RU1841058C - Optoelectronic system - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to direction-finding and heat imaging means and can be used in developing systems for displaying the surrounding thermal environment. The system includes a lens (1), a scanning element (2), a one-dimensional condenser (8), a line of radiant energy detectors (9) with power supply units (10), two groups of delay lines (11, 12), electronic switches (13), an amplifier (14), a synchroniser (15), a video monitor (16), a computer (17), a turning angle sensor (18) and a spring (19). The scanning element (2) is located in the focal region of the lens (1) and comprises a scanning frame (3), a pusher (4), a cam (5), a reducing gear (6) and an electric motor (7). The scanning frame (3) is in the form of a rectangular opaque plate, the longitudinal axis of symmetry of coincides with the axis of the pusher. Slits, whose height is equal to the height of the analysed frame, are made perpendicular to the longitudinal axis of symmetry of said plate. The distance between the slits is equal to the width of the one-dimensional condenser (8). The one-dimensional condenser (8) is in the form of a cylindrical lens, the height of which is equal to the length of the line of detectors (9) and the width is equal to the width of the analysed frame. The one-dimensional condenser (8) is optically interfaced with the line of detectors (9) and is placed at a minimal distance from the scanning element (2).

EFFECT: simple system and high image quality.

2 dwg

Description

The present invention relates to the field of thermal imaging and direction finding tools and can be used to develop systems for displaying the surrounding thermal environment, detecting brighter small objects against its background and determining their coordinates in the infrared range of radiation waves.

In the analogues and prototype are not considered information processing systems, since they do not relate to the subject of the invention.

Typically, an information processing system includes electronic keys, delay lines, power supplies, amplifiers, etc. One of the possible implementations of this invention is shown in the device of this invention.

In optical-electronic devices, there are two main types of scanning systems: scanning in parallel and converging beams of rays. The following elements are usually used as scanning elements: an oscillating mirror, a rotating mirror drum, a rotating prism, a rotating wedge, etc.

Consider the advantages and disadvantages of the above types of optical scanning devices.

The location of the scanning mirror in a parallel beam of rays (in front of the lens) does not introduce additional aberrations, but leads to large dimensions and weights of the mirror, as well as to tight tolerances on the manufacturing quality of its reflective surface, which causes astigmatism when the mirror is tilted at an angle of 45 ° to the optical axis the lens.

If you place an oscillating mirror between the telescopic system and the lens of the radiation receiver, then its size decreases sharply. The disadvantage is that the scanning angle in the space of objects varies depending on the distance over which the system is focused. Similarly, depending on the distance over which the system is focused, the movement of the rays in the image plane changes.

In a converging beam of rays, the oscillating mirror is small, but due to the aberrations of the lens, the scattering circle of the point source of radiation increases.

A significant drawback of oscillating mirrors when scanning at high speed is their instability near the edges of the field of view. Therefore, at high scanning speeds, rotating mirror drums are often used. In a converging beam, they have a strong defocus in the image plane due to the displacement of the center of the face. Therefore, they are used in a parallel beam. In this case, the dimensions and weight of the mirror drum are greatly increased. Although the movement of the mirror drums is continuous, nevertheless, all the disadvantages of the scanning mirror in a parallel beam of rays are inherent in them.

Prismatic scanning systems in a converging beam are small in size. Their movement is continuous and stable. Small motors are used to drive them.

Disadvantages: low sweep utilization, focus shift, aberration, large reflection losses, the creation of a modulated interference superimposed on the thermal picture due to a change in intrinsic radiation depending on the scanning angle.

Rotating refracting wedges try on in a parallel beam of rays, because in convergent beams they cause strong aberrations. Using two rotating wedges allows you to get a linear sweep, sweep in a circle, etc. The disadvantages include blurring of the scattering circle due to the movement of the wedges, nonlinearity of the sweep in time, low sweep utilization due to a change in speed according to the sinusoidal law (when scanning according to the linear law).

See L.Z. Kriksunov, ″ Guide to the basics of infrared technology ″, M., publishing house ″ Soviet Radio ″, 1978, pp. 207-218; J. Lloyd, ″ Thermal Imaging Systems ″, M., publishing house ″ Mir ″, 1978, pp. 258-291.

In devices (see auth. USSR certificate No. 778690, No. 606503, No. 563742), the input optical stream is deployed frame-by-frame using a frame mirror and is projected using a lens onto a linear multi-element radiant energy receiver (LLLF), i.e. scanning in a parallel beam of rays is applied.

As mentioned above, such devices have the following disadvantages:

- large size and weight of the mirror;

- the appearance of astigmatism in the image of a point radiation source due to the quality of manufacture of the mirror and its location at an angle of 45 ° to the optical axis of the lens;

- low frequency of mirror scanning.

The device, which is taken as a prototype (see ed. Certificate of the USSR No. 847887), also uses scanning in a parallel beam of rays, where the scanning device is a rotating mirror drum.

The disadvantages of this device are as follows:

- large size and weight of the drum;

- the appearance of astigmatism in the image of a point source of radiation;

- at small scan angles, a small sweep utilization coefficient is observed.

The purpose of the invention is to simplify the system while improving image quality.

This goal is achieved due to the fact that in an optical-electronic system containing a lens, a scanning device with a gearbox and an actuator, located in the focal plane of the lens, LMPLE, VKU, a computing device, a synchronizer and an information processing system, the output of which is connected to the first inputs of the VKU and the computing device, and the second and third inputs of the VKU are connected to the first and second outputs of the synchronizer, the third output of which is connected to the input of the information processing system and the second input In addition to the computing device, the scanning device is made in the form of a rectangular opaque plate, in which there are vertical slots, the height of which and the distance between them are equal to the height and width of the analyzed frame, the plate being connected to the spring on one side and through the pusher on the other connected to a cam, which on two sides relative to the X axis of the Cartesian coordinate system from 45 ° to 180 ° is made in an Archimedean spiral, and the gap between 45 ° and -45 ° is in the form of a straight line, and a one-coordinate condensate is introduced into it optically connected to LLLF, located at the minimum possible distance from the plate and overlapping the analyzed frame, its height equal to the length of LLLF, its width to the width of the analyzed frame, and a rotation angle sensor was introduced, connected to the gearbox by the input and connected to the output the third input of the computing device and the first input of the synchronizer.

The essence of the invention lies in the fact that the proposed scanning device:

- does not introduce any optical distortion into the image plane of the lens of the system;

- does not introduce modulated interference superimposed on the thermal picture of the image;

- has a (80 ÷ 90)% sweep utilization rate;

- has small dimensions and weight;

- it moves continuously;

- at a low speed of rotation of the cam, you can get a higher frame rate of the image;

This technical solution meets the criterion of ″ significant differences ″.

In FIG. 1 shows a functional block diagram of a system, and FIG. 2 shows a scanning device in a perspective view.

The composition of the proposed device (see Fig. 1) includes a lens 1, a scanning device 2 containing a scanning frame 3, a pusher 4 and a cam 5, a reducer 6, an actuator motor 7, a cylindrical lens 8, LMPLE 9 with power supplies 10, two groups delay lines 11 and 12, electronic keys 13, amplifier 14, synchronizer 15, video monitoring device (VKU) 16, computer 17, rotation angle sensor 18 and spring 19.

The scanning frame 3 is a rectangular opaque thin plate 20, in which there are narrow vertical slots 21. The height of the slots 21 and the distance between them are equal to the dimensions of the analyzed frame 22. The plate 20 is located in the focal plane of the lens 1. At the minimum possible distance from the plate 20 is located a cylindrical lens 8 optically coupled to LMLET 9.

The signal outputs of the elements LLLFME 9 (except the first one, which is connected directly) through the first group of delay lines 11 and electronic keys 13 are connected to the input of the amplifier 14, the output of which is connected to the first inputs of the VKU 16 and the computing device 17. The second and third inputs of the VKU, respectively connected to the first and second outputs of the synchronizer 15, the third output of which is connected to the supply inputs of the power supplies 10 of the elements LMLE 9, through the second group of delay lines 12 with the control inputs of electronic keys 13, with the second input countably -resolving device 17. The angle sensor 18 is connected to the gearbox 6, and its output is connected to the third input of the computing device 17 and the fourth input of the VKU.

A cam is a disk cam, i.e. it is external flat (see Fig. 2). It is outlined on two sides relative to the X axis by 135 ° in an Archimedean spiral (sections SA and SB), and between points A and B there is a straight AB. The pointed pusher 4 is rigidly connected to the scanning frame 3, which is connected to the spring 19.

The device operates as follows. The lens 1 in its focal plane forms a thermal picture of the investigated area of space, which is determined by the size of the analyzed frame 22. The actuating motor 7 rotates the cam 5 with the help of a reducer 6, which moves the scanning frame 3 by means of the pusher 4. The spring 19 compresses the scanning frame 3 against the cam 5. When the cam 5 is rotated, the scanning frame 3 will move along the X axis of the Cartesian coordinate system. Its slots 21 will sequentially pass through the analyzed frame 22. One slit leaves the frame, the other enters it. The number of slots 21 in the scanning frame 3 is determined by the stroke of the cam 5 (segment SD) and the width of the analyzed frame 22.

So, for example, Archimedes relied on the equation r = a φ (where r is the polar radius, a is the constant, φ is the angle of rotation), for a = 2.5 cm, the working stroke of cam 5 is ≈ 6.0 cm. When the width of the analyzed frame 22, equal to ≈1.0 cm, 6 slots 21 are made in the scanning frame 3, which scan the analyzed frame 22 6 times from left to right and 6 times from right to left, i.e. at one complete rotation of the cam 5 (360 °), 12 frames of the analyzed frame 22 are observed.

Since the cam 5 is outlined in an Archimedean spiral, the slots 21 have a constant speed when passing through the analyzed frame 22.

The lines of the thermal image with the help of a cylindrical lens 8 are supplied to the LMPLE 9, the elements of which generate electrical signals proportional to the magnitude of the incoming radiation flux. Electrical signals from the elements of the LLLFME 9, passing through the first group of delay lines 11 and electronic keys 13, are fed through an amplifier 14 to the first inputs of the VKU 16 and the computing device 17. From the third output of the synchronizer 15, power supply pulses 10 are supplied, forming the image lines of the analyzed frame 22. These same pulses through the second group of delay lines 12 are supplied to the control inputs of electronic keys 13, as well as to the second input of the computing device 17. The second group of delay lines 12 and electronic keys 13 serve so that at any given moment of time only one element of LMPLE 9 is connected to the amplifier 14. From the first and second outputs of the synchronizer 15, synchronization pulses are sent in rows and frames to the second and third inputs of the VKU 16. From the angle sensor 18, the pulses from the shaft-code converter are received at the third input of the computer and at the first input of the synchronizer.

On the screen of VKU 16, a visual thermal picture of the analyzed frame 22 with brighter point sources of radiation is formed. The computing device 17 provides the Cartesian coordinates of these point radiation sources.

The proposed scanning device has the following significant advantages compared with the known:

- does not make any optical changes to the image plane of the lens of the system;

- does not create modulated interference superimposed on the thermal picture of the image;

- has a (80 ÷ 90)% sweep utilization rate;

- has small dimensions and weight;

- it moves continuously;

- at a low speed of rotation of the cam, you can get a higher frame rate of the image;

In the proposed device, as an optical system, you can use mirror, mirror-lens or lens lenses such as PIKAR-11, Irtal-4, V-1604, etc. As radiation detectors, indium antimonide, lead-cooled receivers cooled to 80 K can be used -tin-tellurium, mercury-cadmium-tellurium, etc., for example, FUL-132 OS2.003.023 TU, FRO-152P OC4, 681.070 TU, "Arga-2" and other linear or matrix radiation detectors.

As a computer, a computer is used. For these purposes, you can use computers of type K1-20, K1-30, DVK-2M, EC1840 or any other, the functionality of which allows you to perform the operations described below (see. "Microprocessor means and systems", M., No. 4, 1986 , p. 7, 15.). It is possible to perform a computing device also in hardware, since the operations are simple.

The proposed device uses a photovoltaic type OEPMK-16 (see. "Photoelectric information converters", M., publishing house "Engineering", 1974, p. 367). From the OEPMK-16 output, a natural binary parallel code is received characterizing the angle of rotation of the shaft of the gearbox of the executive electric motor. The digital code is linearly dependent on the angle of rotation of the shaft. The OEPMK-16 code is sent to the computer. The computer also receives horizontal pulses of the synchronizer. At the moment of arrival of the target's pulse on the computer, its coordinates are issued to the information use device. Knowing the code at each moment the angle of rotation of the shaft and from which element of the receiver the target impulse arrived, it is possible to determine its coordinates 7.

Claims (1)

Optoelectronic system containing a lens, a scanning element with a gearbox and an electric motor located in the focal plane of the lens, a line of radiant energy receivers, a video monitoring device, a computing device, a synchronizer and an information processing system, the output of which is connected to the first inputs of the VCU and a deciding device, and the second and third inputs of the ACU are connected to the first and second outputs of the synchronizer, the third output of which is connected to the input of the information processing system and the second input of the counting o-resolving device, characterized in that, in order to simplify the device and improve image quality, it is equipped with a single-axis condenser, the height of which is equal to the length of the receiver line, and the width is the width of the analyzed frame, optically paired with the receiver line and placed at a minimum distance from the scanning element, a spring connected to one end of the scanning element, a pusher interacting with the opposite end of the scanning element, a cam, which on both sides relative to the axis X ″, coinciding with the axis of the pusher, the Cartesian coordinate system in the range of angles from 45 ° to 180 ° is made in an Archimedean spiral, and in the interval between + 45 ° and -45 ° - in the form of a straight line, as well as a rotation angle sensor mounted on the gearbox electrically connected to the third input of the computing device and the first input of the synchronizer, while the scanning element is made in the form of a rectangular opaque plate, the longitudinal axis of symmetry of which coincides with the axis of the pusher and in which perpendicular to the longitudinal axis of symmetry are made and whose height is the height of the analyzed frame, and the distance between which is equal to the width of the one-coordinate of the condenser.

Images