Inkjet nozzle device with cantilevered actuating arm

• US 20080211875A1
• Filed: 04/04/2007
• Published: 09/04/2008
• Est. Priority Date: 06/30/1999
• Status: Active Grant

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Granted Patent: US 7,635,177 B2
• Time in Patent Office: Days
• US Class Current: 347/54
• CPC Class Codes: B41J 2/04508 aiming at correcting other parameters
• CPC Class Codes: B41J 2/0451 for detecting failure, e.g. clogging, malfunctioning actuator
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• 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 2/0459 Height of the driving signal being adjusted
• 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 2/125 Sensors, e.g. deflection sensors nozzle clogging detection for cleaning reasons B41J2/16579; detection for compensation for failed nozzles B41J2/2139
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14354 Sensor in each pressure chamber
• CPC Class Codes: B41J 2002/14435 Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 29/38 Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
• CPC Class Codes: B41J 29/393 Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
• CPC Class Codes: Y10T 137/8225 Position or extent of motion indicator
• CPC Class Codes: Y10T 137/8242 Electrical

Abstract

A nozzle device is provided for an inkjet printer. The nozzle device includes a support structure defining an ink inlet chamber connected to a source of ink. A nozzle chamber structure defines a nozzle chamber for receiving ink from the ink inlet chamber and a nozzle opening through which ink in the nozzle chamber can be ejected. An elongate actuating arm is cantilevered relative to the support structure and terminates in a movable free end within the nozzle chamber. The actuating arm includes an active portion connected electrically to a current source, and which heats and expands upon activation of the current source. The actuating arm further includes a passive portion which is electrically isolated from the current source and is mechanically coupled to the active portion via at least one separating element. Differential expansion between the active and passive portions can cause the actuating arm to bend and the free end of the actuating arm to move within the nozzle chamber to eject ink therein through the nozzle opening.

Claims

1. A nozzle device for an inkjet printer, the nozzle device comprising:

a support structure defining an ink inlet chamber connected to a source of ink;

a nozzle chamber structure defining a nozzle chamber for receiving ink from the ink inlet chamber and a nozzle opening through which ink in the nozzle chamber can be ejected; and

an elongate actuating arm cantilevered relative to the support structure and terminating in a movable free end within the nozzle chamber, the actuating arm comprising an active portion connected electrically to a current source and which heats and expands upon activation of the current source, the actuating arm further comprising a passive portion which is electrically isolated from the current source and is mechanically coupled to the active portion via at least one separating element so that differential expansion between the active and passive portions can cause the actuating arm to bend and the free end of the actuating arm to move within the nozzle chamber to eject ink therein through the nozzle opening.

2. A nozzle device as claimed in claim 1, further comprising a movement sensor which can facilitate determination of the degree or rate of pivotal movement of the actuating arm.

3. A nozzle device as claimed in claim 2, wherein the movement sensor comprises a movable contact element extending from the active portion, and a fixed contact element which extends from the support structure in a position so that the movable contact element can contact the fixed contact element upon activation of the current source.

4. A nozzle device as claimed in claim 3, wherein the active portion is substantially U-shaped and the movable contact element is located proximal to the centre of the active portion.

5. A nozzle device as claimed in claim 4, wherein the free ends of the active portion define a pair of enlarged contacts.

6. A nozzle device as claimed in claim 1, wherein the nozzle chamber structure comprises:

a static portion extending from the support structure and which defines the nozzle opening; and

a movable wall portion mounted to the cantilevered actuating arm between its fixed and free ends.

7. A nozzle device as claimed in claim 6, further comprising a static formation extending from the support structure toward the actuating arm at a location proximal to the movable wall portion, the static formation impeding the escape of ink from within the nozzle chamber during actuation of the actuating arm whereby an ink meniscus is formed between the static formation and the actuating arm.

8. A nozzle device as claimed in claim 7, wherein the static formation defines a bent free end which bends away from the nozzle chamber.

9. A nozzle device as claimed in claim 8, wherein the support structure defines a well located in alignment with the bent free end so that any escaped ink from the nozzle chamber can collect in the well.

10. A nozzle device as claimed in claim 1, wherein the free end of the actuating arm comprises a paddle which spans the nozzle chamber.