Monochrome

For the first 50 years of television, the most common television sets in people’s homes were black and white sets. This was because black and white was the technology standard of the day, while colour sets were unreliable at best. During the 1940s and 1950s, even if one could afford a colour television, it was disheartening to turn it on and realize that most broadcasts were black and white transmissions only.

This is not the case today. In the age of High Definition Television (like Sony HDTV) and digital broadcasting, black and white television screens have been relegated to mostly cheap security video monitors and camping televisions.

There may always be a market for black and white or monochrome television technology simply because it is so easy use (by television standards, at any rate).

The CRT in a monochrome television is pretty much the same as a colour television, but with a few important exceptions. Where the phosphors of a colour set are bunched in groups of blue, green, and red, the phosphors in a monochrome set are all white. That means that when an electron beam is directed at them they give off white light. To get black, the phosphors are simply switched off.

This balance of white phosphors and black ones are able to create the many soft “greys” of a monochrome set. By manipulating the amount of light the white phosphors give off and which phosphors are turned off, a monochrome CRT can reproduce a perfect black and white version of any image.