Abstract: An imaging system for a printer utilizing a friction belt drum drive is comprised of a drum position sensor, drum pulley, drive belt, motor pulley, drive motor, drive motor position sensor, and controller. The velocities of the drum and motor drive pulleys are measured using the controller and position sensors. These velocities along with the drive ratio are used to determine and monitor slip between the belt and pulleys. The magnitude of the slip measured can be used to trigger the controller to respond to the slip event. These responses may include, for example, disabling the motor or reducing motor current or providing a warning indicative of an excessive slip event. Slip measurement combined with other measurements such as motor current can be used to determine the torque capacity of the friction drive. Further, long-term changes in the ratio of pulley velocities can be used to determine drive belt wear.

Abstract: A method is implemented by a printer to move a transfix roller selectively to clean the transfix roller. The transfix roller is moved from a transfix nip with the print drum to a position where the transfix roller remains in rolling contact with the print drum, but exerts a pressure on the print drum that is less than the transfix pressure. The transfix roller is later moved out of rolling contact with the print drum in response to the transfix roller rotating a predetermined distance.

Abstract: A method is implemented by a printer to move a transfix roller selectively to clean the transfix roller. The transfix roller is moved from a transfix nip with the print drum to a position where the transfix roller remains in rolling contact with the print drum, but exerts a pressure on the print drum that is less than the transfix pressure. The transfix roller is later moved out of rolling contact with the print drum in response to the transfix roller rotating a predetermined distance.

Abstract: An encoder position signal processing system comprises an analog encoder reader and a codewheel. The codewheel possesses an optical track that modulates the quadrature encoder signal amplitude in order to generate an amplitude change (home pulse) once per revolution of the codewheel. The analog encoder reader outputs a quadrature signal comprised of sine and cosine signals. The quadrature signal is converted to a magnitude signal that is sampled in order to generate a rate of change (ROC) signal, which increases the signal-to-noise ratio. An algorithm using the characteristic shape of the ROC home pulse signal can then be applied to the ROC signal to increases robustness of detecting the home pulse.

Abstract: Ghosting conditions occur less frequently during duplex printing when a transfix roller in a printer is enabled to remain in rolling contact with release agent on a print drum after a trailing edge of a media sheet has left a transfix nip between the transfix roller and the print drum.

Abstract: An imaging system for a printer utilizing a friction belt drum drive is comprised of a drum position sensor, drum pulley, drive belt, motor pulley, drive motor, drive motor position sensor, and controller. The velocities of the drum and motor drive pulleys are measured using the controller and position sensors. These velocities along with the drive ratio are used to determine and monitor slip between the belt and pulleys. The magnitude of the slip measured can be used to trigger the controller to respond to the slip event. These responses may include, for example, disabling the motor or reducing motor current or providing a warning indicative of an excessive slip event. Slip measurement combined with other measurements such as motor current can be used to determine the torque capacity of the friction drive. Further, long-term changes in the ratio of pulley velocities can be used to determine drive belt wear.

Abstract: An encoder position signal processing system comprises an analog encoder reader and a codewheel. The codewheel possesses an optical track that modulates the quadrature encoder signal amplitude in order to generate an amplitude change (home pulse) once per revolution of the codewheel. The analog encoder reader outputs a quadrature signal comprised of sine and cosine signals. The quadrature signal is converted to a magnitude signal that is sampled in order to generate a rate of change (ROC) signal, which increases the signal-to-noise ratio. An algorithm using the characteristic shape of the ROC home pulse signal can then be applied to the ROC signal to increases robustness of detecting the home pulse.

Abstract: Ghosting conditions occur less frequently during duplex printing when a transfix roller in a printer is enabled to remain in rolling contact with release agent on a print drum after a trailing edge of a media sheet has left a transfix nip between the transfix roller and the print drum.