The Third-Generation HP Thermal InkJet Printhead The monolithic integration of driver transistors with the thermal inkjet heater resistors leads to vastly improved performance with reduced cost per page for the customer.

Abstract

For the third generation of HP thermal inkjet printers, three parameters were selected for significant improvement: print quality, print speed, and cost per printed page. Elsewhere in this issue, print quality and cost per page improvements are discussed. This article describes a printhead designed for the new HP DeskJet 1200C printer that permits a significant increase in the print swath with a corresponding increase in print speed. Increasing print swath means more nozzles on the printhead from which to fire ink, hence a larger number of heater resistors. The printhead used in the current family of DeskJet printers (for example, the DeskJet 550C) has 50 nozzles and 50 corresponding heater resistors. The new printhead described here has 104 nozzles with 104 corresponding heater resistors. The direct drive technology used in the 50-nozzle printhead requires 54 interconnections between the printhead and the printer. A 104-nozzle printhead fabricated using the same direct drive technology would have some 112 interconnections between the printhead and the printer. By more