Then, an original light image is exposed to {HEAD ~ the thus charged surface} of {TAIL ~ the drum} 1 through an exposure system 4 thereby forming an electrostatic latent image 
of
Then , an original light image is exposed to { HEAD ~ the thus charged surface } of { TAIL ~ the drum } 1 through an exposure system 4 thereby forming an electrostatic latent image
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH