CN116539166A - Thermal infrared imager capable of preventing burn - Google Patents

Abstract

The invention discloses an anti-burn thermal infrared imager which comprises a detector and a filter film, wherein the detector is used for receiving light rays; the filter film is positioned on the light propagation path to cut off the strong light rays with any wave band within the range of 0.5-5.5 mu m. The filter film is arranged on the propagation path of the light received by the detector, so that the filter film can cut off strong light with the wavelength of 0.5-5.5 mu m, and the harmful light intensity is effectively reduced; meanwhile, only the light with the wavelength being outside 0.5-5.5 mu m is transmitted through the filter film, so that the proportion of the effective infrared light of the target is improved. By the arrangement, the purpose of preventing the thermal infrared imager from being burnt is achieved, and the traditional complex anti-burning mechanism and image algorithm are replaced, so that the thermal infrared imager has a simple integral structure and effectively reduces the cost of the thermal infrared imager. When the detector is used, the same type of filter film can be selected according to the types of strong light such as solar rays, laser beams and the like, so that irreversible burns on the detector are avoided.

Description

An anti-burn infrared thermal imager

technical field

The invention relates to the technical field of infrared detection, in particular to an infrared thermal imager for preventing burns.

Background technique

The infrared thermal imaging camera uses the infrared light emitted or reflected by the scene to image on the infrared focal plane through the optical system, and uses the infrared detector and the readout circuit to display the scene. When there are strong light sources such as sunlight and lasers in the field of view of the infrared thermal imaging camera, the infrared energy emitted by strong light sources such as sunlight and lasers is extremely high, and it is easy to cause irreversible damage to the detector after focusing on the infrared detector. This kind of damage is called "burn", so when using the thermal imaging camera, try to avoid the thermal imaging camera from being burned by strong light.

In the prior art, the anti-burn of the infrared thermal imaging camera is mainly aimed at sunlight, and there are mainly the following three methods:

1. Infrared image discrimination method, such as described in the invention patent with the application number "CN202010153062.1": by analyzing the gray distribution of the obtained infrared image, identify whether there are arc or circular high-temperature pixels in the picture , so as to determine whether there is a sun in the picture. This method requires a full-frame search for each frame of image, the algorithm is complex and takes up a lot of computing resources, and the cost is high; at the same time, it lacks prompts for burning scenes that are or will be produced.

2. Azimuth feedback, through the algorithm to determine whether the sun is within the field of view of the thermal imager, so as to protect against burns. For example, it is described in the invention patent with the application number "CN202111519428.3": By obtaining the field of view angle of the thermal imager, obtaining the orientation information of the sun, obtaining the orientation information of the boresight of the infrared thermal imager, and determining the field of view of the sun and the thermal imager location, burn protection. This method needs to use modules such as GPS or Beidou, inertial measurement unit, etc., the system is complex and the cost is high.

3. The method of physical isolation, which uses the partial occlusion of the light bar to cut off the external light source. For example, the invention patent with the application number "CN202211389868.6" uses a linear transmission device to drive the light bar to partially block the sunlight in the scene. Although it can ensure the acquisition of other target images in the scene, there are problems such as complex structure and high cost.

Therefore, the existing technologies mainly focus on preventing sunburn from sunlight and have limitations in use, and the system is more complicated and the cost is higher.

Contents of the invention

In view of the above problems, the present invention provides an anti-burn infrared thermal imaging camera that overcomes the above problems or at least partially solves the above problems, which can solve the limitations and high cost of preventing sun burns in the prior art, The effect of effectively preventing the burn of the infrared thermal imager and lowering the protection cost is achieved.

Specifically, the present invention provides an anti-burn infrared thermal imaging camera, including:

a detector for receiving light;

A filter film, the filter film is located on the propagation path of the light, so as to cut off strong light rays of any wavelength within the range of 0.5 μm-5.5 μm.

Optionally, the cut-off band of the filter film is 0.5 μm-5.0 μm; preferably, the cut-off band of the filter film is 0.5 μm-4.2 μm.

Optionally, the filter film is configured to make the transmittance of the strong light in the cut-off wavelength band lower than 1%.

Optionally, the cut-off band of the filter film is set according to the strong light to be cut off, and the strong light includes at least one of sunlight and laser beams.

Optionally, the detector includes a detector window and a detector focal plane, and the detector window and the detector focal plane are spaced apart; the light passes through the detector window and is incident on the detector focal plane. on flat surface;

The filter film is coated on the detector window.

Optionally, the infrared camera also includes:

an optical system, the optical system is arranged in front of the detector, so that the light rays are converged by the optical system and incident on the detector;

The filter film is arranged on the optical system.

Optionally, the optical system includes one or more lenses; the filter film is coated on one or both surfaces of the lenses.

Optionally, the infrared camera also includes:

an optical system, the optical system is arranged in front of the detector, so that the light rays are converged by the optical system and incident on the detector;

The optical window is arranged on the front side or the rear side of the plurality of optical systems; the filter film is coated on one side or both sides of the optical window.

Optionally, the infrared camera also includes:

An optical system, the optical system is arranged in front of the detector, so that the light rays are converged by the optical system and incident on the detector; the optical system includes a plurality of lenses;

An optical window, the optical window is arranged between a plurality of the lenses; the filter film is coated on one side or both sides of the optical window.

Optionally, the detector is a long-wave infrared detector.

The beneficial effects of the present invention are:

In the anti-burn infrared thermal imager provided by the present invention, since a filter film is provided on the propagation path of the light received by the detector, the filter film can block strong light rays of any wavelength within the range of 0.5 μm-5.5 μm, Effectively reduces the intensity of harmful light; at the same time, only light with a wavelength outside 0.5μm-5.5μm passes through the filter film, increasing the proportion of effective infrared light of the target. This setting not only achieves the purpose of preventing the burn of the infrared thermal imager, but also replaces the traditional complex anti-burn mechanism and image algorithm, the overall structure is simple, and the cost of the infrared thermal imager is effectively reduced.

Further, in the anti-burn infrared thermal imaging camera provided by the present invention, the strong light includes at least sunlight and laser beams. In addition to sunlight, strong light such as laser beams is also likely to cause irreversible burns to the detector, so the cut-off band of the filter film is set according to the strong light to be cut off. Strong light includes sunlight, laser beams, etc. at least one. When applying, the same type of filter film can be selected according to the type of strong light to avoid irreversible burns to the detector.

According to the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will be more aware of the above and other objects, advantages and features of the present invention.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of illustration and not limitation with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the attached picture:

Fig. 1 is a schematic structural diagram of an anti-burn infrared thermal imaging camera according to an embodiment of the present invention.

Description of reference numerals: 1. Optical window, 2. Lens, 3. Filter film, 41. Detector window, 42. Detector focal plane.

Detailed ways

Referring to FIG. 1 , the burn-proof thermal imaging camera according to the embodiment of the present invention will be described below. In the description of this embodiment, it should be understood that the terms "first" and "second" are only used for descriptive purposes, and cannot be interpreted as indicating or implying relative importance or implicitly indicating the number of indicated technical features . Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined. When a feature "comprises or comprises" one or some of the features it encompasses, unless specifically stated otherwise, this indicates that other features are not excluded and that other features may be further included.

Unless otherwise expressly specified and limited, terms such as "disposed", "installed", "connected", "connected", "fixed" and "coupled" should be interpreted in a broad sense, for example, it may be a fixed connection or a detachable Disconnected connection, or integrated; may be mechanically connected, may also be electrically connected; may be directly connected, may also be indirectly connected through an intermediary, may be an internal communication between two components or an interactive relationship between two components, unless otherwise There are clear limits. Those of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention according to specific situations.

In addition, in the description of this embodiment, the first feature being "on" or "under" the second feature may include that the first and second features are in direct contact, and may also include that the first and second features are not in direct contact but is through additional feature contacts between them. That is to say, in the description of this embodiment, the first feature being "above", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontal The height is higher than the second feature. "Below", "beneath" or "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this embodiment, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "examples," "specific examples," or "some A specific feature, structure, material, or characteristic described in an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

When the infrared thermal imaging camera is working during the day, if there are strong light sources such as sunlight and lasers in the field of view, the infrared energy emitted by strong light sources such as sunlight and lasers is extremely high, and it is easy to damage the detector after focusing on the infrared detector. Cause irreversible damage, usually this kind of damage is called "burn". Therefore, when using the infrared thermal imaging camera, try to avoid the infrared thermal imaging camera from being burned by strong light. At the same time, strong light sources such as sunlight and lasers will cause serious interference to the infrared thermal imager, forming a high-brightness area on the infrared image. If the target uses the high-brightness area as the background, the signal-to-noise ratio of the target will be reduced or even be obscured by the background. Annihilation, which seriously affects the detection device to lock and track the target.

The infrared image discrimination method in the prior art requires a full-frame search for each frame of image, the algorithm is complex and takes up a lot of computing resources, and there is no prompt for the occurrence or imminent burning scene. The azimuth feedback method in the prior art uses an algorithm to determine whether the sun is within the field of view of the thermal imager, so as to protect against burns. This method is complex and requires modules such as GPS, Beidou, and inertial measurement units, and the cost is relatively high. The physical isolation method in the prior art utilizes the partial occlusion of the light bar to cut off the external light source, which requires the use of a linear module transmission mechanism. This method has complex structure and high cost.

So far, the impact of strong light sources on thermal imaging cameras and the existing protection methods have been introduced. Based on this, the inventor creatively proposed a design concept of setting a filter film to cut off the strong light, so as to avoid the strong light from affecting the infrared thermal imager. Among them, Fig. 1 is a schematic structural diagram of an anti-burn infrared thermal imager according to an embodiment of the present invention. As shown in Fig. 1, an embodiment of the present invention provides an anti-burn infrared thermal imager, including a detector And a filter film 3, the detector is used to receive light; the filter film 3 is located on the propagation path of the light to cut off strong light of any wavelength within the range of 0.5 μm-5.5 μm.

In the embodiment of the present invention, since the optical filter film 3 is provided on the propagation path of the light received by the detector, the optical filter film 3 can cut off strong light rays of any wavelength within the range of 0.5 μm-5.5 μm, effectively reducing harmful light Intensity; this setting not only achieves the purpose of preventing the thermal imager from burning, but also replaces the traditional complex anti-burn mechanism and image algorithm, the overall structure is simple, and the cost of the infrared thermal imager is effectively reduced.

At the same time, since only the light with a wavelength of 0.5 μm-5.5 μm is transmitted through the filter film 3, the proportion of the target infrared light is increased, and high-brightness areas are avoided on the infrared image, so that the signal-to-noise ratio of the target will not be reduced It is even obliterated by the background, so that the detection device can continue to lock and track the target.

Preferably, the cut-off band of the filter film 3 is 0.5 μm-5.0 μm; more preferably, the cut-off band of the filter film 3 is 0.5 μm-4.2 μm. Since the infrared wave bands that are likely to cause irreversible damage to the detector of the infrared thermal imager are mostly concentrated in the wavelength range of 0.5 μm-5.0 μm, and more of them are concentrated in the interval of 0.5 μm-4.2 μm, the preferred filter in the embodiment of the present invention The wavelength of the strong light cut off by the optical film 3 is 0.5 μm-5.0 μm; and more preferably, the wavelength of the strong light cut off by the filter film 3 is 0.5 μm-4.2 μm.

In some embodiments of the present invention, the filter film 3 is configured to make the transmittance of the strong light in the cut-off wavelength band lower than 1%, so as to avoid causing irreversible damage to the detector after the strong light is focused on the detector. burns.

In some embodiments of the present invention, the strong light includes at least sunlight and laser beams. In addition to sunlight, strong light such as laser beams is also likely to cause irreversible burns to the detector, so the cut-off band of the filter film 3 is set according to the strong light to be cut off. The strong light includes sunlight, laser beams, etc. at least one of . During application, the same type of filter film 3 can be selected according to the type of strong light to avoid irreversible burns to the detector.

In some embodiments of the present invention, the detector includes a detector window 41 and a detector focal plane 42, and the detector window 41 and the detector focal plane 42 are arranged at intervals; light passes through the detector window 41 and is incident on the detector focal plane 42 on; the filter film 3 is plated on the detector window 41 .

In the embodiment of the present invention, light converges on the detector window 41, passes through the detector window 41 and is imaged on the detector focal plane 42. After the filter film 3 is plated on the detector window 41, the filter film 3 can Cut off the strong light to avoid irreversible burns to the detector. At the same time, a corresponding filter film 3 can be plated on the detector window 41 according to the type of strong light.

In some embodiments of the present invention, the anti-burn infrared thermal imager also includes an optical system, and the optical system is arranged in front of the detector, so that the light is converged through the optical system and incident on the detector; the filter film 3 is arranged in the optical system superior.

The optical system in the embodiment of the present invention refers to a coaxial spherical system composed of two or more refracting spherical surfaces whose centers of curvature are on the same straight line and which are combined in a certain order by various optical elements such as lens 2 and diaphragm. After passing through the optical system, the light converges and passes through the detector window 41 . Because the optical system is also provided with a filter film 3, so that the strong light rays are cut off; and the filter film 3 on the detector window 41 cuts off the strong light rays passing through the filter film 3 on the optical system again, so that The intensity of the glare rays impinging on the focal plane 42 of the detector is further reduced.

Specifically, the optical system includes one or more lenses 2 ; the filter film 3 is coated on one side or both sides of the lens 2 . The filter film 3 can be coated on one or more lenses 2 as required, and can be coated on one side or both sides of the lens 2 as required.

In some embodiments of the present invention, the anti-burn infrared thermal imaging camera also includes an optical system and an optical window 1, the optical system is arranged in front of the detector, so that the light is converged by the optical system and incident on the detector; the optical window 1 is set On the front side or back side of multiple optical systems; the filter film 3 is coated on one side or both sides of the optical window 1 .

Or, in other embodiments of the present invention, the anti-burn infrared thermal imager also includes an optical system and an optical window 1, and the optical system is arranged in front of the detector, so that the light is converged by the optical system and incident on the detector; The system includes a plurality of lenses 2; an optical window 1 is arranged between the plurality of lenses 2; a filter film 3 is coated on one side or both sides of the optical window 1.

In the embodiment of the present invention, since the optical window 1 is also coated with a filter film 3, the strong light can be further cut off to avoid irreversible burns to the detector. At the same time, a corresponding filter film 3 can be plated on the detector window 41 according to the type of strong light.

Specifically, the optical window 1 is made of high transmittance infrared material. Preferably, the optical window 1 is made of germanium material. Specifically, the optical window 1 is made of germanium single crystal, which has good mechanical properties and thermal conductivity, and its transmission spectrum ranges from 2 to 12 μm, and has a wide light transmission range and opacity in the visible light band. Therefore, it is suitable for the infrared optical lens and the infrared optical window 1 for protecting the infrared optical lens.

In some embodiments of the invention, the detector is a long wave infrared detector. Since the wavelength range detected by the long-wave infrared detector is 8-14 μm, the light with a cut-off of 0.5 μm-5.5 μm will not have an adverse effect on the long-wave infrared detector, and can effectively reduce the intensity of harmful light; at the same time, because only the wavelength is within The light beyond 0.5 μm-5.5 μm passes through the filter film 3, which increases the proportion of target infrared light and avoids forming high-brightness areas on the infrared image, so that the signal-to-noise ratio of the target will not be reduced or even be obliterated by the background, thereby enabling Make the detection device continuously lock and track the target.

Specifically, the coating position of the filter film 3 can be located at one or more of the surface of the optical window 1, the surface of the lens 2, and the surface of the detector window 41; filter film 3, to solve the problems of complex algorithms and structures, high system cost, and untimely response in the methods of preventing sun burns in the prior art, so as to realize real-time protection against sun rays, lasers, etc. Strong light burn protection, simple structure, and effective system cost reduction; at the same time, the anti-burn infrared thermal imaging camera burn protection range is expanded from simple sun burn protection to laser and other harmful strong light burn protection.

So far, the technical solutions of the present invention have been described in conjunction with the foregoing embodiments. However, those skilled in the art can easily understand that the protection scope of the present invention is not limited to these specific embodiments. Without departing from the technical principles of the present invention, those skilled in the art can split and combine the technical solutions in the above-mentioned embodiments, and can also make equivalent changes or replacements to the relevant technical features. Any changes, equivalent replacements, improvements, etc. made within the concept and/or technical principles will fall within the protection scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other changes, equivalent replacements or improvements.

Claims (10)

1. An anti-burn thermal imager, characterized in that, comprising: a detector for receiving light; A filter film, the filter film is located on the propagation path of the light, so as to cut off strong light rays of any wavelength within the range of 0.5 μm-5.5 μm. 2. The anti-burn thermal imaging camera according to claim 1, characterized in that, The cut-off band of the filter film is 0.5 μm-4.2 μm. 3. The anti-burn thermal imaging camera according to claim 1, characterized in that, The filter film is configured to make the transmittance of the strong light in the cut-off band lower than 1%. 4. The anti-burn thermal imaging camera according to claim 1, characterized in that, The cut-off band of the filter film is set according to the strong light to be cut off, and the strong light includes at least one of solar light and laser beam. 5. The anti-burn thermal imaging camera according to claim 1, characterized in that, The detector includes a detector window and a detector focal plane, the detector window and the detector focal plane are spaced apart; the light passes through the detector window and is incident on the detector focal plane; The filter film is coated on the detector window. 6. The anti-burn thermal imaging camera according to claim 1, wherein the thermal imaging camera further comprises: an optical system, the optical system is arranged in front of the detector, so that the light rays are converged by the optical system and incident on the detector; The filter film is arranged on the optical system. 7. The anti-burn thermal imaging camera according to claim 6, characterized in that, The optical system includes one or more lenses; the filter film is coated on one side or two sides of the lens. 8. The anti-burn thermal imaging camera according to claim 1, wherein the thermal imaging camera further comprises: an optical system, the optical system is arranged in front of the detector, so that the light rays are converged by the optical system and incident on the detector; The optical window is arranged on the front side or the rear side of the optical system; the filter film is coated on one side or both sides of the optical window. 9. The anti-burn thermal imaging camera according to claim 1, wherein the thermal imaging camera further comprises: An optical system, the optical system is arranged in front of the detector, so that the light rays are converged by the optical system and incident on the detector; the optical system includes a plurality of lenses; An optical window, the optical window is arranged between a plurality of the lenses; the filter film is coated on one side or both sides of the optical window. 10. The anti-burn thermal imaging camera according to claim 1, characterized in that, The detector is a long-wave infrared detector.