RU96263U1 - LASER RANGE TRANSMITTER CHANNEL OPTICAL SYSTEM - Google Patents

Abstract

 The optical system of the channel of the laser rangefinder transmitter, in which a telescope is installed on a common axis with the active element, which is a reversed afocal nozzle consisting of two components, characterized in that it also includes an inverted afocal nozzle in which the second component is made with a large focal length.

Description

The utility model relates to optical systems for the formation of a laser beam and can be used in the optical-mechanical industry in the design and manufacture of optical systems for military devices, in particular the channel of a laser rangefinder transmitter.

The problem of obtaining a collimated laser beam currently does not present any particular problems. There are various types of telescopic systems that make it possible to obtain collimated radiation [1], including Galilean-type telescopic systems [2]. However, such designs do not allow changing the divergence of radiation at a given distance.

At present, for laser rangefinders in the transmitter channel, an optical system is used to form a laser beam with a constant angular divergence of the radiation pattern, which provides reliable measurement of ranges up to 5000 m [3, 4]. Long-range measurement of typical objects (tanks) over distances of more than 5000 m leads to the fact that the diameter of the laser beam spot exceeds the overall dimensions of the object. This leads to a decrease in the energy of reflected laser radiation and the reliability of measuring the distance to the object. It is desirable to have a device that allows you to change the divergence of the radiation pattern of the laser rangefinder.

The known optical channel system of the transmitter of the laser rangefinder, which is mounted on a common axis with the active element, is designed to reduce the angular divergence of radiation [3, 4]. The optical system is a reversed afocal nozzle with a magnification of 0.16 and includes two components: the first is a negative lens, the second is two positive. This allows you to get the angle of divergence of radiation no more. When measuring the range, the diameter of the spot of laser radiation at the object is calculated by the formula

where s is the distance from the laser rangefinder to the object;

2 ω is the angle of divergence of the laser radiation after the afocal nozzle.

Calculations show that at a distance of 5000 m the diameter of the laser spot at the object does not exceed 3 m, and at 10,000 m it is about 7 m, with a typical target height of 2.5 - 2.7 m. The spot becomes large, which leads to a decrease in accuracy taking measurements and does not allow for the ranging of a typical object. Additional measures are required to reduce the diameter of the spot of focused laser radiation, which can be done, for example, using an optical device that would discretely change the angle of divergence of laser radiation by 1.5 - 2 times.

The technical result of the utility model is to increase the measured distance to a typical object by changing the angular divergence within the limits at which the laser radiation focuses into a spot with a size close to the size of the object.

This result is achieved in that an inverted afocal nozzle with an increased focal length of the second component is additionally included in the channel of the laser rangefinder transmitter.

This utility model is illustrated by the presented drawing. Figure 1 shows the optical system of the transmitter channel with an additional afocal system, where 1 is the active element; 2 - the first component (negative lens); 3 - the second component (two positive lenses); 4 - transmitter channel housing; 5 - the second component of the additional system.

Figure 2 shows examples of the use of the transmitter channel for a typical object at different ranges: Fig. 2a) is a view of the field of view of the range finder grid with a focus spot (where 1 is a spot of laser radiation; 2 is an aim mark (gap of a goniometric grid)); Fig.26) - measuring the range of a typical object up to 5000 m (where 3 is a typical object); figv) - measuring the range of a typical object over 5000 m; 2 g) - change in range for a typical object with an optical system.

The overall calculation of the optical system of the transmitter channel was carried out using the visible magnification formula:

where D is the diameter of the entrance pupil;

- diameter of the exit pupil;

2ω is the angle of divergence of the laser radiation;

2 - angle of divergence of the laser radiation after the channel of the transmitter.

The calculations showed that at a focal length of the second component of 120 mm, the laser beam divergence was that allows you to get a spot with a diameter of 2 m at a distance of 5000 m. This ensures that the spot captures the radiation of the dimensions of a typical target.

The principle of operation of the channel of the laser rangefinder transmitter is as follows. Pointing the range finder at the object, its minimum area falling into the gap of the goniometer grid is estimated (Fig. 2a), if the dimensions of the object fit into the grid gap of the laser range finder (Fig. 2b), then on the common axis with the active element 1 (Fig. 1) optical system with components 2,3. With increasing range, the dimensions of the object become smaller than the gap of the goniometric grid (Fig.2c), the laser spot 1 will exceed the overall dimensions of the target 3, then using the mechanism on the common axis with the active element 1 (Fig.1) an optical system with components 2 is turned on 5 with an increased focal length of component 5, which will cause a decrease in the angular divergence of the laser radiation of the range finder. When measuring distances of more than 5000 m, the diameter of the laser spot 1 (Fig. 2a) will completely fit into the overall dimensions of a typical target, thereby increasing the probability of a reliable measurement.

The implementation of the utility model allows to increase the range of reliable measurements by reducing the angular divergence of the laser rangefinder radiation by using an additional optical system in the transmitter channel.

Information sources:

1. Rusinov M. M. Composition of optical systems. - L.:

Engineering, 1989 .-- 268 p.

2. Optical devices in mechanical engineering: a directory. - M.:,

Engineering, 1974.- 238 p.

3. Rangefinder artillery quantum DAK - 2M (index 1D11M).

Technical description and instruction manual. D 36.48.070 TO

4. Laser reconnaissance device LPR-1 (index 1D13). Technical

Description and instruction manual. D 36.48.063 TO

Authors: Fedotov VN

Fedotov A.V.

Agunkin P.N.

Ustinov E.M.

Udalkin A.G.

Kurenkov A.V.

Claims (1)

The optical system of the channel of the laser rangefinder transmitter, in which a telescope is installed on a common axis with the active element, which is a reversed afocal nozzle consisting of two components, characterized in that it also includes an inverted afocal nozzle, in which the second component is made with a large focal length.