SU1425572A1 - Zoom lens - Google Patents

Abstract

The invention relates to optical instrument making and allows for an increase in the aperture ratio, the angular field of view of a device, and the image quality. Component 1 of the lens consists of a double-closed 3 and two-concave 4 lenses and a positive meniscus 5. In component 2, the first lens is glued together, of the two lenses 6 and the negative meniscus 7, the ratio of the coefficients. dispersions of materials which are not less than 1.2. Component 1 allows one to correct the distortion, the spherical aberration of colored rays with a min. focal length, component 2 - chromatic aberrations for all focal distances. 1 il.

Description

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The invention relates to optical instrumentation, more precisely to lenses with a variable focal length, and can be applied in photographs of both amateur and professional

The purpose of the invention is to increase the luminosity, angular field of view and image quality.

The drawing shows the optical layout of the variable focus lens ™: distance.

j The lens contains eight lenses, I combined into two components 1 and 2.

Component 1 consists of a double-convex lens 3, a double-concave lens 4 and a positive meniscus 5, j Component 2 consists of glued together | a double convex lens 6 to a negative meniscus 7, a positive meniscus 8 located up to aperture 9, a double-curved line - Zy 10 and a double lens 11, located after the diaphragm, Aperture - on the diaphragm 9 is located on a distance of 2 mm from the last surface of the lens 8 o

I The design of the proposed first component allows to correct the spherical aberration of the Color rays at a minimum focusing distance.

i The design of the proposed second | component allows to fix the | | Atomic aberrations for all focal lengths | I) 1X distances In a lens, the focal length varies from 35 to 70 mm. The relative aperture is from 1: 2.8 to 1: 3.7 at a large focal distance. The angular field of view reaches

With a high angle of field of view, the Dissorption is at the edge of the field of view, 0%

In the position of the components, shown in the drawing, when both components are as close to each other as possible, the focal length of the lens reaches a maximum value of 70.0 mm while the angular field of view is 3248.

At the maximum distance of the components from each other, the focal length of the lens reaches a minimum S of 35.0 mm, while

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The new visual field has the highest value, equal to „

Calculations of contrasting characteristics show that the resolution for the three focal lengths of the lens is: at the center of the field at least 50 lines / mm, at the edge of the field (at - 19.5 mm) at least 30 LIN / MM.

With a minimum focal length of 35 mm, the spherical aberration for the main wavelength (line C) does not exceed 0.5 mm. The chromatic difference of spherical aberrations for the edge of the entrance pupil is 0.3 mm, distortion 3%, astigmatism is not more than 0.1 mm, wide aberrations inclined beams no more than 0.1 mm.

At a maximum focal length of 70 mm, the spherical aberration is 0.3 nm, the chromatic difference of spherical aberrations is 0.4 mm, the distortion is less than 1%, the astigmatism is 0.3 mm, the aberration, and the wide inclined beams are not more than 0.1 mm.

Claims (1)

Invention Formula A lens with variable focal length, containing two components that are installed with the possibility of movement along the optical axis, the first component is negative and contains three lenses, the second of which is negative, the third is a positive meniscus facing the subject, the second component is positive and contains four lenses , the first of which two are positive; the second is a positive meniscus facing the object, a third is double-bended, a fourth is double-convex, and the diaphragm is placed For the second and third lenses, characterized in that, in order to increase the aperture, angular field of view and image quality, in the first component the first lens is made two-convex, the second one is double-curved, in the second component the first lens is made of a glued two-convex lens and negative meniscus, the ratio of the coefficients of dispersion of materials which is not less than 1.2. S6789 S11 Flat / pc images