100Hz and 200Hz Televisions ?

Introduction to 50hz televisions

A regular PAL television changes the picture at a frequency of 50 Frames Per Second (FPS) or 50Hz. The illusion of movement in the picture is produced by the successive frame changes of the picture 50 times per Second. A 50 FPS (50Hz) Cathode Ray Television (CRT) creates the picture with an electron scan and there is a visible flicker that is sensed by the human eye.

Our eyes are at times are sensitive to this frequency depending on the speed of the image, the level of darkness, and the level of brightness so you will sometimes notice the picture flicker on a 50Hz TV. Also the larger the screen is the more noticeable the flicker is.

How 100 hertz used to work

A 100 hz TV operates at twice the Frames Per Second (100FPS) by producing a replica of every frame and inserting it after the previous one. The result of this doubling of the scan frequency to 100Hz and inserting a copy frame is that this problem was eliminated as far as the eye perceived it. The result of this is to significantly lower the flicker.

100hz on LCD and Plasma tv’s

LCD and Plasma televisions dont produce flickering because they don’t produce the picture with an electron scan. However LCD TV’s still benefit from 100Hz because advanced digital circuitry creates an extra frame or middle image. This is done by the TV inventing an extra frame using complex interpolation and motion compensation calculations to work out what the extra fields and frames look like rather than inserting a replica frame. (e.g. the second frame is not the same as the first frame).

However even at 100 FPS the picture still does not deliver a entirely smooth picture particularly with fast motion images. Some television manufactures attempt to reduce this further by employing digital picture processing. Typically there is still a little blurring on quick moving images but the benefits are clearer and better-defined surfaces, sharper pictures, and smoother movement than is possible from 50 Frames Per Second Plasma and LCD televisions.

e.g. For a football that travels ten pixels from left to right between frames one, two and three, the 100 hertz TV will digitally create two further frames between one and two, and two and three, between which the ball will move five pixels. This will result in five frames where the football moves a total of ten pixels i.e. the original frames one, two and three plus the digitally created frames inserted between one and two, and in between two and three. The result of this is that the eye sees an image that moves smoother than before.

100hz improves the picture

100Hz televisions have the clear benefit of eliminating a lot of the ghosting effects occasionally seen in LCD TVs. Ghosting effects caused by the next image being shown before the earlier one has faded away. Even on Plasma tv the creation of the middle frame results in a more fluid picture

Most leading manufactures have now got 100Hz LCD and Plasma televisions including Panasonic, JVC, Samsung, Toshiba, Sony, Philips, LG, Pioneer, and Hitachi.

Sony lead the way into 200Hz

A new series of 200 hertz televisions have been launched by Sony which digitally inserts three additional frames between the original 50 hertz frames. Thus fast moving sequences are delivered with a smoother, more fluid and sharper picture than 50Hz or even 100 hertz TV’s.

Additional benefit for photosensitive epilepsy sufferers

Scientific studies have proven that for patients with photosensitive epilepsies 100Hz televisions can help prevent seizures when playing video games or watching Tv.