What is Fresnel Lens:
The Fresnel lens was invented by French physicist Augustine Fresnel, the Augustin Fresnel first used this lens design to build a glass Fresnel lens - lighthouse lens in 1822.
The Fresnel lens is a thin, flat optical lens which consists of a series of small narrow concentric grooves on the surface of a lightweight plastic sheet in order to reduce the thickness, weight and cost. Each groove is at a slightly different angle than the next and with the same focal length in order to focus the light toward a central focal point. Every groove can be considered as an individual small lens to bend parallel Fresnel light waves and focus the light. The lens actually eliminates some spherical aberration.
The Fresnel lens is a special optical lens. It can now be made from plastic such as acrylic fresnel lens, PMMA, polyvinyl cholride (PVC), polycarbonate (PC) and HDPE. A traditional glass convex lens would be thick, heavy and very expensive, but a plastic Fresnel lens is a thin, flat, lightweight and low cost alternative.
A high groove density has a better quality projection image. The Fresnel lens is a good solution for quality image and efficiency at a significantly lower cost. The Fresnel lens is usually corrected for spherical aberration.
Application of Fresnel Lens:
The applications for Fresnel lenses include lighting, fresnel lamp, lighthouse, overhead projector, projector accessories, fresnel magnifier, reading magnifier, TV projection, condenser system, camera spotlight, automobile headlight, solar energy, solar concentrator, solar photovoltaic, screen, rear projection screen, passive motion detector, traffic sign, collimator, flight simulator, optical landing system, LED magnifier, LED photometric, LGP(light guide plate), PIR lens, stage light, virtual reality head mount display, Oculus Rift, bank ATM, car back window, etc.
Types of Fresnel Lenses:
Types of Fresnel lens: positive Fresnel lens, negative Fresnel lens, Fresnel lens array, cylindrical Fresnel lens, circular Fresnel lens, linear Fresnel lens, lenticular Fresnel lens, diffraction Fresnel, Fresnel reflection, Fresnel beamsplitter and Fresnel prism.
Advantages of Fresnel Lens:
The Fresnel lense can be designed and manufactured in very large sizes with light weight due to less than 4mm thickness, so the cost will be lower than traditional magnifiers. In contrast, a conventional glass lens would be 200mm thick at the edge, weigh over 50kgs and cost thousand of dollars.
Significantly reduced lens thickness results in a substantial savings in material cost. Fresnel lenses can reduce weight, which reduces mounting and assembly cost. Extremely giant Fresnel lens up to 1000mm can be used to replace a very expensive conventional mirror assemblies in large optical systems.
Design of Fresnel Lens:
To determine the optical Fresnel lens design equation, all of the parameters are determined for each individual application. Several Fresnel zone formulas are used in Fresnel technologies for precision diamond tooling machines and electroforming and molding processes.