Monitor/Power Management

[Nigel Verity]

Hi

I'm running Xfce 4.8 on Debian, installed on a laptop. I need to display a static image for a long period of time (> 2 hours) without the screen going blank. No matter how I set the power management, the screen always blanks after a few minutes, whether running on AC power or the battery.

Could anybody advise on the simplest way to keep the screen "alive" continuously?

Thanks

Nige