Fresnel lens

Fresnel lensPrisms that make up aFresnel lens bend andmagnify light rays, creatinga single, concentrated beamof light.

Fres·nel lens

F0322400 (frə-nĕl′)n. A thin optical lens consisting of concentric rings of segmental lenses and having a short focal length, used primarily in lighthouses, spotlights, overhead projectors, and the headlights of motor vehicles.

[After Augustin Jean Fresnel.]

Fresnel lens

n (General Physics) a lens consisting of a number of smaller lenses arranged to give a flat surface of short focal length [C20: named after Augustin Jean Fresnel (1788–1827), French physicist]

Thesaurus

Noun

Fresnel lens - lens composed of a number of small lenses arranged to make a lightweight lens of large diameter and short focal lengthheadlamp, headlight - a powerful light with reflector; attached to the front of an automobile or locomotivelens, lens system, lense - a transparent optical device used to converge or diverge transmitted light and to form imagessearchlight - a light source with reflectors that projects a beam of light in a particular direction

Translations

lente di Fresnel

Fresnel Lens

Fresnel lens

[frā′nel ′lenz] (optics) A thin lens constructed with stepped setbacks so as to have the optical properties of a much thicker lens.

Fresnel Lens

a complex compound lens used in lighthouse and signal beacons. It was proposed by A. J. Fresnel. The lens does not consist of a single polished piece of glass with spherical or other surfaces like conventional lenses but instead is made of a

Figure 1. Cross section of ring-type Fresnel lens. In the center are rings whose outer surfaces are parts of toroidal surfaces. Along the edges of the lens are rings in which full internal reflection occurs in addition to refraction.

succession of individual, thin concentric rings, which in cross section have the shape of a special type of prism (see Figure 1). Such a design gives the Fresnel lens very low thickness, and therefore also very low mass, even for a large coverage angle. The sections of the rings are such that the spherical aberration of the Fresnel lens is slight and beams of light from point source S placed in the focus of the lens emerge, after refraction in the rings, in a practically parallel beam (in ring-type Fresnel lenses).

There are two types of Fresnel lenses: ring and belt. The ring-type (circular) lens is the system obtained by rotating the type shown in Figure 1 around optical axis SO; these lenses direct the stream of light in one particular direction. Belt-type (cylindrical) Fresnel lenses are obtained by rotating the type shown in Figure 1 around axis ASA’, perpendicular to SO; they propagate light from the source in all horizontal directions. The diameters of Fresnel lenses range from 10–20 cm to several meters.

Fresnel lens

Fresnellens In lighting, a lens that concentrates light from a small source such as an incandescent filament; similar to but thinner and lighter than a plano-convex lens owing to steps on the convex side; used in many types of luminaires, esp. downlights and spotlights.

Fresnel lens

Fres·nel lens

(frā'nel), a lens with a surface consisting of a concentric series of zones that duplicate the power of a lens or prism but with less thickness. Synonym(s): lighthouse lens

Fresnel,

Augustin Jean, French physicist, 1788-1827. Fresnel lens - a lens with a surface consisting of a concentric series of zones that duplicate the power of a lens or prism but with less thickness. Synonym(s): Fresnel prism; lighthouse lensFresnel prism - Synonym(s): Fresnel lens

Fresnel lens

Fres·nel lens

Fresnel lens

Fresnel Lens

Fresnel lens

Fresnel Lens

Fresnel lens

Fresnel lens

Fres·nel lens

Fresnel,

Fresnel lens

Words related to Fresnel lens

noun lens composed of a number of small lenses arranged to make a lightweight lens of large diameter and short focal length

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