PDP basic

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threshold voltage for discharge, and consequently, during sustain phase only selected cells

ignite and emit light.

2.3

PDP driving sequence

The most common method of displaying one picture field is using the Address Display-

Separation method (ASD).

All X electrodes are bused together and connected to a sustain driver, while the Y

electrodes are connected to sustain driver through several scan ICs. One TV field is divided

into 10 subfields (SFs) in a 10-bit codification case, and each consists of a reset period, an

address period, and a display period (Figure 9).

On every subfield, each cell is addressed, sustained and erased.

Figure 9.

Subfield structure

During the reset period a slow ramping positive voltage up to 400 V followed by slow

ramping negative voltage down to -150 V is applied across the X and Y electrodes to put out

ionization and to set an identical initial condition for all the panel cells. In the address period,

the Y electrodes receive scan pulses, along with data pulses on the address electrodes, in

order to control wall charges in appropriate cells according to the image to be displayed.

Note that reset period and address period have the same duration in each subfield, only the

number of sustain pulses varies among different subfields.

During sustain period, selected cells are sustained in order to display the whole image on

the panel. Gray scales are expressed by using the binary-coded light-emission-period

method. The display periods are filled with trains of constant width and constant period

pulses, and their lengths are arranged according to the binary sequence, 1: 2: 4: 8: 16: 32:

expressed with an 10-bit sequence. This means that each color element has 1024 color

possible graduations and each pixel has 1024 x 1024 x 1024 = 1 billion colors. Figure 10

shows a simplified 8-bit system with 8 subfields. The subfields are weighted according to

their binary values and a typical TV field is 1/50 of a second.