Abstract: A method is provided for actuating an liquid discharge element in an array of discharge elements of a print head. The liquid is provided to the elements of the array through a channel in the print head. A discharge element is provided with a driving signal from a set of signals comprising a discharging signal, a non-discharging signal, and a null signal. Only the first signal generates a drop of liquid, the second and third do not. An amount of discharging signals supplied to the print head is determined in accordance with a required number of droplets. A ratio of non-discharging signals versus null signals for the elements that do not discharge a drop of liquid increases with increasing amount of discharging signals. The elements receiving an non-discharge signal are selected randomly from the elements not discharging a drop of liquid. This extends the time that the print head may be operated without maintenance.

Abstract: A method for determining functioning of a print head cooler includes operating the print head cooler, the print head cooler including a first surface in thermal contact with a surface of a print head; providing a predetermined amount of heat to the print head; measuring the temperature of the print head; based on the measured temperature, determining the functioning of the print head cooler. The predetermined amount of heat is provided by applying at least one non-jetting pulse to a liquid present in the print head. An assembly of a print head and a print head cooler is also disclosed. The assembly includes a control that is configured to perform the method for determining functioning of a print head cooler.

Abstract: An ink jet printer has a number of ink discharge nozzles, a number of actuators respectively associated with the nozzles and arranged to create pressure waves in the ink to be discharged from the respective nozzles, and a controller arranged to apply drive signals to the actuators in accordance with print instructions for an image to be printed. The drive signals include print pulses causing ink droplets to be ejected from the nozzles at timings when the respective nozzle faces an image part of a print medium, and spitting pulses causing ink droplets to be ejected from the nozzles at timings when the respective nozzle faces a non-image part of the print medium. The drive signals further include pre-fire pulses which have an amplitude below a threshold at which ink droplets are ejected, and the controller is arranged to apply the spitting pulses in the form of combined pulse sequences that each include a number of pre-fire pulses preceding the spitting pulse.

Abstract: An ink jet printer has a number of ink discharge nozzles, a number of actuators respectively associated with the nozzles and arranged to create pressure waves in the ink to be discharged from the respective nozzles, and a controller arranged to apply drive signals to the actuators in accordance with print instructions for an image to be printed. The drive signals include print pulses causing ink droplets to be ejected from the nozzles at timings when the respective nozzle faces an image part of a print medium, and spitting pulses causing ink droplets to be ejected from the nozzles at timings when the respective nozzle faces a non-image part of the print medium. The drive signals further include pre-fire pulses which have an amplitude below a threshold at which ink droplets are ejected, and the controller is arranged to apply the spitting pulses in the form of combined pulse sequences that each include a number of pre-fire pulses preceding the spitting pulse.

Abstract: A transfer apparatus for transferring an image of a developer from an image-bearing medium onto an image receiving medium in a transfer zone includes a heating device that heats the image-bearing medium, an adjustable power supply device that supplies electrical power to the heating device, a first temperature sensor for sensing a basis temperature in the vicinity of the image-bearing medium away from the transfer zone and for transmitting to a controller a signal indicative of the basis temperature. The controller is adapted to adjust the power supplied by the power supply device to the heating device to obtain a target temperature in the transfer zone, in response to the signal indicative of the sensed basis temperature and based on a pre-established relationship between the power supplied to the heating device and a temperature difference between a temperature in the transfer zone and the basis temperature.

Abstract: An image transfer device for a sheet-fed image reproduction system is disclosed in which an improved removal of contaminants from the surface of an image transfer member is possible by using a tacky surface cleaning member contacting the image transfer member surface. The tacky surface of the cleaning member is rejuvenated substantially without affecting the productivity of the image reproduction system by applying predetermined patterns of cleaning substance on the image transfer member surface in the non-image areas, being the part of the inter-image areas coinciding with the inter-sheet areas. Also disclosed is a method for cleaning the image transfer member surface of such image transfer device.

Abstract: An image transfer device for a sheet-fed image reproduction system is disclosed in which an improved removal of contaminants from the surface of an image transfer member is possible by using a tacky surface cleaning member contacting the image transfer member surface. The tacky surface of the cleaning member is rejuvenated substantially without affecting the productivity of the image reproduction system by applying predetermined patterns of cleaning substance on the image transfer member surface in the non-image areas, being the part of the inter-image areas coinciding with the inter-sheet areas. Also disclosed is a method for cleaning the image transfer member surface of such image transfer device.

Abstract: A method of forming a multi-color image, wherein color separation images are generated at least two colors, and color separation images are formed by the use of colored toner powder and are transferred, in successive image-transfer steps under the influence of pressure, to an elastically deformable adhesive intermediate medium provided with a top layer, where the color separation images are collected to form a multi-color image, the method comprising softening the multi-color powder image and transferring it under pressure to a receiving support, wherein between two consecutive image transfer steps the powder image consisting of one or more color separation images is so deformed on the intermediate medium, under the influence of heat and/or pressure, that the powder image becomes adhesive for toner powder, subsequently transferring the color separation image not only to the intermediate medium but also to the powder image already present, wherein the intermediate medium comprises a heat-insulating layer in wh

Abstract: A method of forming visible images in which magnetically attractable toner powder comprising resin particles containing magnetically attractable material is introduced to an image forming zone between an image registration medium and a moving conveying medium which has, within said image forming zone, a magnetic induction of at least 0.2T at its surface, thus imparting a force of attraction on the toner powder in which image forming zone the toner powder is selectively deposited on the image registration medium by electrostatic attraction in accordance with an image pattern, the toner powder used containing no more than 3% by volume of the magnetically attractable material.