That a configuration of the X server. If you want to disable it you've to edit your /etc/X11/xorg.conf.
You can find information about this with man xorg.conf and going to the ServerFlags section, it says the default BlankTime it's 10 minutes. I don't know how to disable because the only option is the delay time, but I guess passing 0 should do it.
Take a look at your xorg.conf if you've a Section "ServerFlags" and if you don't create it and make it look like:
Option "BlankTime" "0"
You can also set this while X is running with the xset command (see it's man page).