Energy control of a nozzle of an inkjet printhead

• US 7,669,950 B2
• Filed: 07/08/2008
• Issued: 03/02/2010
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Do; An H
• Application Number:
  US12/169,604
• Publication Number:
  US 20080266361A1
• Time in Patent Office: 602 Days
• Field of Search: 347/9, 347/47, 347/54, 347/56, 347/65, 347/11, 347/62
• US Class Current: 347/11
• CPC Class Codes: B41J 2/04528 aiming at warming up the head
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04553 detecting ambient temperature
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• CPC Class Codes: B41J 2/0457 Power supply level being detected or varied
• CPC Class Codes: B41J 2/04585 controlling heads based on thermal bent actuators
• CPC Class Codes: B41J 2/04588 using a specific waveform
• CPC Class Codes: B41J 2/04591 Width of the driving signal being adjusted
• CPC Class Codes: B41J 2/04596 Non-ejecting pulses
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2002/14362 Assembling elements of heads
• CPC Class Codes: B41J 2002/14491 : Electrical connection

Abstract

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 shift register comprising a plurality of successive registers, the shift register receives input data in a first register, and shifts the input data to successive registers upon receipt of a shift signal, a transfer register for latching data in one of the registers of the shift register; a control gate for outputting a control pulse in response to data in the transfer register, and a drive transistor for providing an energy pulse to the resistive element of the actuator upon receipt of the control pulse. Each energy pulse has energy of less than 1 microjoule.

Claims

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 shift register comprising a plurality of successive registers, said shift register receives input data in a first register, and shifts said input data to successive registers upon receipt of a shift signal;

a transfer register for latching data in one of the registers of said shift register;

a control gate for outputting a control pulse in response to data in said transfer register; and

a drive transistor for providing an energy pulse to said resistive element of said actuator upon receipt of said control pulse,

wherein each energy pulse applied to said resistive element for ejecting the ink droplet has energy of less than 200 nanojoule.

2. The nozzle assembly according to claim 1, wherein each energy pulse has a pulse voltage of less than 8 Volt.

3. The nozzle assembly according to claim 1, wherein said nozzle assembly covers an area of less than 15,000 square microns.

4. The nozzle assembly according to claim 1, wherein said nozzle is spaced from other nozzles ejecting ink of a same colour by less than 25 microns in a direction transverse to the direction of movement of a print media upon which ink is ejected.

5. The nozzle assembly according to claim 1, wherein said inkjet nozzle is formed by photolithographic processes.

6. The nozzle assembly according to claim 1, wherein said ink droplet has a volume of less then 5 picoliter.

7. The nozzle assembly according to claim 1, wherein said shift register, transfer register, control gate and drive transistor are formed in a single silicon substrate.

8. The nozzle assembly according to claim 1, wherein said shift register, transfer register, control gate and drive transistor are formed from MOSFETs.

9. The nozzle assembly according to claim 1, wherein said printhead prints process color.