Display screen driving control device

Abstract

The invention provides a display screen driving control device. The display screen driving control device comprises a mainboard, a switched capacitor voltage converter and a display screen driving circuit, a shielding case is arranged on the main board, and the switched capacitor voltage converter is arranged in the shielding case; a power receiving end of the switched capacitor voltage converter is connected with a power supply of the mainboard, a first power supply end of the switched capacitor voltage converter is connected with a positive power receiving port of the display screen driving circuit, and a second power supply end of the switched capacitor voltage converter is connected with a negative power receiving port of the display screen driving circuit; the switched capacitor voltage converter is used for supplying power to the display screen driving circuit through the first power supply end and the second power supply end; and the display screen driving circuit is used for performing driving control on the display screen connected with the display screen driving circuit. According to the display screen driving control device provided by the invention, the influence of electromagnetic noise on the receiving sensitivity of the radio frequency module is avoided.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a display driving and controlling device. Background Art

[0002] In terminal devices, such as mobile terminal devices like smart phones and Portable Android Devices (PADs), the display screen is an important part. The Liquid Crystal Display (LCD) is a commonly used display screen, and it requires a switched-capacitor voltage converter (also known as a charge pump) for power supply when the screen is lit.

[0003] In related technologies, a Flexible Printed Circuit (FPC) is used to provide control signals and transmit data to the LCD driving circuit, and the switched-capacitor voltage converter is placed on the FPC close to the antenna. When the switched-capacitor voltage converter works, the power transistors are in a continuous switching state, generating a large amount of electromagnetic noise. These noises will radiate outward through the chip body, and the noises falling in the relevant receiving frequency bands will seriously deteriorate the receiving sensitivity of the radio frequency module after being received by the antenna of the radio frequency module near the LCD. Summary of the Invention

[0004] This application provides a display driving and controlling device to solve the problem that the electromagnetic noise generated by the switched-capacitor voltage converter in related technologies deteriorates the receiving sensitivity of the radio frequency module, and realizes the shielding of the electromagnetic noise of the switched-capacitor voltage converter.

[0005] This application provides a display driving and controlling device, including a main board, a switched-capacitor voltage converter, and a display driving circuit;

[0006] A shielding cover is provided on the main board, and the switched-capacitor voltage converter is disposed inside the shielding cover;

[0007] The power receiving end of the switched-capacitor voltage converter is connected to the power supply of the main board, the first power supply end of the switched-capacitor voltage converter is connected to the positive power receiving port of the display driving circuit, and the second power supply end of the switched-capacitor voltage converter is connected to the negative power receiving port of the display driving circuit;

[0008] The switched-capacitor voltage converter is used to supply power to the display driving circuit through the first power supply end and the second power supply end;

[0009] The display driving circuit is used to drive and control the display screen connected to the display driving circuit.

[0010] In an alternative embodiment, the display screen driving and controlling device further includes a flexible printed circuit board connected between the main board and the display screen driving circuit;

[0011] The flexible printed circuit board is used for transmitting communication signals between the main board and the display screen driving circuit.

[0012] In an alternative embodiment, the first power supply terminal of the switched-capacitor voltage converter is connected to the positive power-receiving port of the display screen driving circuit through the first signal path of the flexible printed circuit board, and the second power supply terminal of the switched-capacitor voltage converter is connected to the negative power-receiving port of the display screen driving circuit through the second signal path of the flexible printed circuit board.

[0013] In an alternative embodiment, the flexible printed circuit board is connected to the main board through a circuit board connector.

[0014] In an alternative embodiment, a first filtering circuit is connected to the first power supply terminal of the switched-capacitor voltage converter;

[0015] The first filtering circuit is used for filtering the output signal of the first power supply terminal.

[0016] In an alternative embodiment, the first filtering circuit includes a first filtering capacitor, and the first filtering capacitor is connected between the first power supply terminal and the ground.

[0017] In an alternative embodiment, the first filtering circuit includes a first magnetic bead;

[0018] The first magnetic bead is connected in series to the first power supply terminal.

[0019] In an alternative embodiment, a second filtering circuit is connected to the second power supply terminal of the switched-capacitor voltage converter;

[0020] The second filtering circuit is used for filtering the output signal of the second power supply terminal.

[0021] In an alternative embodiment, the second filtering circuit includes a second filtering capacitor, and the second filtering capacitor is connected between the second power supply terminal and the ground.

[0022] In an alternative embodiment, the second filtering circuit includes a second magnetic bead;

[0023] The second magnetic bead is connected in series to the second power supply terminal.

[0024] The display driving control device provided by the present application includes a main board, a switched-capacitor voltage converter, and a display driving circuit. A shielding cover is provided on the main board, and the switched-capacitor voltage converter is disposed within the shielding cover; the power receiving end of the switched-capacitor voltage converter is connected to the power supply of the main board, the first power supply end of the switched-capacitor voltage converter is connected to the positive power receiving port of the display driving circuit, and the second power supply end of the switched-capacitor voltage converter is connected to the negative power receiving port of the display driving circuit; wherein, the switched-capacitor voltage converter is used to supply power to the display driving circuit through the first power supply end and the second power supply end, and the display driving circuit is used to drive and control the display connected to the display driving circuit. In this way, by disposing the switched-capacitor voltage converter within the shielding cover of the main board, the electromagnetic noise generated by the switched-capacitor voltage converter can be shielded, and compared with the solution of placing the switched-capacitor voltage converter on the FPC closer to the radio frequency module, by disposing the switched-capacitor voltage converter on the main board, the distance from the radio frequency module near the display is increased, and the electromagnetic noise radiated by the switched-capacitor voltage converter is not easily transmitted to the radio frequency module, thereby avoiding the influence of electromagnetic noise on the receiving sensitivity of the radio frequency module. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the principle of electromagnetic noise generation when a switched-capacitor voltage converter supplies power to an LCD driving circuit in the related art;

[0026] Figure 2 One of the structural schematic diagrams of the display driving control device provided by the embodiment of the present application;

[0027] Figure 3 Another structural schematic diagram of the display driving control device provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B may be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a alone, b alone, or c alone may represent: a alone, b alone, c alone, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b, and c. Wherein, a, b, and c may be single or multiple. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] The orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0030] The terms "connected" and "coupled" should be understood in a broad sense. For example, the "connection" or "coupling" of a circuit structure can refer not only to a physical connection, but also to an electrical connection or a signal connection. For example, it can be a direct connection, that is, a physical connection, or it can be indirectly connected through at least one intermediate element, as long as the circuit is connected. It can also be the communication inside two elements; the signal connection can refer not only to the signal connection through a circuit, but also to the signal connection through a media medium, such as radio waves. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0031] In a terminal device, such as a mobile terminal device like a smart phone or a PAD, the display screen is an important component, which can convert an electronic signal into a visual image, text, video, etc., to achieve visual human-computer interaction. Among them, the LCD display screen is a commonly used display screen, and it needs a switched-capacitor voltage converter (also called a charge pump) for power supply when the screen is lit.

[0032] In the related art, Figure 1 shows a schematic diagram of the principle of electromagnetic noise generated when a switched-capacitor voltage converter supplies power to an LCD driving circuit. Refer to Figure 1As shown in the figure, the switched-capacitor voltage converter that powers the LCD driving circuit is disposed on a flexible printed circuit board (FPC) relatively close to the LCD driving circuit. The LCD driving circuit supplies power to the switched-capacitor voltage converter through the power supply terminal VCI via the FPC. The switched-capacitor voltage converter supplies power to the positive power receiving port VSP and the negative power receiving port VSN of the LCD driving circuit through the FPC. In a mobile terminal device, the LCD driving circuit is close to the lower edge of the main body of the LCD display screen. Generally, this area is an ideal location for the radio frequency module of the mobile terminal device, and the radio frequency module will be disposed in this area. When the switched-capacitor voltage converter operates, the power transistor is in a continuous switching state, generating a large amount of electromagnetic noise. These noises will radiate outward through the chip body and output signal lines of the switched-capacitor voltage converter. The noises falling within the relevant receiving frequency bands will seriously deteriorate the receiving sensitivity of the radio frequency module after being received by the antenna of the radio frequency module near the LCD, especially for low-frequency signals, such as signals in the B5, B8, B12, B20, B28, B71 and other frequency bands, and this influence will be more obvious.

[0033] Based on this, an embodiment of the present application provides a display screen driving control device. The switched-capacitor voltage converter is disposed in the shielding cover of the main board, which is not only far away from the radio frequency module, but also can use the shielding cover to shield the electromagnetic noise of the switched-capacitor voltage converter. Further, a filter circuit can be respectively provided at the first power supply terminal and / or the second power supply terminal where the switched-capacitor voltage converter is used to supply power to the LCD driving circuit, and the noise of the output signal of the switched-capacitor voltage converter is suppressed through the filter circuit, further reducing the influence on the receiving sensitivity of the radio frequency module.

[0034] The following will be combined with Figures 2 to 3 to specifically describe the display screen driving control device provided by the embodiment of the present application.

[0035] Figure 2 Fig. 1 shows a schematic structural diagram of the display screen driving control device provided by the embodiment of the present application. Referring to Figure 2 as shown in the figure, the display screen driving control device may include a main board 21, a switched-capacitor voltage converter 22, and a display screen driving circuit 23. A shielding cover 211 is provided on the main board 21, and the switched-capacitor voltage converter 22 is disposed in the shielding cover 211. The power receiving end of the switched-capacitor voltage converter 22 is connected to the power supply VCC of the main board 21, and the switched-capacitor voltage converter 22 can be powered through the main board 21. The first power supply terminal G1 of the switched-capacitor voltage converter 22 is connected to the positive power receiving port VSP of the display screen driving circuit 23, and the second power supply terminal G2 of the switched-capacitor voltage converter 22 is connected to the negative power receiving port VSN of the display screen driving circuit 23.

[0036] Among them, the switched-capacitor voltage converter 22 is used to supply power to the display driving circuit 23 through the first power supply terminal G1 and the second power supply terminal G2; the display driving circuit 23 is used to drive and control the display connected to the display driving circuit 23.

[0037] The main board 21 is the core component of the mobile terminal device, playing a key role in connecting, controlling, and managing the various functions of the mobile terminal device, including connection and integration functions, data processing and operation control, power management, and security protection, etc.

[0038] Exemplarily, the main board 21 may include components such as a central processing unit (CPU), a memory, a power management chip, a communication chip, a sensor, a camera module interface, a battery connector, etc.

[0039] Exemplarily, the display connected to the display driving circuit 23 may be an LCD display, and the LCD display can achieve image display through the coordinated action of a backlight, a polarizer, a liquid crystal layer, and a color filter based on the optical characteristics regulation of liquid crystal molecules under the action of an electric field.

[0040] Correspondingly, the display driving circuit 23 may be an LCD driving circuit. For example, the LCD driving circuit may be an LCD driving chip of model SED1520, an LCD driving chip of ST7565P, an LCD driving chip of RA8816, etc.

[0041] In one embodiment, as Figure 2 shown, the display driving control device may further include a flexible printed circuit board 24, and this flexible printed circuit board 24 is connected between the main board 21 and the display driving circuit 23. Among them, the flexible printed circuit board 24 is used to transmit communication signals between the main board 21 and the display driving circuit 23.

[0042] Among them, the flexible printed circuit board is also called a flexible circuit board, a flexible printed circuit board, or a flex board, and is a printed circuit made of a flexible insulating substrate. The flexible printed circuit board can be freely bent, wound, and folded, can withstand millions of dynamic bends without damaging the wires, can be arranged arbitrarily according to the spatial layout requirements, and can move and stretch arbitrarily in three-dimensional space, so as to achieve the integration of component assembly and wire connection. Therefore, the flexible circuit board can greatly reduce the volume and weight of the mobile terminal device, meeting the needs of the development of mobile terminal devices towards high density, miniaturization, and high reliability.

[0043] Specifically, the flexible printed circuit board 24 can route the communication signals between the main board 21 and the display driving circuit 23, and transmit communication signals such as control signals, data signals, and power signals between the main board 21 and the display driving circuit 23 to realize the control and data interaction of the main board 21 with respect to the display driving circuit 23.

[0044] Exemplarily, as Figure 2 shown, the flexible printed circuit board 24 can be connected to the main board 21 through the circuit board connector 20.

[0045] Specifically, the circuit board connector 20 can include a first connection interface and a second connection interface. The first connection interface can be disposed on the main board 21, and the second connection interface can be disposed on the flexible printed circuit board 24. The circuit board connector 20 can connect the flexible printed circuit board 24 to the main board 21 through the clamping connection of the first connection interface and the second connection interface.

[0046] Exemplarily, the first power supply terminal G1 of the switched-capacitor voltage converter 22 can be connected to the positive power receiving port VSP of the display driving circuit 23 through the first signal path L1 of the flexible printed circuit board 24, and the second power supply terminal G2 of the switched-capacitor voltage converter 22 is connected to the negative power receiving port VSN of the display driving circuit 23 through the second signal path L2 of the flexible printed circuit board 24.

[0047] In this way, through the flexible printed circuit board 24, long-distance power supply transmission between the switched-capacitor voltage converter 22 and the display driving circuit 23 can be realized, and the transmission path can follow the flexible printed circuit board 24 and be laid in any space in the mobile terminal device. The wiring is relatively flexible and can be moved and stretched arbitrarily.

[0048] The display driving control device provided by the embodiment of the present application includes a main board, a switched-capacitor voltage converter, and a display driving circuit. A shielding cover is provided on the main board, and the switched-capacitor voltage converter is disposed in the shielding cover; the power receiving end of the switched-capacitor voltage converter is connected to the power supply of the main board, the first power supply terminal of the switched-capacitor voltage converter is connected to the positive power receiving port of the display driving circuit, and the second power supply terminal of the switched-capacitor voltage converter is connected to the negative power receiving port of the display driving circuit; wherein, the switched-capacitor voltage converter is used to supply power to the display driving circuit through the first power supply terminal and the second power supply terminal, and the display driving circuit is used to drive and control the display connected to the display driving circuit. In this way, by disposing the switched-capacitor voltage converter in the shielding cover of the main board, the electromagnetic noise generated by the switched-capacitor voltage converter can be shielded, and compared with the solution of placing the switched-capacitor voltage converter on the FPC closer to the radio frequency module, by disposing the switched-capacitor voltage converter on the main board, the distance from the radio frequency module near the display is increased, and the electromagnetic noise radiated by the switched-capacitor voltage converter is not easily transmitted to the radio frequency module, thereby avoiding the influence of electromagnetic noise on the receiving sensitivity of the radio frequency module.

[0049] Based on Figure 2For the display driving and controlling device of the corresponding embodiment, in an alternative embodiment, a first filtering circuit is also connected to the first power supply terminal G1 of the switched-capacitor voltage converter 22, and this first filtering circuit is used to filter the output signal of the first power supply terminal G1.

[0050] Figure 3 FIG. 2 shows the second structural schematic diagram of the display driving and controlling device provided by the embodiment of the present application. Refer to Figure 3 As shown, the first filtering circuit may include a first filtering capacitor C1, and the first filtering capacitor C1 is connected between the first power supply terminal G1 and the ground GND.

[0051] In this way, by connecting a first filtering capacitor C1 in parallel to the first power supply terminal G1 of the switched-capacitor voltage converter 22, the signal output from the first power supply terminal G1 can be filtered, the noise of the output network of the switched-capacitor voltage converter 22 can be suppressed, and further interference caused by the switched-capacitor voltage converter 22 to the RF module can be avoided.

[0052] Exemplarily, the first filtering capacitor C1 can be a 100 picofarad (pF) capacitor.

[0053] In an alternative embodiment, the first filtering circuit may include a first magnetic bead, and this first magnetic bead can be connected in series to the first power supply terminal G1. In this way, the signal output from the first power supply terminal G1 can be filtered through the first magnetic bead, and the noise of the output network of the switched-capacitor voltage converter 22 can be suppressed.

[0054] For the display driving and controlling device provided by the embodiment of the present application, by connecting a first filtering circuit to the first power supply terminal of the switched-capacitor voltage converter, the signal output from the first power supply terminal of the switched-capacitor voltage converter can be filtered, the noise of the output network of the switched-capacitor voltage converter can be suppressed, and further the influence on the receiving sensitivity of the RF module caused by the switched-capacitor voltage converter can be avoided.

[0055] Based on Figure 2 For the display driving and controlling device of the corresponding embodiment, in an alternative embodiment, a second filtering circuit is also connected to the second power supply terminal G2 of the switched-capacitor voltage converter 22, and this second filtering circuit is used to filter the output signal of the second power supply terminal G2.

[0056] Refer to Figure 3 As shown, the second filtering circuit may include a second filtering capacitor C2, and this second filtering capacitor C2 is connected between the second power supply terminal G2 and the ground GND.

[0057] In this way, by connecting a second filter capacitor C2 in parallel to the second power supply terminal G2 of the switched-capacitor voltage converter 22, the signal output from the second power supply terminal G2 can be filtered, the noise of the output network of the switched-capacitor voltage converter 22 can be suppressed, and further interference caused by the switched-capacitor voltage converter 22 to the radio frequency module can be avoided.

[0058] Exemplarily, the second filter capacitor C2 can be a 100 picofarad (pF) capacitor.

[0059] In an alternative embodiment, the second filter circuit can include a second magnetic bead, which can be connected in series to the second power supply terminal G2. In this way, the signal output from the second power supply terminal G2 can be filtered by the second magnetic bead, and the noise of the output network of the switched-capacitor voltage converter 22 can be suppressed.

[0060] The display driving control device provided by the embodiments of the present application can filter the signal output from the second power supply terminal of the switched-capacitor voltage converter by connecting a second filter circuit to the second power supply terminal of the switched-capacitor voltage converter, suppress the noise of the output network of the switched-capacitor voltage converter, and further avoid the influence of the switched-capacitor voltage converter on the receiving sensitivity of the radio frequency module.

[0061] It can be understood that, as shown in Figure 3 a first filter circuit can be connected to the first power supply terminal G1 of the switched-capacitor voltage converter and a second filter circuit can be connected to the second power supply terminal G2 at the same time, so as to filter the signal output from the first power supply terminal and the signal output from the second power supply terminal of the switched-capacitor voltage converter at the same time, and suppress the noise of the output network of the switched-capacitor voltage converter 22.

[0062] Taking the B71 frequency band of the radio frequency module as an example, testing is carried out using the power supply scheme as shown in Figure 1 When the LCD display screen is in the screen-off state, the sensitivity of the radio frequency module is measured to be -92.6 decibels relative to one milliwatt (dBm), while when the LCD display screen is in the screen-on state, the sensitivity of the radio frequency module is measured to be -77.3 dBm, and the sensitivity of the radio frequency module deteriorates by 15.3 decibels (dB). It can be seen that when the switched-capacitor voltage converter is placed on the FPC near the radio frequency module, the electromagnetic noise radiated by it is easily received by the radio frequency module, seriously affecting the sensitivity of the relevant frequency band of the radio frequency module.

[0063] By using the display driving and controlling device provided in the embodiment of the present application, the switched-capacitor voltage converter is disposed in the shielding cover of the main board, and filter circuits are respectively arranged at the first power supply terminal and the second power supply terminal of the switched-capacitor voltage converter. During the test, when the LCD display screen is in the lit state, the sensitivity of the RF module is measured to be able to reach -92.1 dBm, which is close to -92.6 dBm in the state where the LCD display screen is turned off, effectively avoiding the influence of the electromagnetic noise of the switched-capacitor voltage converter on the receiving sensitivity of the RF module.

[0064] The display driving and controlling device provided in the embodiment of the present application not only realizes the power supply required for the operation of the LCD display screen, but also takes into account the performance of the RF module in a compatible manner, realizing the perfect coexistence of the functions of the LCD display screen and the RF module.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; those skilled in the art will easily think of other implementation solutions of the present application after considering the specification and the content disclosed herein. The present application aims to cover any variations, uses or adaptive changes herein, and these variations, uses or adaptive changes follow the general principles of the present application and include the common general knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the claims.

Claims

1. A display driving control device, characterized in that, It includes a main board, a switched-capacitor voltage converter, and a display driving circuit; A shielding cover is provided on the main board, and the switched-capacitor voltage converter is disposed within the shielding cover; The power receiving end of the switched-capacitor voltage converter is connected to the power supply of the main board, the first power supply end of the switched-capacitor voltage converter is connected to the positive power receiving port of the display driving circuit, and the second power supply end of the switched-capacitor voltage converter is connected to the negative power receiving port of the display driving circuit; The switched-capacitor voltage converter is configured to supply power to the display driving circuit through the first power supply end and the second power supply end; The display driving circuit is configured to perform driving control on a display connected to the display driving circuit.

2. The display driving control device according to claim 1, wherein It further includes a flexible printed circuit board connected between the main board and the display driving circuit; The flexible printed circuit board is configured to transmit communication signals between the main board and the display driving circuit.

3. The display drive control device according to claim 2, wherein The first power supply end of the switched-capacitor voltage converter is connected to the positive power receiving port of the display driving circuit through a first signal path of the flexible printed circuit board, and the second power supply end of the switched-capacitor voltage converter is connected to the negative power receiving port of the display driving circuit through a second signal path of the flexible printed circuit board.

4. The display driving and controlling device according to claim 2, wherein The flexible printed circuit board is connected to the main board through a circuit board connector.

5. The display driving and controlling device according to claim 1, characterized in that, A first filtering circuit is connected to the first power supply end of the switched-capacitor voltage converter; The first filtering circuit is configured to filter the output signal of the first power supply end.

6. The display driving control device according to claim 5, wherein The first filtering circuit includes a first filtering capacitor, and the first filtering capacitor is connected between the first power supply end and the ground.

7. The display driving control device according to claim 5, characterized in that, The first filtering circuit includes a first magnetic bead; The first magnetic bead is connected in series to the first power supply end.

8. The display driving and controlling device according to claim 1, wherein, A second filtering circuit is connected to the second power supply end of the switched-capacitor voltage converter; The second filtering circuit is configured to filter the output signal of the second power supply end.

9. The display driving and controlling device according to claim 8, wherein, The second filtering circuit includes a second filtering capacitor, and the second filtering capacitor is connected between the second power supply end and the ground.

10. The display screen driving and controlling device according to claim 8, wherein The second filtering circuit includes a second magnetic bead; The second magnetic bead is connected in series to the second power supply end.

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