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Positive Focal Length Fresnel Lens Used as a Collector |
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Positive Focal Length Fresnel Lens Used as a Collimator |
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Negative Focal Length Fresnel Lens Used as a Diverger |
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| What is Fresnel Lens? |
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Fresnel lenses resemble a planoconvex or planoconcave lens that is
cut into narrow rings and flattened. If the steps are narrow, the surface of
each step is generally made conical and not spherical. The convex surface is
reduced to concentric ridges, to avoid overheating and to reduce weight.
Fresnel lenses are flat rather than thick in the center and can be stamped out
in a mold. Fresnel lenses are commonly used on spotlights. Lamps equipped with
this lens are called Fresnels.
Fresnel lenses can be positive or negative. A positive lens is a Fresnel lens
with a positive focal length. Negative lenses are Fresnel lenses with a
negative focal length. Lens application is an important parameter to consider
when searching for Fresnel lenses. Lens application refers to the desired
wavelength range for the lens. This wavelength range is mostly dependent upon
the lens material. Near infrared Fresnel lenses are designed for use in the 750
nm to 2500 nm wavelength range. Visible Fresnel lenses are designed for use in
the 380 nm to 750 nm wavelength ranges. Ultraviolet Fresnel lenses are designed
for use in the 4 nm to 380 nm wavelength ranges.
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. |
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| Application of Fresnel Lens. |
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These items generally fall into the following
categories:
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Overhead projector Fresnel lenses
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Positive focal length aspheric Fresnel lenses
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Cylindrical (actually acylindrical) Fresnel lens
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Negative focal length aspheric Fresnel lenses
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Off-axis Fresnel lens
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Lenticular arrays
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Arrays of prisms (Fresnel prisms)
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Rectangular arrays of Fresnel lenses
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Microlens arrays, both rectangular and hexagonal symmetries, as well as custom
symmetries
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| Where to buy The Highest Quality
Fresnel Lens? |
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bhlens.com supplies the highest quality plastic Fresnel Lenses,
Polarizers and bhlens available worldwide at the lowest prices. We have more
than 18 years of professional experience in making Fresnel lens.We export
products to USA,Germany,France,Brazil,Italy,Turkey and so on.Our clients
include Carl zeiss.
If you need large quantity, please
E-mail us with your request. If you need to
place a small order, it would be better to buy On our website. |
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