A projection apparatus, an illumination module and a color-level correcting method therefor are provided. The projection apparatus comprises a projection lens, an imaging unit and an illumination module. The illumination module comprises a light source, a color wheel and a controlling unit. The light...http://www.google.co.uk/patents/US7956937?utm_source=gb-gplus-sharePatent US7956937 - Projection apparatus and color-level correcting method therefor
