Repeat Step 1 To Step; Sub-Field Drive; Sustain Step 4; Sustain Step 5 - Panasonic TC-42P1 Service Manual

Sustain Step 4

Fig. M
When sustain pulse is stopped, Ions and Electrons are
remained again as Wall voltage. However polarity of wall volt-
age is reversed.

Sustain Step 5

Fig. N
Ions and Electrons which is generated by 2nd sustain dis-
charge are charged on the pixel wall (dielectric) around the
electrodes.

Repeat Step 1 to Step 5

To keep discharge continuously step 1 to 5 operation will be
repeated.
As the result sustain pulse is alternated. Therefore we call
this drive system AC Drive type.
If sustain operation is repeated longer, brightness level of
the pixel is increased. Therefore depend on sustain dis-
charge time brightness of pixel is controlled.

Sub-Field drive

Vs
Sub-Field drive is PDP unique system.
While one TV field period, 8 bits digital video signal compo-
nent is reproduced by 8 sub-fields operation.
Each Sub-Field's address period are all same.(Consist of
one initialization and 480 scanning operation.)
But Sustain period of each Sub-Field are different.
1st Sub-Field (SF) reproduce only 1 step brightness.
2nd SF reproduce 2 steps brightness.
Each sub-field's sustain period are increased gradually.
However total 256 brightness difference can be reproduced
on the screen.
- 6 -
Sustain Cycle
Sustain Pulse
AC Drive Type Plasma Display
Fig. O
1 TV Field
8 Sub Fields
1st 2nd 3nd 4th 5th 6th
1 2 4 8 16 32
Address Period
Fig. P
7th 8th
84 128
Sustain Period