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You are here: Home > Step 2 - Types of TV Screens |
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Step 2 - Types of TV Screens
The television screen that you finally choose will determine the quality of your viewing experience.
It is therefore important that you familiar yourself with the different picture tubes and flat panels that are available in the market. Summarised below is the latest information regarding the different kinds of picture tubes and flat screen panels that are currently in the marketplace.
Plasma Screens
Plasma television screens are being replaced by LED and OLED screens due to new technology advances. Plasma screens work very well under most ambient light conditions because the screen pictures are created by thousands of gas cells emitting ultraviolet light. This means that very bright light does not wash out the image on the screen. The beauty of these flat screens is that, unlike front view projection screens, you don't have to turn off the lights to see the image clearly and easily which make them excellent for watching DVD's and high definition television programmes. Another characteristic of a plasma panel is the extreme viewing angles both vertically and horizontally. With 160 degrees viewing angle, people sitting off to the side of the plasma screen will still be able to see the image.
LCD screens
Liquid Crystel Display (LCD) television screens are significantly brighter than most traditional picture tube sets and offer higher picture contrast with no picture flicker. This means that LCD TVs perform well under most ambient light conditions as well as viewing in a well lit room. High quality LCD screens also allow viewing up to 80 degrees from the centre of the display. The picture quality of a LCD screen is determined by how close the colour and sub-colour pixels are to each other (called dot pitch). When choosing a LCD screen it is important to remember that the higher the dot pitch then the sharper and more realistic the picture will be.
LED screens
LED televisions screens employ standard LCD technology but have one citical difference in that they have a larger number of tiny LEDs that replace the backlight lamps which traditionally illuminate the LCD screen. This enables LED TVs to be much slimmer than their LCD counterparts. There are 2 types of LED formats. One is Edge Lit which as the name suggest only features LEDs around the edge of the television. This technology can produce a very slim TVs. The second type is Back Lit where the LEDs cover the entire rear of the screen. These models are less thin than Edge Lit. Both technologies vary the backlight in different parts of the screen to give darker, richer blacks and brighter whites where needed.
OLED screens
Organic Light Emitting Diodes (OLED) television screens can give you very bright picture quality, with deep blacks, vibrant colours and smooth motion whilst being slimmer than even LED-backlit LCD TVs. OLED technology has organic cells sitting behind the TV’s panel that create their own light source so that light doesn’t spread into unwanted areas, helping to create a more vibrant picture. This technology is currently quite expensive compared to LED and Plasma screens.
3D Screens
3D TVs are capable of viewing both 3D and 2D video content as they use the same electronic video processing systems to display the images. To view 3D content however requires a set of 3D glasses that are specially designed to create the 3D effect when watching a 3D video signal. Full HD 3D requires the panel to refresh twice as fast as a regular Full HD TV. Currently the image processing technology in Plasma TVs is best suited to cope with the required screen image refresh rates (500Hz to 600Hz typically). This helps to shorten the panel's illumination time and raises the image intensity simultaneously to produce bright and crisp 3D images. Blurry doubles images are removed by reducing the afterimage time (typically down by two thirds) to create smooth, sweeping motion. Super-high contrast levels found on a 3D TV help to deliver very deep blacks. This allows the eye to distinguish the different depth planes of the picture and is essential for an immersive 3D experience.
4K Screens
4K TVs feature an ultra HD TV picture that consists of 3,840 x 2,160 pixels. This is more than a total of 8 million pixels, which is four times the number of pixels than a 'normal' high-definition pictue of 1,920 x 1,080 pixels. UHD technology utilises smaller pixels when compared to HD screens of the same size. This means you'll see a more detailed picture when sitting up close than you would with the HD equivalent. 4K screens are the future of tv broadcasting and downstreaming once media providers have found a way to efficiently deliver the data required through suitable compression technology.
Rear Projection Screens
Rear projection televisions have very large screens, however they are generally lighter and slimmer than traditional cathode ray tube televisions. They work on the principle of a projector inside the television that transmits the picture by bouncing it off thousands of tiny mirrors. The market is now split between Liquid Crystal Display (LCD), Digital Light Processing (DLP) and Liquid Crystal on Silicon (LCOS) units with specific brands now focusing on individual technologies. These television units can now provide excellent picture quality in both fully lit and darkened rooms.
Flat Picture Tubes
Flat picture tubes are now no longer being made by leading brands due to the advances in technology of other television screen technologies.
The Picture Frequency
Picture frequency (or picture flicker) of 100Hz is good for moving objects. Ordinary televisions flicker at 50 Hz, which is sufficiently high for most people not to notice. Screen flicker is barely obvious when the TV is viewed from the front, but when viewed at an angle it becomes noticeable. 100 Hz screens eliminate the flicker effect making viewing a more pleasurable experience - but this does come at a higher price.
Please note that many manufacturers have have developed their own brand names for specific screen technologies, which is why you may find different names amongst similar television models.
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