3.5-time continuous zooming solar blind ultraviolet optical system for corona detection

Abstract

A 3.5-time continuous zooming solar blind ultraviolet optical system for corona detection belongs to the field of ultraviolet detection technology. Existing technology has a defect of relatively low zooming ratio. The system is characterized in that a front fixed set is composed of a first lens which is a binary diffraction lens; a zooming set is composed of a second lens and a third lens which are successively arranged, wherein the second lens and the third lens are respectively a convex-concave lens and a concave-convex lens; a compensating set is composed of a fourth lens, a fifth lens anda sixth lens which are arranged successively, wherein the fourth lens, the fifth lens and the sixth lens are respectively a biconvex lens, a biconcave lens and a biconvex lens; a back fixed set is composed of a seventh lens which is a concave-convex lens; the lenses are made from calcium fluoride and fused silica; the front lens surface of the first lens is a binary diffraction surface; the frontlens surface of the third lens is an aspheric surface; and other lens surfaces are spherical surfaces; the working waveband of the optical system is 240-280nm; the F number (f / d) is 4; the focal length is 35-122.5mm; and a zooming ratio is 3.5. The 3.5-time continuous zooming solar blind ultraviolet optical system can be used for state detection of a high-voltage power transmission line and can satisfy requirement in large-visual-field searching and small-visual-field positioning.

Description

technical field [0001] The invention relates to a 3.5 times continuous zoom solar-blind ultraviolet optical system for corona detection and belongs to the technical field of ultraviolet detection. Background technique [0002] Corona discharge detection is often required in the daily maintenance of high-voltage transmission lines. Since the corona contains ultraviolet radiation, ultraviolet imaging has become an optical detection method for corona discharge. "Solar-blind" ultraviolet radiation refers to ultraviolet radiation with a wavelength range of 240-280nm. In the near area, the ultraviolet radiation in this band is almost completely absorbed by the ozone layer in the atmosphere. Therefore, when using this band for corona detection, the sky is a dark background. Useful for signal detection. [0003] The corona discharge optical detection method uses an ultraviolet optical system and an ultraviolet photodetector to receive the image signal generated by the corona discha...

AI Technical Summary

Problems solved by technology

However, its lens materials are calcite and magnesium fluoride, both of which are not commonly used ultraviolet optical materials, which are expensive and difficult to process; the calcite in it will produce birefringence, which is difficult to image and is not suitable as a lens material; in addition , the zoom ratio of the optical system is low, only 2 times

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