Patent ID: 7355305

Claim:
A small-size direct-acting actuator having a width of 1 to 10 mm, a length of 1 to 10 mm, and a height of 0.1 to 5 mm, comprising: a stator section; a stator attachment section secured to the stator section; metallic micro-beams extending from the stator attachment section and shaped by bending; a rotor section supported for swing motion by the micro-beams; a permanent magnet disposed in the stator or rotor section; and a coil disposed in the rotor or stator section, wherein a member including the stator attachment section, micro-beams, and rotor section is formed by a method comprising the steps of: preparing a member including a part to be the stator attachment section, a part to be the micro-beams, and a part to be the rotor section by punching a configured blank out of a thin plate by pressing or etching, the blank being configured such that the part to be the stator attachment section and the part to be the rotor section are bridged or connected at laterally opposed sides by side strips to be the micro-beams: folding the side strips at intermediate points at an angle of about 180Â° so that the part to be the rotor section overlies the part to be the stator attachment section; then folding back the side strips at intermediate points an angle of about 180Â° so that a rear or inside edge of the part to be the rotor section is situated close to a front or inside edge of the part to be the stator attachment section, and subsequently; folding the side strips along their longitudinal inner side at right angles so as to form the micro-beams; whereby a pair of the micro-beams is extended from the stator attachment section toward the rotor section, once folded back toward the stator attachment section, and folded again toward the rotor section so as to support the rotor section, and the micro-beams are flexible enough to be displaced by a drive force developed between the stator and rotor sections in a drive direction which is parallel to a plane sandwiched between the pair of micro-beams and perpendicular to a longitudinal direction of the micro-beams, but highly stiff in other directions, and wherein electric current is conducted through the coil in the magnetic field created by the permanent magnet for causing the micro-beams to be displaced for inducing swing motion of the rotor section.