Plasma Display Panel: Basic Notes

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A plasma display panel (PDP) is a type of flat panel display. Its functioning is based on small cells containing electrically charged ionized gases, which are plasmas.

1. Structure 

In the figrue 1 is shown the layout of a PDP.

Figure 1: PDP Layout

A PDP is constituted of two parts : the front substratum ( from spectator side ) and the rear substratum.
The two parts, once connected ,will make a PDP : between them there is a gap of 150-200 µ.
The front substratum is constituted from:
1. Glass panel ( PD200 material )
2. Transparent electrodes (horizontally disposed )
3. Conductive electrodes ( generally silver paste made )
4. Dielectric layer
5. MgO protective layer ( magnesium oxide )

The rear substratum is constituted from:
1. Phosphorous
2. Barrier ribs
3. Dielectric layer
4. Addressing electrodes ( vertically disposed )
5. Glass panel

2. Operating principles

In a PDP the visible light is produced from the phosphorous that have been excited from the ultraviolet ( UV ) radiation. The UV radiation is generated from a gas that is between the two substratum ( front and rear ). The gas is excited from a local electrical field. The electrical field is produced from a voltage that is applied between the conductive electrodes and the addressing electrodes : they are each other disposed perpendicularly and they constitute the addressing grid.
The gas is a mixture of Neon and Xenon: once it is excited, part of it changes in plasma ( mixture of electrons and ions ), part of it moves to a higher status of energy.
The plasma allows the current flow between conductive electrodes and addressing electrodes ( gas discharge ). The gas part that has moved to a higher status of energy , coming back to the initial status, emits UV radiation. The phosphorous, hit from the UV radiation, emits visible light. There are three phosphorous – Red, Green, Blue – and every pixel is constituted from three sub-pixel, one per colour. The image is got addressing every sub-pixel that is associated to a junction of the addressing grid. The luminous intensity of the emission is controlled changing the number of discharges in the time unit.

Based on text written by arag61

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