With the help of the structures explain lcd, Electrical Engineering

Assignment Help:

Q. With the help of the structures explain LCD.

A liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. It is prized by engineers because it uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices.

Each pixel (picture element) consists of a column of liquid crystal molecules suspended between two transparent electrodes, and two polarizing filters, the axes of polarity of which are perpendicular to each other. Without the liquid crystals between them, light passing through one would be blocked by the other. The liquid crystal twists the polarization of light entering one filter to allow it to pass through the other.

The molecules of the liquid crystal have electric charges on them. By applying small electrical charges to transparent electrodes over each pixel or subpixel, the molecules are twisted by electrostatic forces. This changes the twist of the light passing through the molecules, and allows varying degrees of light to pass (or not pass) through the polarizing filters.

Before applying an electrical charge, the liquid crystal molecules are in a relaxed state. Charges on the molecules cause these molecules to align themselves in a helical structure, or twist (the "crystal"). In some LCDs, the electrode may have a chemical surface that seeds the crystal, so it crystallizes at the needed angle. Light passing through one filter is rotated as it passes through the liquid crystal, allowing it to pass through the second polarized filter. A small amount of light is absorbed by the polarizing filters, but otherwise the entire assembly is transparent.

When an electrical charge is applied to the electrodes, the molecules of the liquid crystal align themselves parallel to the electric field, thus limiting the rotation of entering light. If the liquid crystals are completely untwisted, light passing through them will be polarized perpendicular to the second filter, and thus be completely blocked. The pixel will appear unlit. By controlling the twist of the liquid crystals in each pixel, light can be allowed to pass though in varying amounts, correspondingly illuminating the pixel.


Related Discussions:- With the help of the structures explain lcd

What is photovoltaics?, Photovoltaics  is a high-technology approach  to ch...

Photovoltaics  is a high-technology approach  to changing sunlight  directly  into  electrical  energy.  The  electricity  is direct  current  and  can  be  used  that  way,  chnag

Write a note on the application of emitter-follower, Q. Write a note on the...

Q. Write a note on the application of emitter-follower? An emitter follower can serve as a buffer for a voltage source. The voltage divider at left is a poor voltage source bec

Efficiency Equations for AC Generators., Most ac generators used in Power S...

Most ac generators used in Power Stations are of the " Flux Cutting " types. Their effiencies range from less than 33% to slightly more than 60%. In their efficiency equations, the

Transistor, what is bias compensation

what is bias compensation

Conducting material, #question.classification of conducting material.

#question.classification of conducting material.

Indicate the condition of the overflow and carry bits, Q. Do the following ...

Q. Do the following operations with 8 bit bytes, and indicate the condition of the overflow and carry bits. a) 10111011 + 00000011 b) 11101101 + 11111001 c) 11011011 + 110

#titl4 bit binary addere.., Ask question #Madvantages of 4 bit binary adder...

Ask question #Madvantages of 4 bit binary adder inimum 100 words accepted#

What is threaded system, What is Threaded system. Threaded system: At...

What is Threaded system. Threaded system: At times we require implementing an operating system which can process multiple threads. Many threads are handled through the kernel

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd