Patent ID: 8446440

Claim:
An illumination device for an optical printer, the illumination device comprising: a first array of light sources comprising a plurality of light source elements that are each operable to emit light within a red band of the visible electromagnetic spectrum, a second array of light sources comprising a plurality of light source elements that are each operable to emit light within a blue band of the visible electromagnetic spectrum; and a third array of light sources comprising a plurality of light source elements that are each operable to emit light within a green band of the visible electromagnetic spectrum; wherein said first, second and third arrays of light sources are generally linearly arranged along respective substantially parallel notional lines on a substrate; said first, second and third arrays of light sources are each operable to emit a strip of light, and a predetermined number of light source elements at one or both ends of each said array are arranged not to be energised so that when said light source arrays are energised a first of said arrays of light source elements emits a strip of light that is linearly offset along the associated notional line from a strip of light emitted by a second adjacent one of said arrays of light source elements.