first roller for electrostatically transferring toner from the second roller to the first roller. Alternately, the positive charge on the second roller relative to the first roller may be produced by placing a negative charge on the first roller or by placing a negative charge on the second roller and a more negative charge on the second roller. By placing a negative charge on the second roller, the toner will also be negatively charged before transfer to the first roller. The apparatus is further provided with a housing containing a solid desiccant material that serves to absorb harmful moisture that may be present at times throughout the interior of the apparatus, as a result of changes in relative humidity.