What is the difference between crt and lcd

In computer or in a television set, images and color are produced by shooting and controlling the electrons beams representing each additive color light red, blue and green using the video signal as the reference.

The brightness, color and persistence of the illumination can be varied using different kinds of phosphor. So, in order to sustain an electrical equilibrium, the secondary emitted electrons must be collected which is done by aquadag.

In LCD liquid crystal is utilized in order to generate a definite image on the screen. Liquid crystal is basically termed as the fourth state of matter. It permits the display to be very thin and thus supports numerous applications. Among different liquid crystals, we prefer a nematic type liquid crystal display that is twisted at an angle of 90 degrees. When we talk about LCD then its principle of working is such that light energy is not produced by LCD, despite light energy generated by an external source is controlled in order to have light or dark appearance at some particular areas.

Here, a layer of liquid crystal is placed between 2 polarizing films. When light emitted by an external source falls on the layer of liquid crystal then their combination generates a coloured visible image that is displayed on the screen.

A backlight present at the back end of the screen emits light that after passing through the polarizing film gets polarized. The light can be horizontally or vertically polarized that rely on the type of polarization filter.

To be safe, all high-quality CRT monitors comply with a set of standards that defines acceptable levels of EMR for a monitor. An LCD monitor is a desktop monitor that uses a liquid crystal display to produce images.

LCD monitors have a small footprint; that is, they do not take up much desk space. LCD monitors are available in a variety of sizes, with the more common being 19, 20, 22, 24, 26, 27, and 30 inches — some are 45 or 65 inches.

Most are widescreen, which are wider than they are tall. You measure a monitor the same way you measure a television, that is, diagonally from one corner to the other.

To understand the complete working of LCD, we need to look at its internal structure. The back lights are generated at the bottom of the computer monitor. Then at the above side, there exists an element with several layers. Because of that element and its several layers, the light is evenly spread over the whole LCD and it starts glowing.

The secret however is the glass panel at the top of that element. That glass panel has two layers that are aligned perpendicular to each other. The light passes vertically through that panel. Glass panel layers cannot align the direction of light. Therefore a crystal liquid is present between the two layers of glass panel. That liquid makes it sure to let the light pass only vertically when it reaches the screen.

Those colors are red, green and blue. These are primary colors while the rest of all the colors are made by combining these three colors. This is how the LCD works to display pictures on the screen. Complete internal structure is described in pictorial form in the picture shown below:. Concluding the difference of the two types of screen, we can say that LCD screens perform better than CRT monitors for displaying images on screens.

LCDs are lightly weighted and thinner and it is easy to move LCD monitors because of their less weight.