HD66781 Datasheet, PDF (174/196 Pages) Renesas Technology Corp – 720-channel Source Driver for a-Si TFT/Low Temperature Poly-Si TFT Panels with 262,144-color display RAM

HD66781
Preliminary
n-raster-row Inversion alternating Drive
The HD66781, in addition to LCD inversion alternating drive by frame, supports n-raster-row inversion
alternating drive where alternation occurs by n raster-rows, where n takes a number from 1 to 64. The n-
raster-row inversion alternating drive enables to overcome the problems related to display quality.
In determining n (the value set by the NW bit +1), the number of raster-rows by which alternation occurs,
check the display quality on the actual liquid crystal panel. Setting a small number of raster-rows will raise
the alternating frequency of the liquid crystal and increase the charge/discharge current on the liquid crystal
cells.
Frame alternating drive
-320 raster-rows
1 frame
1 frame
Back
porch
1234
Front porch Back
porch
321 322
336 1 2 3 4
Front porch
321 322
336
N-raster-row alternating drive
-320 raster-row drive
-3 raster-row inversion
-EOR = 1
n-raster-row alternating drive
Note 1) Make sure to set EOR = 1 to avoid direct bias on liquid crystal during n-raster-row alternating drive.
Rev.0.5, July.31.2003, page 174 of 196