How does a projector produce black?

Question

A TV uses black as the neutral colour, although a projector uses a white screen.

The only explanation anyone has come up wish is that the white screen is darker with no lights on - however, you are able to get projectors capable of working in a brightly lit room, so how do the pull that off?

Edit: Colours mixed produce white - not black! That is how a TV works.

Answer 1

Projectors with a single light source (DLP, etc.) use a color wheel. If you display equal amounts of Red/Green/Blue you get black.

The alternative is to block the light.

Answer 2

Hi. I'm no expert when it comes to projectors but i have learned a bit since using my own one. Well as black is absence of light the projector must block the light from the lamp for the black portions of the image to be seen. The projector cannot actually project "black."There is never total black on a white screen but from a distance it appears black next to very bright images .Our eyes perceive it as black.That is why it is best to buy a projector with a high contrast ratio which is the difference between the light and dark area of the images Some projectors achieve a contrast ratio of 10,000 to 1 which is very high and they achieve a very dark "black'
Those projectors that work in a bright room are usually data /slide projectors with very bright colors where black is not important.
Some Home Cinema projectors can work in a dimly lit room because of their high brightness level but the blacks will not be very good. The only way to achieve the correct balance is to watch in a totally dark room.
I hope i've explained it correctly for you.

Answer 3

if you mix all the colours you get black its science.