Up converters and GaAs based semiconductor light source system for large color gamut display and projection displays

A method for up conversion lighting for a display comprising the steps of:

• providing a red up converter and corresponding semiconductor light source for emitting a bandwidth of red emission wavelengths and an unwanted green emission wavelength simultaneously with the red emission;
• providing a green up converter and corresponding semiconductor light source for emitting a bandwidth of green emission wavelengths and an unwanted red emission wavelength simultaneously with the green emission;
• and
• providing a blue up converter and corresponding semiconductor light source for emitting a bandwidth of blue emission wavelengths and an unwanted red emission wavelength simultaneously with the blue emission;
• and
• placing a first optical element in the path of the red and the green up conversion emission for selectively passing green emission and reflecting red emission;
• and
• a second optical element in a path of the blue up converter to reflect the blue wavelengths of the blue up conversion emission and transmitting the unwanted red emission wavelengths, the first and second optical element each having a thin film coating selected to dump the unwanted red emission from the green and blue up converters and the unwanted green emission from the red up converter.