Apparatus for detecting the oscillation amplitude of an oscillating object

摘要

Apparatus for detecting the oscillation amplitude of an oscillating object (3) includes an optical radiation source (9) and a detector (10) including first and second optical radiation sensing areas (24A, 24B) adjacent each other. The detector (10) and the optical radiation source (9) are adapted to be located opposite each other with the oscillating object (3) located between the source (9) and the detector (10) so that the object (3) blocks a portion of the sensing areas (24A, 24B) from receiving optical radiation from the source (9). A processor (18) coupled to the detector (10) receives first and second output signals representing the magnitude of optical radiation sensed by the first and second optical radiation sensing areas (24A, 24B), respectively. The processor (18) processes the first and second output signals to obtain an indication of the amplitude of oscillation of the object (3).