SU903784A1 - High speed lens - Google Patents

Description

(54) LIGHTFLOWER LENS

The invention relates to optical. instrumentation, namely, lenses that work with image intensifiers, and is designed to work with image intensifiers in night vision devices. The lens is known, whose optical scheme consists of four components. The first component is made of glued from two-convex and flat surface lenses. The second component is made in the form of a positive meniscus reversed in the diaphragm. The third component is a glued lens, consisting of double-convex and double-curved lenses. The fourth component is a flat-concave near-focus lens. The known lens is characterized by a simple design, provides good image quality with a high relative opening l: l ,. However, this objective is characterized by an insufficient field of vision in the space of objects, the composition and the spectral range of work (486-656 nm), which makes it impossible to use it together with an image intensifier. Also known is the Tahar lens, which contains a triplet of two positive and a double-curved lens located between them, a diaphragm and a positive lens. The lens has a simple four-lens scheme and provides good image quality with a relative aperture of 1: 2 and an angular field of view. The lens operates in the visible spectrum 2. The disadvantages of the lens are a small relative aperture and a narrow spectral range of operation (486-656 nm). Kpov, moreover, aberration lens correction. It does not give high quality images, especially on the edge of the floor. These shortcomings are due to the fact that in a simple structural scheme, the lens does not have enough correction elements to completely correct its residual aberrations. The large aberrations of the higher orders of the known lens do not allow

further increase the relative aperture and lead to a significant drop in illumination to the edge of the field of view in the image space.

The aim of the invention is to increase the relative aperture while simultaneously improving the degree of aberration correction in the expanded spectral range.

This goal is achieved in that a high-aperture lens containing a triplet consisting of two positive lenses and a double-bent lens located between them, a diaphragm and a positive lens is additionally introduced with a negative Smith lens located at a distance not exceeding 0.25 focal length there is no lens from a positive lens, and the diaphragm is positioned after the first positive lens of the triipet, which is made in the form of a positive meniscus with a concavity facing the diaphragm, is the second positive for triplet made of glued biconvex lens and a negative meniscus facing concavity to the diaphragm, a positive lens formed of a negative meniscus glued facing convex to the image, and biconvex lenses.

Fig. 1 shows the principle optical layout of the proposed lens; in fig. 2 and 3 - residual aberration graphs.

The lens contains a positive meniscus 1 facing inward toward the diaphragm 2. The second component is a double-curved lens 3, the third component is glued from. a two-convex lens 4 and a negative menus 5, facing inward to the diaphragm. The fourth component is glued from a negative meniscus 6 concave-shaped to the image and a two-convex lens 7. The fifth component is a near-focal Smith lens 8.

The lenses; i and 3 and the glued lens 4, 5 serve to correct spherical aberration, coma, distortion, chromatism of position and astigmatism.

Lens 8 corrects the curvature of the field of view. The basic element of this optical scheme, creating a positive optical system, is two glued lenses 4-7. The remaining elements of the optical scheme (lenses 1, 3, 8) are correction power elements and provide correction for the residual aberrations of the system. The magnitude of the residual distortion of the lens is a value of minus 6%, which allows for the introduction of aberration vignetting, which provides an improvement in light transmission in the image space. An increase in the relative aperture is achieved by using two lenses as the base epement. Expansion of the spectral range of the lens is achieved by selecting glass grades and introducing chromatic radii in two different components 4-7. Lens 8 must be located no further from the previous component than at a distance of 0.25 of the focal length of the lens, since this arrangement ensures that the image is located on the last surface of the lens 8 of the lens.

Claims (2)

The resulting lens has the parameters listed in the table. A preventable high-aperture lens encloses a relative aperture of 1: 1.4 with an angular field of view. The image is formed on the posites of the surface of the Smith lens. The focal length of the object is 31.6 mm, the luminance at the edge of the field of view is 89% compared to the luminance at the center of the field. Thus, in the proposed object, compared with the known relative hole, the opening is increased by 1.5 times and the spectral range in the infrared region of the spectrum is expanded by 20 nm. An aperture lens containing a triplet consisting of two positive lenses interposed with a double-curved lens, a diaphragm and a positive lens, characterized in that in order to increase the ratio of the lengthy table and improve the aberration correction in the expanded spectral range, into it Smith’s negative lens is introduced, located at a distance not exceeding 0.25 of the objective’s focal length from the positive lens, the aperture being located after the first triplet lens, which is made in the form of a positive meniscus with a concavity facing the diaphragm, the second positive triplet lens is made of glued from a two-convex lens and a negative meniscus with a concavity ts, a co-convex lens. Sources of information taken into account in the examination 1. US patent number 2541484, CP. 35O-176, pub. 13.O2.51. 2.Rusinov M.M. Technical optics. L. Mechanical Engineering, 1979, p. 431.  0.2-0.1 O / a / 0.2 Wide ttf -o, g im -ai 0.1 lou but/ tJ m about/. JO fuz.3 tilted beams