LED has features of high luminous efficiency, dimmable, small monomer power, high selling prices. As technology advances, LED stage lighting applications has been widely used.
Since the promotion of blue-ray, white-ray and high-brightness LEDs in 1990s, the luminous efficiency of LEDs improved continuously. The luminous efficiency of commercialized LED tubes has reached up to 50lm/W – 100lm/W. And it is still increasing with time. It is estimated that the maximum luminous efficiency can reach up to 200lm/W at last, far more than 10lm/W – 30lm/W of incandescent bulbs (including halogen lamps) and other exceeding light sources. But single LED chip has small power, only 1W – 5W. The maximum output luminance can only be a few hundred lumens. While stage lighting applications usually require a luminous flux of tens of thousands lumens. Previously, LED designers and engineers never think of using LED lighting products on stages.
In the beginning of this century, blue-ray LEDs has been popularized and white-ray LED lighting technology has been mature gradually. The luminous efficiency of LED lamps exponentially increased. At the same time, it also has advantages of prompt respond and simple dimming method. Combing multiple LED lamps as single LED stage lighting applications with output luminance quickly became the favorite way to stage lighting designers. At first, due to some technical reasons and the expensive price, these lamps received very little notice. Recently, with the popularity of further improved luminous efficiency, condenser cups, internal dies, housing and other parts, many manufacturers started to assemble the production by themselves.
There are two LED white-ray lighting modes: blue-ray dies with phosphors, some part of blue-rays will be converted into yellow light through phosphors. Yellow rays combine with blue rays can generate white rays; another method is grouped red-ray LEDs, green-ray LEDs and blue-ray LEDs together to create white rays. The former is typically used in LED display applications. The later is typically used in LED stage lighting applications. Compared LED lamps with incandescent bulbs, the current luminous efficiency of the former is two times of the later. Secondly, thanks to the small size and low temperature characteristics of LEDs, optical designs with higher luminous efficiency make the whole luminous flux of LED stage lighting applications several times higher than that of incandescent stage lighting applications. Combined these two factors, same luminous flux, incandescent lamps consumed far more power than LED lamps does. Thus low-powered LED lamps still can meet the light intensity requirements of stages.