1.Fresnel Lens Basic Principle
1.1 What is Fresnel Lens？
Fresnel lens was invented by French physicist Augustine. Fresnel, who originally used this lens in 1822 to build a system of glass Fresnel lenses, the lighthouse lens.
Fresnel lens is an optical element with a fine structure,The front of this lens looks like a dart board, but each ring is tilted at a different angle, Each ring is an independent lens, which together is a lens group,through different structural design, the direction of light can be adjusted to produce different optical effects.
1.2 Work Principle
The work principle is simple；assuming that the refraction energy of a lens occurs only on the optical surface (e.g., the surface of the lens), remove as much of the optical material as possible while preserving the curvature of the surface.
Another way of thinking about it is that the continuous surface portion of the lens "collapses" into a plane. The diagram below:
From the profile, its surface is composed of a series of serrated grooves, and the central part is an elliptical arc. Each groove is at a different Angle from its neighbor, but all focus the light in one place, forming the central focus, the focus of the lens. Each groove acts as an independent little lens, adjusting the light to be parallel or focused. The lens also eliminates part of the spherical aberration.
2. Fresnel Lens Classification
2.1 From the optical design can be divided into:
2.1.1 Positive Fresnel Lens
The light comes in on one side, passes through the Fresnel lens and comes out on the other side focusing into a single point or coming out in parallel. The focus is on the other side of the ray, and it's finite conjugate.
Such lenses are usually designed as quasi-direct lenses (e.g. Fresnel lenses for projection, magnifying lenses) and convergent lenses (e.g. Fresnel lenses for concentrating light and heat on the sun).
2.1.2 Negative Fresnel lens:
In contrast to a normal Fresnel lens, the focus is on the same side as the light, and its surface is usually coated as the first reflector.
2.2 From the Structure can be divided into：
Circular Fresnel lens
Fresnel lens array,
Columnar Fresnel lens,
Linear Fresnel lens,
Diffraction Fresnel lens,
Fresnel reflecting lens,
Fresnel beam separator and Fresnel prism
Fresnel lens is a very widely used optical components, its design and manufacturing design into a number of technical fields, including optical engineering, polymer materials engineering, CNC machining, diamond turning process, nickel plating process; Molding, injection molding, casting and other manufacturing processes. In China, Not many companies have design and manufacturing capabilities.
Since 1999 Chengdu Fscreen S-Tech Co., LTD was committed to the R&D and production of Fresnel lens.With advanced large-scale single point diamond ultra precision mold processing equipment and a variety of production means.Fscreen is specializes in the design, development and production of large and high precision Fresnel lens.At the same time, it is the supporting unit of Chengdu Photoelectric display Engineering and Technology Center.