Shadow Mask technique

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 1) Shadow Mask technique is used in Raster Scan Display and produces wide range of colour, which wasn't possible in Beam penetration technique.


2) Here on the screen we have 3 dots of each color which means one pixel has three value of color i.e RGB which can create many different shades of color.

3) So in this technique we have 3 electron gun's which are assigned for there respective color RGB and one more most important thing that is a grid just behind the screen which is known as "Shadow Mask Grid".

4) Shadow mask grid is pierced with small round holes in a triangular pattern.

5) The 3 electron beams are deflected and focused as a group onto the shadow mask, which contains a sequence of holes aligned with the phosphor- dot patterns.

6) There is one gun for each of 3 Color RGB.


7) when these three colors mixed together can create all the colors we see on the screen, but remember these gun don't shoot the bullets instead they shoot a powerful beam of electrons towards the face of monitor.


8) Special chemical phosphore are painted on the inside of the monitor, energy from the electrons beams makes the individual phosphore glow either red, blue or green depending on the type of phosphore.


9) The stronger the electron beam the brighter the phosphore glow.


10) A sheet of metal with holes in it helps to keep the electron beam aligned exactly with the phosphore this is called the Shadow Mask.




11) Let's see the Advantage and disadvantage of Shadow Mask technique.

A) Advantage

• Realistic image

• Million different colors to be generated

B) Disadvantage

• Relatively expensive compared with the monochrome CRT

• Relatively poor resolution

• Convergence Problem

*You can leave a comment if you have doubt in it.

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