Patent ID: 7396136

Claim:
An illumination unit, comprising: a first heat conducting plate; and a plurality of light source modules emitting a plurality of lights having different colors, each light source module having at least one LED commonly mounted on the first heat conducting plate and at least one corresponding collimator to collimate light emitted from the at least one LED, wherein the collimator has a reflection surface shaped to reflect the light emitted from the at least one LED in substantially one direction; and wherein each of the light source modules comprises: a plurality of collimator groups in which one or more collimators are linearly arranged, and a plurality of LED groups in which one or more LEDs are linearly arranged, the LED groups are arranged in a stepwise manner with respect to one another, and a plurality of mounting portions are arranged in a stepwise manner on the first heat conducting plate to correspond with the LED groups such that the LEDs of the corresponding LED groups are mounted thereon.