Qn about Functions & difference between a LCD & CRT ???
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How CRT works
The terms anode and cathode are used in electronics as synonyms for positive and negative terminals. For example, you could refer to the positive terminal of a battery as the anode and the negative terminal as the cathode.
In a cathode ray tube, the "cathode" is a heated filament (not unlike the filament in a normal light bulb). The heated filament is in a vacuum created inside a glass "tube." The "ray" is a stream of electrons that naturally pour off a heated cathode into the vacuum.
Electrons are negative. The anode is positive, so it attracts the electrons pouring off the cathode. In a TV's cathode ray tube, the stream of electrons is focused by a focusing anode into a tight beam and then accelerated by an accelerating anode. This tight, high-speed beam of electrons flies through the vacuum in the tube and hits the flat screen at the other end of the tube. This screen is coated with phosphor, which glows when struck by the beam.
There is a cathode and a pair (or more) of anodes. There is the phosphor-coated screen. There is a conductive coating inside the tube to soak up the electrons that pile up at the screen-end of the tube. However, in the above diagram you can see no way to "steer" the beam -- the beam will always land in a tiny dot right in the center of the screen.
That's why, if you look inside any CRT, you will find that the tube is wrapped in coils of wires. The steering coils are simply copper windings. These coils are able to create magnetic fields inside the tube, and the electron beam responds to the fields. One set of coils creates a magnetic field that moves the electron beam vertically, while another set moves the beam horizontally. By controlling the voltages in the coils, you can position the electron beam at any point on the screen.
steering coils (copper colour) -
How LCD work
To create an LCD, you take two pieces of polarized glass. A special polymer that creates microscopic grooves in the surface is rubbed on the side of the glass that does not have the polarizing film on it. The grooves must be in the same direction as the polarizing film. You then add a coating of nematic liquid crystals to one of the filters. The grooves will cause the first layer of molecules to align with the filter's orientation. Then add the second piece of glass with the polarizing film at a right angle to the first piece. Each successive layer of TN molecules will gradually twist until the uppermost layer is at a 90-degree angle to the bottom, matching the polarized glass filters.
As light strikes the first filter, it is polarized. The molecules in each layer then guide the light they receive to the next layer. As the light passes through the liquid crystal layers, the molecules also change the light's plane of vibration to match their own angle. When the light reaches the far side of the liquid crystal substance, it vibrates at the same angle as the final layer of molecules. If the final layer is matched up with the second polarized glass filter, then the light will pass through. -
actually what i posted above is only a summary of the important points. there are more to it. if u ae interested to know more, click here:
how television work (include CRT)
http://stuffo.howstuffworks.com/tv.htm how LCD works
http://computer.howstuffworks.com/lcd.htm
as for the rest, don't be lazy, do your own research.
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so chim
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that's the way of life. we might not know how a thing works, but we know the reason for it to work.Originally posted by shinta:so chim -
So which is better...y? cheaper???
wad ur advice?? isit necessary?? -
both have their pros and cons. but i'll recommend LCD cos it's space saving, easy on the eye and saves electricity.Originally posted by progene:So which is better...y? cheaper???
wad ur advice?? isit necessary?? -
ohh...thanks alot Gordonator for the info.
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ok..thanks a lot gordonator....so can buy 1 LCD for me??Originally posted by Gordonator:both have their pros and cons. but i'll recommend LCD cos it's space saving, easy on the eye and saves electricity. 
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wait long long.Originally posted by progene:ok..thanks a lot gordonator....so can buy 1 LCD for me?? 
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Nvm, I can wait...Originally posted by Gordonator:wait long long.