LV14373B - These š s ē teladoptric telescope - Google Patents

Abstract

The invention relates to a direct image optical surveillance devices, and it can be used as a compact planetary telescope, a high magnification binocular for terrestrial observations, as well as astrograph's object-lens with high resolution. A catadioptric telescope contains in two kinds curved positive front lens 1, primary mirror, which is produced in the way of the negative Manzhen mirror 2, the secondary mirror 3 and the positive field lens 4. The following table shows the geometric parameters of the geometric elements. The ratio of the first lens diameter to the focal length of the optical system of the telescope is chosen 1/10.

Description

DESCRIPTION OF THE INVENTION

The invention relates to direct-image optical observation devices and can be used as a compact planetary telescope, high magnification binoculars for terrestrial observations, and as a high resolution astronomer lens.

Analysis of prior art

There is known a dual-mirror optical system of the Gregori telescope which is described, for example, in U.S. Pat. No. 6667831 and has been investigated as a prototype of the invention. It consists of two aspherical mirrors and gives a direct view of the focal plane of the system. However, with the aid of aspheric optical devices, aberrations such as coma, astigmatism, magnification chromatography, and field curvature cannot be corrected outside the optical axis. In this way, it is possible to obtain an accurate image only at the center of the field of view, which can be sufficient only by looking at one small point in the field, such as a star.

There is known a direct image telescope catadioptric system (PCT Application Publication No. WO 99/53354), which is constructed according to the Maksutov-Cassegren scheme and consists of a front lens, a primary and a secondary mirror, which uses a rotating lens system to obtain a direct image. The disadvantage of this solution is that the inverse system uses additional optical elements which cause additional errors in the optical system and prevent resolution near the diffraction limit.

There is a known mirror and lens lens (RU 12264 Ul), which consists of a front lens and a main mirror, and gives a direct image produced by the secondary use of a convex Mancene mirror. The disadvantage of this solution is that the optical system uses a high degree of unification. This is achieved by the fact that a total of two surfaces are selected for the front lens and the secondary mirror, one of which passes through the beam twice and the other three times. Therefore, this system can only be optimized within very narrow limits, which in turn does not allow high resolution to be achieved overall. This design can be used on low budget surveillance devices with not too high resolution.

The design is closer to the proposed solution with a light-capable mirror-lens lens with a spherical optical surface as described in the Russian Federation patent RU 2 368 924, which consists of five components made of the same type of glass. The main disadvantage of this scheme is that it is built on the Maksutov-Cassegren scheme, which gives an inverse image in the focal plane and has a dimension of 1 / 2.2, characterized by the ratio of the front surface to the focal plane relative to the focal length. In addition, the system is built with one specific grade of K8 glass.

Technical object and essence of the proposed invention

The technical objective of the present invention is to reduce the dimensions to 1/4, while maintaining a resolution level close to the diffraction limit within the 0.4 - 1.0 micrometer wavelength range, which corresponds to the sensitivity range of modern FPA Image Sensors. In addition, it is possible to use any brand of glass with an Abbes number greater than 0.5, which allows the use of glass varieties that operate under extremely harsh conditions, such as the open space.

This problem is solved by the fact that the Gregori system's direct view catadioptric telescope with spherical optical surfaces containing a front positive lens, a main mirror executed in the form of a negative Manen mirror, a secondary mirror and a positive field lens, according to the invention concave mirror, but the focal length ratio of the front lens and telescope optical system to the diameter of the mirror is selected within the range of 1/6 to 1/12, with the ratio of the front surface to the focal plane being selected within the range of 1 / 3.5 to 1 / 4.

The proposed telescope construction scheme is a modification of the Gregori system. Such a scheme is chosen because it provides the ratio of the distance from the front surface of the first component to the focal plane to the focal length of the system in the range of 1 / 3.5 to 1/4. In order to correct the aberration outside the optical axis, the circuit uses only spherical optics, which in turn makes the implementation of the invention more technological than the classical Gregorian system. In addition, the optimum number of optical elements has been selected in the proposed catadioptric telescope, which allows for optimization of calculations and justification within a sufficiently wide range during assembly and operation. In addition, all system elements are made of the same type of glass. It can be any type of glass (bracket). with an average degree of dispersion (Abbes number) greater than 0,5. The proposed catadioptic telescope has a high resolution close to the diffraction limit. This is achieved by minimizing the number of optical elements in the proposed scheme to optimize the optical system while minimizing the number of refractive surfaces. For a sufficiently small number of optical parameters participating in the calculation optimization, the automatic calculation method described in / 1 / can be used for the calculation, using all the parameters of the optical system at the same time for optimization.

EXAMPLES OF THE INVENTION

FIG. 1 shows a schematic diagram of a proposed catadioptric telescope with spherical surfaces according to the Gregorian scheme comprising a positive dual-convex lens 1, a main mirror executed in the form of a Mancene negative mirror 2 located in front of the first focal surface 5, i.e. a mirror 3 and a positive field lens 4 located behind the surface 5, i.e., the area behind the focal plane, forming an image system in the main focal plane. The attached table shows the geometric characteristics of the optical elements.

Table

Surface Above- mas no- sau- gums Above- mas type Y radius Thickness Glass Breaking mode Y pusertura Subject matter Sphere Infinity Endless the league Break Aperture Sphere 685.0493 8.0000 NBK7 SCHO Break 38.0000 2 Sphere -854.4047 166.0000 Break 37.9203

3 Sphere 159.5544 7.0000 NBK7 SCHO Break 30.6244 4 Sphere -251.6798 -7.0000 NBK7 SCHO Reflected 30.9232 5 Sphere -159.5544 158.3000 Break 29.2664 6th Sphere 53.4495 165.0000 Reflected 8.1545 7th Sphere 17.0000 3.0000 NBK7 SCHO Break 6.5897 8th Sphere -100.0000 5.2460 Break 6.3887 Picture Sphere Infinity -0.1335 Break 4.9590 Subject matter Sphere Infinity Infinity a Break Aperture Sphere 790.6963 8.0000 SK16_ SCHO Break 38.0000 2 Sphere 1031.5910 166.0000 Break 37.8827 3 Sphere -167.4798 7.0000 SK16_ SCHO Break 29.2694 4 Sphere -250.7363 -7.0000 SK16_ SCHO Reflected 29.5466 5 Sphere -167.4798 158.3000 Break 27.9973 6th Sphere 53.4495 165.0000 Reflected 6.9615 7th Sphere 22.0000 3.0000 SK16_ SCHO Break 0.3636 8th Sphere -150.0000 5.2460 Break 0.2704 Picture Sphere Infinity -0.1858 Break 0.0000

The focal length ratio of the front lens to the telescope optical system is selected at 1/10. The rays pass through the front lens 1, are refracted on the front surface of the Mannequin mirror 2, reflected from the rear surface of the Mannequin mirror 2, are refolded a second time on the front surface of the Mannequin mirror 2 and focus at one point on the first focal plane. This way the image is cropped. Further, the rays are reflected from the secondary mirror 3 and, passing through the field lens 4, are concentrated at a single point in the main focal plane 6, thus forming a direct image. The front lens 1, together with the Manhattan mirror 2, corrects the overall spherical aberration of the optical system and additionally corrects the spherical aberration of the secondary mirror 3. Field 4 lens axis corrects telescope optical system aberrations such as coma, astigmatism, magnification chromaticism and field curvature.

Used information sources:

1. Πεκ Υ. ABTOMaTHHecKHii pacneT oSbcktobob {b KHHre: «flpoeKTHpoBaHue omraraecKirc cncTeM» / non penaKinreH IIIeHHOHa P., BanaHTa, φκ. /, MocKBa, Mnp, 183, c. 99-128.

Claims (2)

Claims 1. Direct view catadioptric telescope according to the Gregori system with spherical optical surfaces comprising a front positive lens, a main mirror executed in the form of a negative Manen mirror, a secondary mirror and a positive field lens other than a convex mirror and the ratio of the distance from the first surface to the focal plane to the focal length of the system is selected within the range of 1: 3.5 to 1: 4. A telescope according to claim 1, characterized in that the system components are made of brass glass of any variety with an average dispersion of greater than 0.5.