FLYING SPOT MICROSCOPY 



HORIZONTAL 

 SAWTOOTH 



VOLTAGE 

 COMPARATOR 



/^^ 



V 



VARIABLE 



WIDTH PULSE 



GENERATOR 



VERTICAL 

 SAWTOOTH 

 1-^ 



COINCIDENCE 

 CIRCUIT 



VOLTAGE 

 COMPARATOR 



VARIABLE 



WIDTH PULSE 



GENERATOR 



.JUIJI- 



^U-V EMITTING 

 SCANNER TUBE 



Fig. 3. Spot-irradiation technique. 



COINCIDENCE 

 CIRCUIT 



< 



uu^ 



c 



COMPOSITE IN 

 SPECIMEN PLANE 



BEAM 

 SPLITTER I 



<l> 



<> 

 REFLECTING 

 MICROSCOPE 



DISPLAYED IMAGE 

 ON MONITOR TUBE 



Fig. 4. Double scanner tube arrangement. 



and a subsequent loss of information. There 

 was also the possibiHty that the background 

 radiation would cause biological damage to 

 the cells in the field which were to be used 

 as controls. 



These difficulties were overcome by apply - 



to the visible light tube a pulse of opposite 

 polarity to that applied to the ultraviolet 

 tube. The two rasters were brought into 

 optical registration. This allowed the ultra- 

 violet background to be at zero level and the 

 background to be filled in with visible light 



336 



