Introduction
A standard PAL television will refresh the picture 50 Frames Per Second (FPS).The Frames Per Second (FPS) are the quantity of frames required to create the illusion of motion. The human eye is often aware of this frequency depending on the speed of the image, the level of darkness, and the degree of brightness so you will sometimes notice the picture flicker on a 50Hz Television. Moreover the bigger the screen is the more noticeable the flicker is.
A 100hz (100 FPS) TV operates at double the Frames Per Second by creating a replica of every frame and putting it after the previous one. On a 50Hz Cathode Ray Television (CRT) since the picture was created by an electron scan there was a visible flicker that is seen by the eye. As a result of doubling the scan frequency to 100FPS and inserting a copy frame this effect was eliminated as far as the eye perceives it. The effect of this is to significantly lessen the flicker.
The benefits for LCD & Plasma televiosns
LCD and Plasma televisions dont produce flickering because they dont create the picture with a scan. However LCD TVs still benefit from 100Hz because sophisticated digital circuitry creates an further frame or middle image. This is done by the TV inventing an further frame using complicated interpolation and motion compensation calculations to calculate what the addition fields and frames look like rather than inserting a copy frame. (e.g. the first frame is not the same as the second).
Nonetheless even at 100 herz the picture still does not create a entirely smooth picture especially with fast motion images. A number of TV producers attempt to further reduce this by employing digital picture processing. Typically there is still some blurring on rapidly moving images but the benefits are sharper pictures, clearer and better defined surfaces, and smoother movement than you get from 50 hertz LCDand Plasmascreens.
For example if a football moves ten pixels from right to left between frames one, two and three, the 100 hertz television will digitally produce two additional frames between one and two, and two and three, in which the ball will move five pixels. This results in a total of five frames in which the football moves a total of ten pixels i.e. the initial frames one, two and three plus the digitally created frames inserted in between one and two, and between two and three. The consequence of this is that the human eye sees an image that moves more smoothly than before.
100Hz TVs have a clear benefit of eliminating the majority ghosting effects occasionally seen in LCD TVs. The ghosting artifact caused by the next image being displayed before the preceding one has faded away.
200 Hz Television
Sony has just launched a 200 hertz range that digitally inserts three further frames between the original 50Hz frames. Thus fast moving scenes are delivered with a smoother, more fluid and sharper picture than 50 hertz or even 100 hertz TV's.
Most leading manufacturers have now got 100Hz Plasma and LCD televisions including Panasonic, JVC, Toshiba, Samsung, Sony, Philips, LG,Hitachi and Pioneer .
Benefits to photosensitive epilepsy suffers
Studies have shown that 100 hertz Tv's can assist in preventing seizures in people who suffer with photosensitive epilepsies when watching TV or playing computer games.
Fri Oct 07, 2011 3:47 pm
