Colorocs Corporation

Maurice S Wheatley, Jr

Danny L Slayton

Kirk W Charles

David R Davis

Khosrow Lak

Charles S Palm

Wayne C Jones

Peter F Sampson

Gregory A Chatham

Anthony J Ireland

A method and apparatus for controlling belt movement and separated image registration in a belt oriented full color double transfer electrophotographic print engine is disclosed. The photoreceptor and transfer belts have a ratio of lengths which is nominally equal to an integer. Independent servos control rotation of the belts driving each at a constant rotational period. The rotational periods are calculated so that their ratio is precisely equal to the above referenced integer value which is the nominal ratio of the belt lengths. A plurality of separated image creation and development control signals are provided under the control of an event timing clock. The event timing clock is preset to a predetermined modulo M value, M being the units of time for the targeted rotational period of the transfer belt, each time a reference pulse is provided from a reference station associated with the transfer belt indicating that a predetermined location on the transfer belt has arrived at the reference station. This temporally synchronizes image creation with the physical rotation of the transfer belt assuring proper registration of the images. Electrostatic binding forces between the photoreceptor and transfer belts are controlled by deposition of toner on the photoreceptor belt and selectively de-energizing a transfer corona when charged, non-image carrying, areas of the photoreceptor belt are in the transfer station. Initial, and intermediate if needed, registration of seam areas on the belts is provided for embodiments using seamed belts where the seams are inappropriate area for developing or maintaining images.

Method and apparatus for registration control in an electrophotographic

An improved full color electrophotographic print engine using flexible belts to carry a photosensitive electrostatic image developer and a transfer belt for building up composite developed images. Each belt, and an optical scanner, are driven by mechanically independent motors which are synchronized by an electronic digital controller implementing precise servos. The use of the flexible belts allows the machine to be relatively inexpensive, very small compared to previous full color print engines, and yet maintain precise registration of color composite images. An improved fuser mechanism with increased dwell time at constant machine speed is also shown. The fuser includes a pair of spaced-apart rollers, both of which urge a sheet of image receptor against the heated roller over a predetermined angular portion of the roller. The machine is specifically designed to be used interchangeably with an optical bench source as a copier or with a laser bench as a laser printer. Improved copy quality monitoring by sensing actual amounts of toner deposited on a photoreceptor belt is also shown. Also, improved downwardly facing gravity-fed toner deposition modules are shown including an embodiment which has a purely magnetic gate for opening and closing the toner supply.

Fuser assembly for an electrophotographic print engine

Print engine for color electrophotography

Toner modules for electrophotographic print engine

Improved print quality monitoring for color electrophotography

Growing community of inventors

Duluth, GA, United States of America

Maurice S Wheatley, Jr