I have a digital voltmeter using the ICL7106 chip and the FE0203 LCD display. It has not been used for many years. It is still working but some useless segments on the LCD display are always visible. Especially the first and second dots and the colon at the center of the display. Since those segments are not used by the voltmeter, they are not connected at all. When I clean between the LCD pins on the glass, those segments get invisible for a short time. They get soon visible again probably because of humidity.
I have searched the web to know where should not used pins of such LCD display be connected to. But no luck. Nothing is said in the datasheet regarding this problem.
My aim is to make those unused segments always invisible. I think there should be a standard way to connect them. When I connect them to the backplane pin of the display, they get totally invisible. Is it a proper way to connect them?
Thanks for your help.
Best Answer
The LCD driver connects 'off' segments to the backplane, and 'on' segments to a voltage in anti-phase to the backplane.
Connecting unused segments to the backplane is the correct way to keep them invisible, minimise current consumption, and keep them safe against degradation should you ever want to use them again.