Lexmark International, Inc.

Matthew Russell Smither

Gregory Alan Cavill

Robert Watson McAlpine

Douglas Anthony Able

Michael Brian Bacelieri

Andrew Pryse Dale

Jared Kuohui Lin

James Anthany Carter, Ii

Benjamin Keith Newman

Christopher Gene Vowels

Joshua Carl Poterjoy

Daniel Lee Thomas

Matthew David Heid

Marc Cousoulis

Michael Alan Gist

Stephen Andrew Brown

Michael Charles Day

David William Shuman

Christopher Hayden Noffsinger

Kweku Korsah

Jared Kouhui Lin

An imaging device has a developer roll to provide toner to a photoconductive drum to develop a latent image on the drum for direct transfer to media or an intermediate transfer member. A power supply in communication with a controller sets relative voltages on the developer roll and drum. During transfer of the toner, the imaging device determines a current between the developer roll and drum. In turn, the controller determines a charge and mass of the toner for setting with the power supply an operating voltage on the drum or developer roll. Preventing and reporting toners with insufficient charge are other embodiments.

Electrophotographic control in imaging devices, including sensing current between a developer roll and drum pertaining to current of a latent image and a paschen breakdown

An imaging device includes a photoconductive drum charged by a charge roll and opposed by a transfer roll to transfer an image from the drum. The drum becomes biased to a negative voltage by setting charges of negative voltage on both the charge roll and transfer roll. A controller switches the bias of the transfer roll to a positive voltage from the negative voltage and a delta or difference in a charge of the drum is determined from before and after the switching. Based on the delta, the voltage on the charge roll is boosted by a boost voltage to improve the charge on the drum. In this way, deteriorating or defective charge rolls can be still used to charge the drum to a proper voltage for imaging. Techniques for determining the delta, the boost and the magnitude of voltage charges are further embodiments.

Compensation for deficient charge roll in an imaging device

A photoconductor unit for an electrophotographic image forming device according to one example embodiment includes a housing and a photoconductive drum rotatably mounted on the housing. The photoconductive drum includes a drive coupler that is positioned to mate with a corresponding drive coupler of the image forming device to receive rotational and axial force therefrom for rotating and axially biasing the photoconductive drum when the photoconductor unit is installed in the image forming device. A wear member is positioned to receive frictional contact from a portion of the photoconductive drum in a direction of the axial bias on the photoconductive drum such that as the photoconductive drum rotates, the frictional contact on the wear member gradually wears away the wear member in the direction of the axial bias on the photoconductive drum thereby gradually shifting the photoconductive drum axially in the direction of the axial bias.

Axially shifting a photoconductive drum using a wear surface

A removable unit for an electrophotographic imaging device includes a housing having an opening, a rotatable roll disposed near the opening and adjacent to a bottom of the housing and a blade assembly coupled to the housing. The blade assembly includes a support bracket secured to a wall defining at least a part of the opening of the housing, and a blade member coupled to the support bracket and being positioned in the removable unit so that a distal end portion of the blade member engages with the rotatable roll. The housing, the blade assembly, and a portion of a surface of the rotatable roll define a substantially sealed enclosure for containing toner therein.

Developer unit architecture for an imaging device

Growing community of inventors

Lexington, KY, United States of America

Matthew Russell Smither