Patent ID: 7695103

Claim:
An image forming apparatus, comprising: a plurality of nozzles; a plurality of individual liquid supply channels each of which is communicated with a corresponding one of the plurality of nozzles and supplies a liquid to the corresponding one of the plurality of nozzles, the plurality of individual liquid supply channels including a plurality of pressure chambers corresponding to the plurality of nozzles, respectively, each pressure chamber being defined by four walls forming substantially a rectangular shape and a top and bottom surface, where said corresponding nozzle and liquid supply channel are located diagonally from each other at opposite sides of the pressure chamber; a plurality of drive elements each of which applies pressure in the liquid in a corresponding one of the individual liquid supply channels so as to eject the liquid as a droplet from the corresponding one of the plurality of nozzles; at least one pressure determination device which is arranged through the plurality of individual liquid supply channels and determines a pressure of the liquid in each of the pressure chambers applied by a corresponding one of the plurality of drive elements, the pressure determination device being separated from the plurality of drive elements; and a failed ejection detection device which detects failed ejection of the droplet from each of the plurality of individual liquid supply channels according to the pressure determined by the pressure determination device.