SU1374167A1 - Zoom lens - Google Patents

Abstract

The invention relates to optical instrument making and allows an increase in the aperture ratio and the back focal length of the device. The lens consists of positive fixed components 1, 4 and negative components 2, 3 installed with the possibility of moving along the optical axis to change its focal distance. In component 2, the negative meniscus, facing its concavity to the object, is glued together from twofold-bent 9 and twofold-curved 10 lenses (L). The aperture diaphragm 13 in component 4 is located between the L 12 double block and the L block, consisting of a positive 14, a negative 15 meniscus facing in concavity to each other, and also a twin L 16, negative meniscus 17 and glued L 18 and a two-bout L 19. The lens is designed to work in an amateur movie camera and has a rear focal length of 13 mm and a light diameter of the front component of 37 mm. Component 2 can additionally include a frontal meniscus, facing its concavity to the object. 1 hp f-ly, 4 ill. i (L

Description

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The invention relates to optical instrumentation, more precisely to high-aperture pancritical lenses, and can be applied in cinema, video and television equipment.

The aim of the invention is to increase the aperture and rear focal length of the lens.

Fig. 1 shows the optical scheme of the proposed lens for a threefold interval of change of the focal distance.

The lens contains 14 lenses combined in the component 1-4. Component 1 consists of lenses, a negative meniscus 5 and a positive lens 6, glued together: x between each other, and a positive meniscus 7. Component 2 consists of a negative meniscus 8 and glued together from bentone 9 and two convex 10 lenses of a negative meniscus. Component 3 is made of a negative meniscus 11. Component 4 is made of a two-convex lens 12, an aperture diaphragm 13 and a lens unit consisting of a positive meniscus 14, a negative meniscus 15, a two-convex lens 16, a negative meniscus 17 and a positive lens glued from two 18 double and double bent 19 lenses. .

In the position of the components indicated in FIG. 1 ,, lens has focal

one . The lens has a distance containing four components, the first and fourth of which are positive and stationary, and the second and third are negative and mounted for movement along the optical axis, while the first components are made of a positive dual-gated lens and a positive meniscus facing concavity to the image , the second - in the form of a negative meniscus, facing its concavity to the image, and a negatively double-glued lens, the third - in the form

distance 9 mm. When moving the second negative meniscus reversed

of the third and third components, its focal length varies to 27 mm. The lens is designed for work in an amateur movie camera, its diagonal is 2Y 7 mm.

The relative aperture is 1: 1.1, the rear focal length is 13 mm, which is 3.7 Y. The light diameter of the front component is 37 mm, the optics length is .103 mm.

40

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concavity to the object, and the fourth in the form of a two-convex lens and a lens unit with an aperture diaphragm located between them, which is also distinguished by the fact that, in order to increase the aperture and the rear focal segment, the lens unit of the fourth component is positive and negative meniscus, facing concavity to each other, a group of lenses consisting of a two-convex lens, a negative meniscus reversed by a concavity to the image, and a positive meniscus glued from two double-convex and two-curved lenses: a negative A celled two-glue lens of the second component is made in the form of a meniscus with a concavity facing the object.

Figure 2 shows the values of the frequency-contrast characteristics of the lens at three values of the focal length, from which the resolution can be assessed on the KH1 film used in amateur movie cameras: in the center of the floor; vision over the entire range of 60 l / mm, at the edge of the floor 40 l / mm, and only with the greatest focus- nom distance of 30 l / mm.

Fig. 3 shows the optical scheme of the proposed lens for the sixfold interval of change of the focal distance, which differs from the scheme for the threefold interval by a complicated second component, which consists of negative meniscuses 8a, 86 and gluing 9, 10. The range of the focal distance The object is from 8 to 48 mm with a relative aperture of 1: 1.1.

Figure 4 shows the values of the frequency-contrast characteristics of this lens, which characterize the resolution of the lens as 60-75 min / mm at the center of the field of view and 45 l / mm at the edge. Optics dimensions: front light diameter 49 mm, optics length 116 mm, rear focal segment 13 mm.

inventions with variable focal

Formula

Claims (2)

one . The lens is a distance containing four components, the first and fourth of which are positive and stationary, and the second and third are negative and mounted for movement along the optical axis, while the first component is made of a positive dual-gated lens and a positive meniscus facing concavity to the image , the second - in the form of a negative meniscus, facing its concavity to the image, and a negative two-glued lens, the third - in the form negative meniscus reversed concavity to the object, and the fourth - in the form of a two-convex lens and lens unit with an aperture diaphragm located between them, which is also distinguished by the fact that, in order to increase the aperture and rear focal length, the lens unit of the fourth component is positive in the form of and negative meniscus facing each other in concavity, a group of lenses consisting of a two-convex lens, a negative meniscus reversed by the concavity of the image, and a positive meniscus glued from two two-convex and two-curved lenses: Yelnia dvuhskleenna second lens component is formed as a meniscus facing concavity .k subject. 2. The lens according to claim 1, characterized in that the second component further comprises a frontal meniscus, facing a concavity to the image. W-O .9 i / tf.7 ., ..., .., n.7: .T..g „i.iM,, .. .. 1 15 SO "5 tofS 30 5 9O H 7 J W puf.Z 11 12 JS 1 15 W P16 Yu image plane 50 W 60 7, 50 45 60 75 MspuSuoHOJWfoe cBQetme sagittal section 50 45 60 If 50 is bo 7S SO It5 SO 7G 30 SO