RU2079153C1 - Lens objective of 1x magnification - Google Patents

Abstract

FIELD: illumination systems of opticoelectron transducers of annular position of shaft. SUBSTANCE: objective lens incorporates two components placed in symmetry relative to diaphragm. Each component includes plano-convex lens, biconvex lens and negative meniscus facing diaphragm with concavity. First lens faces space of objects with its plano surface. EFFECT: improved functional accuracy. 1 dwg

Description

 The invention relates to instrumentation and, in particular, to projection lenses. It can be used in lighting systems of optoelectronic sensors for the angular position of the shaft.

A large number of projection lenses containing six lenses are currently known. This number includes lenses "Ortoprotar", "Anochromat-Koplinear", "Planar", PM-1, etc. (1)
A six-lens lens (2) is also known, containing two parts symmetrically located relative to the aperture diaphragm from the two positive components facing it with a concavity and a negative meniscus, which is taken as a prototype.

 Known lenses have the disadvantage that they require tight tolerances for the mutual alignment of the optical surfaces forming the lens and do not provide good image quality with values of numerical equipment of more than 0.1.

 Thus, the purpose of the image was to increase the value of the numerical aperture while facilitating the manufacturing technology of two lenses.

 The essence of the invention lies in the fact that in a lens lens containing two components symmetrically located relative to the aperture diaphragm, each of which contains two positive lenses and a negative meniscus facing concavity to the diaphragm, the positive lenses are made in the form of a plano-convex and biconvex lenses, while the first lens and the negative meniscus are made of a material with an equal refractive index, in addition, the first lens faces the space of objects with its flat surface.

 The drawing shows a schematic optical diagram of the proposed lens.

 The proposed lens contains positive lenses 1,2, negative meniscus 3, aperture diaphragm 4, negative meniscus 5 and positive lenses 6,7. The lenses 1,2 and the negative meniscus 3 constitute a component located relative to the diaphragm 4 symmetrically to another component, which includes lenses 7,6 and the negative meniscus 5.

 Lenses 1 and 7 are given a flat convex shape. In this case, the lens 1 faces its flat surface to the space of objects, and the convexity to the aperture diaphragm. Lens 7 faces its flat surface to the space of images, and to the aperture diaphragm with its bulge. Lenses 2 and 6 are biconvex. Negative menisci 3 and 5 face the aperture diaphragm with its concave surface. The first lens and negative menisci are made of a material with an equal refractive index.

 The ray path in the lens is as follows. The rays from the object A mounted in front of the first lens fall onto its flat surface, are refracted on it, then refracted on the second surface of the lens I fall on lens 2 and successively refracted on the working surfaces of the biconvex lens 2, negative menisci 3 and 5, and the biconvex lens 6 and a plano-convex lens 7 build a real inverted image A 'of the subject A, with an increase equal to minus one. Aperture diaphragm 4 limits the size of the beams of rays.

 Calculations showed that for a numerical aperture of 0.25, the effective diameter of a scattering circle in a field of ± 3.4 mm does not exceed 0.1 mm.

Claims (1)

 A lens lens containing two symmetrically located relative to the aperture diaphragm components, each of which contains two positive lenses and a negative meniscus facing concavity to the diaphragm, characterized in that the positive lenses of the components are made in the form of a plano-convex and biconvex, with the first lens and the negative meniscus made from a material with an equal refractive index, and the first lens faces the space of objects with its flat surface.