Difference between Beam Penetration and Shadow Mask method

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Beam Penetration Method

Beam–Penetration Method: It is used with a random scan monitor for displaying pictures. There are two phosphorus layers- Red and Green are coated inside the screen. The color shown depends on how far the electron beam penetrates the phosphorus surface.

A powerful electron beam penetrates the CRT, it passes through the red layer and excites the green layer within. A beam with slow electrons excites only the red layer.

A beam with the medium speed of electrons, a mixture of red and green light is emitted to display two more colors- orange and yellow.

Also Read: Difference Between OLED And QLED

Shadow Mask Method

Shadow–Mask Method is used with a raster scan monitor for displaying pictures. It has more range of color than the beam penetration method. It is used in television sets and monitors.

A Shadow Mask is a metal plate with tiny holes present inside a color monitor. A Shadow Mask directs the beam by consuming the electrons so that the beam hits only the desired point and displays a resulting picture.

It has three different guns. These guns direct their beams to shadow mask, which allows them to pass. It is a task of a shadow mask to direct the beam on its particular dot on the screen and produce a picture on the screen. A Shadow Mask can display a wider range of pictures than beam penetration.

Structure

  1. It has three phosphorus color dots at each position of the pixel. First Dot: Red color. Second Dot: Green color. Third Dot: Blue color.
  2. It has three different guns. Each for one color.
  3. It has a metal screen or plate just before the phosphorus screen, named “Shadow-Mask.”
  4. It also has a shadow grid just behind the phosphorus coated screen with tiny holes in a triangular shape.

Also Read: Difference Between CRT And LCD Monitors

Beam Penetration vs Shadow Mask Method

BASIS OF COMPARISON BEAM PENETRATION SHADOW MASK
Application It is used with Random Scan System to display color. It is used with Raster scan system to display color.
Colors It can display only four colors i.e Red, Green, Orange and Yellow. It can display millions of colors because it depends upon the intensity value of three available guns.
Resolution It gives high resolution.   It gives low resolution.
Color Dependency Less colors are available because the colors in Beam Penetration depends on the speed of the electron beam. Millions of colors are available because the colors in Shadow Mask depends on the type of the ray.
Picture Quality Quality of the picture is not so good i.e poor with Beam Penetration Method. Shadow Mask gives realism in picture with shadow effect and millions of color.
Color Display. In Beam Penetration method, color display depends on how far electron excites outer Red layer and then Green layer. In Shadow Mask Method, there are no such criteria for producing colors.
Cost It is less expensive as compared to shadow mask. It is more expensive than other methods.
Realistic View This method is not suitable for providing the realistic view. This method is suitable for providing the realistic view.
Electron Guns In this method, only one electron gun is used. In this method, three electron guns are used.