US Patent 8017955 Composite LED modules

A composite multi-color light emitting diode device includes a first light emitting diode unit and a second light emitting diode unit that is arranged on top of the first light emitting diode unit for emitting two different wavelengths of electromagnetic radiation. A third light emitting diode unit may be arranged on top of the second light emitting diode unit, thereby providing a stack of three light emitting diode units. Alternatively, the third light emitting diode unit may be arranged on the first light emitting diode unit, thereby providing two light emitting diode units side-by-side on top of the first light emitting diode unit.