SU1737396A1 - Magnifying glass - Google Patents

Abstract

The invention relates to optical instrumentation, namely to loupes, and can be used by people with impaired vision. The purpose of the invention is to improve the image quality by reducing astigmatism while improving the manufacturability. In a magnifying glass containing two mirrors, applied on convex surfaces of flat-convex lenses with parallel optical axes and glued by flat sides onto opposite legs of two identical rectangular prisms, facing each other with guillotine faces and shifted one relative to the other along these faces, rectangular prisms performed isosceles, and the main optical axes of the lenses are the same. All optical parts are made of the same glass brand. Magnification magnification 3,5x. 3 il.

Description

The invention relates to optics and can be used as a magnifying glass for observing and reading small objects, texts, etc.

Small magnification loupes are known (see the book by GE.S.Kvortsovidid. Microscopes. Leningrad: Mashinostroenie, 1969, p. 14), consisting of one simple lens. Their disadvantages are low magnification and low image quality.

The mirror lens is also known, for which, according to application no. 4358709/10, a positive decision was issued on July 26, 2008, adopted as a prototype. The advantages of this magnifying glass are increased magnification, the field of view in the sagittal direction with the possibility of binocular observation. This magnifying glass, however, has an insufficiently high image quality due to substantial astigmatism caused by asymmetry of the structure. In addition, this loop has a design flaw: its prisms are oblique, i.e. have unequal sharp corners, which requires complex manufacturing technology, special equipment and control parameters.

The aim of the invention is to improve the image quality by reducing astigmatism while improving the manufacturability.

The goal is achieved by the fact that rectangular prisms are made isosceles with acute angles of 45 °, and the sighting axis is normal to the plane of the object located at an angle of arcC arc sin n sln (45 ° - arc sin 1 / n) relative to the normal to the input face the first prism, where n is the index of refraction of prisms and lenses, while the main optical axes of plane-convex lenses coincide.

WITH

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ABOUT

There are two reflections in the magnifying glass on the force surfaces of the mirrors, which provides small dimensions and large magnifications with gentle radii of curvature. The radius of curvature of the specular force surface of a plane-convex lens glued onto a prism is 2 / (n-l) times the radius of curvature of the lens with the same focal length, where n is the refractive index of the lens material. Therefore, the force surface of the mirror-prism element works with a smaller relative aperture than the equivalent lens. Since the radii of the mirror-prism elements of the magnifying glass are gentle, it can have a significant size in the sagittal section, which makes it possible, on the one hand, to increase the size of the floor in the sagittal section, and on the other hand, it can provide binocular observation of the object.

Figure 1 shows the optical scan of a magnifying glass: Figure 2 shows the optical design.

Magnifier works as follows.

Rays from an object located in the front focal plane of the magnifying glass, successively pass through the following surfaces: refracting 1, reflecting 2, reflecting concave 3, refracting 4 (it’s reflecting second), refracting 5, reflecting concave 6, reflecting 7 (it’s the same refractor), refracting 8.

The optical system uses four parts, and two are identical. All optical parts are made of the same glass brand.

Since rectangular prisms are made isosceles, they and the design of the loop as a whole have a higher degree of symmetry. At the same time, this design is also more technologically advanced, since its component prisms are rectangular isosceles, i.e. these are prism AR-90 widely used in optics (see the Handbook of the designer of optical-mechanical devices. Edited by V.A.Panov. L .: Mashinostroenie, 1980, p.170). For prisms of this type on

any optical production has the necessary equipment and technological equipment. In order to manufacture a rectangular, non-isometric prism (as in Application No. 4358709/10), it is necessary to use special technological equipment for making sharp angles other than 45 °, or for prolonged manual finishing, which is unacceptable under mass production conditions.

As an example of a specific embodiment, a loop was designed, the components of which are made of K8 glass. With a radius of force surfaces r3r re -425.6, it has a CH 3.15X.

From the tables and graphs of aberrations shown in Fig. 3, it can be seen that the system, within a linear field in a 220 mm long meridional section, has an image quality that meets the requirements imposed on observational instruments,

The above helps to get a magnifying glass with a good image quality, compact and technological.

Claims (1)

Claims of the invention A magnifying glass containing two mirrors applied to the convex surfaces of two plane-convex lenses with parallel optical axes glued by flat sides onto opposite legs of two identical rectangular prisms, facing each other with hypotenuse edges and shifted relative to each other along these faces, characterized in that, in order to improve image quality by reducing astigmatism while improving manufacturability, rectangular prisms are made isosceles, and the main optical axes of convex lenses are the same. 96ESH.1 uzff / Sh -W -four/  Zj Motn. W W- / 4