A window-through viewing device based on narrow-band filtering technology

Abstract

This utility model relates to the field of detection imaging reconnaissance technology, specifically a window-penetrating observation device based on narrowband filtering technology. It includes a laser illumination component, a television imaging component, and a signal processing and control component. The laser illumination component, consisting of a laser, a temperature controller, and a beam-shifting objective lens, provides a stable light source for window-penetrating detection imaging. The television imaging component, consisting of a CMOS detector and a continuous zoom objective lens, enables clear imaging of targets behind the window. The signal processing and control component facilitates information exchange with a higher-level system and controls the laser and CMOS detector. This window-penetrating observation device uses a TEC temperature controller to control the laser temperature, reducing the laser's wavelength drift range. Combined with narrowband filtering technology, it intercepts stray light from the environment, improving the window-penetrating imaging effect. Modulating the continuous laser into a pulsed laser and controlling the laser emission timing reduces the laser emission duration, improving the device's reliability.

Description

Technical Field

[0001] This utility model belongs to the field of all-weather detection imaging reconnaissance technology, specifically relating to a window observation device based on narrowband filtering technology. Background Technology

[0002] Penetration imaging technology is an advanced reconnaissance technique that utilizes laser scanning penetration imaging, X-ray imaging, infrared imaging, and ultrasonic penetration imaging to observe the situation behind obstacles. Currently, it is mainly used in the medical and military fields. Window-through observation equipment is a type of penetration imaging equipment and plays an important role in military reconnaissance, enabling clear detection and imaging of targets behind windows in complex environments. Furthermore, it has wide applications in urban warfare, public security counter-terrorism, border and coastal defense, and intelligent transportation. During the day, in good weather and with high visibility, the light inside a room is much weaker than the outside light, and some windows may be coated with light-blocking film, significantly reducing the brightness inside the room. Conventional imaging observation equipment struggles to effectively and clearly observe target information inside windows. At night, ordinary imaging observation equipment is even less capable of detecting and imaging targets behind windows in unlit rooms. Therefore, to achieve all-weather detection and reconnaissance of targets behind windows in unlit rooms, there is an urgent need to develop a dedicated window-through observation device. Utility Model Content

[0003] In response to the above situation, this utility model provides a window observation device based on narrowband filtering technology. By using narrowband filtering technology to avoid the influence of ambient light interference, it ensures that the final output of the imaging detector contains only the image detected by laser illumination, and can achieve clear imaging detection of targets behind the window in all weather conditions.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A window-through observation device based on narrowband filtering technology mainly consists of a laser illumination component, a television imaging component, a signal processing and control component, a main body, and cables. The laser illumination component comprises a laser, a temperature controller, and a beam-shifting objective lens, used to provide a stable light source required for window-through detection imaging. The television imaging component comprises a CMOS detector and a continuous zoom objective lens, used to achieve clear imaging of the target behind the window. The signal processing and control component is used to realize information interaction with the upper-level system and to control the operation of the laser and CMOS detector. The main body provides installation space for the various components of the window-through observation device. The electrical signals between the components are connected via cables.

[0006] Furthermore, the laser is a semiconductor laser with an external synchronization triggering function. Under normal operating conditions, it operates in pulse mode with a frequency of 30Hz, an emission power of ≥10W, an fiber core diameter of 0.22mm, a beam uniformity of ≥85%, and a native laser wavelength of 808nm±5nm.

[0007] Furthermore, the temperature controller is a TEC temperature controller, which is used to control the temperature of the semiconductor laser. The TEC temperature controller has bidirectional temperature control capability and can control the temperature of the semiconductor laser at 60℃±3℃ in the working state, thereby ensuring that the laser wavelength of the semiconductor laser after temperature control is stable in the range of 820nm±5nm.

[0008] Furthermore, the beam divergence objective adopts a three-element zoom optical system structure, including a front fixed group, a zoom group, and a compensation group, with a beam divergence range of 0.2° to 4.5°, a focal length of 2.29mm to 57.29mm, and an optical system transmittance of ≥95%.

[0009] As a crucial component of window-based observation equipment, the laser illumination assembly provides a stable illumination beam energy for the television imaging components. It automatically adjusts the beam divergence angle based on received target distance information, ensuring a constant laser beam diameter across different operational distances. The laser illumination assembly primarily consists of a semiconductor laser assembly and a beam-diverging objective. The semiconductor laser assembly comprises the laser, a laser driver power supply board, a homogenizer, a TEC temperature controller, and a cooling fan. The laser uses a TEC temperature controller to stabilize its operating temperature at approximately +60℃ (±3℃), thereby reducing wavelength drift. To reduce the average power consumption of the laser, the laser driver power supply board receives an external synchronization signal emitted by the signal processing control board and modulates the laser into a quasi-pulse mode, reducing the average power consumption to 1 / 6. The beam-diverging objective assembly consists of a zoom motor assembly and a transmitting objective assembly. By driving the zoom motor to rotate, the focal length of the optical system is changed, thus altering the beam divergence angle.

[0010] Furthermore, the CMOS detector uses a black-and-white television, with a QE response efficiency ≥40% for 820nm±5nm wavelength laser, a pixel size ≥3.45μm×3.45μm, and a resolution ≥1024×768. This window-penetrating observation device uses a CMOS detector as its receiving imaging system. In unlit rooms, the ambient light behind the window is weaker than the ambient light outside, resulting in low contrast of the target behind the window, which inconveniences window-penetrating observation. Using active laser illumination can improve the brightness of the ambient light behind the window; narrowband filtering can effectively increase target contrast and improve the detection and observation effect.

[0011] Furthermore, the continuous zoom objective lens adopts a four-element zoom optical system structure, using a traditional mechanical compensation design approach. Specifically, it includes a front fixed group, a zoom group, a compensation group, and a focusing group. The focal length range of the entire four-element zoom optical system is 28mm to 380mm, and the zoom ratio is 13.6. X The continuous zoom objective lens includes a narrowband filter, which is made of HB720 filter glass.

[0012] The television imaging assembly consists of a CMOS detector and a continuous zoom objective lens. It adaptively adjusts the size of the detection field of view based on target distance information to achieve excellent detection results. The CMOS detector employs a high-sensitivity, low-noise, global shutter exposure mode. The continuous zoom objective lens comprises a zoom optical system, a zoom motor, and a zoom motor assembly. By driving the zoom motor and zoom motor to rotate, the focal length of the optical system is changed, thereby altering the size of the detection field of view and ensuring optimal detection performance.

[0013] Furthermore, the signal processing and control component adopts an ARM embedded system, including a power supply circuit, a core control circuit, a communication circuit, a synchronization signal circuit, and a motor drive circuit. The MCU receives the distance information of the target window through the CAN port, converts this distance information into a corresponding motor drive signal, and drives the motor to change the beam divergence angle of the beam divergence objective lens, automatically adjusting it to the required laser spot size. It also provides an external synchronization signal to the semiconductor laser and the CMOS detector, ensuring that the laser emission timing of the semiconductor laser and the exposure timing of the CMOS detector are synchronized.

[0014] The electrical system of the window-through observation device is mainly implemented through the signal processing control board in the signal processing control component. This board controls the semiconductor laser, TEC temperature controller, zoom motor, CMOS detector, and other components to achieve the window-through observation function. It employs an ARM embedded system, primarily consisting of a power supply circuit, core control circuit, interface communication circuit, signal synchronization circuit, and motor drive circuit. This system enables functions such as lighting switching, light power adjustment, motor drive, detector control, and communication with higher-level systems.

[0015] This utility model also includes other components that enable its normal use, all of which are conventional means in the field. In addition, devices or components not limited in this utility model, such as: semiconductor lasers, laser drive power supply boards, TEC temperature controllers, beam-shifting objectives, continuous zoom objectives, CMOS detectors, signal processing control boards, ARM embedded systems, and upper-level systems, all adopt existing technologies in the field.

[0016] The beneficial effects of this utility model are as follows:

[0017] The window observation device based on narrowband filtering technology provided by this utility model uses a TEC temperature controller to precisely control the operating temperature of the semiconductor laser, reducing the wavelength drift range of the laser and making the wavelength relatively stable. Combined with narrowband filtering technology, it effectively intercepts stray light in the environment, reduces its impact on the detector, and improves the window imaging effect.

[0018] By modulating continuous laser light into pulsed laser light and controlling the laser emission timing based on the detector's frame rate and exposure time, the laser emission duration is reduced, effectively lowering the average power consumption and improving the reliability of the window observation device.

[0019] Using a semiconductor laser as the illumination source for window detection can effectively reduce the adverse effects of temperature drift of the laser center wavelength on the window detection effect and improve the stability of the laser temperature within the entire allowable operating temperature range. The laser operating temperature can be monitored and adjusted in real time by a TEC temperature controller to ensure its constant operating temperature.

[0020] The illumination source is homogenized by optical fiber and then coupled to a beam-expanding and collimating objective for illumination. The beam reflected by the target is projected onto the target surface of the CMOS detector through a continuous zoom objective. The continuous zoom objective is designed with narrowband filters and cutoff filters, which can effectively block ambient stray light and improve imaging contrast. The CMOS detector converts the received optical signal into an electrical signal, which is then processed by an algorithm to output an imaging detection video.

[0021] The system employs active laser illumination to project the target behind the window, utilizes a CMOS detector for imaging, and leverages narrowband filtering to enhance the imaging effect. Furthermore, it adaptively adjusts the laser beam divergence and the field of view based on the distance to the target window, effectively ensuring optimal image representation of the target behind the window.

[0022] Prioritizing the military applications of the product and analyzing and optimizing existing technical routes, based on narrowband filter-type laser active window imaging technology, a quasi-continuous laser with a wavelength of 808nm in the near-infrared band is selected as the illumination source. With the help of narrowband filter technology, the influence of ambient light interference is effectively avoided, ensuring that the final output of the imaging detector contains only the image of laser illumination detection. This greatly improves the clarity of target detection imaging behind the window and realizes high-accuracy all-weather window detection imaging reconnaissance. Attached Figure Description

[0023] Figure 1 This is a block diagram showing the structural components of the window observation device in this utility model;

[0024] Figure 2 This is a block diagram illustrating the working principle of the window observation device in this utility model;

[0025] Figure 3 This is a schematic diagram of the optical system of the laser illumination component in this utility model;

[0026] Figure 4 This is a schematic diagram of the optical system of the television imaging component in this utility model;

[0027] Figure 5 This is an interface diagram of the electrical system of the window observation device in this utility model. Detailed Implementation

[0028] The technical solution of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0029] Example

[0030] like Figure 1-2 As shown, a window observation device based on narrowband filtering technology mainly consists of a laser illumination component 1, a television imaging component 2, a signal processing and control component 3, a main body 4, and cables 5.

[0031] The laser illumination assembly consists of a semiconductor laser assembly 10 and a beam-shifting objective lens 11, with laser transmission between them via optical fiber, providing a stable light source required for window-penetrating detection imaging.

[0032] The television imaging component consists of a CMOS detector 20 and a continuous zoom objective lens 21, which is used to achieve clear imaging of the target behind the window. It can adaptively adjust the size of the detection field of view according to the target distance information to achieve good detection effect.

[0033] The signal processing and control component is used to realize information interaction with the upper-level system and to control the operation of the semiconductor laser and CMOS detector.

[0034] The main body provides installation space for the various components of the window-viewing device; the electrical signals between the components are communicated through the cables.

[0035] The semiconductor laser assembly consists of a semiconductor laser 101, a laser driver power supply board 102, a TEC temperature controller 103, and a cooling fan 104.

[0036] The TEC temperature controller has bidirectional temperature control capability, which can ensure that the laser is at a stable operating temperature. In the working state, the temperature of the semiconductor laser can be controlled at 60℃±3℃, thereby ensuring that the laser wavelength of the semiconductor laser after temperature control is stable within the range of 820nm±5nm.

[0037] The cooling fan is used to assist in cooling, reduce wavelength drift, and provide a stable and reliable light source for the window observation equipment.

[0038] The semiconductor laser has an external synchronization triggering function, operates in pulse mode under normal conditions, has a frequency of 30Hz, an emission power of ≥10W, an optical fiber core diameter of 0.22mm, a beam uniformity of ≥85%, and a native laser wavelength of 808nm±5nm.

[0039] like Figure 3 As shown, the optical system of the laser illumination component is designed around a high-magnification beam-divergence optical path, and the optical system design is carried out according to the technical specifications. To obtain a highly stable illumination source and achieve beam-divergence functionality, the laser illumination component optical system consists of two parts: a semiconductor laser and a beam-divergence objective. The semiconductor laser optical path is responsible for providing a high-quality illumination source; the beam-divergence objective optical path is used to change the beam divergence angle of the laser beam.

[0040] The beam divergence objective adopts a three-element zoom optical system structure, including a front fixed group, a zoom group, and a compensation group. The beam divergence conversion range is 0.2° to 4.5°, the focal length is 2.29mm to 57.29mm, and the optical system transmittance is ≥95%.

[0041] The beam divergence objective consists of a zoom motor 111 and an emitting objective assembly 112. Driving the zoom motor to rotate changes the focal length of the emitting objective, thereby changing the beam divergence angle of the laser beam.

[0042] The CMOS detector is a black and white television-type detector with high sensitivity, low noise, and global shutter exposure mode. It has a QE response efficiency of ≥40% for 820nm±5nm band laser, a pixel size of ≥3.45μm×3.45μm, and a resolution of ≥1024×768.

[0043] The continuous zoom objective lens consists of a focusing motor 211, a zoom motor 212, and a receiving objective lens assembly 213. Driving the zoom motor to rotate enables changes in the receiving field of view, while the focusing motor can fine-tune the focusing of the receiving objective lens, thereby improving the imaging clarity of the CMOS detector.

[0044] like Figure 4 As shown, the optical system of the television imaging component is based on the design of a high-magnification zoom optical path system. Combining technical specifications and functional requirements, CMOS detector parameters, and fully considering factors such as structural spatial layout, manufacturing precision, actual electrical zoom requirements, and motor control precision, a continuous zoom objective lens optical system is designed. A four-element zoom optical structure is adopted to achieve continuous zoom of the television imaging component, ensuring lens imaging quality and optical axis consistency during the zoom process.

[0045] The continuous zoom objective lens employs a four-element zoom optical system structure, using a traditional mechanical compensation design. Specifically, it includes a front fixed group, a zoom group, a compensation group, and a focusing group. The focal length range of the entire four-element zoom optical system is 28mm to 380mm, with a zoom ratio of 13.6. X The continuous zoom objective lens includes a narrowband filter. The narrowband filter material is based on GB / T 15488-2010 and uses HB720 filter glass. This narrowband filter meets the requirements of laser cutoff in the range of 400nm to 700nm and laser transmittance in the range of 810nm to 830nm > 90%.

[0046] like Figure 5 As shown, the signal processing control component includes a signal processing control board and an ARM embedded system. The signal processing control board, as the core control hub of the window-viewing device, primarily functions to communicate with the system, send external synchronization trigger signals, communicate with the laser driver power supply board, communicate with the CMOS detector, and drive the motor.

[0047] The signal processing control board adopts an ARM embedded system and mainly includes a power supply circuit, a core control circuit, an RS-232 interface circuit, an RS-422 interface circuit, a CAN communication circuit, a signal synchronization circuit, a motor drive circuit, and an interface circuit. Both the signal processing control board and the ARM embedded system are existing technologies and will not be described in detail here. The distance information of the target window is received through the CAN interface, and the obtained distance information is converted into a corresponding motor drive signal. The motor is then used to change the beam divergence angle of the beam-changing objective lens, automatically adjusting it to a suitable detection spot size. Simultaneously, synchronization signals are provided to the semiconductor laser and CMOS detector to ensure that the emission and exposure of the semiconductor laser and CMOS detector are synchronized.

[0048] The window-viewing device uses a semiconductor laser assembly as the illumination source. A TEC temperature controller maintains the laser's operating temperature in real time, minimizing wavelength temperature drift. The illumination source is fed to a beam-shifting objective via fiber optic cable. After collimation and beam expansion, the beam illuminates the target behind the window. The reflected beam is projected onto a CMOS detector through a continuous zoom objective. This objective incorporates narrowband and cutoff filters to effectively block stray light. The CMOS detector converts the received optical signal into an electrical signal, which is then processed by an algorithm to output a video image containing the target. Zoom and magnification motors adjust the laser beam divergence and imaging field of view in real time based on the target's distance. The signal processing and control board provides external synchronization signals to the CMOS detector and semiconductor laser, controlling synchronized exposure and illumination. It also interacts with the upper-level system, monitors the operating status of each sensor, and proactively reports faults when abnormalities occur.

[0049] The main functions of this window observation device are as follows:

[0050] a) Capable of clear imaging and detection of targets behind selected windows;

[0051] b) It can automatically adjust the size of the laser spot and the detection field of view according to the distance to the window;

[0052] c) It has image enhancement and defogging functions;

[0053] d) It has power-on self-test, periodic self-test, and command self-test functions;

[0054] e) It has a fault information reporting function (capable of locating specific replaceable components).

[0055] The main performance and technical specifications of this window-viewing device are as follows:

[0056] a) Laser wavelength: 820nm±5nm;

[0057] b) Maximum laser emission power: ≥10W;

[0058] c) Laser emission frequency: 30Hz;

[0059] d) Detection range: Daytime observation range ≥ 400m, nighttime observation range ≥ 500m (target size 0.5m × 0.5m);

[0060] e) Beam divergence angle: 0.2°~4.5°;

[0061] f) Imaging field of view: 8°×6°~0.6°×0.4°.

[0062] The structural composition of this window-through observation device system is based on the analysis of its main functions and technical specifications. The overall structural layout is developed around the optical system design parameters, taking into account requirements such as device size, mechanical interfaces, and general mass characteristics. The overall structural design centers on the optical system of the beam-shifting objective and television imaging components. Considering requirements such as optical axis consistency and environmental adaptability during zooming, the structure employs a cam-curve sleeve zoom structure, achieving optical zoom through gear transmission. The main body serves as the supporting component of the entire system, providing installation space for each component and offering external installation interfaces. Its strength directly affects the optical axis consistency of the laser illumination component and television imaging component in the window-through observation device. As the largest component, it incorporates weight-reduction grooves to meet lightweight design requirements while ensuring installation strength.

[0063] The main working principle of this window observation device is as follows:

[0064] a) The signal processing and control components provide synchronization signals for the CMOS detector and semiconductor laser, controlling the synchronous exposure and illumination of the CMOS detector and laser;

[0065] b) The semiconductor laser assembly uses a TEC temperature controller to keep the laser's operating temperature constant, thereby reducing the temperature drift of the laser wavelength;

[0066] c) The beam-shifting objective includes an emitting objective assembly and a zoom motor. With the cooperation of the zoom motor and the emitting objective assembly, the beam emitted by the laser ensures that the size of the illumination spot remains constant at different distances from the target.

[0067] d) The continuous zoom objective changes the focal length of the receiving objective's optical system by using a zoom motor and a focus motor to change the receiving field of view based on the distance information of the target window. To reduce the interference of stray light from the outside environment, the receiving objective assembly is designed with narrow-band filters and cutoff filters, which can effectively block stray light.

[0068] e) The CMOS detector converts the received light signal reflected from the target into an electrical signal, and after processing by an algorithm, outputs a video image containing the target.

[0069] The technical solution of this utility model is not limited to the specific embodiments described above. Without departing from the scope and spirit of the described embodiments, many modifications and changes will be obvious to those skilled in the art. Any technical modifications made within the spirit and principles of this utility model shall fall within the protection scope of this utility model.

Claims

1. A window observation device based on narrowband filtering technology, characterized in that: The system includes a main body, and a laser illumination assembly, a television imaging assembly, and a signal processing and control assembly installed inside the main body and electrically connected by cables. The laser illumination assembly consists of a laser, a temperature controller, and a beam-diverging objective lens, providing a stable light source for window-penetrating detection imaging. The laser is a semiconductor laser with external synchronization triggering, operating in pulse mode at a frequency of 30Hz under normal conditions, with a beam uniformity ≥85%, and a wavelength of 808nm±5nm. The temperature controller is a TEC temperature controller with bidirectional temperature control capability, maintaining the semiconductor laser temperature at 60℃±3℃, and stabilizing the laser wavelength at 820nm±5nm after temperature control. The beam-diverging objective lens employs a three-element zoom optical system structure, including a front fixed group, a zoom group, and a compensation group, with a beam divergence range of 0.2°~4.5° and a focal length of 2.

2. The optical system has a transmittance of ≥95% and a focal length of 9mm to 57.29mm. The television imaging component consists of a CMOS detector and a continuous zoom objective lens, used to achieve clear imaging of targets behind the window. The CMOS detector uses a black-and-white television with a QE response efficiency of ≥40% for 820nm±5nm wavelength lasers, a pixel size of ≥3.45μm×3.45μm, and a resolution of ≥1024×768. The continuous zoom objective lens adopts a four-element zoom optical system structure, including a front fixed group, a zoom group, a compensation group, and a focusing group. The focal length variation range of the entire four-element zoom optical system is 28mm to 380mm. The signal processing and control component is used to realize information interaction with the upper-level system and to control the operation of the laser and CMOS detector. The signal processing and control component adopts an ARM embedded system, including a power supply circuit, a core control circuit, a communication circuit, a synchronization signal circuit, and a motor drive circuit.

2. The window observation device based on narrowband filtering technology according to claim 1, characterized in that: The continuous zoom objective lens includes a narrowband filter, which is made of HB720 filter glass.

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