{HEAD ~ A method} for detecting {TAIL ~ the speed} of a sledge motor in an optical storage device 
for detecting
{ HEAD ~ A method } for detecting { TAIL ~ the speed } of a sledge motor in an optical storage device
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH