LED lamps, spotlight s and other lighting equipment are actively used to create artistic lighting, decorative lighting, for landscape and architectural lighting, as well as in the design of advertising objects.
In this area, most often used over bright white LEDs with a large scattering angle (100-120 °).
To solve the problem of lighting there is a need to obtain light beams with different scattering angles. To do this, the LEDs must be provided with a secondary optical lens (or reflector), providing the necessary distribution of light flux in space.
A lens that can collect and focus (collimate) radiation at a specified scattering angle is a complex lens with an internal refractor and an external reflector. An external refractive surface can also be used in addition.