SU1649492A1 - Wide-angle hydrolens - Google Patents

Abstract

The invention relates to optical instrument making, to optical systems of hydro-lenses, and can be used to obtain visual information from underwater objects. The purpose of the invention is to improve the image quality by correcting aberrations of wide oblique beams while reducing the relative dimensions. The wide-angle Aperl7 (/ p // ЈG / 7 iris) contains six components, the first of which is a positive meniscus 1, the second and third are single negative menisci 2, 3, protruding to the image, glued together from a negative meniscus 4 and a double convex lens 5, the fourth component, glued from a positive 6 and 7 negative meniscus, facing concavity to the object, the fifth component, located at a distance from the fourth component, not exceeding 1.1 fw, and the sixth component, a two-fold lens 8c. meniscus 1 along the optical axis is not less than fyy, where fw is the focal length of the lens in water. The relative aperture is 1: 2.8, the angular field in water is 26Jyu 90, the focal distance in water is fw -8.47, in air is f 6, 35, the reduced coefficient characterizing the relative dimensions of a hydro-lens, K 137.8. 1 or a. The image of the expressions on SS (L СО CO 4 ь CO ic

Description

The invention relates to optical instrumentation, more precisely to optical systems of hydro-lenses, and can be used to obtain visual information from underwater lenses.

The aim of the invention is to improve the image quality by correcting aberrations of wide oblique beams while reducing the relative dimensions.

The drawing shows the optical layout of the lens with the course of the rays.

The wide-angle lens works as follows.

The luminous flux from an object located in an aqueous medium falls on the first objective lens 1, which is simultaneously a protective illuminator. Then the luminous flux passes through the remaining components 2-8 of the lens and forms an image in the plane of the photosensitive layer of the image receiver, for example, a transmitting television tube.

The coefficient evaluating the relative dimensions of the lens means a reduced coefficient that takes into account the length of the lens relative to its focal length in water, the relative aperture, the angular field, the relative maximum light diameter of the lens, calculated by the formula

- b, 1. ° lЈ4y "e with f.

Lw

tg "v

vv

where is l

system length with back focal length; fw is the focal length of the lens

in water;

About the relative aperture of the lens, OES, - the angular field of the lens in the water

de, 1

OA is the maximum light diameter of the lens, which determines the transverse dimensions of the lens. Making the first component 1 positive allows the heights of the inclined rays of the wide oblique beam to be reduced to subsequent components of the lens, thereby reducing higher order aberrations, especially in the meridional section. The thickness of the first lens 1 along the optical axis plays an important role both in the aberration correction and in ensuring the strength

9

five

0

five

lens. The optimal value in this case is the value of the order of the focal length of the lens in the water, reducing this value violates the correction of aberrations of the wide oblique beam, especially in the sagittal section, which does not allow for high image quality. The first objective lens 1 performs the role of a protective window at the same time, which leads to a decrease in the relative diameter of the lens and to reduce higher-order aberrations in wide oblique beams, including chromatic ones, since the beams of the said beams are less sharp because of a smaller refractive index difference water is glass than air is glass. Limiting the distance between the fourth and fifth components to 1.1 focal length, the lens in water is necessary to simultaneously achieve high quality from the point of view, especially spherical aberration in wide oblique beams, as well as reducing the longitudinal dimensions of the lens.

An example of a specific implementation is a wide-angle hydro lens with a relative aperture of 1: 2.8, an angular field in water of 2W 90 °, a focal length in water of f -8.47, in air of f-6.35, a back focal length of Sp 12.47 mm, relative dimensions characterizes K 137.8.

For the point, on the uSjq axis, 0.03 mm, for the edge of the field, the chromatism of the increase does not exceed 0.012 mm, and the chromatic difference of spherical aberration in the wide inclined beams for the edge of the field is not more than 0.05 mm, the chromatic coma is 0.03 mm.

Claims (1)

The diameter of the circle in wide oblique beams does not exceed 0.025 mm. Invention Formula The homogenous hydra lens contains six components, the first, second and third of which are single menisci facing concavity to the image, the second and third are negative, the fourth component is glued from a negative meniscus and a two-convex lens, the fifth component is glued from a positive and negative meniscuses facing the concavity of the object, and the dough - polo5 16494926 strong, different optical axis of the lens is not less than f ,, In order to improve quality, the distance between the fourth and images by correcting with aberration components does not exceed the wide oblique beams from the same time as Ijlf, where f is the focal alternating reduction of the relative distance of the lens in the water, and the sixth barite, in it the first component you component is made in the form of double combs with a positive thickness of a convex lens.