Patent ID: 6857729
Filing Date: 2005-02-22
Classification: B41J

Abstract:
1. A micro-electromechanical drive mechanism that comprises a substrate that incorporates drive circuitry; at least one pair of elongate actuator arms that are anchored at a fixed end to the substrate and connected to the drive circuitry, each actuator arm being of an electrically conductive material and having an active portion that defines a heating circuit that is in electrical contact with the drive circuitry to heat and expand on receipt of an electrical signal from the drive circuitry and cool and contract on termination of that signal and a passive portion that is spaced from the active portion relative to the substrate so that the actuator arm bends and straightens as a result of differential thermal expansion and contraction and an opposed moving end undergoes reciprocal arcuate movement, the actuator arms of the, or each, pair being oriented with the moving ends aligned and facing each other; at least one pair of coupling structures that are fast with respective moving ends of the actuator; and a working member that is fast with and interposed between the, or each, pair of coupling structures, the coupling structures being configured so that said arcuate movement is translated into substantially rectilinear movement of the working member.