Abstract: In an image forming device where first and second components are disposed in rotating contact with one another, the first component is driven by a first motor and a second component is driven by a second motor through a gear train with some predetermined backlash. The first and second components can be controllably accelerated according to respective first and second velocity profiles. The second component may be accelerated at a rate faster than the first component by an amount sufficient to substantially eliminate backlash in the gear train by a time the first and second components reach a common process speed. The first and second profiles may be adapted such that the mathematical integral of the time area between curves defining the profiles substantially matches the backlash amount.

Abstract: The present invention relates to an assembly or method for use with an image forming device. The device may include an image transfer device capable of receiving an extraneous electrostatic charge from a source. A discharge path may then be configured to remove all or a portion of the extraneous electrostatic charge from the image transfer device.

Abstract: A method and apparatus to clear the accumulation of toner particles from a doctor element by periodically reversing a bias field between a doctor element and a developer member. The developer member may be biased to a first electrical potential while the doctor element may be biased to a second electrical potential. The second electrical potential may be higher than the first electrical potential. The doctor element and the developer member may be biased from a single voltage supply and a voltage dividing circuit. A bias reversing circuit may cause the second electrical potential to fall, at least temporarily, below that of the first electrical potential when power from the voltage supply is removed. The bias reversing circuit may also cause the first electrical potential to fall with a longer time constant than that of the second electrical potential when power from the voltage supply is removed.

Abstract: The present invention relates to an apparatus and method that is capable of adjusting the position of a developing agent metering device. Developing agent may therefore be metered in an image forming device.

Abstract: An image forming device and method of detecting the presence or absence of components of one or more image forming units. Each image forming unit includes a replaceable component. A power supply transmits an input signal to the replaceable component. A detection circuit is coupled to the replaceable component and generates an output signal indicative of the presence or absence of an electrical coupling that is established when the replaceable component is installed. The detection circuit thus senses the input signal propagating through the replaceable component. A controller may be adapted to halt image formation or generate an error indication if the detection circuit detects the absence of necessary components or the presence of components not necessary for a current mode of operation.

Abstract: A method of determining a relative speed between two separately driven members in an image forming apparatus, includes the steps of: transporting a print medium using a print media transport assembly including a first nip, the print media transport assembly operable at a first transport speed; driving a rotatable member associated with a second nip at a second transport speed which is independent from the first transport speed; printing a first image on the print medium when the print medium is in at least one of the first nip and the second nip; printing a second image on the print medium when the print medium is in each of the first nip and the second nip, the second image overlapping the first image; detecting a moiré pattern caused by the first image and the second image; and determining a speed relationship between the first transport speed and the second transport speed, dependent upon the detected moiré pattern.

Abstract: A method of determining a relative speed between two separately driven members in an image forming apparatus, includes the steps of: transporting a print medium using a print media transport assembly including an exit nip, the print media transport assembly operable at a first transport speed; driving a rotatable member associated with an entrance nip using an electric motor at a second transport speed which is independent from the first transport speed; transferring the print medium from the exit nip to the entrance nip; detecting an electrical characteristic of the motor when the print medium is present in each of the exit nip and the entrance nip; and determining a relative speed between the first transport speed and the second transport speed.

Abstract: An optical scanner is provided having a memory device thereon. The memory device may store operational characteristics of the optical scanner or data that characterizes laser beam scan path and/or laser power requirements by each laser of the optical scanner. The memory device may be used to store historical information such as device temperature, cycles of operation and other historical information of components within a corresponding electrophotographic device. Still further, the electrophotographic device to which the optical scanner is installed may write operational data to the memory device, for example, to store a backup of registration and other operational parameters that are typically stored by the controller of the electrophotographic device.

Abstract: An image transfer assembly in a color printer or the like includes four image forming units. Each of the image forming units includes a photoconductive unit and a transfer device. A voltage is applied to the transfer device thereby creating a voltage potential between the photoconductive unit and the transfer device to facilitate the transfer of toner to a media substrate, such as paper. The transfer devices in the first two image forming units share a single high voltage power supply while separate high voltage power supplies supply the necessary voltage to the transfer devices of the other two image forming units.

Abstract: A method of operating an electrophotographic printer includes the steps of: transporting a print medium at a first operating speed using a print medium transport assembly; transporting the print medium from the print medium transport assembly to a fuser assembly, the fuser assembly including a fuser roll; creating a bubble in the print medium between the paper transport assembly and the fuser assembly; determining a temperature associated with the fuser roll; and rotating the fuser roll at a second operating speed which is dependent upon the determined temperature.

Abstract: A method of forming a registration pattern to enable detection of registration errors in an image forming device comprises forming a first registration mark on a substrate at a first image forming station, and partially erasing the first registration mark formed on the substrate at a second image forming station to form the registration pattern. A method of automatically detecting the registration errors further comprises sensing the registration pattern, and detecting registration errors based on the registration pattern.

Abstract: A method of correcting plane-to-plane registration in an electrophotographic machine having a plurality of color planes includes printing a calibration pattern using each of the color planes; measuring at least one misregistration between the color planes on the calibration pattern; adjusting at least one top margin by setting a first time delay before a first line; adjusting one of a right margin and a left margin by setting a second time delay; determining a longest line length of the calibration pattern; and adjusting an other of the right margin and the left margin to match the longest line length.