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Technology: Behind the screen

September 14, 2013

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WHILE watching cartoons or movies on your television set, have you ever wondered how a television screen works?

The conventional box-shaped television sets in our homes are made of cathode rays tubes. However, with the passage of time, the shape of TV sets changed and today flat screen televisions are a common sight at home and in offices. They are sleek in shape and attractive in design.

These flat screen televisions consist of a plasma display panel (PDP) which creates high definition images. Therefore, LCD televisions produce brighter and sharper pictures as compared to conventional televisions. The difference in picture quality is because of the way LCD display and a cathode ray tube generates pictures. A normal television creates pictures by reflecting an electron beam on a fluorescent screen while an LCD TV uses pixels.

The term ‘plasma’ comes from the technology that utilises small cells containing electrically charged ionised gases. Various forms of displays are part of the flat panel display technology. These panels are lighter and much thinner than traditional television sets. Apart from producing sharper images, they do not strain the eye. Since the flat panel TV sets are thin, people normally mount them on the wall or if placed on a table, they take less space.

The history of a flat panel display isn’t that old as it was in 1964 when the first such panel was invented. A major feature of the flat panel display is the backlit, which illuminates the LCD screens. The backlit provides light to the LCD screen’s interior since the LCD panel doesn’t have a light of its own. That is why a backlit produces smooth and crisp images on an LCD TV.

LCD panels are more popular than conventional televisions because they generate low heat, display brighter pictures and do not generate ghost images on the screen. Ghost images refer to the shadow of the image that remains on the screen for some seconds and it occurs during switching between channels. This is the reason why LCD TVs are becoming popular.

With the advancements in screen displays, LED (light-emitting diode) displays took the innovation to a new level. Where LCD panels use fluorescent lights, LED, on the other hand, are composed of thousands of tiny bulbs that form a layer that emits light.

There are two types of LED panels, conventional and self-mounted. Furthermore, LCD and LED display screens enjoy benefits over conventional cathode ray televisions because they have a greater viewing angle. Viewing angle refers to the maximum angle at which we can view images on a screen. Have you noticed that no matter from which angle you see the LCD/LED display, you can still watch the image. However, in conventional TV sets you have to sit in a straight line to view the images.

The television has come a long way from the large box that displayed only black and white images and worked without a remote control. Don’t you think you are lucky to be born in the era of LEDs and 3-D TVs?