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  • Wuxi Kinglux Glass Lens Co.Ltd
  • ADD:No.286,Changjiang North Rd,New Dist,Wuxi,JS prov,China
  • Tel: 86-510-66759801
  • Fax: 86-510-84602998
  • Mobile phone: 86-18168862789
  • E-mail: ledglasslens@163.com
  • Contact person: Huimin Zhang
  • LED Secondary optics
    Mar 28, 2018

    LEDs Need to Focus

    High power LEDs are constantly improving and becoming smart options for a wide range of applications. As we have stated above, for a lot of these applications, such as interior spot/down lighting, street lighting, architectural lighting and spot lighting, the emitter and primary optic on their own cannot deliver enough intensity to the target surface. We dove into emitters output above but another way of describing it is that emitters give off a Lambertian light distribution. This basically means that the brightness to an observer is the same, regardless of the observers position. If you have ever seen a bare emitter light up, you can see this instantly. Even if you are far to the side, you can still see that the light source is extremely bright, it will probably even bother your eyes to look at. The problem is that this light is just thrown out there with nothing harnessing the rays.

    Secondary optics are used to collimate the light rays into a controlled beam that will bring that full intensity to the area you need. Collimated light rays spread in parallel, although it is impossible to make the light perfectly parallel because of diffraction and the finite physical size of the bare emitter. It is important to note that the smaller the light source (emitter), the more effective the process will be.

    In describing how a certain secondary optic or lens can collimate a beam, we often look at the viewing angle or full width half maximum (FWHM). FWHM is the angular width of the beam when the intensity at the edge is half the intensity in the center of the beam. This is a helpful way to classify optics, but it doesn’t take into account the differences between certain optical platforms (different sized diodes). It is good to know that optics with identical viewing angles can differ quite a lot in intensity and quality of the beam depending on the emitters optical design. On the optics pages on our site, we try to list all the different angles and FWHM for each LED we carry.

    Secondary optics are not only made to collimate the light, sometimes they are used to improve color uniformity and light distribution within the targeted area. Choosing the appropriate optic or lens depends on the application. Reflectors and TIR optics are used in many different applications and both have advantages and disadvantages.