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
- It has three phosphorus color dots at each position of the pixel. First Dot: Red color. Second Dot: Green color. Third Dot: Blue color.
- It has three different guns. Each for one color.
- It has a metal screen or plate just before the phosphorus screen, named “Shadow-Mask.”
- 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. |