IMAX has only started switching to 4K laser projectors a few years ago, they were one of the last hold outs for 2K projectors (and many IMAX cinemas still use 2K projectors sadly).

Are those cinema projectors or more like video projectors? The cinema ones are more heavy duty and not changed so often.

Cinema projectors. It should be said that I worked in the business in Norway which had converted all auditoriums to digital in 2010, so many theatres were looking at upgrading their projectors around the time I left for something else.