How to turn off screen (DPMS) together with locking session in KDE?

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http://askubuntu.com – First of all, I'm aware a similar question for GNOME is asked here: "Switch off laptop backlight when locking screen". Objective I would like to turn off my screen on locking the session for power saving reasons. Actual problem Locking the screen on Kubuntu (KDE) inevitably triggers the screensaver as far as I can see. There's no screensaver option other than 'Blank screen' together with its background colour set to black that comes just close to my goal. It blanks the screen, but doesn't turn off the screen. Screen's backlight will still be on and not saving any power. Current workaround (HowTos)