Patent ID: 6799819
Filing Date: 2004-10-05
Classification: B41J

Abstract:
A printhead assembly, comprising:a plurality of ejection elements, each of the ejection elements configured to cause fluid to be ejected when the ejection element is activated; a plurality of photosensors, each photosensor coupled to one of the ejection elements, each photosensor configured to cause the ejection element coupled to the photosensor to be activated when the photosensor is illuminated by a light source; a plurality of amplifiers, each photosensor being coupled to one of the ejection elements via one of the amplifiers; wherein each amplifier comprises a first and a second FET, each FET including a gate, a source, and a drain; and wherein each amplifier further comprises a latch, and wherein the latch of each amplifier is coupled between one of the photosensors and the gate of the first FET of the amplifier, and wherein the first FET of each amplifier is configured to be turned on when the photosensor coupled to the first FET via the latch is illuminated by the light source.