DRIVE CIRCUIT FOR A THERMAL INK JET PRINTHEAD

摘要

This invention relates to an integrated circuit for the driving of ink jet printheads. The circuit (10) comprises a thermal resistor (11) for generating a bubble of steam and ejecting a droplet of ink, a logic drive circuit (14, 15) and a power transistor (12) connected to the thermal resistor (11) and controlled directly by the logic circuit (14, 15). The transistor (12) is made from the same technology as the logic circuit (14, 15) and is driven with a gate voltage VG of between 4.5 and 5.5 Volts. The circuit (10) does not require the insertion of voltage boost devices between the logic circuit (14, 15) and the power transistor (12) while guaranteeing a low total resistance RON of the transistor, in practice in the region of 3.5 DIVIDED 4.5 OMEGA .