How advantageous are flat panel displays ? Explain the functioning of LCD with suitable diagrams.

Advantages of flat panel displays are :-

• It consumes very low power.
• It has very thin display which occupies small volume.
• Cost is low.
• Used for long lifetime.
• Good reliability and brightness.

Functioning of LCD :-

• The principle behind the LCD is that when an electrical current is applied to the liquid crystal molecule, the molecule tends to untwist.

• This changes the angle of light which is passing through the molecule of the polarized glass and also cause a change in the angle of the top polarizing filter.

• As a result a little light is allowed to pass the polarized glass through a particular area of the LCD.

• Thus, that particular area will become dark compared to other.

• The LCD works on the principle of blocking light. While constructing the LCD, a reflected mirror is arranged at the back.

• An electrode plane is made of Indium Tin Oxide (ITO) which is kept on top and a polarized glass with a polarizing film added on the bottom of the device.

• The complete region of the LCD has to be enclosed by a common electrode and liquid crystal matter should be above it.

• When there is no current, the light passes through the front of the LCD that will be reflected by the mirror and bounced back.

• As the electrode is connected to a battery the current from it will cause the liquid crystals between the common plane electrode and the electrode shaped like a rectangle to untwist.

• Thus, the light is blocked from passing through and that particular rectangular area appears blank.