A Continuous Zoom Fresnel Lens

Abstract

The invention discloses a continuous zooming Fresnel lens, wherein an Fresnel waveband pattern electrode is formed on at least one of electrode faces of upper and lower planar substrates of the continuous zooming Fresnel lens, and the adjacent wavebands are insulated and isolated; the odd-numbered wavebands are respectively led out by a public lead electrode, and the even-numbered wavebands are respectively led out by another public lead electrode; or a first waveband is led out by an independent lead electrode, the odd-numbered wavebands except the first waveband are respectively led out by a public lead electrode, and the even-numbered wavebands are respectively led out by another public lead electrode; and by applying a voltage between the lead electrodes and the pattern electrode, the effective refractive index of a liquid crystal layer of a pattern coverage region is adjusted, the optical path of a light beam when the light beam passes through the liquid crystal layer is changed, so that the optical path differences of different regions of the pattern electrode can be distributed according to the Fresnel waveband collection demand. According to the invention, a double-waveband or three-waveband electrode pattern is designed, the refractive index of the liquid crystal layer can be changed by adjusting the drive voltages of the odd-numbered wavebands and the even-numbered wavebands, the two-level focal length adjustment is realized, the continuous zooming effect is good, and the zoom range is not limited theoretically.

Description

technical field [0001] The invention relates to the field of optical devices, in particular to a novel continuous zoom Fresnel lens that uses an electric field to change the refractive index of a liquid crystal to adjust the focus. Background technique [0002] Lenses are basic optics that can be found everywhere in optical instruments and equipment. With the development of optical technology, the requirements for lenses are getting higher and higher. One is that the focal length of the lens is continuously adjustable, and the other is that it is required to provide a lens with a large focal length. The traditional zoom lens is to change the spatial position between the lenses through mechanical movement, thereby achieving the purpose of changing the focal length. After that, some electronically controlled zoom lenses were developed, among which: some can achieve zoom effect, but the electrode control is complicated; some control is simple, but the focusing is very rough; s...

AI Technical Summary

Problems solved by technology

The odd (even) numbered bands in the Fresnel lens are ITO electrodes, which are connected and drawn out with a lead wire, and the even (odd) numbered bands are etched away, and the liquid crystal layer is controlled by a single band, and there are certain restrictions: on the one hand , can only zoom between 0.5 and 2 times the original focal length, and cannot zoom freely (unlimited); on the other hand, the clear aperture cannot be enlarged, and cannot be used for glasses, etc.

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