REEL BASE ROTATION DETECTOR

摘要

PURPOSE:To provide a reel base rotation detector capable of reducing the number of parts and costs in a reel base rotation detector used for a video tape recorder, etc. CONSTITUTION:Real gears 3 and 4 meshed with reel bases 1 and 2 in supplying and winding sides change cyclically a light quantity from a light emitting element 5 to first and second light receiving elements 6 and 7 respectively. The light emitting element 5 and the first and second light receiving elements 6 and 7 are made integral by means of resin-molding, position-restricted by the respective rotational center axes of the reel gears 3 and 4 and by means of one light emitting element 5 and two light receiving elements 6 and 7 rotations of the reel bases 1 and 2 in the supplying and winding sides are detected.