The fixed and rotatable mirrors are disposed such that a pattern of {TAIL ~ a comparatively large number} of {HEAD ~ relatively short scan lines} partly overlapping each other is created as seen on the window 
The fixed and rotatable mirrors are disposed such that a pattern of { TAIL ~ a comparatively large number } of { HEAD ~ relatively short scan lines } partly overlapping each other is created as seen on the window
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH