Ultrasonic ink metering for variable input control in keyless lithographic printing

摘要

An ultrasonic printing fluid input apparatus and method for use in a keyless lithographic printing press. The system has a rotatable metering roller 20 having at least an olephilic and hydrophobic surface and a source 100 of printing fluid. A metering blade 62 for applying a thin film of printing fluid to the surface of the metering roller 20 has at least one device 63 for imparting ultrasonic vibrations to the metering blade 62 such that a thickness of the thin film of printing fluid is a function of the amplitude of ultrasonic vibrations. A control 65 for varying the amplitude of ultrasonic vibrations is connected to the device 63 for imparting ultrasonic vibrations. A fixed end of the metering blade 62 is attached to a stationary support 42 via a decoupling material 65. A printing fluid removal device 73 is also provided for substantially removing a return printing fluid film on the oleophilic and hydrophobic surface of the metering roller 20.