A user navigational apparatus. The user navigational apparatus includes a
code wheel and an encoder. The code wheel is coupled to a dial. The code
wheel includes a track of alternating reflective and non-reflective
sections. The optical reflective encoder includes an emitter and a
detector. The emitter generates a light signal incident on the track of
the code wheel. The detector detects a reflected light signal. The
reflected light signal corresponds to a portion of the incident light
signal that is reflected off of the reflective sections of the track. The
detector also generates a channel signal corresponding to the reflected
light signal. Embodiments of this type of user navigational apparatus
achieve reduced thickness compared to conventional implementations of jog
wheels.