Abstract: An optical encoder comprises a measuring section and a scanning grating plate. The measuring section comprises parallel light beam sources, light receiving elements located in opposition to the parallel light beam sources, converging devices disposed between the parallel light beam sources and the light receiving elements and a main grating plate arranged between the converging devices and the light receiving elements. The scanning grating plate is located between the main grating plate and the light receiving elements while allowing the scanning grating plate to move relative to the measuring section.

Abstract: A counterbalance mechanism for a laser knife device which includes a manipulator in which the overall height of the balance mechanism is quite short and all rotational moments of the manipulator are cancelled for all operative positions thereof. A base support arm is rotatably mounted around a short first hollow arm with a second hollow arm extending through upright portions of the base support arm joined at its two ends through articulations to the upper end of the first hollow arm and a third hollow arm. A parallelogram link mechanism is formed including the upright members of the base support arm, first and second substantially parallel support arms and a third substantially vertical support arm upon which a counterbalance weight is mounted. One end of the first support arm is pivotably mounted between the upright members of the base support arm while the corresponding end of the second support arm is pivotably mounted around the second hollow arm between the upright members.

Abstract: A manual manipulator mechanism for a surgical or industrial laser employs reflecting mirrors 1, 3 each rotatable about two perpendicular axes, to thereby reduce the total number of mirrors required and simplify the overall mechanism. Optical alignment is maintained by a linkage arm and yoke arrangement which is fully rotatable about a first axis, and which causes the controlled mirror to pivot through an angle one-half as much as the laser beam outlet tube 13 pivots about a second axis. The linkage arms may be replaced by a gear or friction wheel mechanism.