I don't know with any authority but I have an old rear projection TV (not HDTV)that has been angled against my gameroom window since 1990. The sunlight hits the left side and the rear of the TV. It is a 41' Mitsubishi and I don't think the light has hurt it. For the first 5 years someone would come out to clean the lenses. They never mentioned anything about it being in front of a window.
