Xerox Corporation

Jerry Floyd Adams

William R Harris

David Bradley Montfort

Alan J Werner, Jr

John R Falvo

Gerald M Fletcher

Fred F Hubble, Iii

Augusto E Barton

Derek Albert Bryl

Michael D Borton

Francisco Zirilli

Paul S Bonino

Ralph A Shoemaker

Bruce J Parks

Eliud Robles-Flores

Joseph L Filion

James P Martin

Mohamad M Mojaradi

Andrew James Bonacci

Anthony E Audi

John F O'Brien

Brian John McNamee

William M Lindenfelser

Thomas Edward Higgins

William R Haag

Peter G Fournia

Alfred J Claflin

John E Werner

Charles A Ruffino

Virginia N MacDonald

Bruce A Collier

Thomas J Brockman

Gary K Bauer

Susan A Turner

According to aspects of the embodiments, an apparatus and method is proposed to detect nip width by use of at least one piezoelectric (PZT) crystal embedded into a roll at both the inboard and outboard ends. A piezoelectric (PZT) crystal generates a charge when subjected to a load and when the load is released. The PZT generate signal is channeled to the ends of the roller such as with a brush contact to be processed and used within machine control. The duration measure from application and released of the load is indicative of the dwell time and the amplitude PZT generate signal is a function of the pressure. The time and amplitude of the PZT signal can be calibrated to correlate directly to nip width or pressure and tracked in machine control.

Piezoelectric sensors for automatic measurement of NIP width for fuser member control

A method and system for measuring and compensating for a leakage current in a high voltage transformer. Such a method and/or system include the use of a primary winding and a secondary winding, which can be provided on a core of a soft-magnetic material. A current transformer can be placed about the leads to both the terminals of the primary winding. The current transformer can be utilized to reliably measure the leakage current flowing from the secondary winding to the primary winding through one or more amplifiers to a ground terminal. The leakage current flows back to the transformer secondary winding through a low-side current sense resistor. The total current monitor signal can be generated by the low-side current sense resistor and the leakage current measured by the current transformer is vector-subtracted from the total current monitor signal. The result is a current monitor signal fully representative of the high voltage transformer's actual load current.

Leakage current compensation for high voltage transformers

A measurement module for a printer generally includes a page diverter mechanism configured to selectively divert a sheet of media from a main media path to a module media path; a rotating drum configured to receive the media from the module media path and to affix the media on an outer surface of the drum; a measuring device spaced adjacent to the drum and configured to measure as aspect of the media affixed to the surface of the drum; and a sheet transport configured to remove the media from the drum. According to one embodiment, the module may include a drum with an electrostatic hold-down mechanism that captures a sheet and an axially translating measuring device that is configured to read the entire surface as the drum rotates. The measurement module also allows the printed media to cool to eliminate problems with color measurements due to thermo chromaticity.

Universal module for enabling measurements on color printers

A method and apparatus that generates a spread spectrum signal in a printer power supply unit is disclosed. The method may include receiving an enable signal to power on the printer power supply unit, generating an initial power signal for the printer power supply unit based on the signal received from the power supply controller, the initial power signal being generated in a predetermined frequency range around a predetermined center frequency value, powering on the printer power supply unit using the generated initial power signal, repeatedly updating the initial power signal, wherein the updated power signal has a frequency value in the predetermined frequency range and the predetermined center frequency value is maintained, and powering the printer power supply unit using the updated power signal.

Method and apparatus for generating a spread spectrum signal in a printer power supply unit

Acoustic Transfer Assist (ATA) systems are used in media printing devices to help transfer toner to paper by use of ultrasonic vibrations. The transducer is driven at its resonant frequency, though somewhat dampened. To shorten the decay time of the transducer when its vibration is not desired, a compensating signal is used. A reverse drive voltage is used during transducer shut-off. The reverse drive causes the transducer to vibrate at its normal resonant frequency, but at a 180&#xb0; phase shift, causing the transducer to stop vibrating significantly faster than without a reverse drive. An open phase-locked loop system drives the transducer from resonance to rest. When the transducer stops vibrating, current to the reverse drive loop is cut off.

Fast decay ultrasonic driver

System and methods may calibrate an AC rms voltage applied to a coronode of a charging device to achieve a predefined operating current at a target value of DC shield voltage. The target value of DC shield voltage may be set to be substantially below an over-voltage condition. System and methods may use a calibration routine that may determine a minimum AC voltage required to achieve the target value of DC shield voltage. Systems and methods may alternatively, or additionally, sense current and adjust the applied voltage to obtain a target current.

Calibration apparatus and method for charging unit of image forming device

An electrophotographic document production device having a transformerless high voltage power supply located distal to its load and a transformer at the point of load.

Point-of-load design for high voltage AC power supplies

Techniques for correcting for internal resistance losses in the secondary windings of a transformer to reduce errors in output voltage from a high voltage power supply.

Secondary current compensation method

An electrophotographic printing machine of the type having a latent image recorded on an imaging member wherein said latent image is developed and transferred to a media substrate during successive printing cycles of successive print jobs, including a charging device for producing a voltage potential on the media substrate to transfer the developed latent image to the media substrate, said charging device including a coronode member and shield; a first voltage supply for apply a shield voltage to said shield; a second voltage supply for applying a wire voltage to said coronode member; a voltage monitor for measuring the voltage on the shield, said voltage monitor periodically polling the voltage during a cycle of a print job and generating a voltage measured signal as a function thereof; controller, responsive to a media type of each media substrate and said voltage monitor, for adjusting said wire voltage to said coronode member in respect to said shield voltage to said shield to compensate for process impedance as said media substrate passes under said charging device to obtained desirable image transfer.

Closed loop control function for corona device

A xerographic charging device corona current is determined by forming a first signal across a sense resistor in series with the charging device power supply, forming a second signal using a resistive voltage divider network across the power supply, and forming a third signal using a resistor-capacitor charging circuit across the power supply, and then processing the first, second and third signals to form an output signal that is based on the corona current.

Method of determining a resistive current

A combined charge/recharge xerographic power supply is provided that utilizes one power supply to drive the charge pin scorotron and recharge discorotron grids of a electrophotographic or xerographic system. The power supply uses recycled power from the pin scorotron grid to drive the discorotron grid. In particular, the power supply uses power that is dissipated in the traditional shunt regulator attached to the pin scorotron grid terminal to drive and provide active current to the discorotron grid through a series-pass regulation circuit. Thereby providing reduced electromagnetic emissions and reduced unit manufacturing costs.

Combined charge/recharge xerographic power supply

A sensor and associated method is disclosed for detecting presence of a sheet which is being advanced on a photoreceptor of an electrophotographic printing device. The sensor includes a vibratory member which is configured to be positioned in contact with the photoreceptor. The sensor further includes a drive circuit operable to generate an input signal on a signal line which is coupled to the vibratory member. In addition, the sensor includes a sensing circuit operable to (i) determine if a current level of the input signal falls below a threshold value, and (ii) generate a control signal in response thereto. The control signal may be used to stop advancement of the photoreceptor such as in the case where the control signal indicates that the sheet is improperly being advanced on the photoreceptor such as into a cleaning station. Alternatively, the control signal may be used to commence operation of a machine component such as in the case where the control signal indicates that the sheet has advanced to a particular position along the path of advancement of the photoreceptor.

Sensor and associated method

Power factor control in an AC powered machine having multiple input electrical power requirements. AC input power is continuously applied to a low input power load and selectively to a high input power load. The AC power to the high input power load is pulse modulated to have an input power that depends upon the input AC line voltage and upon the input AC line current. The pulse modulated AC power is controlled such that the total AC input power remains less than a design limit. If the high input power load is a heater, the pulse modulated AC power also depends on the heater's temperature.

Printer fuser heater controller with power factor correction

A printing process determines a maximum pixel printing rate of a printer. An area coverage of an image to be printed is estimated. When the area coverage multiplied by the printing speed exceeds the maximum pixel printing rate, the area coverage of the images to be printed is automatically reduced and the resulting image is printed.

Systems and methods for selectively blocking image data

An interlock switch (14) is provided between a housekeeping power supply (12) and a pulse width modulator (16). The pulse width modulator (16) pulses a field effect transistor (18) to generate alternating current (AC) to be passed by a transformer (26). The AC is converted to direct current (DC) by a converter 34 to provide an output voltage. If the switch (14) is opened, power to the modulator (16) and transistor (26) is terminated. No AC power is transmitted. Thus, since the transformer (26) only transfers AC, no voltage is generated at the output of the system.

Growing community of inventors

Waterport, NY, United States of America

Jerry Floyd Adams