FLM330-300,Minus Focus Fresnel lens

Fresnel lens,also known as threaded lens, is a sheet made of PMMA material,which is also made of glass.the surface of the lens is smooth on one side and the concentric circles on the other side are small to large.its texture is designed according to the dryness of the light involved in the disturbance and the relative sensitivity and acceptance angle requirements.The light enters from one side passes through the Fresnel lens on one side and focuses out to a point or in parallel light.Such lenses are usually designed as collimating mirrors(such as Fresnel lenses for projection,magnifying)and concentrating mirrors(such as Fresenl lenses for collecting heat for solar energy)

The transmittance of the material is important to be the influence of the lens, so the high transmittance material Fresnel Factory using is Poly visible (UV CUT).

Normal type Fresnel lens such as magnifiers, lighting equipment, 3D display is being used in a variety of areas.

Groove(Prism) on the opposite side condensing

(A flat surface condensing)

Also we design to use more 3mm Optical PMMA for loner life time and to have 0.5 ~ 1.0mm groove pitch for higher solar concentration.

(If groove pitch is density, then quality of image that is maginifed is clearer.If groove pitch is width, then efficince of concentration of light is higher.)

◈ Refraction of light with Conve and Concave lens

◈ Cone lux diagram (50, 90, 120˚)

The basic functions of the lens to refract light, can spreading or condensing the light emitted from the light source.

Fresnel lens a lighter and thin than convex(concave) lens.

So, when the Fresnel lens used in lighting equipment to make a lighter, smaller apparatus.

◈ Light distribution changes video

◈ Fresnel lens concentration rate

Concentration rate is ratio between area of solar cell and area of Fresnel lens.

Ex) Fresnel lens size 120*120mm → area of lens is 14400mm2
Solar cell size 5*5mm → area of solar cell is 25mm2
Concentration rate is 14400/25 = 576 times

However because of transmittance rate and other obstructs, multiple 80% is reasonable.
Adjusted concentration rate is (14400*0.8)/25 = 460 times

◈ Using a Fresnel lens solar concentrator

◈ Efficiency and F number

F=focal legnth/Diameter

From F1.2, the efficency is dramatically droped. It shows there is a certain ratio between focal length of fresnel and diameter of lens.

Bigger size Lens is not always the answer.

◈ Comparing transmittance of SOG(Silicone On Glass) and PMMA

Our Optical PMMA has higher transmitive than glass, which is 92~95%, and absorption in visual ray is almost 0%

According to our customer’s needs, we recommend ideal solution from our 106 existing products, which are increasing in diversity.
We are prepared to take from design to prototype to volume production.

Contact us

Email : ashton@fresnelfactory.com
Tel : +82 70-7605-1652 Tel:+1 669 293 4193

Webpage : www.FresnelFatory.com