an optical lens, wherein {HEAD ~ the image beam} emits to the optical lens and a part of {TAIL ~ the image beam} passes through the optical lens to form a first projecting beam, and a part of the image beam is reflected by the optical lens to form a second projecting beam 
an optical lens , wherein { HEAD ~ the image beam } emits to the optical lens and a part of { TAIL ~ the image beam } passes through the optical lens to form a first projecting beam , and a part of the image beam is reflected by the optical lens to form a second projecting beam
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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