Ricoh Company, Ltd.

Ricoh Systems, Inc.

Donald F Pfeuffer

Edward F Mayer

Victor B Van Blerk

Elden R Morrison

A particle cleaning blade is mounted to cause the edge of the cleaning blade to describe an arc having both radial and axial components relative to the drum surface so that at its lowest point the blade comes into contact with the surface of the photoconductive drum. The mounting incorporates sufficient mechanical tolerances in the mechanical components to cause the final position of the blade relative to the surface of the drum to shift slightly from one wiping sequence to the next; any defects in the blade are shifted laterally across the drum. The mounting is a parallelogram type arrangement, which is spring-biased to hold the blade in a position removed from the surface of the drum by rotating the sides away from the vertical. A solenoid actuator is provided, located laterally with respect to the parallelogram and near one upright side. When the solenoid is actuated, it overcomes the biasing spring force, and draws the arms upright by overcoming the spring biasing force. The mounting which supports the parallelogram ideally also incorporates a scraper blade made of a flexible sheet of material held against the side of the cleaner blade.

Electrophotographic copying apparatus including a guillotine cleaner

An electrophotographic copying apparatus utilizing a rotatable drum having a photosensitive outer circumferential surface is disclosed herein along with its method of operation. In making copies of a given sheet of information, an electrostatic latent image corresponding to the information to be copied is formed on a circumferential segment of the drum surface and the image is developed by applying toner onto the image bearing segment of the drum surface. Thereafter, the applied toner is transferred to a blank sheet thereby forming the copy. Once one or more copies are made from a given electrostatic image, any applied but untransferred toner on the drum surface is moved onto a second circumferential segment, preferably by means of a pliant roller segment and preferably with the aid of electrostatic attraction. The toner accumulated on the second segment of the drum surface is then moved by the latter to a specific point and removed from the second surface segment. During this latter movement, the toner is electrostatically held in place on the second drum surface segment.

Electrophotographic copying apparatus and method of use including

A crossmixing method for ensuring adequate mixing of a developer in an electrostatic printing machine. The method utilizes a screw conveyor having a left-hand thread on one portion thereof and a right-hand thread on another portion thereof, to move developer material from the end of the screw conveyor toward the middle thereof. Material is discharged from the screw conveyor into the sump of the machine in a direction generally toward the opposite end of the screw conveyor from where it originated. Developer material is moved from the sump upwardly onto a plate assembly which includes angled separators for guiding the developer particles and shifting them in opposite lengthwise senses on opposite halves of the plate assembly. From the plate assembly, the developer material moves in a curtain downwardly into the sump.

Developer crossmixing method

A crossmixing device for ensuring adequate mixing of a developer in an electrostatic printing machine. A screw conveyor is utilized having a left-hand thread on one portion thereof and a right-hand thread on another portion thereof, to move developer material from the end of the screw conveyor toward the middle thereof. Material is discharged from the screw conveyor into the sump of the machine in a direction generally toward the opposite end of the screw conveyor from where it originated. Developer material is moved from the sump upwardly onto a plate assembly which includes angled separators for guiding the developer particles and shifting them in opposite lengthwise senses on opposite halves of the plate assembly. From the plate assembly, the developer material moves in a curtain downwardly into the sump.

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San Jose, CA, United States of America

Donald F Pfeuffer