Patent ID: 8201966

Claim:
An illumination device capable of emitting an output light comprising: a housing; one or more white LEDs emitting a first light along a first path and one or more red LEDs emitting a second light along a second path, wherein the one or more white LEDs and the one or more red LEDs are mounted in the housing such that the first light and the second light are mixed to form an output light transmitted along a third path or to form an output light at a field position; and a colour filter positioned in one or more of the first path, the second path and the third path, wherein a chromaticity coordinate X of each of the one or more white LEDs is in a range 0.270 to 0.480 and a chromaticity coordinate Y of each of the one or more white LEDs is in a range 0.270 to 0.460 and wherein the or each red LED has a dominant wavelength in a range 613 to 645 nm, wherein a colour rendering index Ra of the output light is 80 or more.