Low-leakage tablet computer

Abstract

The invention discloses a low-leakage tablet computer, and relates to the technical field of electronic equipment. Comprising a front shell, a middle frame and a rear cover, the front shell is fixedly connected with the middle frame, and the front shell and the middle frame form a first sealed cavity; a prototype tablet computer is placed in the first sealing cavity; a touch screen is arranged on the front shell corresponding to the prototype tablet computer; one side, close to the prototype tablet computer, of the touch screen is integrally covered with an electromagnetic shielding layer; the electromagnetic shielding layer is electrically connected with the front shell through a conductive piece; the middle frame is fixedly connected with the rear cover, and the middle frame and the rear cover form a second sealing cavity; the prototype tablet computer is matched with a main control board and a driving board, and a third sealing cavity for placing the main control board and the driving board is formed in the rear cover; the third sealing cavity is located in the second sealing cavity. The electronic devices such as the main control board, the driving board and the external interface board are installed in the multiple sealing cavities, and electromagnetic protection is conducted on the prototype tablet computer and the external electronic devices at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic equipment, and in particular to a low-emission tablet computer. Background Art

[0002] With the rapid development of the information industry, tablet computers have been widely used in highly confidential office systems for information collection, transmission, and processing. Low-emission tablet computers include essential hardware components such as LCD screens, touch screens, and circuit boards. Displays and touch screens are the windows for information processing. When in operation, they can generate strong electromagnetic radiation. This radiated electromagnetic field not only interferes with various electronic devices, but also easily intercepts and reproduces the information emitted by electromagnetic radiation, making it a key means for intelligence personnel to steal military, commercial, and other intelligence. Therefore, it is necessary to improve existing tablet computers and enhance their electromagnetic shielding protection to overcome the problem of strong electromagnetic radiation, which makes important intelligence easily stolen.

[0003] To address this problem, a utility model application with application number "202222878269.2" and titled "A Low-Emission Tablet Computer" discloses a device comprising a frame, a shielding portion provided on one side of the frame, a touch portion provided on one side of the shielding portion, the touch portion being closely fitted with the shielding portion, a display screen provided on one side of the touch portion, pressure plates provided around the shielding portion, a threaded groove provided inside the frame, a bolt being threadedly connected to the internal thread of the threaded groove, one side of the pressure plate being closely fitted with one end of the bolt, a rear cover provided on one side of the frame, a metal mesh gasket provided between the rear cover and the frame, the frame being made of low-carbon alloy structural steel, the pressure plate being arranged in a "Z" shape, and an integrated filter being threadedly connected to the internal thread of the frame, and the shielding portion being provided to achieve the function of shielding touch and prevent information leakage; however, this solution can only improve the electromagnetic shielding protection effect of ordinary tablet computers, and the protection effect is poor. Moreover, in actual use, the functions of the tablet computer are limited by itself, and external electrical accessories need to be connected to the tablet computer to meet the usage requirements.

[0004] Therefore, the present invention has developed a low-emission tablet computer to solve the above technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-emission tablet computer to solve the problems existing in the above-mentioned prior art, thereby improving the electromagnetic shielding protection level of the tablet computer with external electrical accessories, preventing important information from being easily stolen, and also enhancing the anti-interference ability of the device.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a low-emission tablet computer, comprising: a front shell, a middle frame and a back cover, all of which are conductive;

[0008] The front shell is fixedly connected to the middle frame, and the front shell and the middle frame form a first sealed cavity; a prototype tablet computer is placed in the first sealed cavity, and the prototype tablet computer is fixedly connected to the middle frame; a touch screen is installed on the front shell at a position corresponding to the prototype tablet computer; the side of the touch screen closest to the prototype tablet computer is entirely covered with an electromagnetic shielding layer; the electromagnetic shielding layer is electrically connected to the front shell via a conductive member;

[0009] The middle frame is fixedly connected to the back cover, and the middle frame and the back cover form a second sealed cavity; the prototype tablet computer is equipped with a main control board and a driver board, and the back cover is provided with a third sealed cavity for placing the main control board and the driver board; the third sealed cavity is located inside the second sealed cavity.

[0010] Preferably, the electromagnetic shielding layer is electromagnetic shielding glass, electromagnetic shielding mesh or electromagnetic shielding film; the conductive member is copper foil; one end of the copper foil is adhered to the electromagnetic shielding layer, and the other end is adhered to the front shell.

[0011] Preferably, grooves are provided at the edge positions of the middle frame and at the corresponding positions of the front shell and the back cover; protrusions corresponding to the grooves are provided on the front shell and the back cover; and conductive rubber strips are provided between the grooves provided at the edge positions of the middle frame and at the corresponding positions of the front shell and the back cover and the protrusions corresponding to the front shell and the back cover.

[0012] Preferably, an annular protrusion is provided in the back cover for placing the main control board and the drive board respectively; an isolation plate is provided on the middle frame; an annular groove is provided at the upper end of the annular protrusion for placing a conductive rubber strip; the conductive rubber strip is located between the annular protrusion and the isolation plate; the annular protrusion and the isolation plate form a third sealed cavity.

[0013] Preferably, the middle frame is provided with a first wire outlet for leading out the circuits of the prototype tablet computer and the touch screen; the first wire outlet is sealed by wrapping the copper foil around the outside of the circuit.

[0014] Preferably, a first conductive bus bar is provided around the driving board; the copper foil is adhered around the first conductive bus bar and overlapped with the isolation plate.

[0015] Preferably, a battery, a battery management board and an external interface board are also fixedly installed in the back cover; a second wire outlet for leading out the main control board circuit and the driver board circuit is provided on the annular protrusion; the second wire outlet is sealed by wrapping the copper foil on the outside of the circuit; the external interface board is connected to the main control board through a first shielded cable; the battery management board is connected to the external interface board through a second shielded cable; the driver board is connected to the external interface board through a third shielded cable; and the battery and the battery management board are connected through a fourth shielded cable.

[0016] Preferably, a rear camera opening is provided on the back cover at a position corresponding to the rear camera of the prototype tablet computer; and an electromagnetic shielding layer is fixedly installed at the position corresponding to the rear camera opening.

[0017] Preferably, the external interface board is provided with a reserved interface electrically connected to the prototype tablet computer and a plurality of external interface connectors; the back cover is provided with a plurality of alignment interface openings corresponding to the plurality of external interface connectors.

[0018] Preferably, it also includes a communication antenna assembly, a filter and a filtering circuit;

[0019] The communication antenna assembly is fixedly mounted on the outer side of the back cover;

[0020] The filter is located in the second sealed cavity and is fixedly mounted on the back cover; one end of the filter is electrically connected to the communication antenna assembly; and the other end of the filter is electrically connected to the communication interface on the main control board.

[0021] The filter circuit is arranged on the external interface board and is located at the rear end of the external interface connector; the filter circuit is electrically connected to the external interface connector.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] 1. In the present invention, the front shell and the middle frame form a first sealed cavity, the middle frame and the rear cover form a second sealed cavity, and the rear cover is provided with annular protrusions for placing the main control board and the drive board respectively; the annular protrusions and the isolation plate form a third sealed cavity, and the main control board and the drive board are sealed and isolated by the third sealed cavity to prevent mutual influence between the main control board, the drive board and the electronic device circuits. At the same time, the third sealed cavity can improve the electromagnetic shielding effect of the main control board and the drive board, and the function of preventing electromagnetic wave leakage is achieved through multiple sealed cavities, with better protection effect;

[0024] 2. The present invention enhances the functionality of the prototype tablet computer by installing electronic components such as the main control board, driver board, and external interface board on the back cover. Furthermore, by installing the main control board, driver board, external interface board, and other electronic components inside a multi-sealed cavity, electromagnetic protection is achieved for both the prototype tablet computer and external electronic components.

[0025] 3. The present invention realizes electromagnetic protection at the external interface by setting a filter circuit on the external interface board;

[0026] 4. The present invention achieves reception and transmission of electromagnetic wave signals in a specified frequency band and improves shielding performance by installing a communication antenna assembly on the outside of the rear shell and connecting a filter to the rear end of the communication antenna assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1-5 It is a schematic diagram of the overall assembly structure of the present invention;

[0029] Figure 6 Schematic diagram of the explosion of the front housing, the first silicone rubber plate and the touch screen of the present invention;

[0030] Figure 7 An exploded schematic diagram of the middle frame and parts mounted on the middle frame of the present invention;

[0031] Figure 8 An exploded schematic diagram of the back cover and parts mounted on the back cover of the present invention;

[0032] Figure 9 It is a partial structural diagram of the frame of the present invention;

[0033] Figure 10-11 This is a schematic diagram of the assembly structure of the customized rubber stopper and the customized rubber stopper bracket of the present invention;

[0034] Figure 12-13 Schematic diagram of the assembly structure of the sliding door assembly and the rear cover of the present invention;

[0035] Figure 14 Schematic diagram of the cross-sectional structure of the sliding door assembly and the rear cover of the present invention;

[0036] Figure 15 Schematic diagram of the assembly structure of the sliding door and the sliding door assembly of the present invention;

[0037] Figure 16-17Schematic diagram of the structure of the sliding door assembly of the present invention;

[0038] Figure 18 Schematic diagram of the assembly structure of the back cover and communication antenna assembly of the present invention;

[0039] Figure 19 Schematic diagram of the cross-sectional structure of the front housing, the first silicone rubber plate, the touch screen, the electromagnetic shielding layer and the copper foil of the present invention;

[0040] Figure 20 This is a schematic diagram of the connection relationship between various components in the low-leakage tablet computer disclosed in an embodiment of the present invention.

[0041] Among them, 100, tablet computer; 1, front shell; 2, middle frame; 3, back cover; 4, button; 5, button guide shaft; 6, prototype tablet computer; 7, customized rubber plug; 8, rubber plug fixing frame; 9, first silicone rubber plate; 12, external interface board; 13, main control board; 14, driver board; 15, battery; 16, battery management board; 17, self-reset button; 18, sliding door assembly (1801, sliding door; 1802, sliding door bracket; 1803, spring plunger); 19 , electromagnetic shielding glass; 20, touch screen; 21, first antenna shell; 22, second antenna shell; 23, first filter; 24, second filter; 25, third filter; 26, first communication antenna; 27, second communication antenna; 28, third communication antenna; 29, Type-C shielded cable; 30, folding bracket assembly (3001, bracket; 3002, damping hinge; 3003, bracket decorative cover) 31, first shielded cable; 32, second shielded cable. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] The purpose of the present invention is to provide a low-emission tablet computer to solve the problems existing in the above-mentioned prior art, thereby improving the electromagnetic shielding protection level of the tablet computer with external electrical accessories, preventing important information from being easily stolen, and also enhancing the anti-interference ability of the device.

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Example

[0046] This embodiment provides a low-emission tablet computer 100, such as Figure 1-8 As shown,

[0047] A low-emission tablet computer, characterized by comprising: a front shell 1, a middle frame 2, and a back cover 3, all of which are conductive;

[0048] The front housing 1 and the middle frame 2 are fixedly connected by bolts, and the front housing 1 and the middle frame 2 form a first sealed cavity; a prototype tablet computer 6 is placed in the first sealed cavity, and the prototype tablet computer 6 is fixedly connected to the middle frame 2; a touch screen 20 is installed on the front housing 1 at a position corresponding to the prototype tablet computer 6; the side of the touch screen 20 closest to the prototype tablet computer 6 is entirely covered with an electromagnetic shielding layer; the electromagnetic shielding layer is electrically connected to the front housing 1 via a conductive member;

[0049] The middle frame 2 and the back cover 3 are fixedly connected by bolts, and the middle frame 2 and the back cover 3 form a second sealed cavity; the prototype tablet computer 6 is equipped with a main control board 13 and a drive board 14, and the back cover 3 is provided with a third sealed cavity for placing the main control board 13 and the drive board 14; the third sealed cavity is located inside the second sealed cavity.

[0050] Furthermore, the front housing 1, middle frame 2, and back cover 3 are all made of AZ91 D magnesium alloy, and all surfaces are treated with a conductive finish. AZ91 D magnesium alloy offers superior initial shielding effectiveness. By applying a conductive finish to the surfaces of the front housing 1, middle frame 2, and back cover 3, a continuous conductive path is formed, preventing shielding blind spots caused by oxidation of the outer surfaces.

[0051] As a specific implementation of this embodiment, Figure 6 and Figure 19 As shown, a first silicone rubber plate 9 is provided between the front shell 1 and the prototype tablet computer 6; the first silicone rubber plate 9 is elastic and can absorb external impacts to prevent the touch screen 20 from being damaged when the front shell 1 is bumped; in addition, because the first silicone rubber plate 9 is elastic, it can better fit with the front shell 1 and the touch screen 20, preventing dust and water from entering the first sealed cavity through the gap between the front shell 1 and the touch screen 20.

[0052] Furthermore, the electromagnetic shielding layer is electromagnetic shielding glass, electromagnetic shielding mesh, or electromagnetic shielding film. In this embodiment, the electromagnetic shielding layer is an electromagnetic shielding film. The electromagnetic shielding film is fully bonded to the touch screen 20. The conductive member is a copper foil. One end of the copper foil is bonded to the electromagnetic shielding film, and the other end is bonded to the front housing 1. The copper foil electrically connects the electromagnetic shielding film to the front housing 1.

[0053] Furthermore, grooves are provided at the edges of the middle frame 2 corresponding to the front shell 1 and the back cover 3; protrusions are provided on the front shell 1 and the back cover 3 to mate with the grooves; and a conductive rubber strip is provided between the grooves provided at the edges of the middle frame 2 corresponding to the front shell 1 and the back cover 3 and the protrusions provided on the front shell 1 and the back cover 3 to mate with the grooves. As a specific embodiment of this embodiment, the groove provided at the edges of the middle frame 2 corresponding to the front shell 1 and the back cover 3 is an annular groove that conforms to the outer contour of the middle frame 2; a conductive rubber strip is placed within the annular groove; the conductive rubber strip can fill the gap between the groove and the protrusion, establishing a continuous conductive path, and together with the front shell 1 and the middle frame 2, and the middle frame 2 and the back cover 3, respectively, form a complete Faraday cage, namely, a first sealed cavity and a second sealed cavity.

[0054] As a specific implementation of this embodiment, Figure 7 and Figure 9 As shown, the middle frame 2 is provided with a mounting groove for mounting the prototype tablet computer 6; the prototype tablet computer 6 is fixedly mounted in the mounting groove, and a second silicone rubber plate is filled between the prototype tablet computer 6 and the side wall of the mounting groove; the second silicone rubber plate fits the prototype tablet computer 6 more closely, increasing the stability of the prototype tablet computer 6 while playing a role in anti-vibration and anti-impact.

[0055] The front shell 1 and the touch screen 20 (including the electromagnetic shielding layer) are provided with a yield structure at the position corresponding to the front camera of the prototype tablet computer 6 to avoid blocking the front camera; as a specific implementation of this embodiment, the touch screen 20 is composed of an external mounting frame and a screen installed in the external mounting frame; the external mounting frame is installed on the front shell 1, and a semicircular notch is provided on the external mounting frame to avoid the front camera of the prototype tablet computer 6; the middle frame 2 is provided with a hole corresponding to the speaker hole of the prototype tablet computer 6 so that the sound can be normally transmitted to the outside. The middle frame 2 is provided with a key mounting groove at the position corresponding to the volume key and power key of the prototype tablet computer 6; a key 4 is installed in the key mounting groove by a bolt, and a first through hole for the bolt to pass through is provided in the key mounting groove, and the bolt corresponds to the volume key or power key on the prototype tablet computer 6 at the corresponding position; the key 4 is connected to the middle frame 2 by the bolt and a 0.5mm movement gap is reserved so that the key 4 can move in the direction facing the volume key or power key of the prototype tablet computer 6; at the same time, in order to accurately control the movement direction of the key 4, two key guide shafts 5 are threadedly connected to each key 4; a key guide shaft through hole is provided in the key mounting groove, and the direction of the key guide shaft through hole is the same as the movement direction of the corresponding volume key or power key on the prototype tablet computer 6; when controlling the volume key or power key, it is only necessary to press the corresponding key 4, and the key 4 drives the bolt to move downward, and one end of the bolt presses the corresponding volume key or power key on the prototype tablet computer 6; after releasing the key 4, the volume key or power key on the prototype tablet computer 6 will drive the corresponding key 4 to reset.

[0056] The prototype tablet computer 6 is located in the first sealed cavity, which can effectively block the electromagnetic waves generated by the prototype tablet computer 6, prevent the electromagnetic waves from leaking, and increase the safety of the device.

[0057] Further, such as Figure 8 As shown, annular protrusions are provided in the back cover 3 for placing the main control board 13 and the drive board 14 respectively; the main control board 13 and the drive board 14 are fixedly installed in the two annular protrusions respectively; an isolation plate is provided on the middle frame 2; an annular groove is provided at the upper end of each annular protrusion for placing a conductive rubber strip; the conductive rubber strip is located between the annular protrusion and the isolation plate; the annular protrusion and the isolation plate form a third sealed cavity; the conductive rubber strip can fill the gap between the annular protrusion and the isolation plate, construct a continuous conductive path, and together with the annular protrusion and the isolation plate form a complete Faraday cage, that is, the third sealed cavity.

[0058] Furthermore, a first conductive bus bar is provided around the driving board 14; copper foil is pasted around the first conductive bus bar and overlapped with the isolation board; as a specific implementation of this embodiment, a second conductive bus bar is provided around the main control board 13; copper foil is pasted around the second conductive bus bar and overlapped with the isolation board.

[0059] The main control board 13 and the driving board 14 are respectively installed in the two third sealed cavities. The third sealed cavities can prevent the electromagnetic waves generated by the main control board 13 and the driving board 14 from spreading outward. The main control board 13 and the driving board 14 are isolated by the two third sealed cavities to avoid mutual interference between the two. At the same time, when the electromagnetic waves generated by the main control board 13 and the driving board 14 spread upward, they need to pass through the third sealed cavity, the second sealed cavity and the first sealed cavity before they can spread to the outside. Therefore, this application enhances the functions of the prototype tablet computer 6 by adding electronic devices, while better preventing the leakage of electromagnetic waves, and has a higher safety factor.

[0060] Further, such as Figure 7-8 As shown, the rear cover 3 is also fixedly installed with a battery 15, a battery management board 16 and an external interface board 12; the external interface board 12 is fixedly installed on the right side of the rear cover 3;

[0061] A second wire outlet for the main control board 13 circuit and the driver board 14 circuit is provided on the annular protrusion; the second wire outlet is sealed by wrapping copper foil on the outside of the circuit; the external interface board 12 is connected to the main control board 13 through a first shielded cable 31; the battery management board 16 is connected to the external interface board 12 through a second shielded cable 32; the driver board 14 is connected to the external interface board through a third shielded cable; the battery 15 and the battery management board 16 are connected through a fourth shielded cable; a first wire outlet for the prototype tablet computer 6 circuit and the touch screen 20 circuit is provided on the middle frame 2; the first wire outlet is sealed by wrapping copper foil on the outside of the circuit; by sealing the first wire outlet and the second wire outlet, the electromagnetic shielding effect at the first wire outlet and the second wire outlet can be enhanced to prevent electromagnetic waves from leaking from the first wire outlet and the second wire outlet.

[0062] Furthermore, the external interface board 12 is provided with a reserved interface electrically connected to the prototype tablet computer 6 and multiple external interface connectors; the back cover 3 is provided with multiple external interface openings corresponding to the multiple external interface connectors; the middle frame 2 is provided with a Type-C shielded cable routing groove, and after the Type-C shielded cable 29 is inserted into the prototype tablet computer 6, it is installed in the corresponding position of the middle frame 2, and the other end of the Type-C shielded cable 29 is passed through the first outlet and docked with the reserved interface on the external interface board 12; by connecting the prototype tablet computer 6 to the external interface board 12, the prototype tablet computer 6 is transformed from having only one external interface to having multiple external interfaces, thereby expanding the function of the prototype tablet computer 6, supporting the simultaneous access of multiple external devices, and solving the compatibility bottleneck of the prototype interface shortage. Secondly, no additional adapter equipment is required, which reduces the complexity of use and the cost of accessories, and enhances the practicality of the device.

[0063] As a specific implementation of this embodiment, Figure 7and Figure 10-11 As shown, a rubber plug fixing frame 8 is fixedly installed on one side of the middle frame 2 by bolt connection; the rubber plug fixing frame 8 passes through one end of the customized rubber plug 7 and is fixedly installed on the middle frame 2, and one end of the customized rubber plug 7 is fixed between the rubber plug fixing frame 8 and the middle frame 2; the other end of the customized rubber plug 7 is provided with a plug head that is the same in number as the external interface openings and matches the external interface openings; the plug heads on the customized rubber plug 7 correspond one-to-one to the external interface openings on the back cover 3; dust and waterproof treatment is performed by inserting the plug heads on the customized rubber plug 7 into the external interface openings on the back cover 3.

[0064] Further, such as Figure 8 and Figure 18 As shown, a rear camera opening is provided on the back cover 3 at a position corresponding to the rear camera of the prototype tablet computer 6; an electromagnetic shielding layer is fixedly installed at the opening position; the electromagnetic shielding layer is an electromagnetic shielding glass 19; the electromagnetic shielding glass 19 is electrically connected to the back cover 3 through copper foil; the rear camera opening is provided on the back cover 3 to avoid blocking the rear camera of the prototype tablet computer 6, and at the same time, the electromagnetic shielding glass 19 is provided at the rear camera opening position to effectively enhance the electromagnetic shielding effect at the rear camera and avoid leakage of electromagnetic waves.

[0065] As a specific implementation of this embodiment, Figure 8 and Figure 12-18 As shown, a sliding door assembly 18 is provided at the upper left corner of the back of the rear cover 3; the sliding door assembly 18 includes: a sliding door 1801, a sliding door bracket 1802 and a spring plunger 1803; a first self-reset switch is electrically connected to the external interface board 12, and in this embodiment, the first self-reset switch is a first self-reset button 17; when the first self-reset button 17 is pressed, the data inside the tablet computer 100 can be destroyed; a sliding door assembly opening and an annular mounting pit are provided at the upper left corner of the back of the rear cover 3, and a conductive rubber strip is installed in the annular mounting pit; the sliding door bracket 1802 is fixed to the rear cover 3 by bolts; an annular protrusion is provided on the sliding door bracket 1802 corresponding to the annular mounting pit; the conductive rubber strip is located between the annular mounting pit and the annular protrusion, and is used to fill the gap between the annular mounting pit and the annular protrusion to form a continuous conductive path;

[0066] The sliding door 1801 is slidably mounted on the sliding door bracket 1802 corresponding to the opening of the sliding door assembly; a pushing block is provided on the end of the sliding door 1801 facing away from the sliding door bracket 1802, and the pushing block is located in the opening of the sliding door assembly, which is convenient for people to push the sliding door 1801 to slide on the sliding door bracket 1802; as a specific implementation method of this embodiment, the sliding door 1801 is slidably mounted between the sliding door bracket 1802 and the back cover 3, and the sliding door 1801 is larger than the opening of the sliding door assembly so as to block the opening of the sliding door assembly; the ends of the sliding door 1801 that contact the sliding door bracket 1802 and the sliding door 1801 and the back cover 3 are both provided with a 0.2mm raised structure to reduce the resistance during the sliding process, while also effectively protecting the appearance from being scratched; a mounting post is provided on the sliding door bracket 1802, and the mounting post is used to install a spring plunger 1803; A conical hole is provided corresponding to the mounting column; the diameter of the conical hole is largest on the side away from the sliding door bracket 1802; the fixed end of the spring plunger 1803 slides into the mounting column from the conical hole and is fixedly connected to the mounting column; a through hole is provided at the center of the sliding door bracket 1802, and the position of the through hole corresponds to the self-reset button 17 on the external interface board 12; when there is no external force, the sliding door 1801 is in a closed state, that is, the sliding door 1801 blocks the through hole at the center of the sliding door bracket 1802 to prevent the self-reset button 17 from being exposed; when the data in the tablet computer 100 needs to be destroyed, the sliding door 1801 is pushed to slide to expose the self-reset button 17, and the self-reset button 17 is pressed to destroy the data; after the human hand leaves the sliding door 1801, the sliding door 1801 will be reset under the action of the spring plunger 1803, and the self-reset button 17 will be blocked again.

[0067] As a specific implementation of this embodiment, a second self-reset switch is fixedly installed on the back cover 3 and is located in the second sealed cavity; the second self-reset switch is electrically connected to the external interface board 12 through a cable; in this embodiment, the second self-reset switch is a second self-reset button; after the middle frame 2 is fixedly connected to the back cover 3, the middle frame 2 squeezes the second self-reset button so that the second self-reset button is in a pressed state; a destruction program is written in the tablet computer 100; when the middle frame 2 is removed from the back cover 3, the second self-reset button pops up, the destruction program is started, and the data in the tablet computer 100 is destroyed; the tablet computer 100 is prevented from being stolen and information leakage caused by others; when it is necessary to disassemble the tablet computer 100 by yourself, the destruction program is closed through the program control in the tablet computer 100, and then the tablet computer 100 is disassembled.

[0068] As a specific implementation of this embodiment, Figure 8 and Figure 18As shown, a folding damping bracket 30 is installed on the back of the back cover 3; the folding damping bracket 30 includes: a bracket 3001, a damping hinge 3002 and a bracket decorative cover 3003; a bracket 3001 mounting groove is provided on the back of the back cover 3; one end of the damping hinge 3002 is fixedly installed in the mounting groove of the back cover 3 by bolts; the other end of the damping hinge 3002 is fixedly connected to the bracket 3001 by bolts; the bracket decorative cover 3003 is fixedly installed on the damping hinge 3002 by bolts, and is used to cover the exposed part of the damping hinge 3002; the folding damping bracket 30 can solve the support problem when the computer is placed at different angles, and is easy to store, thereby improving the convenience of using the tablet computer.

[0069] Further, such as Figure 8 、 Figure 18 and Figure 20 As shown, it also includes a communication antenna assembly and a filter;

[0070] A communication antenna assembly is fixedly installed on the outside of the back cover 3; the communication antenna assembly includes a first antenna shell 21 and a second antenna shell 22; antenna shell mounting grooves are provided on the upper and lower sides of the back cover 3, on which the first antenna shell 21 and the second antenna shell 22 are installed respectively; a first communication antenna 26 and a second communication antenna 27 are pasted inside the first antenna shell 21; a third communication antenna 28 is pasted inside the second antenna shell 22; antenna wiring holes are provided at the mounting locations of the back cover 3 and the first antenna shell 21 and the second antenna shell 22; a first filter 23, a second filter 24 and a third filter 25 are fixedly installed inside the back cover 3; the first antenna shell 21 and the second antenna shell 22 are both made of non-metallic material and are fixed to the back cover 3 by bolts; the first communication antenna 26 is connected to the first filter 23 through a coaxial cable, the second communication antenna 27 is connected to the second filter 24 through a coaxial cable, and the third communication antenna 28 is connected to the third filter 25 through a coaxial cable; at the same time, the other ends of the first filter 23, the second filter 24 and the third filter 25 are also connected to the communication interface on the main control board 13 using a coaxial cable.

[0071] As a specific implementation of this embodiment, the interconnecting cables are all cables with a shielding layer.

[0072] This device transmits signals through the communication antenna assembly. By setting a filter between the communication antenna assembly and the main control board 13, the communication antenna assembly can only receive and transmit electromagnetic waves of a specific frequency, preventing electromagnetic waves from leaking and ensuring information security.

[0073] As a specific implementation of this embodiment, the filter used in this device is a customized filter; the signals received and transmitted by the first communication antenna 26 and the second communication antenna 27 are 4G signals, and the first filter 23 and the second filter 24 can allow three frequency bands to pass, namely low frequency, medium frequency and high frequency; the network compatibility and anti-interference performance are improved, which not only solves the hardware redundancy problem of frequency band switching of traditional equipment, but also significantly improves communication survivability.

[0074] The device also transmits signals through a specific communication port, that is, through the external interface connector on the external interface board 12;

[0075] Furthermore, the device further includes a filtering circuit, which is disposed on the external interface board 12 and located at the rear end of the external interface connector. The filtering circuit is electrically connected to the external interface connector. By disposing the filtering circuit on the external interface board 12, electromagnetic leakage at the external interface is prevented. As a specific implementation of this embodiment, the filtering circuit includes an ESD protection device of the signal matching module, a multi-stage filter group, and a common-mode choke.

[0076] Furthermore, the battery management board 16 is designed with current limiting and charge / discharge voltage and current protection. The MCU's built-in ADC collects battery voltage to adapt to the current battery charge and discharge currents. A temperature sensor measures the battery and control board temperatures in real time. To reduce output current ripple, the battery management board 16 does not use a boost device, but instead outputs the battery voltage directly, significantly reducing ripple interference. It also features a backup power output that provides current output when the battery charge is low, ensuring that devices have sufficient time to save data.

[0077] Furthermore, the external interface board 12 and the main control board 13 both adopt various measures to reduce the external radiation of the signal.

[0078] When selecting components, low-radiation devices are crucial for reducing electromagnetic interference and improving electromagnetic compatibility. When choosing ICs, opt for devices with integrated EMI suppression whenever possible, and also choose devices with low electromagnetic noise. When selecting clocks and oscillators, prioritize low-jitter clock sources to reduce high-frequency harmonic radiation, and choose devices with shielded housings to minimize interference. When choosing connectors, prioritize shielded connectors, such as Type-C, and ensure the connector housing is fully connected to the PCB ground. When choosing power supplies, prioritize low-noise LDOs. When voltage differentials are large, opt for DC-DC converters. Modules with built-in filtering circuits are preferred to reduce high-frequency noise and minimize the layout of peripheral components. When choosing capacitors and resistors, prioritize decoupling capacitors and resistors with good high-frequency characteristics to minimize noise impact. When choosing RF components, prioritize low-radiation modules that comply with FCC, CE, and other certifications to reduce antenna radiation leakage. In software configuration, reduce radiation levels by setting device operating modes, such as sleep mode, lowering clock frequencies, and disabling certain circuits.

[0079] Furthermore, both the external interface board 12 and the main control board 13 utilize a multi-layer PCB design, with a complete ground plane on the inner layer to reduce electromagnetic interference, avoid ground plane segmentation, and ensure signal loop integrity. Each board features an independent power supply layer, which is recessed. A combination of single-point and multi-point grounding is used to prevent the formation of radiation loops. Differential routing is used for high-speed differential signals, effectively controlling line length and line spacing while avoiding the presence of other high-speed signals near the differential lines. Grounding is performed around the differential signal lines to further improve signal quality and reduce external radiation. Filtering circuits are implemented at the board entrances. LC filters are added to the power lines to filter out high-frequency noise, while RC filters or filtering devices such as ferrite beads are added to the signal lines to prevent signal ingress or egress. The board utilizes a modular layout, isolating circuits with different functions into separate areas to reduce mutual interference and ensure independent, single-point grounding in each area. Special treatment is provided for high-radiation devices, with grounding holes drilled for the crystal oscillator. A keep-out layer is provided below the crystal oscillator to minimize coupling and crosstalk between high-frequency signals.

[0080] Furthermore, both the external interface board 12 and the main control board 13 adopt a multi-stage filter group, which consists of a first-stage filter and a second-stage filter. The first-stage filter is set at the D+ / D- signal line of the USB interface and all differential signal line entrances of the Type-C interface. The second-stage filter is set at the DATA and CLK signal line entrances of the SIM card interface and the signal line entrance of the network interface. The first-stage filter and the second-stage filter both include low-pass filters and high-pass filters for filtering noise in different frequency bands.

[0081] Furthermore, the common-mode chokes of the external interface board 12 and the main control board 13 are arranged at the entrances of the D+ / D- signal lines of the USB interface, all differential signal lines of the Type-C interface, and the signal lines of the network interface. The common-mode choke includes two magnetic rings with the same winding direction and connected in parallel. The common-mode choke is used to eliminate common-mode noise and match the line impedance to reduce signal reflection.

[0082] Furthermore, a common ground network on the external interface board 12 and the main control board 13 is set on the bottom layer of the circuit board. The common ground network includes multiple ground layers, each ground layer is connected by multiple vias, the spacing between the multiple vias is 1.5mm, and the multiple ground layers are connected by equally spaced vias. The common ground network is used to reduce the impedance of the ground and improve the integrity of the signal.

[0083] Furthermore, the ESD protection device of the USB interface protection and signal matching module of the external interface board 12 and the main control board 13 is set at the entrance of the D+ / D- signal line of the USB interface. The ESD protection device is a TVS diode array. The surge suppressor is set between the USB interface power line (VBUS) and the ground line. The surge suppressor is a TVS tube. The common-mode inductor is set on the D+ / D- signal line. The common-mode inductor resistance is 90Ω. The full differential line ESD protection device of the Type-C and network interface protection module is set at the entrance of all differential signal lines of the Type-C interface. The isolation capacitor is set on the USB 3.0 signal line. The capacitance range of the isolation capacitor is 10nF to 100nF. The common-mode inductor reuses the 90Ω common-mode inductor of the D+ / D- signal line.

[0084] Furthermore, the SIM card interface on the external interface board uses an RGMII interface specification adapter module with a high-frequency optimization module, located at the entrance of the SIM card's DATA and CLK signal lines. The equal-length control and impedance matching module includes a serpentine trace with an equal-length error controlled to ±5 mils. The power decoupling design module includes a 0.1μF ceramic capacitor and a 1μF tantalum capacitor, which are connected in parallel at the SIM card power pin. The multi-stage filter bank, common-mode choke, and shared ground network of the multi-interface collaborative protection and signal integrity optimization module are connected by wires with an impedance of 50Ω, which are used to transmit signals and ensure signal integrity.

[0085] Through the setting of multi-stage filter groups and common-mode choke coils, common-mode noise and noise in different frequency bands are effectively eliminated, the purity of the signal is improved, the signal reflection is reduced, and the reliability of communication is improved.

[0086] Through the multi-layer design of the shared ground network and the equally spaced via connections, the impedance of the ground is reduced, the integrity of the signal is improved, the electromagnetic interference is reduced, and the anti-interference ability of the circuit board is improved.

[0087] Through the multi-level protection design and signal matching optimization of USB interface, Type-C interface, SIM card interface and network interface, comprehensive protection and signal integrity optimization of multiple interfaces are achieved, the anti-interference ability and communication reliability of the circuit board are improved, and it is suitable for applications in various complex environments.

[0088] This technical solution addresses the low electromagnetic shielding protection and poor radiation resistance of existing tablet computers through the selection of components, design of the shielding structure, and the design of the joints between the components. Its novel and rational structure, comprehensive functionality, and ease of portability and operation ensure the security of users when processing and displaying important information, preventing the leakage of device information and interference from external electromagnetic waves. Furthermore, the tablet computer exhibits excellent shock and vibration resistance and water resistance, making it suitable for use in relatively harsh environments. This technical solution addresses many shortcomings of existing products and is particularly suitable for use on instruments and equipment in complex working environments, overcoming the potential for adverse environmental interference with product performance.

[0089] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all changes that fall within the meaning and range of equivalents of the claims be included in the present invention, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0090] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A low-emission tablet computer, characterized in that: include: The front shell, middle frame and back cover are all conductive; The front shell is fixedly connected to the middle frame, and the front shell and the middle frame form a first sealed cavity; a prototype tablet computer is placed in the first sealed cavity, and the prototype tablet computer is fixedly connected to the middle frame; a touch screen is installed on the front shell at a position corresponding to the prototype tablet computer; the side of the touch screen closest to the prototype tablet computer is entirely covered with an electromagnetic shielding layer; the electromagnetic shielding layer is electrically connected to the front shell via a conductive member; The middle frame is fixedly connected to the back cover, and the middle frame and the back cover form a second sealed cavity; the prototype tablet computer is equipped with a main control board and a driver board, and the back cover is provided with a third sealed cavity for placing the main control board and the driver board; the third sealed cavity is located inside the second sealed cavity.

2. The low-emission tablet computer according to claim 1, characterized in that: The electromagnetic shielding layer is electromagnetic shielding glass, electromagnetic shielding net or electromagnetic shielding film; the conductive member is copper foil; one end of the copper foil is adhered to the electromagnetic shielding layer, and the other end is adhered to the front shell.

3. The low-emission tablet computer according to claim 1, characterized in that: Grooves are provided at the edge positions of the middle frame and at the corresponding positions of the front shell and the back cover; protrusions are provided on the front shell and the back cover to correspond to the grooves; conductive rubber strips are provided between the grooves provided at the edge positions of the middle frame and at the corresponding positions of the front shell and the back cover and the protrusions corresponding to the front shell and the back cover.

4. The low-emission tablet computer according to claim 2, characterized in that: An annular protrusion is provided in the back cover for placing the main control board and the drive board respectively; an isolation plate is provided on the middle frame; an annular groove is provided at the upper end of the annular protrusion for placing a conductive rubber strip; the conductive rubber strip is located between the annular protrusion and the isolation plate; the annular protrusion and the isolation plate form a third sealed cavity.

5. The low-emission tablet computer according to claim 2, characterized in that: The middle frame is provided with a first wire outlet for leading out the circuits of the prototype tablet computer and the touch screen; the first wire outlet is sealed by wrapping the copper foil around the outside of the circuit.

6. The low-emission tablet computer according to claim 4, characterized in that: A first conductive bus bar is provided around the driving plate; the copper foil is adhered around the first conductive bus bar and overlapped with the isolation plate.

7. The low-emission tablet computer according to claim 4, characterized in that: A battery, a battery management board, and an external interface board are also fixedly installed in the back cover; a second wire outlet for the main control board circuit and the driver board circuit is provided on the annular protrusion; the second wire outlet is sealed by wrapping the copper foil around the outside of the circuit; the external interface board is connected to the main control board via a first shielded cable; the battery management board is connected to the external interface board via a second shielded cable; the driver board is connected to the external interface board via a third shielded cable; and the battery and the battery management board are connected via a fourth shielded cable.

8. The low-emission tablet computer according to claim 1, characterized in that: A rear camera opening is provided on the back cover at a position corresponding to the rear camera of the prototype tablet computer; an electromagnetic shielding layer is fixedly installed at the position corresponding to the rear camera opening.

9. The low-emission tablet computer according to claim 7, characterized in that: The external interface board is provided with a reserved interface electrically connected to the prototype tablet computer 6 and a plurality of external interface connectors; the back cover is provided with a plurality of alignment interface openings corresponding to the plurality of external interface connectors.

10. The low-emission tablet computer according to claim 9, characterized in that: Also included are communication antenna assemblies, filters, and filtering circuits; The communication antenna assembly is fixedly mounted on the outer side of the back cover; The filter is located in the second sealed cavity and is fixedly mounted on the back cover; one end of the filter is electrically connected to the communication antenna assembly; and the other end of the filter is electrically connected to the communication interface on the main control board. The filter circuit is arranged on the external interface board and is located at the rear end of the external interface connector; the filter circuit is electrically connected to the external interface connector.

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