Lexmark International, Inc.

Other

John Parker Richey

Mark Andrew Omelchenko

Keith Bryan Hardin

Gregory Lawrence Ream

David Anthony Schneider

Jichang Cao

Phillip Byron Wright

Martin Christopher Klement

Gary Scott Overall

Martin Victor DiGirolamo

Danny Keith Chapman

Daniel R Steinberg

Christopher Edward Rhoads

Matthew Christopher Coriale

John Bruce Berry

Dale Randal Danner

John Patrick Spicer

Harald Portig

Michael David Maul

James Ronald Booth

Alan Stirling Campbell

Cary Patterson Ravitz

Raymond Jay Barry

Robert Aaron Oglesbee

Mark Lane Mayberry

Stacy Marie Pargett

Brian Anthony Reichert

Cuong Manh Hoang

Carl P Cole

Warren J Spina

Liqun Larry Wang

Terry Lee Parker

Adrian J Lee

Jonathan Carey Frey

Michael James Klein

Sean Foster Garnett

Larry Wayne True

David Feinauer

Mark Alan Stuart

Steven R Rehmel

Richard M Boothe

Wen-hsiung Adam Tseng

A system and method for controlling the fuser assembly of an electrophotographic imaging device, including determining a resistance of the fuser heater at a predetermined temperature that is less than a fusing temperature for performing a fusing operation; calculating a set point heater resistance based on the determined heater resistance, the set point heater resistance being a resistance of the fuser heater at a predetermined set point temperature; reading a line voltage to the electrophotographic imaging device at a first time; calculating heater power based on the line voltage reading and the calculated set point heater resistance; and controlling a speed of a fusing operation based on the calculated heater power.

Power management and control for a fuser of an electrophotographic imaging device

A system and method for controlling the fuser assembly of an electrophotographic imaging device, including initiating reading line current and line voltage for a plurality of consecutive AC cycles; from the AC cycle readings, identifying heater on cycles in which power is applied to the fuser heater and heater off cycles in which power is not applied to the fuser heater; calculating heater power from the identified heater on cycles and the heater off cycles, the heater power being the power of the fuser heater during a predetermined heater on cycle of the consecutive AC cycles; calculating a fuser heater voltage of the fuser heater during the predetermined heater on cycle based on the voltage readings; calculating a resistance of the fuser heater based on the calculated heater power and the calculated fuser heater voltage; and controlling the fuser assembly based upon the calculated resistance of the fuser heater.

A characterization procedure for the a detector in a toner patch sensor of an electrophotographic image forming device is performed with the toner patch sensor operatively connected to the image forming device's power supply. During the characterization procedure, a gain setting is determined that produces a predetermined target output from the toner patch sensor based on electromagnetic radiation reflected from a reference reflectivity sample. Subsequently, a toner patch is generated by the image forming device and a reflectance of the toner patch is measured based on the gain setting, with the toner patch sensor operatively connected to the power supply. The measurement(s) may then be used to adjust at least one electrophotographic image forming parameter. More than one reference reflectivity sample may be used, with corresponding gain settings stored in the image forming device.

Characterization of toner patch sensor in an image forming device

Methods and devices for operating a toner patch sensor in an electrophotographic image forming device. A characterization procedure for a light detector in the toner patch sensor may use one or multiple reflectance standards. A gain setting is determined that produces a predetermined target output from the toner patch sensing circuit for each of the standards. The characterization procedure may be carried out at a test bench or with the toner patch sensor installed in the corresponding device.

Characterization of toner patch sensor

A method and device for monitoring toner transfer within an image forming device is described herein. A reflectivity sensor senses movement of a toner transfer gear operatively connected to a toner transfer system. A threshold unit generates a dynamic threshold based on the output of the reflectivity sensor. In one embodiment, the threshold unit generates the dynamic threshold based on a time delayed average of the sensor output. An instantaneous sensor output is compared to the dynamic threshold. Based on the comparison, the device determines the how much the toner transfer gear has rotated, and therefore, how much toner has been transferred from the toner cartridge.

Optical sensor system with a dynamic threshold for monitoring toner transfer in an image forming device

An improved data signal electromagnetic emissions system is provided for sending data signals over one or more data pathways. An original data signal is encoded into a set of sideband frequencies that exhibit a lower amplitude than the original data signal; then transmitted over the data pathway and later decoded back into a signal having the original data content. The encoding scheme uses a number of modulation pattern sets that each produce a set of sidebands about the data signal's fundamental and certain harmonic frequencies, in a manner that attempts to make the maximum amplitudes for each set of sidebands substantially equal to one another, although this is also dependent upon the data signal's frequency content.

Method and apparatus for reducing EMI emissions for data signals traveling over a data pathway

Drive train motor speed is varied in a manner that compensates for characteristic rotational velocity errors of the associated drive train, such as by modulating a drive train motor speed control signal at a modulation phase and amplitude derived from the characterized rotational velocity error. Characterization can be performed on a test system for each drive train of interest, and the compensation values thus obtained can be saved for later use by systems in which the characterized drive trains are used. Thus, a drive train used in a consumables cartridge for an electrophotographic printing (EP) system can be characterized and the corresponding data saved via a label or memory circuit that is affixed to the cartridge. Such data can be used by the EP system in which the cartridge is installed to more accurately control the velocity of the image forming process members driven by the cartridge's characterized drive train.

Method and apparatus for characterizing and compensating drive train rotational velocity errors

An electrophotographic device comprises a printhead having at least one laser associated with a corresponding photoconductive surface. Where multiple laser beams are associated with the same photoconductive surface, the laser beams are spaced a predetermined distance from one another in a process direction, which is orthogonal to a scan direction in which the laser beams are swept. The electrophotographic device operates at one of at least two image transfer rates. A controller in the electrophotographic device selectively directs image data to the printhead based, at least in part, upon the selected image transfer rate, the facet resolution, and/or the desired output image resolution. The print speed can thus be adjusted over a relatively wide range.

Multiple speed modes for an electrophotographic device

A media sensor for an image forming apparatus is operative to sense and distinguish opaque, transparent or no media in a media path. In one embodiment, an optical source and detector are positioned on opposite sides of the media path, at an acute, non-zero angle with respect to a direction normal to the media path. In other embodiments, an optical source and detector are co-located on the same side of the media path with an optical barrier between them, and one or more reflective surfaces positioned on the opposite side. With no media in the media path, the detector receives a readily detectable amount of optical energy emitted by the source. For opaque media, the detector receives very little, if any, optical energy emitted by the source. For transparent media, the detector receives a level of optical energy between that in the cases of opaque media and no media.

Combined paper and transparency sensor for an image forming apparatus

Transfer belt subassembly for a color printer includes a transfer belt, home position indicator, temperature sensor, and memory. The transfer belt subassembly is measured and characterized after fabrication, before being installed in a printer. Measurement and calibration data for the transfer belt is stored in memory as part of the subassembly, including data representing velocity characteristics of the transfer belt and temperature compensation factors used by an engine-controller in a method to govern the speed of the drive motor. When the transfer belt subassembly is inserted into a printer, the engine-controller is operative in response to data stored in the memory and sensed belt velocity and temperature data, providing adjustment of belt velocity and compensation for variations in the transfer belt speed. Using the predetermined characterizing data, precise alignment of the color planes with respect to one another is achieved for accurate color printing.

Method and apparatus for controlling transfer belt velocity of a color printer

Waste toner is detected in a container of an image forming apparatus. An auger is provided within the container. A switch is provided which is operable depending upon a torque associated with operation of the auger. A frequency of activation of the switch is detected. A &ldquo;not full&rdquo;, &ldquo;near full&rdquo; and &ldquo;full&rdquo; condition of the waste toner in the container is determined depending upon the frequency of activation of the switch.

Method of detecting waste toner in a container of an image forming apparatus

A motion control system for controlling the motion of an intermediate transfer member in an image forming apparatus is provided in which a measuring member directly contacts the intermediate transfer member and generates signals proportional to the surface motion of the member. The measured surface motion is provided as a feedback signal to a motor controller, which compares the feedback signal with a reference signal. The difference between the signals is used to adjust the control of the drive motor for the intermediate transfer member drive roller in order to maintain a constant velocity for the intermediate transfer member.

Intermediate transfer member motion control via surface wheel feedback

A method of activating an electrophotographic machine includes determining at least one condition of the electrophotographic machine. Power is applied to a polygon mirror. A time period required for the polygon mirror to accelerate from a stationary condition to a target rotational velocity is measured. The measured time period and data associated with the at least one condition are stored in a memory device. The polygon mirror is decelerated back to the stationary condition. Power is reapplied to the polygon mirror at a point in time. The measured time period and the data are used to determine when to begin at least one process in the electrophotographic machine relative to the point in time.

Method of minimizing print delay due to mirror motor warm-up in an electrophotographic machine

An improved clock generation circuit is provided that operates with a single input clock frequency, and includes a Phase Locked Loop circuit (PLL) with a digital accumulator in the feedback loop, in which either the Most Significant Bit or the Carry Bit of the binary adder is used as the modulated feedback clock to the phase/frequency detector of the PLL. In one embodiment, a fixed add/phase amount is used to drive one of the inputs of the binary adder to generate a fixed output frequency. If it is desired to modulate the output frequency, then an Add Amount Modulator circuit can be provided that presents a varying numeric value to one of the inputs of the binary adder. The MSB or Carry Bit is communicated to an address look-up table, which then outputs an address to a memory circuit, which in turn presents a different add amount to the binary adder. If a periodic modulation is desired, the address look-up table will point to add amounts that create a particular periodic output frequency profile, which could include a Spread Spectrum profile. Certain optional circuits may be included, such as: a pre-multiply or pre-divide circuit to either increase or decrease the frequency of the input clock signal before it reaches the phase/frequency detector of the PLL; an output divider to provide a lower output clock frequency; a feedback divider to lower the VCO's output frequency before it is directed into the digital accumulator; a synchronizing input (Sync Input); a synchronizing output (Sync Output); a Base Number register to keep the memory size of the look-up table to a reasonably small value; or a Start Number register to provide the add amount upon initialization.

Method and apparatus for providing a clock generation circuit for digitally controlled frequency or spread spectrum clocking

A method of aligning print images of an electrophotographic machine on a print medium includes reflecting a first laser beam off of a first rotating reflector to thereby scan the first laser beam across a first photoconductive drum to produce a first scan line in a scan direction. The rotation of the first reflector is cyclically repeated to thereby produce a plurality of substantially parallel first scan lines on the first photoconductive drum. A respective line of first toner is applied to each of the first scan lines. A second laser beam is reflected off of a second rotating reflector to thereby scan the second laser beam across a second photoconductive drum to produce a second scan line in the scan direction. The rotation of the second reflector is cyclically repeated to thereby produce a plurality of substantially parallel second scan lines on the second photoconductive drum. A respective line of second toner is applied to each of the second scan lines. A moving toner transfer medium contacts each of the first photoconductive drum and the second photoconductive drum. Each line of first toner is transferred from the first photoconductive drum to the toner transfer medium. Each line of second toner is transferred from the second photoconductive drum to the toner transfer medium such that the lines of second toner are substantially interspersed with the lines of first toner on the toner transfer medium. The lines of first toner and the lines of second toner are transferred from the toner transfer medium to the print medium. A desired phase difference between the rotation of the first reflector and the rotation of the second reflector is determined. The desired phase difference is such that at least one line of first toner is substantially aligned in a process direction with a corresponding line of second toner on the toner transfer medium. The process direction is substantially perpendicular to the scan direction. A speed of the rotation of the first reflector and/or the second reflector is temporarily changed to thereby achieve the desired phase difference therebetween.

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Lexington, KY, United States of America

John Parker Richey