Mems fluid ejection device configured for detecting a fault condition

• US 20050275492A1
• Filed: 06/24/2005
• Published: 12/15/2005
• 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 7,128,093 B2
• Time in Patent Office: Days
• US Class Current: 335/78
• 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 microelectromechanical fluid ejection device configured for detecting a fault condition is provided. The device comprises a mechanical actuator, drive circuitry and a switch device. The actuator is displaceable upon receipt of an electrical current from the drive circuitry and the displacement causes ejection of fluid from an aperture in the device. The switch device determines an extent of displacement of the actuator and comprises a contact element positioned for contact with the actuator; and processing circuitry for detecting when the actuator makes contact with the contact element.

Claims

1. A microelectromechanical fluid ejection device configured for detecting a fault condition, said device comprising:

a mechanical actuator, said actuator being displaceable upon receipt of an electrical current, said displacement causing ejecting of fluid from an aperture in the device;

drive circuitry for supplying the electrical current to the actuator; and

a switch device for determining an extent of displacement of the actuator, said switch device comprising;

a contact element positioned for contact with the actuator at a predetermined extent of displacement; and

processing circuitry for detecting when the actuator makes contact with the contact element.

2. The fluid ejection device of claim 1, wherein the current is directed to the processing circuitry when the actuator makes contact with the contact element.

3. The fluid ejection device of claim 1, wherein the processing circuitry is configured for registering a fault condition when the actuator makes contact with the contact element.

4. The fluid ejection device of claim 1, further comprising a paddle connected to the actuator, the paddle being displaced upon actuation of the actuator, thereby ejecting fluid from the aperture.

5. The fluid ejection device of claim 1, wherein the paddle is suspended in an ink chamber.