The fixed and rotatable mirrors are disposed such that {TAIL ~ a pattern} of 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 { TAIL ~ a pattern } of 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 TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH