摘要 |
Torsional type optical ray deflection apparatus essentially comprises a pair of etched plates, one of which is single crystal semiconductor material such as silicon, and the other is a suitable insulating material such as glass. The semiconductor plate is etched to form an elongated bar of the material having a wider central portion which forms a reflecting surface armature of suitable area suspended internally of the rectangular frame formed by the remainder of the semiconductor plate. The insulating plate is etched to leave an annuloidal depression centrally of the plate. An elongated land in the center of the insulating plate underlies the reflecting surface area and the torsion bars in order to support the torsion bar-reflector structure in the direction normal to the longitudinal axis while allowing rotation about that axis. Planar electrodes are laid down in the bottom of the depression in the insulating plate for exerting an electrostatic force between one of the electrodes and the semiconductor armature, thereby causing angular displacement about the longitudinal axis of the torsion bars which will deflect rays of light incident to the reflecting surface portion. |