What is a CRT?
CRT is an acronym for cathode-ray tube. It is most familiar to us as what we call a picture tube in our television sets. A standard television set uses one CRT with a special mask inside that allows for small dots or lines of the colors red, green and blue to make up a color image. A 3-tube or 3-CRT projector uses 3 separate CRTs, one for each color. A basic CRT is comprised of a cathode-ray in the neck of the tube and a phosphor coated glass at the front of the tube. The cathode-ray shoots a beam of electrons which strikes the phosphors on the front glass causing them to emit visible light.
