LCX027AK
9. Method of Measuring the Optimum Vcom
There are two methods of measuring the optimum Vcom using the photoelectric element.
9-1. Method of Measuring Flicker
In the field invert drive mode, adjust the flicker level of the half tone (Vsig = 1.5 to 2.5V) using the
photoelectric element and oscilloscope so that its 30Hz component becomes minimum. The Vcom value
at this time is taken to be the optimum Vcom.
9-2. Method of Measuring Contrast
In the normal 1H invert drive mode, adjust the optical output voltage of the half tone (Vsig = 1.5 to 2.5V) so
that it becomes minimum. The Vcom value at this time is taken to be the optimum Vcom.
Example of Back Light Spectrum (Reference)
0.6
0.4
0.2
0
380
480
580
680
780
Wave length 380 – 780 [nm]
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