RU87809U1 - LIGHT LIGHT WITH EXTENDED PASSENGER - Google Patents

Abstract

1. A fast lens with a remote entrance pupil containing four components, the first component is glued from two lenses, the second and third are positive, while the third component is glued from positive biconvex and negative lenses, and the fourth component is a single negative lens, characterized in that the first lens of the first component is made in the form of a negative meniscus facing concavity to the object, and the second lens is a positive meniscus facing concavity to the object, the second component is a single biconvex I am a lens, the negative lens of the third component is biconcave, the fourth component is a biconcave lens, and the total optical power of the first component is negative. ! 2. A fast lens with a remote entrance pupil according to claim 1, characterized in that the following relations are fulfilled between the optical forces of the lens components:! ! where φ1, φ2, φ3, φ4, φ5, φ6 are the optical forces of the first, second, third, and fourth components of the lens, respectively.

Description

The proposed utility model relates to optical instrumentation, and more specifically, to small-sized lenses that work with CCD receivers and can be used to obtain information from external objects.

Known fast lens with a remote entrance pupil according to the copyright certificate of the USSR N 1432440, IPC G02B 9/64, B.I. N 39, 10.23.88, which contains four components, the first of which is a biconcave lens, the second component is positive consists of two positive menisci facing concavity to the object, the third is glued from a biconvex lens and negative meniscus facing concavity to the object, and the fourth - glued from three lenses - biconvex, biconcave and positive meniscus, facing concavity to the image.

A disadvantage of the known lens is the low image quality.

The closest in technical solution is a fast lens with a remote entrance pupil according to the USSR copyright certificate N1365018, IPC G02B 11/34, B.I. N 1, 07.01.88, which is selected by the authors for the prototype.

The prototype lens includes four components, a positive component glued from biconvex and biconcave lenses, the second component is positive, consisting of three single positive lenses, the third component is glued from positive biconcave and negative lenses, and the fourth is the concavity facing the object .

A disadvantage of the known lens is a small projection of the entrance pupil and low image quality, which are limited mainly by astigmochromatic aberrations.

The objective of the utility model is to create a high-aperture lens with a remote entrance pupil, which will increase the entrance pupil removal, while improving image quality and expanding the lens functionality (it worked only from infinity, and now also from a finite distance - i.e. it became a reproduction one) .

The solution to this problem is achieved by the fact that: a fast lens with a remote entrance pupil containing four components, the first component is glued from two lenses, the second and third are positive, while the third component is glued from positive biconvex and negative lenses, and the fourth component is single negative a lens, moreover, the first lens of the first glued component is made in the form of a negative meniscus facing concavity to the object, and the second lens is a positive meniscus facing concavity to the object, Torah component - a single biconvex lens, a negative lens component made biconcave third, fourth component - a biconcave lens, the overall optical power of the first component is negative.

The implementation of the first lens of the first glued component in the form of a negative meniscus facing concavity to the object, and the second lens - in the form of a positive meniscus also facing concavity to the object, allows coma to correct, astigmatism, both of the third and higher orders, is also corrected in this component spherical aberration of higher orders in wide inclined beams, which rapidly increases with an increase in the relative aperture of the lens and the extension of the entrance pupil with a simultaneous attempt to increase the depth p Lens viscosity, allowing to use it as the reproduction.

In addition, the total optical power of the first component is negative, which is a necessary condition for the correction of chromatic aberrations, including higher-order aberrations (for example, astigma-chromatism), as well as image curvature.

The second component - a single biconvex lens - serves as an element for the development of the relative aperture of the lens, and also its parameters allow you to correct spherical aberration and coma of higher orders.

The glued third component acts as a corrector for chromatic and monochromatic aberrations, both simple and higher order aberrations, for example, the meridional coma in the sagittal section, which increases with the increase in the relative aperture of the lens and is very difficult to correct. The positive lens of the third component is biconvex (as in the prototype), and the negative lens of the third component is biconcave, which makes it possible to correct distortion and higher order astigmatic aberrations, while other higher order aberrations (spherical, coma, chromatic aberration) are insignificant.

The fourth component, a biconcave lens, contributes to the correction of higher order coma, curvature and astigmatic aberrations, as well as distortion.

A fast lens with a remote entrance pupil according to claim 1, characterized in that the following relations are fulfilled between the optical powers of the objective lenses:

| φ ₁ |> | φ ₂ |; | φ ₄ + φ ₅ | ≤ | φ ₃ |; | φ ₂ | ≤ | φ ₆ |,

Where

φ ₁ , φ ₂ , φ ₃ , φ ₄ , φ ₅ , φ ₆ are the optical powers of the objective lenses.

This ratio of optical forces is an additional factor that allows you to optimally balance the aberration of the fast lens with a remote entrance pupil.

A plane-parallel plate is installed in front of the image surface, which serves to ensure that the lens

utility model, as part of a CCD camera ( ¹ / _{2.5 ”} CCD). The plate thickness of 1.0 mm is taken into account in the correction of aberrations, since the plate installed in the converging path of the rays introduces its aberrations into the system.

The specified combination allows you to get the necessary and sufficient number of parameters of the optical system, allowing you to create a fast lens with a large projection of the entrance pupil and with high information content due to improved image quality, due to the constructive implementation of its optical design. An additional advantage of the proposed utility model is the expansion of its functionality - the proposed lens can work with high image quality both from infinity and from a finite distance, i.e. It is also a reproductive lens.

The totality of all the features allows us to solve the problem, the exclusion of any of them leads to the inability to implement a fast lens with a remote entrance pupil, which has an increased projection of the entrance pupil and at the same time has improved image quality.

The essence of the utility model is illustrated by drawings:

- figure 1 presents the optical scheme of a fast lens with a remote entrance pupil;

- figure 2 presents the astigmatic curves for aperture

a lens with a remote entrance pupil;

- figure 3 presents graphs of the frequency-contrast characteristics of the lens according to the proposed utility model. The graphs are given for a point on the axis and the edges of the angular field 2ω = 32 ° in the sagittal and meridional sections.

A fast lens contains four components sequentially located along the beam: the first component is glued from the negative 1 and positive 2 menisci facing concavity to the object, the second positive component is a biconvex lens 3, the third positive component containing a biconvex 4 and biconcave lens 5, and also the fourth negative component, which is a biconcave lens 6. A plane-parallel plate 7 is installed in the image plane.

The lens works as follows: the luminous flux from an infinitely distant object sequentially passes through all elements of the lens 1-7, after which an image is formed in the focal plane of the lens. The image is then combined with the photosensitive layer of the CCD matrix (not shown in the drawings).

An example of a specific implementation of the proposed utility model is a fast lens with a remote entrance pupil having a focal length of 12.82 ... mm, a relative aperture of 1: 2.0 ... and an angular field of 2w = 32 angular degrees, the thickness of the plate made of K8 glass is 1.0 mm. In the case of using the lens as a reproduction lens (from a finite distance), the total size of the linear field in space by the object is 2y = 1700 mm.

The technical characteristics of the lens are presented in table 1, and its design parameters are shown in table 2.

Table 1.
Lens specifications. N Feature Name Value one Focal length mm 12.82 2 Corner field hail. 32 3 Linear field in the space of objects, if used as a reproduction lens, mm 1700 3 Relative hole 1: 2.0 four Back focal segment, (without plate) mm 2.033 5 Total length (without plate) mm 31.93

Table 2.
Lens design N surface Radii, mm Thickness mm Glass brands Light heights, mm An object infinity Air 1-aperture plane 6.00 Air 2.5 2 -6.57 2.03 F9 3.8 3 -14.38 4.31 TK21 4.83 four -9.98 0.4 air 6.03 5 35.13 5.36 STK12 6.78 6 -41.54 2.74 Air 7.01 7 14.4 4.98 STK12 6.89 8 -10.9 1.56 TF3 6.67 9 -76.79 6.76 Air 5.79 10 46.63 1.91 TF4 4.07 eleven Plane 1.43 air 3.79 12 Plane 1.0 K8 3.47 Picture Plane air 3.47

The technical advantage of the invention in comparison with the prototype are:

- an increase in the relative magnitude of the removal of the entrance pupil by 1.5 times.

- improvement of image quality by the criterion of frequency response at a frequency of 50 lines / mm by 1.5 times.

- Increasing the depth of sharply depicted space from infinity to 2000 mm

Realization of the technical advantages of the lens according to the proposed utility model increases its information content, which allows it to be used as a fast lens with a remote entrance pupil, both when working from infinity, and as a reproduction lens when working at a finite distance. The lens is supposed to be used in monitoring devices, mainly in security and safety systems.

Claims (2)

1. A fast lens with a remote entrance pupil containing four components, the first component is glued from two lenses, the second and third are positive, while the third component is glued from positive biconvex and negative lenses, and the fourth component is a single negative lens, characterized in that the first lens of the first component is made in the form of a negative meniscus facing concavity to the object, and the second lens is a positive meniscus facing concavity to the object, the second component is a single biconvex I am a lens, the negative lens of the third component is biconcave, the fourth component is a biconcave lens, and the total optical power of the first component is negative. 2. A fast lens with a remote entrance pupil according to claim 1, characterized in that between the optical forces of the lens components the following relationships are true:

where φ ₁ , φ ₂ , φ ₃ , φ ₄ , φ ₅ , φ ₆ are the optical forces of the first, second, third, and fourth components of the lens, respectively.