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Fig. E

42 inch plasma display panel has 1,226,880 pixels. 
Each pixels structure is shown fig. E.

Fig. F

Brightness control of plasma display panel is carried out by
plasma discharge time change. To control each pixel’s
brightness  Sub-field drive system is used.
A sub-field is consist of Initialize,  Write and sustain opera-
tion.

Fig. G

To clear any remaining electric charge into the pixel, trape-
zoid voltage is applied between the scan and sustain elec-
trodes.
Plasma discharge is started but the discharge become small
gradually.
Then any electric charge  is cleared.

Fig. H

Data Pulse which is positive polarity is input to data electrode
and Scan pulse which is negative polarity is input to scan
electrode simultaneously.
That means sum of data and scan pulses voltage is applied
between two electrodes as discharge start voltage.
Discharge is started into the pixel and gas is ionized.
During discharging Ion is charged on the scan electrode side
and electron is charged on data electrode side.

Scan Electrode

Sustain Electrode

Xenon

+

Neon

Data Electrode

Colour Phosphor

Rib

Rib

Dielectrics

Rear Glass

Front Glass

Aluminum
Base

Address
Period

Sustain
Period

Sub Field

Initialize

Write

Sustain

VI

+++

l  l  l

+  

Ions

-

 

Electrons

Data Pulse

Scan Pulse

|   |   |   |   |

+++++

|   |   |   |   |

+++++

& 

- 10 -

Fig. I

when input pulses are stopped, Ions and Electrons which are
charged on the dielectric around the electrodes are
remained.
This charge is called Wall Voltage (Pilot voltage).
This operation is called Write.

Fig. J

Negative polarity’s Sustain pulse is input between sustain
and scan electrodes and voltage potential between two elec-
trodes becomes sum of Sustain pulse and wall voltage.
Then discharge start.

Fig. K

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

Fig. L

Positive polarity’s Sustain pulse is input between sustain and
scan electrodes and discharge start again.

++++

Vw

|   |   |   |

++++

+++

|   |   |   |

|   |   |

Vs

Vs + Vw

+++

|   |   |

+++

|   |   |

+++

|   |   |

Vs

Vs + Vw

' 

- 11 -

Fig. M

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

Fig. N

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

Fig. O

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.

Fig. P

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.

+++

|   |   |

+++

|   |   |

+++

|   |   |

Vs

Sustain Cycle   

AC Drive Type Plasma Display

Sustain Pulse

Address Period

8 Sub Fields

1 TV Field 

1

2

4

8

16

32

84

128

=

1st 2nd 3nd 4th

5th

6th

7th

8th

Sustain Period

 

- 12 -

Fig. Q

The sustain period of sub-field drive system. Therefore
brightness peak is limited. Because 480 horizontal lines
scanning is carried out during address period. 
Dual scan system can reduce scanning time from 480 to 240
in the address period.
Then spaced time by dual scanning can be used for sustain
operation.
As the result Brightness peak level can be increased.

Fig. R

Panasonic plasma AI control sub-field drive operation which
is called Multi-Sprit Sub-Field drive control system.
Depend on the picture contents (APL: Average Picture
Level) number of sub-field are changed from 10 to 12. (Vari-
able Sub-field)
Sustain time format of each sub-field are also rearranged
from binary format to linear cording sustain time. (Linear cod-
ing sub-field)

Plasma AI select the best display condition for Plasma dis-
play panel to display natural and crisp picture.

240

240

480

852

Multi Sprit Sub-Field Drive System

1. Linear coding Sub-Field

2. Variable Sub-Field

+

•Increase Peak Brightness in Dark scenes
•Reduce Motion Picture Disturbance
•Keep Reasonable Power Consumption