Patent ID: 6568783
Filing Date: 2003-05-27
Classification: B41J

Abstract:
A recognition circuit for providing identification information of an ink jet printhead to a ink jet printer, the ink jet printhead being disposed in the ink jet printer, the recognition circuit comprising:a plurality of power supply lines; a plurality of address lines; a control circuit for controlling operations of the ink jet printer, applying a working voltage to the plurality of the power supply lines, and applying an address voltage to the plurality of the address lines; a heating circuit having a plurality of heating cells, each of the heating cells being coupled with a corresponding power supply line and comprising: a heating element; and a switch connected in series to the heating element of the heating cell and coupled with a corresponding address line, wherein the control circuit is capable of turning on and turning off the switch via the corresponding address line, and when the working voltage is applied to the power supply line coupled with the heating cell and the address voltage is applied to the address line coupled with the switch, the switch is turned on so that a current flowing through the power supply line, the heating element, and the switch is generated and the heating element generates thermal energy; and an identification circuit having a plurality of identifying cells, each of the identifying cells having a first end and a second end, wherein the first end is coupled with both the heating element and the switch of a corresponding heating cell, and the second end is coupled with a common output terminal of the identification circuit, and the control circuit is capable of determining whether the identifying cell is in a programmed state or in an un-programmed state by applying a recognizing voltage to the power supply line coupled with the corresponding heating cell; wherein the control circuit is capable of generating the identification information of the ink jet printhead by determining the states of the identifying cells.