Patent ID: 7547083

Claim:
An ink jet printer, comprising: a printhead drive unit, including a printhead drive circuit and a printhead selection circuit, said printhead drive circuit outputting a plurality of address signals, said printhead selection circuit outputting a plurality of selection signals; and a plurality of printhead control units, each of said printhead control units receiving said address signals and corresponding one of said plurality of selection signals, each said printhead control unit including: a plurality of operation circuits, each of said plurality of operation circuits for receiving one of said address signals and one of said selection signals, each of said plurality of operation circuits including a plurality of inverters connected in series and outputting a switching signal corresponding to said received selection signal and said received address signal, said plurality of inverters including at least a first inverter and a second inverter, said first inverter being adapted for receiving said received selection signal, each of said plurality of inverters of each of said operation circuits being adapted for receiving the same said received address signal; a plurality of ink jetting circuits, each of said plurality of ink jetting circuits for receiving said switching signal outputting from corresponding said operation circuit and determining whether or not to jet out ink based on said received switching signal, wherein said received address signal and said received selection signal have a voltage level of a logic high voltage level and a logic low voltage level, said received switching signal is a logic high voltage level and selectively enables said ink jetting circuit when said received address signal and said received selection signal are at the logic high voltage level; and a plurality of nozzles, each of said plurality of nozzles corresponding to one of said plurality of ink jetting circuits for jetting out said ink.