Color mixing in experiments on optical profile bench with LED lamp

Principle

When light rays of different colours meet, their spectral colours are added. This is called additive colour mixing. The mixed spectrum always contains more colour volume than the respective individual colours before it. Usually, three different colours are combined in additive colour mixing.



The LED fixture is equipped with a set of LEDs with the primary colours red, green and blue. The fixture consists of six LEDs (three inner LEDs and three outer LEDs). Both the three inner LEDs (red, green and blue) and the three outer LEDs (red, green and blue) are arranged in a circular frame with 120 degree spacing and equal distance to the centre. The radii of curvature for all three outerLEDs are at the same point from the centre of the frame so that the colour mixing is uniform. A control unit is provided to amplify the ultra-bright (red, green and blue) LEDs. The control unit can be operated in indoor or outdoor mode to vary the intensity of the LEDs from 0% to 99%. An LCD screen displays the current setting of each LED. A wide range of colours allows mixing in different ratios. Each LED has a lens that focuses the light into a wide circular beam. A diffuser ensures uniform light distribution. The pinhole included in the scope of delivery creates circles of light that are displayed on the translucent screen.



Tasks

Examine the different combinations of LEDs and observe the resulting spectrum.