CHAPTER  1
BASIC DISPLAY DEVICES AND SYSTEMS
INTRODUCTION
Data   display   devices   are   those   digital   equipments   designed   to   project,   show,
exhibit;  or  display  soft-copy  information.  The  information  displayed  can  be  alpha-
numeric,  graphic,  or  a  combination  of  both  formats.  Some  display  devices  are
limited   incapability   to   just   alphanumeric   display.
Display  devices  provide  an  interface  between  the  human  operator  and  the  digital
computer  system  (the  man-machine  interface).  They  allow  the  operator  to  view
computer  data,  make  decisions  and  modify  the  data,  enter  new  data,  and  enter
commands   to   be   processed.
Data  entry  is  accomplished  in  a  variety  of  ways.
Personal  computers  and  data  terminal  sets  usually  have  a  keyboard  for  entry  and  may
have  a  mouse,  pointer,  or  touch-sensitive  screen.  The  display  systems  used  in  the
Navy  use  a  ball  tab  that  is  moved  around  the  screen  with  a  trackball.
Information  displayed  on  the  display  device  is  not  permanent.  That  is  where  the
term  soft-copy  comes  from.  The  information  is  available  for  viewing  by  the  operator
only as long as it is on the screen of the display. Most display devices use some type
of  cathode-ray  tube  (CRT)  as  the  display  medium;  although  other  types  of  displays,
such  as  liquid  crystal  display  (LCD),  are  common  in  laptop  personal  computers.
After  completing  this  chapter  you  should  be  able  to:
Describe  the  operation  of  a  cathode-ray  tube  (CRT).
Describe  the  operation  of   electromagnetic   and  electrostatic   deflection
systems  used  in  CRTs.
Describe   the   operation   of   interlaced   scan,   noninterlaced   scan,  a n d
radar-scan   methods  used  to  display  images  on  a  CRT.
Describe  the  function  and  characteristics  of  the  Data  Display  Group
AN/UYA-4(V)   and   the   Computer   Display   Set   AN/UYQ-21(V).
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