What is Beam penetration method

Question

Describe what is meant by the Beam penetration method?

Answer 1

Beam penetration technique is utilized in the random scan display systems. Two layers of phosphor: red and green are coated on the inside of CRT screen, the colors which are displayed depends upon how far the electron beam pierces into the phosphors layers. A slow electron beam only excites the outer red layer. A very fast electron beam pierces trench the red layer and hence, excites the green layer. An average electron beam provides the combination of red and green color i.e, yellow and orange. This technique only gives four colors.