Xerox Corporation

Jp Morgan Chase Bank

Mohammad H Rahnavard

Mehrdad Zomorrodi

Russell B Rauch

Thomas M Baretsky

Michael B Neary

Michael J Thomas

Methods and systems formulate the impedance for decoupling capacitors of a multiple power supply printed circuit board considering plane capacitance, series resonant frequencies, parallel resonant frequencies and impedance. The impedances are evaluated at anti-resonant frequencies, which have been found to be the problematic frequencies and potentials for high impedance. Once such impedance at selected frequencies have been determined, they can be compared to target values, set for example by various system integrity or EMI standards or design parameters, to assess whether a particular DC power supply system performs properly from signal integrity or electromagnetic radiation points of view. This ability to readily assess a high probability of compliance theoretically will reduce research and development time and budget, reducing possibly many iterations of board designs and trials and error physical testing.

Characterizing multiple DC supplies decoupling capacitors in PCB by anti-resonant frequencies

An electronic trapping implementation in imager with laser driver is provided by comparing an output image from the imager to a reference image to obtain a difference image and calculating one or more frequency and amplitude modulations based on the difference image and applying the one or more frequency and amplitude modulations to the imager until the difference image is eliminated.

Electronic trapping implementation in imager with laser driver

A system architecture for scanned non-linearity correction in a printer uses any raster output scanner having scanned non-linearity profile previously stored in memory from a test station installed with any pixel board. The pixel board includes a correction table register wherein the pixel board utilizes the scanned non-linearity profile of the raster output scanner to calculate the correction table register to correct for pixel misregistration.

System architecture for scan line non-linearity compensation in a ROS system

A method for banding suppression due to vibration in an image forming and/or image receiving apparatus with laser driver utilizes governing equations which relate the on/off time and intensity to velocity and frequency of vibration are disclosed. Using derived formulas, an amplitude and frequency modulation (AM/FM) combination is used to suppress the banding due to vibration. The equation which governs the on/off time (FM) is t &plus;e sin(2&pgr;ft )/v &equals;t . This transcendental equation can be solved for the required on-time t in terms of the nominal on-time t , e (vibration amplitude), v (nominal velocity) and f (vibration frequency). The equation which governs the intensity is H (t)&equals;v(t)/v . H (t) controls the level of irradiance. This method is further extended to multi-temporal vibration frequency and may correct banding due to irradiance modulation.

Suppression of banding due to vibration in imagers with laser drivers

A method for banding suppression due to vibration in an imager utilizing a light emitting diode (LED) array is disclosed. By characterizing the LED array and knowing the amplitude and frequency of the signal due to vibration which causes the banding, the LEDs' driving currents are modulated in reverse direction corresponding to the banding signal to suppress the banding.

Suppression of banding due to vibration in imager with LED array

The pixel clock of a raster output scanning (ROS) system modulates an emitted light beam to provide pixel placement along a scan line. A method calculates the pixel clock frequency shifts to correct non-linearity of the scan line in a ROS. A data smoothing polynomial is calculated for the non-linearity of the pixels along the scan line. The needed frequency shift based on the polynomial to the first or higher orders is calculated and stored in a frequency shift look-up table. The calculated frequency shift from the frequency shift lookup table modifies the nominal pixel clock frequency to correct for the measured scan linearity of the ROS by modulation of the light beam.

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Rancho Palos Verdes, CA, United States of America

Mohammad H Rahnavard