Black and white television
As a black and white television , even black and white television written is called the technically early form of television . In contrast to color television , only differences in brightness, which are perceived as gray values , are taken into account when recording and reproducing the images.
When color television was introduced - in Europe from the mid-1960s - attention was paid to upward and downward compatibility - black and white televisions should also be able to process the signals from color television and display them as gray values. The brightness signal was transmitted as before, the additional color information in a frequency range in which it hardly interfered with the picture. Conversely, the new color television sets should also be able to display conventional black and white broadcasts.
In terms of broadcast and recording technology, black and white television was quickly replaced by color television in Western Europe from the mid-1960s. But devices with black and white reception remained in use for a long time. Black-and-white devices were much cheaper in terms of purchase price, as they were set up much more simply, among other things, the complex electronics for obtaining the color information could be omitted. The picture tube only needed a single beam system instead of three. The devices were also more economical because the energy- absorbing shadow mask was no longer needed. The acceleration voltage was lower, so the shielding against the X-ray radiation that is inherent in the principle could be kept much easier. And no electronics were needed to bring the colors to convergence ( convergence ) and the magnetic coils required for this .
Black and white televisions continued to be made into the 1980s because they were valued by viewers as an inexpensive alternative or as a simple second device. Today they are mainly used for video surveillance .
Even today, the UK license fee for black and white TV is only about a third of the fee for color television. In 2013, 13,000 Brits were content with black and white television.
See also
Individual evidence
- ↑ Thousands of Brits still look into the black and white tube. Retrieved October 20, 2019 .