LED projection light is also called spotlight, projection light, etc. It is mainly used for architectural decoration lighting and commercial space lighting. The decorative components are heavier, and the appearance is round and square, because heat dissipation is generally considered, its appearance is still somewhat different from traditional floodlights.
The LED projection light has a rotationally symmetrical shape. The LED projection light uses a rotationally symmetrical reflector, and the symmetry axis of the light source with rotationally symmetrical light distribution is installed along the axis of the reflector. The iso-intensity curves of this type of LED projection light are concentric circles. When this type of spotlight is illuminated by a single lamp, an elliptical spot is obtained on the illuminated surface, and the illuminance is uneven; but when multiple lamps are illuminated, the spots are superimposed on each other, which can produce a satisfactory lighting effect. For example, hundreds of rotationally symmetrical floodlights are commonly used in stadiums, and they are installed on high towers around the stadium to obtain lighting effects with high illuminance and high uniformity.
The LED projection light has two symmetrical planes, and the iso-intensity curve of this type of projection light has two symmetrical planes. Most LED projection lights use symmetrical cylindrical reflectors and are installed with linear light sources along the cylindrical axis. The LED projection light with one symmetrical plane has only one symmetrical plane of the isoluminous intensity curve. LED projection light uses an asymmetric cylindrical reflector or a symmetrical cylindrical reflector plus a grid that restricts the light. The most typical is the sharp cut-off block retracted light distribution. This kind of light intensity distribution single lamp can obtain a more satisfactory illuminance distribution.
There are LED projection lights without asymmetrical shapes. The iso-intensity curve of these types of LED projection light has no symmetry plane. They mainly use mixed light lamps with different types of light sources with large differences in light intensity distribution and special lamps designed according to the specific lighting requirements of the place of use.