The highest power white LED announced so far has a 17 lumen output with one Watt input. This is a much lower efficiency that is achieved by arc lamps, so to get equal screen brightness the LED's would actually produce more heat.
If you wanted to project onto a very small screen it might make some sense.
The highest power white LED announced so far has a 17 lumen output with one Watt input. This is a much lower efficiency that is achieved by arc lamps, so to get equal screen brightness the LED's would actually produce more heat. If you wanted to project onto a very small screen it might make some sense.