In contrast to moving heads, however, scanners do not move the entire "heads" of the devices including the light source: instead, the light beam generated by a statically mounted light source is deflected by a movable mirror. Thus the movement of the light is somewhat more limited than with a moving head.
While discharge lamps were traditionally used as illuminants in scanners, today's scanners use powerful, white LEDs. Colors and patterns are usually displayed using color and gobo wheels.