How do I blank my computer screen?

I want to turn my computer screen black, but still have information of what would be there coming out of the mini dvi port. My situation is, my parents want to watch a tv show, but the latest season isn't on dvd yet. I can wirelessly beam the downloaded episode to their tv down the hall, but the movie still plays on the computer screen. I want to be able to make the screen go blank so they can watch the movie when I'm asleep. (I'm in the same room as the computer)

Is there some piece of software that will do this? Or will simply turning the display off work? My computer is an iMac, so I can't just unplug the monitor.

Thanks in advance!

Open System Preferences, select Power and then set the screen to go blank after one minute. Leave the screen untouched for a minute and it goes black.

I do this regularly when I have to leave the machine on all night.

Nighthawk4 said:

Open System Preferences, select Power and then set the screen to go blank after one minute. Leave the screen untouched for a minute and it goes black.

Click to expand...

I don't see Power. Do you mean Energy Saver? In that option I see a computer sleep and display sleep slider. Is the display sleep what you are talking about? I am running Snow Leopard.

I tried the display sleep slider, and the output is black too, until I walk over and shack the mouse.

That's what is suppose to happen. It's saving energy when you aren't using it.

If the power off thing isn't for you, why not make yourself a custom solid black Desktop or Screensaver?

I want the screen to be blank, but have what would be on the screen if it wasn't black still coming out of the mini-dvi port. So if I was playing a movie, the movie would still come out of the port but the screen would be blank.