A carbon fiber heating sheet for vehicle cameras and its preparation method

Abstract

The present invention relates to a carbon fiber heating sheet for a vehicle camera and a preparation method thereof. The heating sheet includes a heating sheet body and shells arranged on both sides of the heating sheet body. The shell includes an upper shell having a cavity and a lower shell that cooperates with the upper shell to fix the heating sheet body. A vacuum sealing space is formed between the heating sheet body and the shell. The inner circle of the heating sheet body is located between the C-shaped outer edge of the upper shell and the lens, and its outer circle is located on the lower shell. At this time, it is ensured that there is no air or fog in the contact surface between the heating sheet body and the lens, improving the direct heating efficiency. At the same time, the heating sheet body and the shell are ensured to be sealed, avoiding contact between the edge of the heating sheet body and the air, which may cause cracking and oxidation of the circuit board covered by the upper and lower PI films at the film contact part, resulting in a reduction in the service life of the heating sheet.

Description

Technical Field

[0001] This application relates to the field of in-vehicle camera components, and particularly to a carbon fiber heating sheet for vehicle cameras and a preparation method thereof. Background Art

[0002] In-vehicle cameras are the basis for implementing numerous warning and recognition ADAS functions. Among many ADAS functions, the visual image processing system is relatively fundamental, and the camera is the input of the visual image processing system. Therefore, in-vehicle cameras are essential for intelligent driving. When the camera encounters cold weather, water mist will form on the lens surface, affecting the photography effect, which will cause inaccurate data obtained by autonomous driving and seriously affect the performance and safety of autonomous driving.

[0003] Currently, in-vehicle cameras generally can use defogging methods to eliminate the influence. The defogging mainly uses a metal silicone heating sheet. Chinese Patent ZL201910222532.2 introduces a lens heating module and a lens using the same. The lens is placed on the heating layer of the heating module, and the whole is heated through a heat conductor. It uses a metal circuit and hot pressing technology to prepare the heating part of the heating module. In terms of function use: (1) The heating-up speed is relatively slow, the electro-thermal conversion efficiency is low, and the power consumption is high; (2) The power consumption decreases rapidly, and the service life is short; (3) Due to the existence of the metal circuit sheet on the film itself, there will be an obvious foreign body feeling when touched. After using for a long time, it is more likely to be worn at the resistance wire part; (4) Due to the thickness of the metal circuit, there will be microscopic air bubbles at the circuit edge after hot pressing, and the expansion of the air bubbles after heating will affect the service life. In terms of process preparation: (1) The metal circuit itself has a thickness, and the upper and lower insulating materials cannot be completely and evenly bonded around the resistance wire during pressing; at the same time, since the existing technology generally heats the lens by covering a heating film arranged outside the lens, on the one hand, the heating film itself does not have a good imaging effect, resulting in a decrease in the imaging quality of the camera itself, but the reduction of the heating film area means a decrease in its heating effect. On the other hand, the heating film itself and its fixedly connected part lack a good heat preservation mechanism, resulting in a decrease in its heating efficiency, fast heat dissipation, and it is difficult to achieve good cooperation with other external parts due to the existence of the metal circuit sheet on the film itself. After heating, thermal expansion and contraction will cause it to be easily detached.

[0004] Therefore, researching a new type of carbon fiber heating sheet for cameras that can solve the above problems, has a fast heating-up speed, high electro-thermal conversion efficiency, is convenient to use, and increases the structural life, as well as the supporting preparation equipment and method, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] To solve the above problems, the technical solution adopted by the present invention is:

[0006] A new carbon fiber heating sheet for a camera, the heating sheet comprising a heating sheet body and housings disposed on both sides of the heating sheet body, the housings including an upper housing having a cavity and a lower housing that cooperates with the upper housing to fix the heating sheet body, a vacuum sealed space being formed between the heating sheet body and the housings, a clamping structure for fixing to a lens cylinder being provided on the lower housing, both the upper housing and the lower housing being circular ring structures, the cross-section of the upper housing being C-shaped and having an opening facing downward, the lower housing partially sealing the opening and forming a gap with the opening edge of the upper housing, the gap allowing the heating sheet body to pass through and being hermetically connected to the upper and lower sides of the heating sheet body, the heating sheet body being circular ring-shaped, the inner ring radius of the heating sheet body being greater than or equal to the inner ring radius of the upper housing and less than or equal to the inner ring radius of the gap, and the outer ring radius of the heating sheet body being greater than or equal to the inner ring radius of the lower housing and less than or equal to the outer ring radius of the upper housing.

[0007] Further, the clamping structure is provided on the outer wall of the inner edge of the lower housing and cooperates with a fitting structure provided on the lens cylinder so that the heating sheet body is fixed outside the lens.

[0008] Further, the clamping structure is specifically a mortise and tenon or threaded structure.

[0009] Further, for the sealed space formed between the heating sheet body and the housings, the sealed space is filled with an inert gas.

[0010] Further, air holes are also provided on the outer edge side wall of the upper housing, and one-way valves are provided on the air holes.

[0011] A preparation method for a new carbon fiber heating sheet for a camera, the preparation method being used to prepare the new carbon fiber heating sheet for a camera as described above, the preparation method comprising the following steps:

[0012] (1) Cutting: Cut the outer shape of the lower insulating PI film and the outer shape of the carbon fiber.

[0013] (2) Wiring: Stick the carbon fiber on the lower insulating PI film according to the design pattern, and cover the upper insulating PI film after sticking.

[0014] (3) Pre-pressing: The composite layer covered with the upper insulating PI film is pre-pressed on a laminating machine.

[0015] (4) Hot pressing: The composite layer material with the film stuck is placed on a hot pressing platform, held under pressure for a period of time at a certain temperature to bond the upper and lower insulating PI films together.

[0016] (4) Wiring: Weld the selected silicone wire to the designed external wiring points.

[0017] (5)Testing: Test the electrical parameters, including voltage, resistance, and current, test the heating temperature, and achieve temperature constancy after reaching the required temperature to obtain the heating sheet body 1.

[0018] Further, the heating temperature of the hot pressing platform is 100~200 °C, and its heating time is 30~90 s.

[0019] Further, the preparation method further includes (6) Assembly: Fix the upper housing and the lower housing to the heating sheet body to obtain a heating sheet with a sealed space; (7) Vacuum pumping: Pump the air in the sealed space through the air hole.

[0020] A preparation device for a new type of carbon fiber heating sheet for a camera, the preparation device is used to prepare the new type of carbon fiber heating sheet for the camera, the preparation device includes a film roll mechanism, a cutting machine, a fiber bundle braiding structure, a hot pressing mechanism, a welding device, and a screening mechanism connected in sequence. The film roll mechanism includes a lower insulating PI film roll and an upper insulating PI film roll. The cutting machine is provided with a fiber bundle braiding structure and a cutting die. On both sides of the cutting die, there are rollers with cutting knives and sliding rollers that can move up and down. The fiber bundle braiding structure is arranged directly above the cutting die; the welding device is used to weld the selected silicone wire to the designed external circuit points. The screening mechanism includes a testing machine, a screening disc, and a waste product table. The screening disc includes several worktables evenly arranged along the circumferential surface. One end of the worktable is provided with a testing machine. The testing machine tests the electrical parameters of the heating sheet body and transmits the results to the central control mechanism of the preparation device. If the test result is qualified, the heating sheet body is transmitted to the assembly machine. If the test result is unqualified, the screening disc can transmit the heating sheet to the waste product table.

[0021] Further, the assembly machine includes a conveyor belt and assembly grippers. The assembly grippers are symmetrically arranged on both sides of the conveyor belt. The heating sheet body is conveyed on the conveyor belt. The assembly grippers are provided with suction cups that can adsorb the housing. The two symmetrically arranged assembly grippers respectively adsorb the upper housing and the lower housing of the housing. When the heating sheet body passes between the two arranged assembly grippers through the conveyor belt, the conveyor belt intermittently moves through the intermittent mechanism. The two symmetrically arranged assembly grippers move up or down respectively under the drive of their lifting structures to seal and fix the heating sheet body between the upper housing and the lower housing.

[0022] Beneficial effects:

[0023] In the present invention, a vacuum sealing space is provided between the heating sheet body and the housing, and the vacuum sealing space is used to achieve heat insulation. This not only improves the heating efficiency but also avoids energy waste caused by excessive heat dissipation, while increasing the overall service life of the heating sheet. At the same time, the inner ring of the heating sheet body is located between the C-shaped outer edge of the upper housing and the lens, and its outer ring is located on the lower housing. At this time, it is ensured that there is no air or fog between the contact surface of the heating sheet body and the lens, improving the direct heating efficiency. Also, the heating sheet body is sealed with the housing to prevent contact between the edge of the heating sheet body and the air, which may cause cracking and oxidation at the film contact part of the circuit board covered by the upper and lower PI films, resulting in a reduced service life of the heating sheet;

[0024] The present invention also provides an annular heating sheet body and upper and lower housings that are hermetically fitted therewith, so that the heating sheet body is integrally fixed between the upper housing and the lens, further preventing bubbles and water mist generated by the gap between the lens and the heating sheet, and avoiding the influence of the covered heating film on the imaging of the lens itself;

[0025] The heating element inside this invention patent is made of carbon fiber material. After being energized, this material has a fast heating-up speed (<3s), which can solve the problem of slow heating-up speed of traditional heating; the electrothermal conversion efficiency of carbon fiber is high, up to 99%. Under the same amount of electricity, it can be used for a longer time with lower energy consumption; the service life of the carbon fiber heating film is longer; the thickness of the carbon fiber (<30μm) is uniform without a foreign body feeling; there is no problem of pressing gap for carbon fiber. After laminating the film, it can be directly hot-pressed, with a faster production efficiency;

[0026] The present invention also designs corresponding preparation equipment according to the characteristics of the heating sheet, enabling it to be better applied to the preparation of the heating sheet body made of carbon fiber material of this application. At the same time, an assembly mechanism is provided to assemble the heating sheet body and the housing, realizing automatic assembly and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0028] Figure 1 It is a side view of the whole heating sheet;

[0029] Figure 2 It is a front view of the whole heating sheet;

[0030] Figure 3 It is a cross-section of the whole heating sheet Figure 1 (The heating sheet body is removed for easy display);

[0031] Figure 4 Overall sectional view of the heating sheet Figure 2 ;

[0032] Figure 5 Overall sectional view of the heating sheet Figure 3 ;

[0033] Figure 6 Overall sectional view of the heating sheet Figure 4 (The heating sheet body is removed for convenient display);

[0034] Figure 7 Overall schematic diagram of the preparation equipment for the heating sheet;

[0035] Figure 8 Schematic diagrams of the film roll mechanism, cutting machine, and fiber bundle braiding structure of the preparation equipment for the heating sheet;

[0036] Figure 9 Schematic diagrams of the cutting machine and fiber bundle braiding structure of the preparation equipment for the heating sheet;

[0037] Figure 10 Schematic diagrams of the welding equipment and screening mechanism structure of the preparation equipment for the heating sheet;

[0038] Figure 11 Schematic diagram of the assembling machine of the preparation equipment for the heating sheet;

[0039] Figure 12 Partial enlarged view of the assembling machine of the preparation equipment for the heating sheet;

[0040] Figure 13 Enlarged schematic diagram of the assembling jaw. Detailed implementation manners

[0041] Hereinafter, the exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0042] As Figures 1-6, this embodiment provides a novel carbon fiber heating sheet for a camera. The heating sheet includes a heating sheet body 1 and housings 2 disposed on both sides of the heating sheet body 1. The housing 2 includes an upper housing 201 having a cavity and a lower housing 202 that cooperates with the upper housing 201 to fix the heating sheet body 1. A vacuum sealed space 3 is formed between the heating sheet body 1 and the housing 2. A clamping structure for fixing to the lens cylinder is provided on the lower housing 202; generally, when the heating sheet body 1 heats the lens, if its own temperature is too high, it will cause high-temperature deformation or oxidation of the components connected to it, and the heat loss also reduces the heat transfer efficiency to the lens, wasting energy. Moreover, the heat dissipation of the contact part between the heating sheet and its fixed components is poor, and the two are easily adhered and damaged after heating, resulting in a limited overall life of the entire heating sheet. In this application, a vacuum sealed space 3 is formed between the heating sheet body 1 and the housing 2, and the vacuum sealed space 3 is used to achieve heat insulation, which can not only improve the heating efficiency but also avoid energy waste caused by too fast heat dissipation, and at the same time improve the overall service life of the heating sheet.

[0043] To further prevent water mist from forming on the glass surface of the lens when the temperature difference between indoors and outdoors is too large and the humidity is too high, if there is a gap between the lens and the heating sheet, bubbles and water mist will be generated and difficult to remove, and to avoid the covered heating film affecting the imaging of the lens itself, both the upper housing 201 and the lower housing 202 are circular ring structures. The cross-section of the upper housing 201 is C-shaped, and its bottom surface faces downward and has an opening 203. The lower housing 202 partially seals the opening 203 and forms a gap 204 with the opening edge of the upper housing 201. The gap 204 allows the heating sheet body 1 to pass through and is hermetically connected to the upper and lower sides of the heating sheet body 1. The heating sheet body 1 is circular ring-shaped, the inner radius of the heating sheet body 1 is greater than or equal to the inner radius of the upper housing 201 and less than or equal to the inner radius of the gap 204, and the outer radius of the heating sheet body 1 is greater than or equal to the inner radius of the lower housing 202 and less than or equal to the outer radius of the upper housing 201. Through the above settings, the inner circle of the heating sheet body 1 is located between the C-shaped outer edge of the upper housing 201 and the lens, and its outer circle is located on the lower housing 202. At this time, it ensures that there is no air or mist in the contact surface between the heating sheet body 1 and the lens, improving the direct heating efficiency, and also ensuring the seal between the heating sheet body 1 and the housing 2, avoiding contact between the edge of the heating sheet body 1 and the air, and causing cracking and oxidation of the circuit board covered by the upper and lower PI films at the film contact part, resulting in a reduced life of the heating sheet.

[0044] The snap-fit structure is arranged on the outer wall of the inner edge of the lower shell 202 and cooperates with the embedded structure arranged on the lens cylinder to fix the heating plate body 1 on the outside of the lens. Through the arrangement of the above-mentioned snap-fit structure, the heating plate of the present application can be easily removed from the camera when not in use. Other fixing methods that can be foreseen in the prior art, such as mortise and tenon joints or threads and other easy-to-disassemble connection methods, can also be used in the present application.

[0045] Furthermore, a sealed space 3 is formed between the heating plate body 1 and the shell 2, and is filled with common inert gases such as helium and nitrogen. An air hole 205 is also opened on the outer side wall of the upper shell 201, and a one-way valve is provided on the air hole 205. The sealed space 3 is evacuated or discharged with inert gas through the one-way valve.

[0046] Preferably, an electrical chamber 206 is further provided on the C-shaped annular circumference of the upper shell 201. The electrical chamber 206 is a separate sealed space and is not connected to the sealed space 3. The electrical chamber 206 separates the sealed space 3. The heating plate body 1 can be connected to an external power source in the electrical chamber 206 to realize power supply. The external power source can be a mobile power source or a plug-in circuit that is powered wirelessly or wired; further preferably, the power source can be directly provided in the sealed space 3, which is a button battery or a dry cell, etc., to realize the autonomous power supply of the heating plate.

[0047] like Figures 1-13 This embodiment provides a method for preparing a novel carbon fiber heating sheet for a camera, and the specific preparation method is as follows:

[0048] (1) Cutting: Cut the shape of the lower insulating PI film and the carbon fiber shape;

[0049] (2) Pasting: Paste the carbon fiber on the lower insulating PI film according to the design pattern, and then cover the upper insulating PI film;

[0050] (3) Pre-pressing: The composite layer covered with the upper insulating PI film is pre-pressed on the laminating machine;

[0051] (4) Hot pressing: The composite material with the film attached is placed on a hot pressing platform and kept under pressure for a period of time at a certain temperature to bond the upper and lower insulating PI films together;

[0052] (4) Wire welding: weld the selected silicone wire to the designed external circuit point;

[0053] (5) Testing: Testing electrical parameters, including voltage, resistance, and current, and testing heating temperature. When the required temperature is reached, the temperature can be kept constant, and the heating plate body 1 is obtained.

[0054] Specifically, the heating temperature of the hot pressing platform is 100~200°C, and its heating time is 30~90 s.

[0055] Further, the preparation method further includes (6) assembly: fixedly assembling the upper housing 201 and the lower housing 202 with the heating sheet body 1 to obtain a heating sheet with a sealed space 3; (7) vacuum pumping: pumping the sealed space 3 to a vacuum through the air hole 205.

[0056] The heating element inside this invention patent is made of carbon fiber material. After being powered on, this material has a fast heating rate (<3 s), which can solve the problem of slow heating rate of traditional heating; the electrothermal conversion efficiency of carbon fiber is high, up to 99%. Under the same power consumption, the usage time is longer and the energy consumption is lower; the service life of the carbon fiber heating film is longer; the thickness of the carbon fiber (<30 μm) is uniform, without a foreign body sensation; there is no problem of lamination gap for carbon fiber. After laminating, direct hot pressing can be carried out, and the production efficiency is faster. Due to the above advantages of the heating sheet of this invention, it can be set as an annular structure while ensuring that the heating efficiency meets the requirements. At the same time, the carbon fiber without a foreign body sensation enables the housing 2 to be tightly fitted, making the vacuum sealing of the annular heating sheet body 1 a reality and increasing the overall service life of the heating sheet.

[0057] As Figures 7-13 , this embodiment provides a preparation device for a novel carbon fiber heating sheet for a camera. The preparation device includes a film roll mechanism 4, a cutting machine 5, a fiber bundle braiding structure 6, a hot pressing mechanism 7, a welding device 8, and a screening mechanism 9 connected in sequence. The film roll mechanism 4 includes a lower insulating PI film roll 401 and an upper insulating PI film roll 402. The cutting machine 5 is provided with a fiber bundle braiding structure 6 and a cutting die 502. On both sides of the cutting die 502, there are rollers 503 with cutting knives 504 and sliding rollers 505 that can move up and down. The fiber bundle braiding structure 6 is arranged directly above the cutting die 50. The cutting die 502 can be lifted and lowered to achieve cutting and pre-pressing.

[0058] Further, the lower insulating PI film extends from the lower insulating PI film roll 401 and is laid on the cutting die 502. At this time, the cutting die 502 moves upward, and the cutting knives 504 inside the rollers 503 on both sides of the cutting die 502 cut the outer shape of the carbon fiber on the lower insulating PI film and the fiber bundle braided structure 6. The fiber bundle braided structure 6 pastes the carbon fiber on the lower insulating PI film according to the design pattern. The cutting die 502 drives the cut lower insulating PI film and carbon fiber to continue rising. The sliding roller 505 moves downward to cover the upper insulating PI film extending from the upper insulating PI film roll 402 on the lower insulating PI film on the cutting die 502, and after pre-pressing, it is conveyed to the hot pressing mechanism 7 for hot pressing. Preferably, a vacuum chuck 501 is provided on the cutting die 502 to adsorb the lower insulating PI film on the cutting die 502. Since the PI film is relatively thin, when the upper insulating PI film covers the lower insulating PI film on the cutting die 502, the vacuum chuck 501 can adsorb the upper insulating PI film on the cutting die 502 together, facilitating operations such as cutting and transportation.

[0059] The welding device 8 is used to weld the selected silicone wire to the designed external wiring points. The screening mechanism 9 includes a testing machine 901, a screening disk 902, and a waste table 903. The screening disk 902 includes a number of workbenches 9021 evenly arranged along the circumferential surface. A testing machine 901 is provided at one end of the workbench 9021. The testing machine 901 tests the electrical parameters of the heating element body and transmits the results to the central control mechanism of the preparation device. If the test result is qualified, the heating element body is conveyed to the assembly machine 10. If the test result is unqualified, the screening disk 902 can transfer the heating element to the waste table 903.

[0060] The assembly machine 10 includes a conveyor belt 1001 and assembly jaws 1002. The assembly jaws 1002 are symmetrically arranged on both sides of the conveyor belt 1001. A heating element body 1 is conveyed on the conveyor belt 1001. A suction cup 1003 capable of adsorbing the housing 2 is provided on the assembly jaws 1002. The two symmetrically arranged assembly jaws 1002 respectively adsorb the upper housing 201 and the lower housing 202 of the housing. When the heating element body 1 passes between the two symmetrically arranged assembly jaws 1002 through the conveyor belt 1001, the conveyor belt 1001 intermittently moves through the intermittent mechanism 1004. The two symmetrically arranged assembly jaws 1002 move upward or downward respectively under the drive of their lifting structures 1005 to seal and fix the heating element body 1 between the upper housing 201 and the lower housing 202, and then sealant is applied to complete the preparation of the heating element.

[0061] This application improves the existing heating sheet preparation equipment so that it can be better applied to the preparation of the heating sheet body of the carbon fiber material of this application. At the same time, an assembly mechanism that can assemble the heating sheet body 1 and the housing 2 is provided, realizing automatic assembly and improving production efficiency.

[0062] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A carbon fiber heating sheet for a vehicle camera, the heating sheet comprising a heating sheet body and housings disposed on both sides of the heating sheet body, the housing including an upper housing having a cavity and a lower housing that cooperates with the upper housing to fix the heating sheet body, wherein: A vacuum sealing space is formed between the heating sheet body and the housing. A clamping structure for fixing with the lens cylinder is provided on the lower housing. Both the upper housing and the lower housing are circular ring structures. The cross-section of the upper housing is C-shaped, and its bottom surface faces downward and has an opening. The lower housing partially seals the opening and forms a gap with the opening edge of the upper housing. The gap allows the heating sheet body to pass through and is hermetically connected to the upper and lower sides of the heating sheet body. The heating sheet body is circular ring-shaped, and the inner radius of the heating sheet body is greater than or equal to the inner radius of the upper housing and less than or equal to the inner radius of the gap. The outer radius of the heating sheet body is greater than or equal to the inner radius of the lower housing and less than or equal to the outer radius of the upper housing.

2. The heating sheet according to claim 1, wherein: The clamping structure is arranged on the outer wall of the inner side edge of the lower housing and cooperates with the fitting structure arranged on the lens cylinder so that the heating sheet body is fixed outside the lens.

3. The heating sheet according to claim 2, characterized in that: The clamping structure is a mortise and tenon structure or a threaded structure.

4. The heating sheet according to claim 1, characterized in that: A sealing space is formed between the heating sheet body and the housing, and an inert gas is filled in the sealing space.

5. The heating sheet according to claim 1, characterized in that: An air hole is further opened on the outer edge side wall of the upper housing, and a one-way valve is arranged on the air hole.

6. A preparation method of a carbon fiber heating sheet for a vehicle camera, characterized in that: The preparation method is used to prepare the carbon fiber heating sheet for a vehicle camera as described in any one of claims 1-5. The preparation method includes the following steps: (1) Cutting: Cut the outer shape of the lower insulating PI film and the outer shape of the carbon fiber. (2) Wiring: Stick the carbon fiber on the lower insulating PI film according to the design pattern, and cover the upper insulating PI film after sticking. (3) Pre-pressing: The composite layer covered with the upper insulating PI film is pre-pressed on the laminating machine. (4) Hot pressing: The composite layer material with the film stuck is placed on the hot pressing platform, kept under pressure for a certain period of time at a certain temperature, and the upper and lower insulating PI films are bonded together. (4) Wiring: Weld the selected silicone wire on the designed external wiring points. (5) Testing: Test the electrical parameters, including voltage, resistance, and current, test the heating temperature, and achieve temperature constancy after reaching the required temperature to obtain the heating sheet body. (6) Assembly: Fix and assemble the upper housing and the lower housing with the heating sheet body to obtain a heating sheet with a sealing space. (7) Vacuum pumping: Pump the sealing space into a vacuum through the air hole.

7. The preparation method according to claim 6, characterized in that: The heating temperature of the hot pressing platform is 100-200 °C, and its heating time is 30-90 s.

8. An in-vehicle camera prepared by using the preparation method according to any one of claims 6-7, characterized in that: The camera includes a heating sheet, and the heating sheet is used for defogging of the vehicle-mounted camera.

9. A preparation device for a carbon fiber heating sheet used in a vehicle camera, characterized in that: The preparation equipment is used to prepare the carbon fiber heating sheet for a vehicle camera as described in any one of claims 1-5. The preparation equipment includes a film roll mechanism, a cutting machine, a fiber bundle braiding structure, a hot pressing mechanism, a welding device, and a screening mechanism connected in sequence. The film roll mechanism includes a lower insulating PI film roll and an upper insulating PI film roll. The cutting machine is provided with a fiber bundle braiding structure and a cutting die. Both sides of the cutting die are provided with roller wheels with cutting knives and sliding roller wheels that can move up and down. The fiber bundle braiding structure is arranged directly above the cutting die; The welding equipment is used to weld the selected silicone wire on the designed external circuit points. The screening mechanism includes a testing machine, a screening disc and a waste table. The screening disc includes a number of workbenches uniformly arranged along the circumferential surface. A testing machine is arranged at one end of the workbench. The testing machine tests the electrical parameters of the heating element body and transmits the results to the central control mechanism of the preparation equipment. If the test result is qualified, the heating element body is conveyed to the assembly machine. If the test result is unqualified, the screening disc can transfer the heating element to the waste table.

10. The preparation device according to claim 9, characterized in that: The assembly machine includes a conveyor belt and assembly grippers. The assembly grippers are symmetrically arranged on both sides of the conveyor belt. The heating element body is conveyed on the conveyor belt. A suction cup capable of adsorbing the housing is arranged on the assembly gripper. The two symmetrically arranged assembly grippers respectively adsorb the upper housing and the lower housing. When the heating element body passes between the two arranged assembly grippers through the conveyor belt, the conveyor belt moves intermittently through the intermittent mechanism. The two symmetrically arranged assembly grippers move up or down driven by their lifting structures to seal and fix the heating element body between the upper housing and the lower housing.

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