Method of operating a thermal bend actuator

US7618109B2 · kind B2 · utility

Assignee

• Silverbrook Research Pty Ltd · AU

Inventors

• John Robert Sheahan · Sydney, AU
• Mark Jackson Pulver · Sydney, AU
• Brian Christopher Morahan · Sydney, AU
• Alireza Moini · Sydney, AU
• Timothy Peter Gillespie · Sydney, AU
• Michael John Webb · Sydney, AU
• Marcelle Louisa Gannon · Sydney, AU
• Kia Silverbrook · Sydney, AU

Key dates

• Filing date: Jul 29, 2008
• Grant date: Nov 17, 2009
• Expiry date: Jul 29, 2028

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41J2002/14491
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

Provided is a method of operating a thermal bend actuator of a printhead nozzle arrangement of a printhead using an open actuator test circuit. The test circuit includes an open actuator test input, a column enable input and a row enable input; a drive transistor operatively linking said thermal actuator to a power supply; a bleed transistor arranged in parallel with the thermal actuator; a sense transistor operatively linking an output of the drive transistor and inputs of the thermal actuator and bleed transistor to a sensing node. The method includes the step of actuating the actuator to facilitate printing by enabling the column and row enable inputs to deactivate the bleed and sense transistors and to activate the drive transistor to link the thermal actuator to the power supply. The method also includes the step of testing the actuator's continuity by enabling the open actuator test input to activate the bleed and sense transistors, so that the thermal actuator is short-circuited and the sense node is pulled high if the integrity of thermal actuator is open-circuit.