Lexmark International, Inc.

Paul Wesley Etter

Kerry Leland Embry

Robert Reed Booth

Claudia Alexandra Marin

Jerry Wayne Smith

Michael Clark Campbell

Ryan David Brockman

James Adrian Riley

Raymond Jay Barry

Richard Gordon Boyatt, Iii

Travis Alan Riggs

Gregorio Balandran

A method and system for fusing toner to media sheets in an imaging device are disclosed. The system includes a fuser heater having a first heating element and a second heating element, the fuser heater providing heat to a fuser nip; and heat control circuitry coupled to the fuser heater for passing current through the first and second heating elements of the fuser heater to generate heat therefrom. The system further includes a controller coupled to the heat control circuitry, the controller controlling the heat control circuitry for passing current through the first heating element during a warm up operation and passing current through the second heating element during a fusing operation following the warm up operation, the fusing operation fusing toner to a sheet of media.

Circuit and method for a hybrid heater with dual function heating capability

A fuser heater member for an electrophotographic imaging device, including a heater member. According to an example embodiment, the heater member includes positive temperature coefficient (PTC) material disposed along a width of a fuser nip of the fuser assembly; first and second electrodes disposed along disposed surfaces of the PTC material; an intermediate layer disposed over the second electrode; and at least one resistive trace disposed along the intermediate layer along the width of the fuser nip. The heater member includes a plurality of wire segments coupled to the first and second electrodes and the resistive elements for use in generating heat from at least one of the PTC material and the at least one resistive trace during a fusing operation.

Hybrid heater with dual function heating capability

A system for adjusting a selected operating parameter of an image forming device to control white vector based on selected environmental conditions includes an image forming station having a photoconductive surface with a latent image formed by discharged areas leaving non-discharged areas different from the discharged areas, a sensor mechanism for measuring selected environmental conditions of dry-bulb temperature and relative humidity, a control mechanism for reading the sensor mechanism to adjust the voltage bias of a charging unit by an offset applied to the charging unit based on a wet-bulb temperature value so as to minimize white vector without enabling onset of development of toner background on non-discharged areas, and a memory connected to and accessible by the control mechanism and storing a lookup table of a list of wet-bulb temperature values related to measured dry-bulb temperature and relative humidity values and correlated to a list of voltage bias offsets.

System and method for adjusting voltage bias of a charge roller of an image forming device based on environmental conditions to control white vector

An electrographic image forming device may use a feedback loop to determine environmental conditions and accordingly set one or more operating parameters. The device may detect a resistance/capacitance characteristic of a feedback loop comprising an interface between a first component and a second component of an image forming unit. The device may detect temperature measurements and humidity measurements that can be used to calculate wet-bulb temperature or other metrics used to characterize ambient environmental conditions. The interface may be one in which a toner image is transferred during image forming device operation. A controller may adjust the resistance/capacitance characteristic in response to wet-bulb temperature in conjunction with measured transfer feedback voltage.

Transfer print voltage adjustment based on temperature, humidity, and transfer feedback voltage

The present application is directed to methods of controlling the transfer voltage in a transfer nip formed between the photoconductive member and the transfer member. The methods offset the effects of large transfer current spikes caused when a media sheet enters and exits the transfer nip and account for temperature and humidity operating parameters using wet-bulb temperature measurements to adjust the transfer voltage. The control may include either ramping up or ramping down the transfer voltage. The ramped transfer voltage may include a series of alternating positive and negative steps that generally trend to ramp up or down. The size of the steps may further be adjusted to provide a smooth transition.

Method for adjusting transfer voltage controls based on environmental conditions to improve print quality in a direct transfer image forming device

A system for adjusting selected operating parameters of an image forming device to improve color registration based on selected environmental conditions includes a first image forming station to print a first registration mark on a substrate, a second image forming station to at least partially erase the first registration mark to form a registration pattern in a reverse transfer process of the color registration, and a control mechanism to adjust voltage biases of charge and developer rolls of the second image forming station based on wet-bulb temperature values determined from measured dry-bulb temperature and relative humidity values and stored in a lookup table so as to maintain a predetermined potential difference between charged and uncharged areas of a PC drum of the second image forming station that avoids Paschen breakdown and the development of toner at charged areas of the PC drum during the reverse transfer process of the color registration.

System and method for adjusting selected operating parameters of image forming device based on selected environmental conditions to improve color registration

A capacitive sensor to detect toner volume levels in a toner container within an image forming device includes opposed electrodes disposed within the interior of the toner container. The opposed electrodes form a capacitor characterized by an inherent capacitance that varies in response to an amount of toner that exists between the opposed electrodes. A corresponding sensor circuit is electrically coupled to the opposed electrodes and adapted to sense an instantaneous capacitance of the capacitor to determine the amount of toner that exists between the opposed electrodes. The opposed electrodes may have different shapes and configurations, including for example, plates disposed within the toner container or the interior walls of the container itself. The sensor circuit is configured to apply an alternating current signal to the opposed electrodes and sense an output voltage that is indicative of an instantaneous capacitance of the capacitor corresponding to toner volume within the container.

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Lexington, KY, United States of America

Paul Wesley Etter