Low pressure nozzle for an inkjet printer
View Patent ↗A nozzle assembly for an inkjet printhead is disclosed. The nozzle assembly includes an inkjet nozzle having an actuator for ejecting an ink droplet from the inkjet nozzle when a resistive element of the actuator is heated by an electrical current. A drive transistor provides an energy pulse to the resistive element of the actuator, and control logic controls the drive transistor. The actuator develops a pressure of less than 100 kPa within the inkjet nozzle.
1. A nozzle assembly for an inkjet printhead, said nozzle assembly comprising:
an inkjet nozzle having an actuator for ejecting an ink droplet from said inkjet nozzle when a resistive element of said actuator is heated by an electrical current;
a drive transistor for providing an energy pulse to said resistive element of said actuator; and
control logic for controlling said drive transistor,
wherein said actuator develops a pressure of less than 100 kPa within said inkjet nozzle.
2. The nozzle assembly as claimed in claim 1 , wherein said drive transistor, control logic and said inkjet nozzle covers an area of less than 20,000 μm 2 .
3. The nozzle assembly as claimed in claim 1 , wherein the diameter of said ink droplet is less than 20 μm.
4. The nozzle assembly as claimed in claim 1 , wherein an aperture of said inkjet nozzle through which said ink droplet is ejected has a diameter of less than 15 μm.
5. The nozzle assembly as claimed in claim 1 , wherein the velocity of said ink droplet is less than 8 m/s.
6. The nozzle assembly as claimed in claim 1 , wherein the volume of said droplet is less than 3 pl.
7. The nozzle assembly as claimed in claim 1 , wherein the energy of said energy pulse is less than 1 μJ.
8. The nozzle assembly as claimed in claim 1 , wherein the voltage of said energy pulse is less than 10 V.
9. The nozzle assembly as claimed in claim 1 , wherein said drive transistor and control logic are formed on a silicon substrate, and said inkjet nozzle is formed over at least one of said drive transistor and control logic.
10. The nozzle assembly as claimed in claim 1 , wherein a channel length of said drive transistor is less than 1 μm.
11. A printhead comprising a plurality of nozzle assemblies as defined in claim 1 , wherein nozzles are spaced from other nozzles ejecting ink of a same color by less than 25 μm in a direction transverse to the direction of movement of a print media upon which ink is ejected.
12. The printhead defined in claim 11 comprising at least 2000 nozzles fabricated on a single monolithic wafer.
13. A printhead comprising a plurality of nozzle assemblies as defined in claim 1 , wherein nozzles are spaced from other nozzles ejecting ink of a different color by less than 400 microns.