English: Internal components of an old 1998 InFocus LP425z single-chip DLP projector, with a 4-segment color wheel.

This shows the inside of the upper shroud over the DMD and optics. The long narrow wedge on the left contains a light sensor used to determine if the lamp has correctly turned on.

The dull steel plate on the right is part of the lightsink which diffuses and absorbs unneeded light not being used to form the display image. Light from the DMD is directed upwards onto this plate which has a dull finish, which reflects and scatters the light downward just to the right of the lens,into the front-right corner of the aluminum body where the originating light beam enters the optics. The rough aluminum body surface further scatters and diffuses the intensely bright waste light.