Projectors don't have pixels......
Most of them do, actually. LCD and DLP projector resolutions include SVGA (800×600 pixels), XGA (1024×768 pixels), 720p (1280×720 pixels), and 1080p (1920×1080 pixels). LCD panels are very small versions of the ones you see in flat screen monitors and TVs, and are capable of showing dead or stuck pixels just like their big brothers. Makers apply dead pixel policies to projectors just like they do for monitors and TVs.
Out of all the projector technologies available, in fact, only the ones with 3 CRTs do not have individually addressable "pixels" in the display device hardware, although (of course) the signal as created in the computer is made up of pixels whatever the type of display.