We recently discussed at length the shadow mask method in CRT monitors. At the beginning of that article, we mentioned that there are two common methods used to produce colors and images on monitors and screens; Beam Penetration and Shadow Mask. In this post, we will examine the difference between the two in depth, covering the colors produced, color dependency, number of electron guns used, picture quality, realistic view, resolution, cost, and applications for each. In this, different colors are coated on an inner surface on the screen in multiple layers; typically two layers of phosphorus, such as red and green are coated. This is a method used for displaying color pictures that has been used with random scan monitors.
This was one the earlier CRTs to produce color displays. Coating phosphors of different compounds can produce different colored pictures. But the basic problem of graphics is not to produce a picture of a predetermined color, but to produce color pictures, with the color characteristics chosen at run time. The basic principle behind colored displays is that combining the 3 basic colors —Red, Blue and Green, can produce every color.