Abstract: In a method to adjust print quality of print images in an electrophoretic digital printer with at least one print group, the print group generates charge images of the print images. The charge images are developed with a developer station into toner images using liquid developer having carrier fluid and toner. The toner images are transfer-printed onto a carrier medium in a transfer station. A first control marking is generated on the recording medium with elements of the first control marking being aligned transverse to a printing direction. A shape of the elements of the first control marking is measured to generate a first measurement signal. The first measurement signal is compared with a predetermined nominal value, and given a difference, an adjustment signal is generated via which an amount of the carrier fluid in the liquid developer is modified so that the first measurement signal approaches the predetermined nominal value.

Abstract: In a method to adjust print quality of print images in an electrophoretic digital printer with at least one print group, the print group generates charge images of the print images. The charge images are developed with a developer station into toner images using liquid developer having carrier fluid and toner. The toner images are transfer-printed onto a carrier medium in a transfer station. A first control marking is generated on the recording medium with elements of the first control marking being aligned transverse to a printing direction. A shape of the elements of the first control marking is measured to generate a first measurement signal. The first measurement signal is compared with a predetermined nominal value, and given a difference, an adjustment signal is generated via which an amount of the carrier fluid in the liquid developer is modified so that the first measurement signal approaches the predetermined nominal value.

Abstract: In a method or digital printer to print a recording material with toner particles applied with a liquid developer, toner concentration of the liquid developer is determined via measurement with aid of ultrasonic pulses. At least one ultrasonic pulse is generated by discharging an ultrasound emitter charged with a charge voltage. The ultrasonic pulse permeates the liquid developer and is received by an ultrasound receiver which generates a reception signal corresponding to the received ultrasonic pulse. With a control device, the charge voltage is regulated to a value such that a representative value of the reception signal corresponds to a predetermined desired value. The toner concentration is determined from the regulated charge voltage.

Abstract: In a method or digital printer to print a recording material with toner particles applied with a liquid developer, toner concentration of the liquid developer is determined via measurement with aid of ultrasonic pulses. At least one ultrasonic pulse is generated by discharging an ultrasound emitter charged with a charge voltage. The ultrasonic pulse permeates the liquid developer and is received by an ultrasound receiver which generates a reception signal corresponding to the received ultrasonic pulse. With a control device, the charge voltage is regulated to a value such that a representative value of the reception signal corresponds to a predetermined desired value. The toner concentration is determined from the regulated charge voltage.

Abstract: In a method to determine concentration of toner particles in a carrier fluid in a liquid developer system for a printer or carrier, a suspension of the carrier fluid in the toner particles is charged with an ultrasonic wave. A propagation time of the ultrasonic wave in the suspension is determined. A concentration of the toner particles in the suspension is determined from the propagation time. A system is also provided employing the above steps.

Abstract: In a method to determine concentration of toner particles in a carrier fluid in a liquid developer system for a printer or carrier, a suspension of the carrier fluid in the toner particles is charged with an ultrasonic wave. A delay of the ultrasonic wave in the suspension is determined. A concentration of the toner particles in the suspension is determined from the delay. A system is also provided employing the above steps.