Printed Secondary Optics: Focus on Target

LED diodes are constantly evolving and become smart options for a broad range of illumination applications. For a lot of applications, including interior spot-/downlighting, street lighting, architectural lighting, the emitter and primary optics on their own cannot deliver enough intensity to the target surface, as emitters give off a Lambertian light distribution and sents light rays into all directions. In addition, secondary optics are needed to control the light and get it available where it’s actually needed.

Secondary Optics: Controlled Collimation

Without having proper secondary optics in place, the light is just ‘thrown out’ from the source emitter with nothing harnessing the rays. Nothing is there in between to make it behave in a functional way. It results in light losses (as the majority of the emitted light is wasted and misses the target area) and unpleasant or even dangerous blinding (glare).

In addition, secondary optics are used to collect the individual light rays and collimate them into a controlled beam. When doing so, the light will be transported to the area you need to its fullest intensity. Collimated light rays are spread in parallel and are directed to the intended illumination target area. Although it is impossible to make the light perfectly parallel because of diffraction and the physical size of the LED source itself, it brings significant advances in efficiency and decreases the light losses and glare. It is important to note that the smaller the light source is, the more effective the optics design and resulting collimation process will be.

Secondary and Tertiary Optics Specialties: Printed Color Lenses and Printed Diffusers

Secondary optics are not only made to collimate the light, sometimes they are used as color lenses to improve color uniformity. In addition, tertiary optics such as printed diffusers much be used to smoothen the light distribution within the targeted area or to avoid glare.

Choosing the appropriate optic or lens totally depends on the target application. Printed reflectors and TIR optics are used in many different applications and both have advantages and disadvantages, while diffuser optics might be needed to correct or reduce the overall glare.

Interesting to know is that with the Luximprint process, secondary (functionally directional smooth surfaces) and tertiary optics (diffusive surfaces) can be easily combined in one single part and process.