Print head drive scheme for serial compression of i/o in ink jets

Abstract

The invention relates to a method and an apparatus for firing the nozzles on an ink jet print head cartridge that requires a reduced number of data lines between the ink jet print head cartridge and the printer electronics. A group data line provides serial group select data that is stored in a set of group select latches on the ink jet print head cartridge and identifies a particular group of nozzles on the ink jet print head. A primitive data line provides primitive select data that is stored in a set of primitive select latches on the ink jet print head cartridge and identifies a particular nozzle in the selected set of nozzles. A first clock line provides a first clock signal that is used to advance the group select data and the primitive select data into the group select latches and primitive select latches respectively. The group select data and the primitive select data is decoded to produce firing data which is advanced to a set of firing latches in accordance with a second clock signal that is provided on a second clock line. The data in the firing latches is logically ANDed or NANDed with a firing pulse provided on a firing line in order to expel a drop of ink from the selected nozzle or nozzles on the ink jet print head cartridge.