RU136198U1 - THREE-CHANNEL MIRROR AND LENS OPTICAL SYSTEM - Google Patents

Abstract

Three-channel mirror-lens optical system containing a mirror lens, including a main concave aspherical mirror and a secondary convex aspherical mirror, a lens compensator for a mirror lens for the visible or near infrared range, a lens for the middle infrared range, the first spectrometer, made in the form of an inclined plane-parallel plate, a receiver radiation of visible or near infrared range, the receiver of radiation of the middle infrared range with a cooling diaphragm, characterized in that a common lens for the middle and far infrared ranges is introduced, including a first biconvex lens, a convex-concave lens, and a second biconvex lens arranged in sequence along the rays, and arranged so that its front focal plane coincides with the rear focal the plane of the mirror lens; introduced a collective lens located in close proximity to the rear focal plane of the mirror lens; introduced a second spectrometer, made in the form of a plane-parallel plate and installed between the main concave and secondary convex mirrors, perpendicular to the optical axis; the first spectrometer is located after the common lens in a parallel beam of rays; introduced a lens for the far infrared range, mounted after the first spectrometer and including three single meniscus-shaped lenses sequentially located along the rays, the first meniscus facing the image plane with a convex side, the second and third concave; Received

Description

The utility model relates to the field of optoelectronic instrumentation, in particular, to multispectral optoelectronic systems, and can be used in thermal imaging devices.

Known multispectral lens [Lebedev O.A., Sabinin V.E., Salk S.V., Oversized multispectral lens. Optical Journal, t.78, No. 11, 2011, p.24-27], containing the main concave aspherical mirror, a secondary convex aspherical mirror, a lens compensator, a radiation receiver. The lens can work in the range of 0.4-10 microns.

The features of the analogue coincide with the following features of the utility model: the lens contains the main concave and secondary convex aspherical mirrors, the lens compensator and can work in the visible range, as well as near, middle and far infrared (IR) ranges.

The disadvantages of the known analogue include the following: firstly, it is impossible to obtain images at the same time on several receivers, and secondly, it is impossible to work with cooled receivers of infrared radiation.

Another analogue may be a multispectral optical system [Patent EP 1862837 B1, publ. 08/08/2012], containing a main concave aspherical mirror, a secondary convex aspherical mirror, a two-lens compensator, a common lens, a spectrometer in the form of an inclined plane-parallel plate, image receivers.

The features of this analogue coincide with the following characteristics of the utility model: the optical system contains the main concave and secondary convex aspherical mirrors, a common lens, a spectrometer, and three image detectors. An inclined plane-parallel plate was used as a spectrodivider.

The disadvantages include the following: firstly, the optical system cannot simultaneously create images on three receivers (either the receiver of the visible or near infrared spectral range or two receivers: the middle and far infrared spectral regions), and secondly, the spectrometer is located in converging beam of rays and introduces aberrations that are difficult to fix.

The closest analogue to the proposed utility model in terms of the set of essential features is a multispectral mirror-lens optical system [United States Patent No. 5,841,574 of Nov.24, 1998] containing a main concave aspherical mirror, a secondary convex aspherical mirror, and a spectral splitter in the form of an oblique plane-parallel a plate installed in front of the focal plane of a two-mirror system, a decentralized entrance pupil using the unshielded part of the mirror system, and optical systems in the visible and IR channels. The IR channel uses a cooled image receiver with an aperture diaphragm inside the receiver.

The features of the prototype coincide with the following features of the proposed utility model:

- the optical system contains the main concave and secondary convex aspherical mirrors;

- the spectrometer is an inclined plane-parallel plate;

- one of the channels - the middle IR region (3-5 microns) - contains a cooled image receiver.

The disadvantages of the prototype include the following:

- the use of an inclined plane-parallel plate as a spectrodivider in a converging beam of rays introduces aberrations of an off-center system that cannot be compensated by aberrations of a centered system. To correct them, a compensator is required, in which one of the surfaces has a cylindrical or toric shape.

- the use of an inclined plane-parallel plate as a spectrometer in a converging beam of rays complicates the lens system after the spectrometer in IR channels with cooled image receivers. In the prototype, in only one channel (3-5 μm), the lens part contains eight lenses, and this with a relative aperture of 1: 5. There are five lenses in the visible channel, which operates on reflection from a spectrum splitter. In total, the prototype has thirteen lenses on two channels. In the proposed utility model, twelve lenses on three channels.

The objective of the utility model, as a technical solution, is to obtain images on three receivers simultaneously. In addition, the claimed utility model should provide an increase in aperture ratio, obtaining image quality close to diffraction, a decrease in the number of lenses with an increase in the number of simultaneously working channels, and also the possibility of working with cooled image receivers not only in the average, but also in the far infrared range ( 8-12 microns).

Technical results were obtained due to the fact that in a three-channel mirror-lens optical system containing a mirror lens, including a main concave aspherical mirror and a secondary convex aspherical mirror, a lens compensator for a mirror lens for visible or near infrared range, a lens for mid-infrared range, the first spectrometer made in the form of a plane-parallel inclined plate, a radiation receiver of visible or near infrared range, a radiation receiver In order to achieve a medium infrared range with a cooled diaphragm, a common lens for the middle and far infrared ranges can be introduced, including a first biconvex lens, a convex-concave lens, and a second biconvex lens sequentially located along the rays, and located so that its front focal plane coincides with rear focal plane of the mirror lens. In addition, a collective lens can be introduced located in close proximity to the rear focal plane of the mirror lens. A second spectrometer can also be introduced, made in the form of a plane-parallel plate and mounted between the main concave and secondary convex mirrors, perpendicular to the optical axis. The first spectrometer can be located after a common lens in a parallel beam of rays. A far infrared lens can also be introduced, mounted after the first spectro-splitter and including three single meniscus-shaped lenses sequentially located along the rays, the first meniscus facing the image plane with a convex side, the second and third concave. In addition, a far infrared radiation detector with a cooled diaphragm can be introduced.

With the introduction of a common medium and far infrared range of the lens forming a parallel beam of rays, the introduction of a collective lens, the introduction of a second spectrometer, the location of the first spectrograph in a parallel beam, the introduction of a lens and a receiver for the far infrared range is achieved:

- image acquisition on three receivers simultaneously;

- increase in aperture ratio;

- obtaining image quality close to diffraction;

- a decrease in the number of lenses with an increase in the number of simultaneously working channels;

- getting the ability to work with a cooled receiver in the far infrared range.

The drawing shows an optical diagram of a three-channel mirror-lens optical system.

The three-channel mirror-lens optical system contains the following elements: a mirror lens, including the main concave aspherical mirror 1 and the secondary convex mirror 2; a lens compensator A of the mirror lens for the visible or near IR range, including a positive meniscus 3 and a negative meniscus 4 facing the image plane with a convex side; an image receiver 5 of the visible or near IR range, a second spectrometer 6, a collective lens 7, a common lens B for the middle and far IR ranges, including a biconvex lens 8, a convex-concave lens 9, and a biconvex lens 10; a first spectrometer 11, a lens C for the mid-IR range, including a negative meniscus 12 facing the image plane with a convex side, a positive meniscus 13 and a negative meniscus 14 facing the image plane with a concave side; a mid-IR image receiver 15 with a cooled aperture, a far-IR lens D including a negative meniscus 16 facing the image plane with a convex side, a positive meniscus 17 and a negative meniscus 18 facing the image plane with a concave side; far infrared image receiver 19 with a cooled diaphragm.

The proposed optical system operates as follows. Radiation from a distant object is reflected successively from the main concave aspherical mirror 1 and the secondary convex aspherical mirror 2 and hits the spectrometer 6. The rays reflected from the spectrometer 6 after passing through lenses 3 and 4 of the compensator A form an image in the plane of the receiver 5. The rays refracted by the spectrometer 6 create an image in the rear focal plane of the mirror lens, and then converted into parallel beams using lenses 8, 9 and 10 of the common lens B. After so obtained t of the telescope system, parallel beams of rays fall onto the spectrometer 11. The rays reflected by the spectrometer 11 passing through the lenses 12, 13 and 14 of the lens C form an image in the plane of the receiver 15. The rays refracted by the spectrometer 11 passing through the lenses 16, 17 and 18 of the lens D form the image in the plane of the receiver 19. The lens-collective 7 serves to coordinate the entrance pupil located on the main mirror with aperture diaphragms, which are exit pupils in the middle and far infrared channels.

The three-channel mirror-lens optical system developed and proposed by the applicant has the following technical characteristics:

Entrance pupil diameter 700 mm Angular field in the space of objects 0.84 ° Relative hole 1: 2 Spectral range 1-1.8 μm 3-5 microns 8-12 microns

Thus, a three-channel mirror lens optical system can be implemented.

The claimed three-channel mirror-lens optical system allows you to:

- receive images on three receivers simultaneously;

- increase aperture ratio;

- get image quality close to diffraction;

- reduce the number of lenses while increasing simultaneously working channels;

- get the opportunity to work with a cooled receiver not only on average, but also in the far infrared range (8-12 microns).

Claims (1)

Three-channel mirror-lens optical system containing a mirror lens, including a main concave aspherical mirror and a secondary convex aspherical mirror, a lens compensator for a mirror lens for the visible or near infrared range, a lens for the middle infrared range, the first spectrometer, made in the form of an inclined plane-parallel plate, a receiver radiation of visible or near infrared range, the receiver of radiation of the middle infrared range with a cooling diaphragm, characterized in that a common lens for the middle and far infrared ranges is introduced, including a first biconvex lens, a convex-concave lens, and a second biconvex lens arranged in sequence along the rays, and arranged so that its front focal plane coincides with the rear focal the plane of the mirror lens; introduced a collective lens located in close proximity to the rear focal plane of the mirror lens; introduced a second spectrometer, made in the form of a plane-parallel plate and mounted between the main concave and secondary convex mirrors, perpendicular to the optical axis; the first spectrometer is located after the common lens in a parallel beam of rays; introduced a lens for the far infrared range, installed after the first spectrometer and including three single meniscus-shaped lenses sequentially located along the rays, the first meniscus facing the image plane with a convex side, the second and third concave; a far infrared radiation receiver with a cooled diaphragm was introduced.

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