In order to improve the permeance and strengthen the magnetic flux density, there exists a method of narrowing the breadth of a magnet across the circumference of the roller from {HEAD ~ a distance} extending toward {TAIL ~ the center} thereof 
extending toward
In order to improve the permeance and strengthen the magnetic flux density , there exists a method of narrowing the breadth of a magnet across the circumference of the roller from { HEAD ~ a distance } extending toward { TAIL ~ the center } thereof
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH