Off-axis total reflection projection objective lens optical system

Abstract

The invention discloses an off-axis total reflection projection objective lens optical system. A visual field off-axis is employed by the optical system, a secondary lens is arranged on a system optical axis, an aperture diaphragm is arranged on the secondary lens, and a primary lens and a third lens leave the system optical axis in opposite directions. Light is converged after being reflected bythe primary lens, is diverged and emitted after being reflected by the secondary lens and is focused to an image surface after being reflected by the third lens. At the same time, a folding mirror isadded into an optical path, a tube length can be reduced further, and object images are at two sides of an objective lens. Light from an object plane at a limited distance is projected on an image surface position according to a certain magnification by a projection object lens. The system has the advantages of good imaging quality, a short tube length and a symmetrical structure, a residual aberration caused by a finite distance of the object can be corrected by bending a curved surface radius and adjusting an aspheric coefficient, the system can be applied to various wave bands such as ultraviolet, visible and infrared bands, at the same time, a problem of the degradation of imaging quality caused by an excessive color difference of a traditional transmission projection objective lens ina wide band is solved.

Description

technical field [0001] The invention relates to the technical field of applied optics, in particular to an off-axis total reflection projection objective optical system. Background technique [0002] The projection objective lens refers to an optical imaging objective lens whose object distance is finite. The projection objective lens can image the finitely distant object or image on the detector according to a certain magnification. , The resolution is the same. [0003] The traditional projection objective lens usually adopts a transmissive optical system. The transmissive optical system is limited by the optical material, and it is difficult to correct the chromatic aberration when the system has a wide band, and it is difficult to ensure the uniformity of the lens material with too large a diameter. These factors will affect the final object. image quality. Compared with the transmissive optical system, the total reflection optical system is not affected by chromatic a...

AI Technical Summary

Problems solved by technology

[0005] Therefore, it is necessary to provide an off-axis total reflection projection objective optical system to solve the problems of the transmissive projection objective optical system such as narrow spectrum, long barrel, and heavy weight.

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