Composite optical imaging assembly

Abstract

The invention discloses a composite optical imaging assembly, and relates to the technical field of optical devices. Comprising a dual-light optical system, an infrared detection assembly and a visible light detection assembly, the dual-light optical system comprises a fairing, an infrared optical system and a visible light optical system; the infrared optical system comprises a plurality of first optical lenses, and a hole is formed in the middle area of one first optical lens close to the fairing. The visible light optical system comprises a plurality of second optical lenses and a reflecting mirror; an optical signal reflected by a target object enters the plurality of first optical lenses through the fairing and reaches the infrared detection assembly to form a first visible image; and the light signal reflected by the target object enters the plurality of second optical lenses through the perforated area of the perforated first optical lens, and is reflected to the visible light detection assembly through the reflector to form a second visible image. Light loss can be avoided, and the imaging quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to a composite optical imaging component. Background Art

[0002] The optical imaging component is the core component of the optical imaging system. The light is precisely controlled by optical components such as lens groups and reflectors to ensure that the light is transmitted along the predetermined path and focused on the target object. Finally, the light is captured by a highly sensitive detector and converted into an electrical signal for recording or further processing, thereby generating high-quality images and providing solid support for various imaging applications.

[0003] A composite optical imaging assembly is an optical device that can respond to light sources of different wavelengths. It usually contains multiple optical elements, such as lenses, prisms, reflectors, gratings, etc. These elements are cleverly combined to achieve specific optical imaging functions. The assembly can control, adjust, change or transmit light to form a clear and accurate image on the imaging surface.

[0004] In the process of generating infrared optical images and visible light optical images, the existing composite optical imaging components need to split the incident light, and then reach the two image sensors through different optical paths. However, the incident light splitting inevitably produces light loss, resulting in distortion or blurring of the generated infrared optical images and visible light optical images. Summary of the invention

[0005] Based on this, it is necessary to provide a composite optical imaging component to address the above technical issues.

[0006] The embodiment of the present invention provides a composite optical imaging assembly, including: a dual-light optical system, an infrared detection assembly and a visible light detection assembly; the dual-light optical system includes a fairing, an infrared optical system and a visible light optical system, and the fairing is arranged outside the infrared optical system and the visible light optical system; The infrared optical system comprises: a plurality of first optical lenses sequentially arranged between a fairing and an infrared detection assembly, and a hole is opened in a middle area of ​​the first optical lenses close to the fairing; A visible light optical system, comprising: a reflector disposed between a fairing and a first optical lens close to the fairing without an opening, and a plurality of second optical lenses, wherein the plurality of second optical lenses are sequentially arranged between the fairing and the reflector; The light signal reflected by the target object enters the plurality of first optical lenses through the fairing, reaches the infrared detection assembly, and forms a first visible image; The light signal reflected by the target object enters the plurality of second optical lenses through the opening area of ​​the first optical lens and reaches the reflector; it is reflected by the reflector to the visible light detection component to form a second visible image.

[0007] Optionally, the multiple first optical lenses include: a first lens, a second lens, a third lens and a fourth lens, and the first lens has an opening in the middle area; the light signal reflected by the target object passes through the first lens, the second lens, the third lens and the fourth lens in sequence.

[0008] Optionally, the first lens is a spherical lens, the second lens is a spherical lens, the third lens is an aspherical lens, and the fourth lens is a diffractive aspherical lens; The surfaces of the first lens, the second lens, the third lens and the fourth lens are all coated with anti-reflection films.

[0009] Optionally, the plurality of second optical lenses include: a fifth lens, a first lens group, a second lens group, a sixth lens and a seventh lens; the light signal reflected by the target object passes through the fifth lens, the first lens group, the second lens group, the sixth lens and the seventh lens in sequence.

[0010] Optionally, the infrared detection component includes: a window glass and a photosensitive surface; the light signal reflected by the target object enters the multiple first optical lenses through the fairing and reaches the window glass; enters the photosensitive surface through the window glass to form a first visible image.

[0011] Optionally, the visible light detection component includes an image sensor module, an image processing module, an interface module, and a power supply module; An image sensor module, used for converting the second visible image into a charge image signal and outputting it according to a set working sequence; The image processing module is used to generate the working timing of the image sensor module, collect the output signal of the image sensor module, and convert it into a standard video stream; Interface module, used to output standard video stream; The power module is used to supply power to the image sensor module, the image processing module and the interface module.

[0012] Optionally, the composite optical imaging assembly further comprises a visible light lens, which comprises: a small lens barrel, a plurality of spacers and a plurality of pressure rings; The inner wall of the small lens barrel is provided with a thread adapted to each pressing ring, and a mounting groove adapted to each pressing ring is chiseled on the side wall of the small lens barrel; A plurality of second optical lenses are placed inside the small lens barrel, and spacer rings and pressure rings are arranged between adjacent second optical lenses.

[0013] Optionally, the composite optical imaging assembly further includes an infrared lens, which includes: a main lens barrel, a plurality of pressure rings, a plurality of spacer rings and an adapter plate; The inner wall of the main lens barrel is provided with a thread adapted to each pressing ring, and a mounting groove adapted to each pressing ring is chiseled on the side wall of the main lens barrel; A plurality of first optical lenses are placed inside the main lens barrel, and spacers and pressure rings are provided between adjacent first optical lenses; The adapter plate includes a shaft connection hole, a main lens barrel mounting hole and an infrared camera mounting hole; the shaft connection hole is set on the adapter plate, the main lens barrel is connected to the adapter plate through the main lens barrel mounting hole, and the adapter plate and the main lens barrel are fixed by a flange connection; the infrared camera is fixed to the adapter plate through the infrared camera mounting hole, and the visible light camera is connected to the main lens barrel through the bottom opening of the main lens barrel.

[0014] Compared with the prior art, the composite optical imaging assembly provided by the embodiment of the present invention has the following beneficial effects: The present invention opens a hole in the middle area of ​​a first optical lens close to a fairing in an infrared optical system, and arranges a reflector and a plurality of second optical lenses between the fairing and the first optical lens close to the fairing without opening a hole, and the plurality of second optical lenses are sequentially arranged between the fairing and the reflector; Compared with the existing composite optical imaging components, this structure is that the light signal reflected by the target object enters the multiple first optical lenses through the fairing, reaches the infrared detection component, and forms a first visible image; the light signal reflected by the target object enters the multiple second optical lenses through the opening area of ​​the open first optical lens, reaches the reflector; and is reflected by the reflector to the visible light detection component to form a second visible image. This structure can solve the problem of light loss caused by splitting the incident light in the prior art, and the generated first visible image and second visible image will not be distorted or blurred, thereby improving the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an overall design diagram of a composite optical imaging assembly provided in one embodiment; Figure 2 A specific layout diagram of a composite optical imaging assembly provided in one embodiment; Figure 3 A general schematic diagram of a dual-light optical system of a composite optical imaging assembly provided in one embodiment; Figure 4 A light diagram of an infrared optical system of a composite optical imaging assembly provided in one embodiment; Figure 5 A visible light optical system light diagram of a composite optical imaging assembly provided in one embodiment; Figure 6 A block diagram of a design of a visible light detection component of a composite optical imaging component provided in one embodiment; Figure 7 A control flow chart of a visible light detection component of a composite optical imaging component provided in one embodiment; Figure 8A schematic diagram of the overall structure of a main lens barrel of a composite optical imaging assembly provided in one embodiment; Fig. 9 A schematic diagram of the internal structure of a main lens barrel of a composite optical imaging assembly provided in one embodiment; Fig.10 A three-dimensional model diagram of a pressure ring of a composite optical imaging assembly provided in one embodiment; Fig.11 A three-dimensional model diagram of an adapter plate of a composite optical imaging assembly provided in one embodiment; Fig.12 A specific layout diagram of a visible light detection component of a composite optical imaging component provided in one embodiment; Fig.13 A structural dimension diagram of a visible light detection component of a composite optical imaging component provided in one embodiment; Fig.14 A three-dimensional model diagram of a visible light lens of a composite optical imaging assembly provided in one embodiment; Fig.15 A schematic diagram of a small lens barrel model of a composite optical imaging assembly provided in one embodiment; Fig.16 A three-dimensional model diagram of a spacer ring of a composite optical imaging assembly provided in one embodiment; Fig.17 A design diagram of a CMOS peripheral circuit U1A of a composite optical imaging component provided in one embodiment; Fig.18 A design diagram of a CMOS peripheral circuit U1B of a composite optical imaging component provided in one embodiment; Fig.19 A CMOS power-on sequence diagram of a composite optical imaging component provided in one embodiment; Fig. 20 A schematic diagram of an SGM2035C power conversion circuit of a composite optical imaging assembly provided in one embodiment; Fig.21 A schematic diagram of an SGM2049 power conversion circuit of a composite optical imaging assembly provided in one embodiment; Fig. 22 A 3.3V image sensor filter circuit diagram of a composite optical imaging assembly provided in one embodiment; Fig.23 A 1.2V image sensor filter circuit diagram of a composite optical imaging assembly provided in one embodiment; Fig.24 An image sensor filter circuit diagram at 2.5V of a composite optical imaging assembly provided in one embodiment; Fig.25 A schematic diagram of a clock circuit design of a composite optical imaging component provided in one embodiment; Fig.26 A schematic diagram of a communication interface of a composite optical imaging assembly provided in one embodiment.

[0016] Among them, 1. Bi-optical system; 2. Infrared detection component; 3. Visible light detection component; 31. Second optical lens group; 32. Visible light camera; 33. Infrared camera; 34. First lens; 35. Second lens; 36. Third lens; 37. Fourth lens; 38. Fairing; 39. Window glass; 310. Photosensitive surface; 311. Fifth lens; 312. First lens group; 313. Second lens group; 314. Sixth lens; 315. Seventh lens; 316. Reflector; 317. Pressing ring; 318. Spacer; 319. Small lens barrel; 41. Shaft connecting hole; 42. Main lens barrel mounting hole; 43. Infrared camera mounting hole. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] 1. Infrared detection component 2.

[0019] 1.1 Detector specifications.

[0020] An uncooled long-wave infrared focal plane detector is selected as the first visible image receiving element. The detector parameters are shown in Table 1.

[0021] Table 1 Detector parameters

[0022] 1.2 Calculation of focal length and field of view angle.

[0023] According to the requirements, the detector resolution is 640×512, and the pixel size is 12um×12um. It can be seen that the photosensitive surface size of the detector is 7.68mm×6.144mm.

[0024] Combining the required focal length of 58mm and the selected detector parameters, the field of view of the optical system can be calculated: Horizontal field of view: ; Vertical field of view: ; Where f′ is the image focal length.

[0025] Calculated from the above formula, the field of view of the infrared optical system is 7.6°×6.1°.

[0026] 1.3 Determination of F number.

[0027] According to the index requirements, the F number is determined to be 1.2.

[0028] 1.4. Optical system design.

[0029] The infrared optical system specifically includes: In order to achieve the purposes of compact structure, light weight, high reliability, etc., and according to the installation method and size requirements, the infrared optical system adopts a transmission structure with 4 lenses.

[0030] The first lens 34 is a spherical lens made of ZNS_IR. The first lens 34 is opened with a diameter of φ15 mm. The second lens 35 is a spherical lens made of ZNS_IR. The third lens 36 is an aspherical lens made of Ge. The fourth lens 37 is a diffractive aspherical lens made of Ge.

[0031] The surfaces of the first lens 34, the second lens 35, the third lens 36 and the fourth lens 37 are all coated with anti-reflection coating to reduce the system reflectivity. The infrared optical system is designed with a focal length of 58mm, the first lens has an aperture of 49mm, and the light diagram of the infrared optical system is as follows: Figure 4 shown.

[0032] 1.5 Transmittance calculation.

[0033] like Figure 5 As shown, the visible light optical system specifically includes 7 lenses + 1 reflector, and the average transmittance of the fairing 38 in the visible light band is greater than 90%. Each piece of glass is coated with an anti-reflection film to ensure that the transmittance of each piece of glass is greater than 99%, and the reflectivity of the reflector is greater than 0.95. The average transmittance of the optical system is: ; Through calculation, we know that its theoretical transmittance is 79.69%, which meets the technical requirements of the visible light band of 450nm to 760nm; the average transmittance of the optical system in the band: not less than 75% (including fairing 38).

[0034] 1.6 Imaging quality evaluation.

[0035] The imaging quality of the system is mainly evaluated through the system transfer function diagram, point diagram and field curvature distortion diagram. Since the operating temperature range of the system is -40℃~60℃, the imaging quality of the system is mainly evaluated at -40℃, 20℃ and 60℃.

[0036] Evaluation of the imaging quality of the system at -40℃: When the system is at 42lp / mm, the function value of the system is greater than 0.28, close to the diffraction limit. The maximum RMS radius (Root Mean Square) of the system's point diagram in different fields of view is 8.29μm. The maximum distortion of the system in the full field of view is 0.911%, which is less than the technical requirement of distortion less than 1%.

[0037] Evaluation of the imaging quality of the system at 20°C: when the system is at 42lp / mm, the function value of the system is greater than 0.28, close to the diffraction limit, the maximum RMS radius of the system's point diagram in different fields of view is 6.719μm, which is smaller than the detector pixel size (pixel size is 12μm), and the maximum distortion of the system in the full field of view is 0.912%, which is smaller than the technical requirement of distortion less than 1%.

[0038] Evaluation of the imaging quality of the system at 60°C: when the system is at 42lp / mm, the function value of the system is greater than 0.28, close to the diffraction limit, the maximum RMS radius of the system's point diagram in different fields of view is 7.171μm, and the maximum distortion of the system in the full field of view is 0.9166%, which is less than the technical requirement of distortion less than 1%.

[0039] It can be seen from the imaging quality of the above system at different temperatures that when the transfer function value of the system at different temperatures is 42lp / mm, the transfer function value is close to the diffraction limit, and meets the technical requirement that the deviation of the optical system transfer function curve from the diffraction limit at the Nyquist frequency does not exceed 0.1pl / mm within the full operating temperature range. At different operating temperatures, the maximum distortion at the full field of view is 0.9166%, which meets the technical requirement that the absolute distortion is no more than 1% within the full field of view.

[0040] 1.7 Tolerance analysis.

[0041] According to the optical design results, combined with the factory processing level and assembly process level, the tolerances of optical parts, optical assembly and special surface processing are given, as shown in Table 2.

[0042] Table 2 Optical parts / optical assembly tolerance table

[0043] Where N is the aperture number, is the local error of the aperture, It is the symbol of sample accuracy grade. A means the sample accuracy grade is A grade (the highest level of accuracy requirement). B means the smoothness. IV means the smoothness B is IV grade. is the lens eccentricity error, Pv is the peak-to-valley value, and Ra is the arithmetic mean deviation of the profile.

[0044] The infrared optical system performs a Monte Carlo probability distribution analysis on the average MTF (Modulation Transfer Function) of the system's full field of view according to the given tolerances above: When f′=58mm, the optical system is given the above tolerances for Monte Carlo probability distribution analysis, and the results are as follows: 90%>0.21290079; 80%>0.22025821; 50%>0.24544040; 20%>0.26506806; 10%>0.27080967; From the analysis results, it can be seen that the MTF value of the system in the full field of view can reach 0.2129 with a probability of 90%, and the MTF value of the system in the full field of view can reach 0.220258 with a probability of 80%. According to the analysis results, as long as the infrared optical system meets the processing and assembly tolerances, it can meet the technical requirement that the measured value of the optical system transfer function curve on the axis at the Nyquist frequency at room temperature is not less than 0.2@42pl / mm.

[0045] 2. Visible light detection component 3.

[0046] 2.1 Calculation of focal length and field of view.

[0047] Calculate the field of view of an optical system: Horizontal field of view: ; Vertical field of view: ; Calculated from the above formula, the field of view of the visible light optical system is approximately 7.02°×7.02°.

[0048] 2.2 Determination of F number.

[0049] According to the assembly method of visible light, the mechanical aperture of visible light is ≤15mm, the focal length and detector and other related indicators are required, and the F number is 6.

[0050] 2.3 Optical system design.

[0051] In order to achieve the goals of compact lens structure, small size, light weight, high reliability, etc., the visible light optical system adopts 5 groups of 7 lenses + reflectors for design and spatial layout, including two groups of double-cemented lenses. All lens surfaces are coated with anti-reflection film, and the reflectivity of the film layer is less than 0.3%; at 0.6μm, the average absorption of the material is less than 0.25% / 5mm. The design focal length of the optical system is 57.4mm.

[0052] 2.4 Transmittance calculation.

[0053] The visible light optical system includes 7 lenses + 1 reflector, and the average transmittance of the fairing in visible light is greater than 90%. Each piece of glass is coated with an anti-reflection film to ensure that the transmittance of each piece of glass is greater than 99%, and the reflectivity of the folding mirror is greater than 0.95. The average transmittance of the optical system is:

[0054] Through calculation, we know that its theoretical transmittance is 79.69%, which meets the technical requirements of the visible light band of 450nm to 760nm; the average transmittance of the optical system in the band is not less than 75% (including the fairing).

[0055] 2.5 Imaging quality evaluation.

[0056] The main evaluation methods for image quality are MTF curve, point diagram, energy diagram, field curvature and distortion diagram.

[0057] The imaging quality of the system is evaluated mainly through the system transfer function diagram, point diagram, and field curvature distortion diagram. Since the operating temperature range of the system is -40℃~60℃, the imaging quality of the system is mainly evaluated at -40℃, 20℃ and 60℃. The analysis results are as follows: Evaluation of the imaging quality of the system at -40℃: When the system is at 91lp / mm, the function value of the system is greater than 0.398, the maximum RMS radius of the system's point diagram in different fields of view is 3.5μm, and the maximum distortion of the system in the full field of view is 1.58%, which is less than the technical requirement of distortion less than 2%.

[0058] Evaluation of the imaging quality of the system at 20°C: when the system is at 91lp / mm, the function value of the system is greater than 0.4, the maximum RMS radius of the system's point diagram in different fields of view is 3.97μm, and the maximum distortion of the system in the full field of view is 1.58%, which is less than the technical requirement of distortion less than 2%.

[0059] Evaluation of the imaging quality of the system at 60°C: when the system is at 91lp / mm, the function value of the system is greater than 0.4, the maximum RMS radius of the system's point diagram in different fields of view is 4.1μm, and the maximum distortion of the system in the full field of view is 1.58%, which is less than the technical requirement of distortion less than 2%.

[0060] In summary, the maximum distortion value of the system in the full field of view is 1.58%, which meets the technical requirement of less than 2% distortion in the full field of view. In the working wavelength range of 0.45μm to 0.76μm, the transmittance of the whole system is 79.69%, which meets the technical requirement of not less than 75% transmittance of the whole system. It can be seen from the MTF curves under various conditions that the change of temperature has little effect on the imaging of the optical system, which can meet the use requirements.

[0061] 2.6 Tolerance analysis.

[0062] According to the optical design results, combined with the factory processing level and assembly process level, the tolerances of optical parts, optical assembly and special surface processing are given, as shown in Table 3.

[0063] When f′=57.4mm, the optical system is given the above tolerances for Monte Carlo probability distribution analysis, and the results are as follows: 90%>0.17773689; 80%>0.20753353; 50%>0.26258366; 20%>0.35260880; 10%>0.39763704; Table 3 Optical parts / optical assembly tolerance table

[0064] in, is the allowable difference between the refractive index and the standard value, is the allowable difference between the dispersion coefficient and the standard value, N is the aperture number, is the local error of the aperture, It is the symbol of sample accuracy grade. A means the sample accuracy grade is A grade (the highest level of accuracy requirement). B means the smoothness. IV means the smoothness B is IV grade. is the lens eccentricity.

[0065] It can be seen from Table 3 and the Monte Carlo probability distribution analysis results that when the MTF value of the full field of view is 80% probability, the MTF can reach 0.20753353, which can ensure that the system has good imaging quality after processing and assembly.

[0066] In one embodiment, a composite optical imaging assembly is provided. According to the distribution of infrared light paths, this solution uses optical processing and mechanical structure processing to adjust the dimensional accuracy of lens eccentricity, tilt, center thickness, air spacing, etc. of each lens group, and finally realizes a lens with good imaging quality. The overall design diagram is shown in FIG. Figure 1 The specific layout is shown in Figure 2 As shown, it includes a dual-light optical system, an infrared detection component and a visible light detection component.

[0067] 1. Bi-optical system1.

[0068] The dual-light optical system 1 includes a fairing 38, an infrared optical system and a visible light optical system. The fairing 38 is arranged outside the infrared optical system and the visible light optical system. Figure 3 shown.

[0069] Depend on Figure 3 It can be seen that the dual-light optical system includes an infrared optical system and a visible light optical system. The infrared optical system includes: a plurality of first optical lenses sequentially arranged between the fairing and the infrared detection assembly 2, and a hole is opened in the middle area of ​​the first optical lens close to the fairing 38. The visible light optical system includes: a reflector 316 and a plurality of second optical lenses arranged between the fairing 38 and the first optical lens without a hole close to the fairing 38, and the plurality of second optical lenses are sequentially arranged between the fairing 38 and the reflector 316.

[0070] The light signal reflected by the target object enters the multiple first optical lenses through the fairing 38, reaches the infrared detection assembly 2, and forms a first visible image. The infrared detection assembly 2 includes: a window glass 39 and a photosensitive surface 310; the light signal reflected by the target object enters the multiple first optical lenses through the fairing 38, reaches the window glass 39; enters the photosensitive surface 310 through the window glass 39, and forms a first visible image.

[0071] The light signal reflected by the target object enters the plurality of second optical lenses through the opening area of ​​the first optical lens, and reaches the reflector 316; it is reflected by the reflector 316 to the visible light detection component 3 to form a second visible image.

[0072] The plurality of first optical lenses include: a first lens 34 , a second lens 35 , a third lens 36 and a fourth lens 37 ; the light signal reflected by the target object passes through the first lens 34 , the second lens 35 , the third lens 36 and the fourth lens 37 in sequence.

[0073] The plurality of second optical lenses include: a fifth lens 311, a first lens group 312, a second lens group 313, a sixth lens 314 and a seventh lens 315; the light signal reflected by the target object passes through the fifth lens 311, the first lens group 312, the second lens group 313, the sixth lens 314 and the seventh lens 315 in sequence. The plurality of second optical lenses form a second optical lens group 31. The first lens group 312 is composed of a convex lens and a concave lens, and the second lens group 313 is composed of a convex lens and a concave lens.

[0074] The composite optical imaging assembly further includes a small lens barrel 319, a spacer 318 and a pressure ring 317. The inner wall of the small lens barrel 319 is provided with a thread matched with the pressure ring 317, and a mounting groove for the pressure ring 317 is chiseled on the side wall of the small lens barrel 319. Spacers 318 and pressure rings 317 are provided between adjacent lenses. The small lens barrel 319 is used to carry the fifth lens 311, the first lens group 312, the second lens group 313, the sixth lens 314 and the seventh lens 315.

[0075] Three rods are used to support and connect the infrared lens structure. At the same time, the main lens barrel and the center of the first lens are solidified by glue dispenser, which reduces the weight of the structure without affecting the optical path.

[0076] The infrared optical system’s obstruction includes the through hole in the middle of the lens (visible light lens) and the light obstruction caused by the support rod. The designed infrared system has an aperture of 48.3mm and an opening diameter of 15mm. Taking the support rod’s obstruction into account, the infrared obstruction ratio is 18.2% based on the area.

[0077] The design block diagram of the visible light detection component is as follows: Figure 6 As shown, it includes an image sensor module, an image processing module, an interface module, and a power module.

[0078] (1) An image sensor module, used for converting the second visible image into a charge image signal and outputting it according to a set working sequence.

[0079] The image sensor module is the core of the optoelectronic imaging device. When designing, the image sensor selection analysis must be carried out first.

[0080] According to the input technical index requirements, CMOS image sensor is selected as the core imaging device under the premise of keeping the system structure as simple as possible, power consumption as low as possible, and reliability as high as possible. CMOS image sensor is selected by investigating the main domestic CMOS image sensor manufacturers and considering image resolution, power consumption, frame rate, environmental adaptability, and flight experience.

[0081] Image sensor peripheral circuit design Fig.17 and Fig.18 As shown, Fig.17 This is the design diagram of the CMOS peripheral circuit U1A. Fig.18 This is the design diagram of the CMOS peripheral circuit U1B, which mainly includes the image sensor bias voltage, decoupling circuit, SPI configuration interface, data interface, and control timing interface. The CMOS device requires three DC voltages for normal operation: +3.3V, +2.5V, and +1.2V. The device has strict requirements on the power-on sequence. The specific power-on sequence is as follows: Fig.19 shown.

[0082] In order to ensure the power-on sequence required for the normal operation of the device, the power-on sequence of the image sensor is strictly controlled by the FPGA (Field-Programmable Gate Array). During the design, the FPGA is powered on first, and then the FPGA controls the output of high / low level signals to enable the secondary power chip on the imaging board, so that the triggered enable signal and the power chip output interval meet Fig.19 requirements.

[0083] Since the image sensor is a mixed digital-analog circuit, it is sensitive to power supply noise, which is specifically manifested in the image as horizontal noise, diagonal noise or granular noise. During the design, a power chip with relatively high noise suppression is selected to power the image sensor, reduce power supply ripple and improve image quality.

[0084] All power supplies for image sensors are directly generated by ultra-low noise LDO. During the design, low-noise LDO power supply chips SGM2049 and SGM2035C were selected. Both LDOs are industrial grade. The maximum output current of SGM2035C is 500mA, and the maximum output current of SGM2049 is 2A. The operating temperature range is -40℃~+85℃. The chip adopts UTDFN packaging. The chip is small in size and can realize the miniaturization of the product. The chip has functions such as soft start, overcurrent protection and overvoltage protection. The low noise performance makes the device better suitable for imaging circuits.

[0085] After component derating analysis, the components selected for the camera imaging circuit are all Class I / Class II derating designs, meeting the design requirements.

[0086] The +2.5V and +1.2V power conversion circuits are the same. Take the +2.5V power conversion as an example. The SGM2035C power conversion circuit is as follows: Fig. 20 The power conversion circuit of the power supply +3.3V is as shown in Fig.21 shown.

[0087] In addition to using low-noise LDO power chips to power the image sensor, filter capacitors are placed near each power pin of the sensor during design to further deal with power noise. The filter capacitors are high-reliability ceramic capacitors from Shenzhen Micro-Capacitor, and all selected filter capacitors meet the Class I / Class II derating requirements. The filter circuit of the image sensor is as follows Fig. 22 , Fig.23 and Fig.24 As shown, Fig. 22 This is the image sensor filter circuit diagram under 3.3V. Fig.23 This is the image sensor filter circuit diagram at 1.2V. Fig.24 Image sensor filter circuit diagram at 2.5V.

[0088] (2) Image processing module, which is used to generate the working timing of the image sensor module, collect the output signal of the image sensor module, convert it into a standard video stream, and realize functions such as automatic exposure and automatic gain. This part of the function is realized by FPGA.

[0089] The functions of the image processing module include image detector register configuration and control (timing control, automatic exposure control, automatic gain control, image noise reduction), image data acquisition, image data processing, communication command reception, video image output, etc. The image processing circuit is the core of the system design, and the main processor is implemented using FPGA.

[0090] Taking into account application requirements, development cycle, technology accumulation and economy and other factors, FMK50 is selected as the control chip of the system. The chip is industrial grade and has a chip size of 15mm×15mm, which can further reduce the volume of the product. The configuration chip used is FM25W128-DNA-CH. FM25W128-DNA-CH is SPI type FLASH with a storage capacity of 128Mb, which can meet the program storage capacity requirements of FMK50 series FPGA.

[0091] The active crystal used in the clock circuit uses the ZA30 series of mounted crystal oscillators, which have the advantages of small size and high reliability. The quality level of the crystal oscillator is military grade, and the operating temperature range is -55℃~+85℃, which can fully meet the needs of derating.

[0092] The clock unit is an important part of the system. When designing the circuit, it is necessary to fully consider the EMC design to ensure the reliability and stability of the system. In the design, the crystal oscillator power supply needs to fully consider the decoupling. 0.1μF and 0.01μF high-frequency ceramic capacitors are connected in parallel at the power supply end as a decoupling circuit. In addition, magnetic beads are connected in series to filter out high-frequency interference. The circuit design is as follows Fig.25 shown.

[0093] (3) Interface module, used to output standard video stream, adopts CML interface (Current Mode Logic) to reduce cables, and at the same time communicates with the overall information through serial port.

[0094] A. Image output interface circuit design.

[0095] The image data output uses a CML interface, and the driver chip is BLK2711MQ from 772 Institute. The device supports 1.6~2.5Gbps data output, which can meet the transmission of image data in 1080p@30fps working mode, and has on-chip 8b / 10b encoding to ensure reliable transmission of image data. The chip operates at a temperature of -55℃~+125℃, meeting the Class I derating design.

[0096] When designing the external interface, the CML interface uses two coaxial cables to output through a connector, or directly welds twisted pair shielded wires for transmission.

[0097] B. Communication interface circuit design.

[0098] The communication interface circuit is mainly used to receive commands and transmit parameters from the external system. The communication interface uses half-duplex 485 serial communication. The interface chip is SIT3485ESA, which is fully compatible with MAX3485 in terms of performance parameters and has a power supply voltage of 3.3V. Fig.26 shown.

[0099] (4) A power module, used to supply power to the image sensor module, the image processing module and the interface module.

[0100] The image processing board requires voltages of 3.3V, 2.5V, 1.8V, and 1.0V according to design requirements.

[0101] In order to fully reduce the power consumption of the imaging component and improve the efficiency of the power conversion unit, the secondary power supply of the image processing part is implemented by 4 SY98103C. The input voltage range of SY98103C is 4.7V to 18V, and the output voltage range is 0.8V to 6V. SY98103C is a single-channel output with an output current of up to 3A. The chip volume is only 3mm×2.8mm×2mm, which can meet the needs of miniaturization design. The rated operating temperature of SY98103C is -40℃~125℃, which can meet the needs of high and low temperature environments. 3.3V, 2.5V, 1.8V, and 1.0V are all generated by SY98103C. In order to meet the power-on sequence of FPGA, the 4 SY98103C uses the PG signal of the previous power supply to control the enable pin of the next power supply to achieve it.

[0102] The control process of the visible light detection component is as follows: Figure 7 As shown, specifically including: After the system is powered on and soft resets for a certain period of time, it starts to work normally.

[0103] First, the registers of the image sensor are configured so that the image sensor works under the set parameters. The FPGA generates a driving timing, and the image sensor generates a digital signal which is input into the FPGA. After data sorting, automatic exposure and automatic gain calculation are performed, and gain control is performed based on the calculation results to save power consumption.

[0104] It can be seen that the automatic exposure function of the camera device is realized by the histogram statistics of the image data and the calculation, adjustment and control of the exposure time; the automatic gain function of the camera device is realized by the judgment of the exposure time and the adjustment and control of the gain coefficient.

[0105] 2. The specific structural design is as follows: 1. Infrared lens structure design.

[0106] According to the distribution of infrared light path, this scheme uses optical processing and mechanical structure processing to adjust the dimensional accuracy of lens eccentricity, tilt, center thickness, air spacing, etc. of each group of lenses, and finally realizes a lens with good imaging quality.

[0107] The infrared lens is mainly composed of a main lens barrel, four pressing rings 317, three spacers 318 and an adapter plate. The inner wall of the main lens barrel is provided with a thread adapted to each pressing ring 317, and a mounting groove adapted to each pressing ring 317 is chiseled on the side wall of the main lens barrel. Multiple first optical lenses are placed inside the main lens barrel, and spacers 318 and pressing rings 317 are provided between adjacent first optical lenses.

[0108] The adapter plate includes a shaft connection hole 41, a main lens barrel mounting hole 42, and an infrared camera mounting hole 43. The shaft connection hole 41 is set on the adapter plate, and the main lens barrel is connected to the adapter plate through the main lens barrel mounting hole 42. The adapter plate and the main lens barrel are fixed by a flange connection; the infrared camera 33 is fixed to the adapter plate through the infrared camera mounting hole 43, and the visible light camera 32 is connected to the main lens barrel through the bottom opening of the main lens barrel. The specific three-dimensional model diagram is as follows: Figure 8 shown.

[0109] (1) Main tube.

[0110] The concentricity of the main lens barrel and the matching position of each lens is controlled to ±0.03mm. Through mechanical processing technology, the eccentricity of each lens group can be controlled within 0.03mm, and the gap can be controlled within ±0.03mm. The material is planned to be aluminum alloy 2A12-T4. Specific infrared lens structure, such as Fig. 9 shown.

[0111] (2) Pressure ring and spacer ring.

[0112] The pressing rings all have threads that match the lens barrel, and the thread length is ≥1.5mm. There is a mounting groove on the side wall of each pressing ring for easy assembly. The material is aluminum alloy 2A12-T4. In order to facilitate centering, assembly and trimming, the thickness of the spacer is greater than 0.5mm, and the material is aluminum alloy 2A12-T4.

[0113] (3) Adapter plate.

[0114] The main lens barrel is connected to the adapter plate through the main lens barrel mounting hole 42. The adapter plate and the main lens barrel are fixed by a flange connection. The infrared camera 33 is fixed to the adapter plate through the infrared camera mounting hole 43. The adapter plate is provided with a shaft connection hole 41 to realize the overall rotation of the lens. The material is aluminum alloy 2A12-T4. The three-dimensional model of the adapter plate is as follows: Fig.11 shown.

[0115] 2. Visible light lens structure design.

[0116] According to the distribution of visible light path, this solution uses optical processing and mechanical structure processing to adjust the dimensional accuracy of each group of lenses, such as eccentricity, tilt, center thickness, air spacing, etc., and finally realizes a lens with good imaging quality. The specific layout is as follows Fig.12 As shown, the structural dimensions are Fig.13 shown.

[0117] Considering the environmental adaptability of the product, the mechanical mounting interface of the lens is designed as a flange mount. At the same time, the image plane can be precisely adjusted by adding or removing gaskets to ensure high-quality imaging quality. The specific three-dimensional model and appearance dimension drawings are as follows: Fig.14 shown.

[0118] The visible light lens comprises: a small lens barrel 319, four spacers 318 and two pressing rings 317. The inner wall of the small lens barrel 319 is provided with a thread adapted to each pressing ring 317, and a mounting groove adapted to each pressing ring 317 is chiseled on the side wall of the small lens barrel 319. A plurality of second optical lenses are placed inside the small lens barrel 319, and spacers 318 and pressing rings 317 are provided between adjacent second optical lenses.

[0119] (1) Small lens tube.

[0120] The small lens barrel is used as the installation reference for each module to ensure the fixation of each optical lens. The concentricity between the small lens barrel and the lens is controlled to ±0.03mm, and the lens gap is controlled to within ±0.03mm. The material is planned to be aluminum alloy 2A12-T4. The specific small lens barrel model is as follows: Fig.15 shown.

[0121] (2) Pressure ring and spacer ring.

[0122] The pressing rings all have threads that match the small lens barrel, and the thread length is ≥1.5mm. There are installation grooves on the side walls of each pressing ring for easy assembly. The material is aluminum alloy 2A12-T4; the thickness of the spacer is set to be above 0.5mm, and the material is aluminum alloy 2A12-T4. Fig.10 As shown, the spacer is Fig.16 shown.

[0123] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A composite optical imaging assembly, characterized in that: include: A dual-light optical system (1), an infrared detection component (2) and a visible light detection component (3); the dual-light optical system (1) comprises a fairing (38), an infrared optical system and a visible light optical system, the fairing (38) being arranged outside the infrared optical system and the visible light optical system; The infrared optical system comprises: a plurality of first optical lenses sequentially arranged between the fairing and the infrared detection assembly (2), and a hole is opened in the middle area of ​​the first optical lens close to the fairing (38); The visible light optical system comprises: a reflector (316) and a plurality of second optical lenses arranged between the fairing (38) and a first optical lens without an opening close to the fairing (38), wherein the plurality of second optical lenses are sequentially arranged between the fairing (38) and the reflector (316); The light signal reflected by the target object enters the plurality of first optical lenses through the fairing (38) and reaches the infrared detection component (2), thereby forming a first visible image; The light signal reflected by the target object enters the plurality of second optical lenses through the opening area of ​​the first optical lens and reaches the reflector (316); it is reflected by the reflector (316) to the visible light detection component (3) to form a second visible image.

2. A composite optical imaging assembly as claimed in claim 1, characterized in that: The plurality of first optical lenses include: a first lens (34), a second lens (35), a third lens (36) and a fourth lens (37); the first lens (34) has an opening in the middle region; The light signal reflected by the target object passes through the first lens (34), the second lens (35), the third lens (36) and the fourth lens (37) in sequence.

3. A composite optical imaging assembly as claimed in claim 2, characterized in that: The first lens (34) is a spherical lens, the second lens (35) is a spherical lens, the third lens (36) is an aspherical lens, and the fourth lens (37) is a diffractive aspherical lens; The surfaces of the first lens (34), the second lens (35), the third lens (36) and the fourth lens (37) are all coated with anti-reflection films.

4. A composite optical imaging assembly as claimed in claim 1, characterized in that: The plurality of second optical lenses include: a fifth lens (311), a first lens group (312), a second lens group (313), a sixth lens (314) and a seventh lens (315); a light signal reflected by a target object passes through the fifth lens (311), the first lens group (312), the second lens group (313), the sixth lens (314) and the seventh lens (315) in sequence.

5. The composite optical imaging assembly according to claim 1, characterized in that: The infrared detection assembly (2) comprises: a window glass (39) and a photosensitive surface (310); a light signal reflected by a target object enters the plurality of first optical lenses through the fairing (38) and reaches the window glass (39); and enters the photosensitive surface (310) through the window glass (39) to form a first visible image.

6. A composite optical imaging assembly as claimed in claim 1, characterized in that: The visible light detection component (3) comprises an image sensor module, an image processing module, an interface module, and a power supply module; The image sensor module is used to convert the second visible image into a charge image signal and output it according to a set working sequence; The image processing module is used to generate the working timing of the image sensor module, collect the output signal of the image sensor module, and convert it into a standard video stream; The interface module is used to output a standard video stream; The power supply module is used to supply power to the image sensor module, the image processing module and the interface module.

7. The composite optical imaging assembly according to claim 1, characterized in that: The composite optical imaging assembly also includes a visible light lens, which includes: a small lens barrel (319), a plurality of spacer rings (318), and a plurality of pressure rings (317); The inner wall of the small lens barrel (319) is provided with a thread adapted to each of the pressing rings (317), and a mounting groove adapted to each of the pressing rings (317) is chiseled on the side wall of the small lens barrel (319); A plurality of the second optical lenses are placed inside the small lens barrel (319), and the spacer ring (318) and the pressure ring (317) are provided between adjacent second optical lenses.

8. A composite optical imaging assembly as claimed in claim 7, characterized in that: The composite optical imaging assembly also includes an infrared lens, which includes: a main lens barrel, a plurality of pressure rings (317), a plurality of spacer rings (318), and an adapter plate; The inner wall of the main lens barrel is provided with a thread adapted to each of the pressing rings (317), and a mounting groove adapted to each of the pressing rings (317) is chiseled on the side wall of the main lens barrel; A plurality of the first optical lenses are placed inside the main lens barrel, and the spacer ring (318) and the pressure ring (317) are provided between adjacent first optical lenses; The adapter plate comprises a rotating shaft connection hole (41), a main lens barrel mounting hole (42), and an infrared camera mounting hole (43); the rotating shaft connection hole (41) is arranged on the adapter plate, the main lens barrel is connected to the adapter plate via the main lens barrel mounting hole (42), and the adapter plate and the main lens barrel are fixed via a flange connection; the infrared camera (33) is fixed to the adapter plate via the infrared camera mounting hole (43), and the visible light camera (32) is connected to the main lens barrel via a bottom surface opening of the main lens barrel.

Images