Patent ID: 9283750
Filing Date: 2016-03-15
CPC Classification: B41J

Claim Text:
1. An inkjet-printing device comprising: a plurality of inkjet-printing nozzles; a plurality of firing circuits corresponding to the inkjet-printing nozzles; a first voltage source at which a parasitic resistance of the firing circuits is concentrated; a ground, wherein each firing circuit comprising: a controller to selectively activate the firing circuits to cause the nozzles to eject ink, such that for each firing circuit that is activated a difference between a voltage at the gate and a voltage at the drain is less than or equal to a voltage between the gate and the source, regardless of the parasitic resistance decreasing the voltage at the drain, the parasitic resistance based on and increasing in correspondence with a number of the firing circuits that are currently firing, wherein the gate is connected to a turn-on voltage circuit including a second voltage source different than the first voltage source to provide the turn-on voltage greter than a threshold voltage defined between the gate and the source, and wherein the voltage at the gate when the heater resistor is activated is greater than a voltage at the first voltage source by at most the threshold voltage of the transistor, so that operation of the switch remains in the constant current mode.