Cam integrated with a rotation sensor

摘要

A gear constructed of a monolithic material having a first reflectivity and having one or more projections is interlocked into a cam constructed of a monolithic material having a second reflectivity substantially different from the first reflectivity. The one or more projections are mated with corresponding one or more openings in the gear whereby such mating provides a torsional lock. A reflective sensor having a focal length corresponding to either a surface of the projections or a surface of the cam detects positions of the gear by transitions from reflective to non-reflective surfaces and vice versa. The detected transitions are used to provide feedback control to a motor driving the gear.