The light source for exposure emits light in accordance with the pulse width of the respective pulses of {HEAD ~ the pulse width modulating signal} outputted by the pulse width modulating signal output device provided at {TAIL ~ the pulse width modulating device} 
The light source for exposure emits light in accordance with the pulse width of the respective pulses of { HEAD ~ the pulse width modulating signal } outputted by the pulse width modulating signal output device provided at { TAIL ~ the pulse width modulating device }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL