Concerned about screen burn in with alarm clock app

I recently downloaded Night Stand HD, then it occurred to me that the clock display would remain on all night. The auto-lock feature needs to be disabled for the alarm to work. Do I need to be concerned about screen burn with the iPad display? I know the latest LCD displays are not susceptible to it, but I want to be sure before I start using it. The app has a dimming feature, but I'm not sure if that is enough protection.

Thanks