An LED based light source unit for an endoscopic imaging system produces illumination for a camera through an endoscope. The light source unit includes an array of LEDs mounted to a thermally conductive substrate, a light guide to collect light emitted from the LEDs and to couple the light into a group of optical fibers within the endoscope, and an interface to allow the light source unit to be removably attached to the endoscope at the endoscopes external light port. The LEDs therein may be overdriven by power for increased light output. When the LEDs reach their lifetime, the light source unit can be discarded.
