EA033868B1 - Night vision system camera - Google Patents

Abstract

The invention relates to the field of optical surveillance in low-light conditions and can be used for dynamic observation in ground, water and air transport. The technical result at which the invention is aimed is reduction of risk of optical defects on an image obtained by a camera of a night vision system. The essence of the invention consists in that a camera of night vision system includes a housing, inside which light-sensitive matrix and objective lens with lenses are located, and is characterized in that a lens end surface comprises a coating of a light-absorbing material.

Description

The invention relates to the field of optical observation in low light conditions and can be used for dynamic observation in land, water and air transport.

A well-known mobile phone camera containing two lenses with inclined end surfaces and a photosensitive matrix, while one of the lenses contains a light-absorbing layer on the end surface [CN 107635090, publication date 01/26/2018, IPC: G02B 3/08, G03B 15/05 , H04M 1/02].

A known mobile phone camera module comprising a housing inside which lenses and a photosensitive matrix are located, wherein the lateral surface of each lens contains a light-protective layer [WO 2008093516, publication date 05/20/2010, IPC: G02B 7/02, H04N 5/225, H04N 5/335].

A disadvantage of the known technical solutions is the low quality of the image obtained when shooting video in low visibility conditions and at night even when using additional infrared illumination. This drawback is due to the fact that the photosensitive matrix used in the known technical solutions has a low sensitivity to light in the infrared range, and the camera module does not have the ability to switch to monochrome night mode, which greatly limits the functionality of known devices.

As a prototype, a camera module is selected that is capable of shooting in the dark, containing a lens with lenses and a matrix that is photosensitive to light in the infrared range, while the lens at the point of contact with the end surface of the lens contains inserts of light-absorbing material [WO 2017090437 A1, publication date 06/01/2017, IPC: G02B 3/00, G02B 7/02, G03B 19/00].

The advantage of the prototype over the known technical solutions is the ability to identify the contours of the object under observation in low light conditions due to the fact that the camera module, configured to shoot at night, has a matrix that is sensitive to light in the infrared range. However, the prototype has drawbacks consisting in optical defects in the image obtained by the camera of the night vision system in low light conditions when the subject is illuminated with infrared light. This is due to the multiple uncontrolled reflection of light passing through the lenses from dust particles that inevitably fall into the space between the end surface of the lens and the insert from the light-absorbing material, while the ingress of dust particles leads to the fact that between the light-absorbing material and the end surface of the lenses a gap is formed. The formation of a gap leads to the fact that the light passing through the lenses does not fall on the surface of the reflective material and is reflected from microroughnesses on the end surface of the lenses, which inevitably form during their manufacture, machining and fitting to the seat in the lens. As a result of this, the infrared light is refracted and scattered in the optical circuit of the lens and distorted light gets on the highly sensitive matrix, causing noise when converting the image projected onto it. As a result, the resulting image has low contrast and sharpness and contains glare and illumination of the subject, which significantly degrades the operational characteristics of the night-vision camera.

The technical problem to which the invention is directed is to improve the operational characteristics of the camera of the night vision system.

The technical result to which the invention is directed is to reduce the risk of optical defects in the image obtained by the camera of the night vision system.

The invention consists in the following.

The camera of the night vision system contains a housing, inside of which there is a photosensitive sensor and a lens with lenses. Unlike the prototype, the end surface of the lenses contains a coating of light-absorbing material.

The lens provides the ability to form an optical image from the reflection of light from objects. The type of lens can be collecting and scattering, and the design of the lens can be biconvex or flat-convex, as well as biconcave or flat-concave. In this case, the lens can be made of an optically transparent material, for example, optical glass, crystal or optical plastics.

The coating of the light-absorbing material makes it possible to reduce the reflectivity of microroughnesses having cracks and complex irregular cavities on the end surface of the lens, and eliminates the occurrence of a gap between the light-absorbing layer and the lens. The coating from the light-absorbing material should have a high level of absorption of electromagnetic radiation in the near, mid and far infrared ranges, which reduces the risk of optical defects in the image received by the camera of the night vision system in low light conditions. The coating may be black and may be represented by a sprayed light-absorbing nanopowder, paste or varnish based on light-absorbing nanopowders. In this case, graphite or cermet nanopowders can be used on

- 1,033,868 based on chromium and silicon monoxide, zirconium oxide or titanium oxide. Moreover, to fill deep and at the same time narrow cracks in the microroughness on the end surface of the lens and optimize its weight and size characteristics, the structural layer of light-absorbing material can be represented by alcohol-containing black ink.

The lens is a frame for lenses and provides the possibility of forming an optical circuit from them. The lens may have a fixed or variable focal length, which can be adjusted automatically and / or manually. The lens may have a collapsible design, which makes it possible to clean and replace lenses and reduce the risk of optical defects in the image received by the camera of the night vision system. Additionally, the lens may contain a removable infrared filter, which provides the ability to receive images by the camera of the night vision system in the daytime.

The photosensitive matrix is an analog or digital-to-analog integrated circuit containing LEDs that are highly sensitive to light in the IR range and provides the ability to convert the optical image projected onto it by an optical lens circuit into an analog electrical signal.

The housing can be of any shape and size, providing the ability to place the components of the camera system of night vision inside it. The housing may have a collapsible design, which allows cleaning or replacing components of the camera of the night vision system and reducing the risk of optical defects in the image obtained by the camera of the night vision system. The housing can be sealed, which reduces the risk of dust and moisture entering inside it and further reduces the risk of optical defects in the image received by the camera of the night vision system. The housing may contain fastening means, presented in the form of holes, brackets, hinges with suction cups, etc., providing the possibility of installing the camera of the night vision system in a vehicle, for example, in a car, motorcycle, boat, etc.

The invention is characterized by a previously unknown significant feature, namely, that the end surface of the lens contains a coating of light-absorbing material, which reduces the intensity of light reflected by the microroughness of the end surface of the lens, thereby reducing the risk of refracted and scattered light entering the photosensitive camera matrix of the night vision system, reducing the risk of noise when converting an image projected onto a matrix, thereby increasing contrast and sharply five and reducing the risk of glare and stray light in the image-capture object, which ensures the achievement of technical result consisting in reducing the risk of optical defects in the image, thereby improving performance night vision camera system.

The presence of previously not known from the prior art, a set of distinctive essential features indicates compliance of the invention with the patentability criterion of novelty and inventive step.

The invention can be made of known materials using known means, which indicates that the invention meets the patentability criterion of industrial applicability.

The invention is illustrated by the following figures.

FIG. 1 - the camera module of the prototype, the refraction of light reflected from microroughnesses on the end surface of the lens;

FIG. 2 - camera night vision system in a sealed enclosure;

FIG. 3 is an optical diagram of a camera of a night vision system, one lens contains a black alcohol-based ink coating;

FIG. 4 is an optical diagram of a night vision camera, all lenses contain black alcohol-based ink;

FIG. 5 - lens coated with reflective material.

The camera of the night vision system contains a housing 1, inside of which there is a lens 2 with lenses 3 and a photosensitive matrix 4, while the end surface of the lens 3 contains a coating of light-absorbing material 5.

The invention works as follows.

The camera is installed in a vehicle (not shown in the figures) to monitor the road situation in low light conditions. Objects on the road are illuminated by infrared light from a source (not shown in the figures) of light that is reflected from objects, passes through the lenses 3 of lens 2 and enters the photosensitive matrix 4. At the same time, due to the light-absorbing material 5, a significant decrease in the intensity of light reflected from irregularities located on the end surface of lenses 3, and only light reflected from objects on the road gets to the photosensitive matrix 4, which allows to increase the contrast and sharpness of the image CONTROL object of observation, and the image has no glare and flare. This ensures the achievement of the technical result, which consists in reducing the risk of

- 2 033868 optical defects in the image, thereby improving the operational characteristics of the camera system of night vision.

Claims (6)

CLAIM 1. The camera system of night vision, comprising a housing, inside of which there is a photosensitive matrix and a lens with lenses, characterized in that the end surface of the lenses contains a coating of light-absorbing material. 2. The chamber according to claim 1, characterized in that the coating of light-absorbing material is represented by sprayed graphite nanopowder. 3. The chamber according to claim 1, characterized in that the coating of light-absorbing material is represented by alcohol-containing black ink. 4. The camera according to claim 1, characterized in that the lens has a collapsible design. 5. The camera according to claim 1, characterized in that the housing has a collapsible design. 6. The camera according to claim 1, characterized in that the housing is sealed.