Flicker-free

Flicker-free (or 100 Hz or 120 Hz, depending on country) is a term given to televisions that operate at a 100 or 120 hertz field rate to eliminate flicker, compared to standard televisions that operate at 50 Hz (PAL, SÉCAM systems) or 60 Hz (NTSC). Flicker-free technology noticeably improves viewing quality.

Flicker-free televisions are often labelled as being 100 or 120 Hz without using the words "flicker-free" in the description. Flicker-free technology is more common in countries using the 50-Hz PAL or SECAM systems, where flicker is perceived to be a more serious problem than at the 60-Hz field rate of NTSC. Flicker is far more noticeable on traditional cathode ray tube television sets than on LCD or plasma displays, which do not require the technology.

The technology involved in doubling the frame rate may consist simply of displaying the same broadcast image twice in rapid succession, or involve the generation of an interpolated image between the two broadcast frames to make motion appear more natural. The issue of interlacing in traditional TV broadcasting, in which one-half of the scan lines of each frame are broadcast at a time, can be addressed with progressive scan imaging that attempts to create a full picture from the two half images.

While flicker-free technology eliminates the problem of flicker, it can cause slight judder on fast moving images or blurring problems: fast scrolling text for example may blur.

See also

*Flicker (screen)
*Flicker fusion threshold

External links

* [http://www.research.philips.com/newscenter/dossier/naturalmotion/judder-free.html Philips Natural Motion Technology, a form of interpolation] .
* [http://www.research.philips.com/newscenter/dossier/naturalmotion/tvimages.html How television works] Page on Philips website, including information on flicker-free.