| 摘要 |
Apparatus for optical measurement of movement of an object, including means adapted to transmit light onto the surface of the object and means adapted to receive light reflected by the surface and arranged to produce an electric signal corresponding to light received from each of a number of mutually spaced light-receiving elements, and a signal processing circuit (5) incorporating a correlator (6) for determining the relative time shift of the two electric signals, this time shift constituting a measurement of the velocity of the object. According to the invention the aforementioned means comprises a sensor having solely one waveguide (9) adapted to transmit light, this waveguide being positioned symmetrically between two waveguides (10, 11) adapted to receive light thus transmitted and reflected by the surface of the object, the centres of respective light-emitting and light-receiving apertures of the three waveguides (9, 10, 11) being placed along a line. |
