Micromachined members coupled for relative rotation by hinges

摘要

A monolithically fabricated micromachined structure (52) couples a reference frame (56) to a dynamic plate (58) or second frame for rotation of the plate (58) or second frame with respect to the reference frame (56). Performance of torsional oscillators or scanners (52) benefits greatly by coupling the frame (56) to the plate (58) or second frame with torsional flexure hinges (56) rather than torsion bars (54). Appendages (122), tethers (142) or an improved drive circuit enhance electrostatic drive stability of torsional oscillators (52). Wide and thin torsional flexure hinges (96) and isotopically pure silicon enhance thermal conductivity between the plate (58) and the frame (56). Dampening material bridging slots (232) adjacent to torsional flexure hinges (96) drastically reduce the dynamic member's Q. A widened section (252) of narrow torsional flexure hinges (96) permit inclusion of a torsion sensor (108). A dynamic member (58) that includes an actuator portion (302) performs light beam switching. Reflective coatings (76), wire grid polarizers (362), photo-detectors (372) and Fresnel lenses (376) enhance optical performance of the torsional scanners (58).