Display device and power supply circuit

Abstract

The invention provides display equipment and a power supply circuit. The display equipment comprises a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit and a third secondary winding circuit, the primary winding circuit is configured to output a first primary voltage and a second primary voltage in a time-sharing manner; the first secondary winding circuit is coupled to the primary winding circuit, is connected with the main board, and is configured to output a first power supply voltage to the main board based on the first primary voltage; the second secondary winding circuit is coupled to the primary winding circuit and is configured to output a second power supply voltage based on the second primary voltage; the third secondary winding circuit is coupled to the primary winding circuit, is connected with the second secondary winding circuit and the backlight assembly, and is configured to generate a third power supply voltage based on the second primary voltage and supply power to the backlight assembly based on the second power supply voltage and the third power supply voltage. The adaptive power of the power supply circuit under the asymmetric half-bridge circuit can be improved.

Description

Technical Field

[0001] This application relates to the field of display device technology, and in particular to a display device and power supply circuit. Background Technology

[0002] With the development of electronic and internet technologies, display devices such as laser TVs and smart displays have been widely used in people's daily lives. These display devices are equipped with power supply circuits to provide power. The power-consuming components of these devices include the motherboard and backlight assembly.

[0003] In related technologies, the power supply circuit includes an asymmetric half-bridge circuit, and outputs corresponding power supply voltages to the motherboard and backlight assembly respectively through the two secondary windings of the transformer in the asymmetric half-bridge circuit. The asymmetric half-bridge circuit achieves dual-loop output through time-division control.

[0004] However, the power supply circuits in these technologies are only compatible with display devices with lower power consumption. Summary of the Invention

[0005] This application provides a display device and a power supply circuit, which aims to solve the problem of low power supply capacity in asymmetric half-bridge circuits.

[0006] In a first aspect, this application provides a display device, including: a motherboard, a backlight assembly, and a power supply circuit; the power supply circuit includes: a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit, and a third secondary winding circuit; the primary winding circuit is configured to output a first primary voltage and a second primary voltage in a time-division multiplexing manner; the first secondary winding circuit is coupled to the primary winding circuit and connected to the motherboard, and is configured to output a first power supply voltage to the motherboard based on the first primary voltage; the second secondary winding circuit is coupled to the primary winding circuit and configured to output a second power supply voltage based on the second primary voltage; the third secondary winding circuit is coupled to the primary winding circuit and connected to the second secondary winding circuit and the backlight assembly, and is configured to generate a third power supply voltage based on the first primary voltage, and supply power to the backlight assembly based on the second power supply voltage and the third power supply voltage.

[0007] Secondly, this application provides a power supply circuit, including: a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit, and a third secondary winding circuit; the primary winding circuit is configured to output a first primary voltage and a second primary voltage in a time-division multiplexing manner; the first secondary winding circuit is coupled to the primary winding circuit and connected to a motherboard, and is configured to output a first power supply voltage to the motherboard based on the first primary voltage; the second secondary winding circuit is coupled to the primary winding circuit and configured to output a second power supply voltage based on the second primary voltage; the third secondary winding circuit is coupled to the primary winding circuit and connected to the second secondary winding circuit and a backlight assembly, and is configured to generate a third power supply voltage based on the first primary voltage, and supply power to the backlight assembly based on the second power supply voltage and the third power supply voltage.

[0008] In the display device and power supply circuit provided in this application, the first secondary winding circuit is used to supply power to the motherboard, the second secondary winding circuit outputs a second supply voltage based on the second primary voltage, and the third secondary winding circuit and the second secondary winding circuit generate a third supply voltage based on the second primary voltage, and supply power to the backlight assembly based on the second supply voltage and the third supply voltage. In effect, it is equivalent to the second secondary winding circuit and the third secondary winding circuit jointly supplying power to the backlight assembly. This can reduce the difference in output power between the first secondary winding circuit and the second secondary winding circuit. Therefore, this solution can improve the output power supplied to the backlight assembly. Attached Figure Description

[0009] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with those of this application and, together with the description, serve to explain the principles of the embodiments of this application.

[0010] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the embodiments of this application in any way, but rather to illustrate the concepts of the embodiments of this application to those skilled in the art through reference to specific embodiments.

[0011] Figure 1 This is a schematic diagram illustrating an operational scenario between a display device and a control device according to some embodiments of this application;

[0012] Figure 2 An exemplary block diagram of the configuration of the control device according to an exemplary embodiment is shown;

[0013] Figure 3 An exemplary schematic diagram of the display device is shown;

[0014] Figure 4A schematic diagram showing the connection relationship between the power supply circuit and the load provided in this application;

[0015] Figure 5 A schematic diagram of the power architecture of the display device provided in this application;

[0016] Figure 6 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 1 ;

[0017] Figure 7 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 2 ;

[0018] Figure 8 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 3 ;

[0019] Figure 9 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 4 ;

[0020] Figure 10 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 5 ;

[0021] Figure 11 This is a schematic diagram of the first feedback circuit in an example;

[0022] Figure 12 This is a schematic diagram of the second feedback circuit in an example;

[0023] Figure 13 This is a schematic diagram of the second feedback circuit in another example.

[0024] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0026] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0027] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities and do not necessarily imply a specific order or sequence, unless otherwise indicated. It should be understood that such terms can be used interchangeably where appropriate, for example, to implement the application in a sequence other than those given in the embodiments illustrated or described herein.

[0028] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to be inclusive but not exclusive. For example, a product or device that includes a series of components is not necessarily limited to those explicitly listed, but may include other components not explicitly listed or inherent to such product or device. As used in this application, the term "circuit" means any known or subsequently developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code capable of performing the functions associated with that element.

[0029] The display device provided in this application can have various implementation forms, such as a smart TV, a laser projection device, a monitor, an electronic bulletin board, an electronic table, etc. Figure 1 and Figure 2 This is one specific embodiment of the display device of this application.

[0030] Figure 1 This is a schematic diagram illustrating an operational scenario between a display device and a control device according to some embodiments of this application. Figure 1 As shown, the user can operate the display device 200 through the smart device 300 or the control device 100.

[0031] In some embodiments, the control device 100 may be a remote control. Communication between the remote control and the display device may include infrared protocol communication, Bluetooth protocol communication, or other short-range communication methods, controlling the display device 200 wirelessly or via wired means. Users can control the display device 200 by inputting user commands through buttons on the remote control, voice input, control panel input, etc.

[0032] In some embodiments, a smart device 300 (such as a mobile terminal, tablet computer, computer, laptop computer, etc.) may also be used to control the display device 200. For example, an application running on the smart device may be used to control the display device 200.

[0033] In some embodiments, the display device may receive instructions not through the aforementioned smart devices or control devices, but through touch or gestures.

[0034] In some embodiments, the display device 200 can also be controlled in ways other than the control device 100 and the smart device 300. For example, it can be controlled by directly receiving the user's voice commands through a module configured inside the display device 200 for acquiring voice commands, or it can be controlled by receiving the user's voice commands through a voice control device set outside the display device 200.

[0035] In some embodiments, the display device 200 also communicates with the server 400. The display device 200 may be communicatively coupled via a local area network (LAN), wireless local area network (WLAN), and other networks. The server 400 may provide various content and interactive features to the display device 200. The server 400 may be a cluster or multiple clusters, and may include one or more types of servers.

[0036] Figure 2 An exemplary block diagram of the configuration of the control device 100 according to an exemplary embodiment is shown.

[0037] In some embodiments, such as Figure 2 As shown, the control device 100 may include a controller 110;

[0038] In some embodiments, such as Figure 2 As shown, the control device 100 may include a communication interface 130;

[0039] In some embodiments, such as Figure 2 As shown, the control device 100 may include a user input / output interface 140;

[0040] In some embodiments, such as Figure 2 As shown, the control device 100 may include a memory;

[0041] In some embodiments, such as Figure 2 As shown, the control device 100 may include a power supply circuit;

[0042] In some embodiments, the control device 100 may receive input operation instructions from the user and convert the operation instructions into instructions that the display device 200 can recognize and respond to, thereby acting as an intermediary for interaction between the user and the display device 200.

[0043] Figure 3 An exemplary schematic diagram of the display device is shown.

[0044] In some embodiments, such as Figure 3 As shown, the display device 200 may include a signal converter 210;

[0045] In some embodiments, such as Figure 3 As shown, the display device 200 may include a communicator 220;

[0046] In some embodiments, such as Figure 3 As shown, the display device 200 may include a detector 230;

[0047] In some embodiments, such as Figure 3 As shown, the display device 200 may include an external device interface 240;

[0048] In some embodiments, such as Figure 3 As shown, the display device 200 may include a controller 250;

[0049] In some embodiments, such as Figure 3 As shown, the display device 200 may include a display 260;

[0050] In some embodiments, such as Figure 3 As shown, the display device 200 may include an audio output interface 270;

[0051] In some embodiments, such as Figure 3 As shown, the display device 200 may include a memory;

[0052] In some embodiments, such as Figure 3 As shown, the display device 200 may include a power supply circuit;

[0053] In some embodiments, such as Figure 3 As shown, the display device 200 may include at least one of the user interfaces.

[0054] In some embodiments, such as Figure 3 As shown, the controller may include a processor; a video processor, an audio processor, a graphics processor, RAM, ROM, and a first interface to an nth interface for input / output.

[0055] In some embodiments, such as Figure 3 As shown, the display 260 may include a display screen assembly for presenting images.

[0056] In some embodiments, such as Figure 3As shown, the display 260 may include a driving component for driving image display, a component for receiving image signals from the controller output, and a user control UI interface for displaying video content, image content, menu control interface, and user control UI interface.

[0057] In some embodiments, such as Figure 3 As shown, the display 260 can be a liquid crystal display, an OLED display, or a projection display.

[0058] In other embodiments, such as Figure 3 As shown, the display 260 can be a projection device and a projection screen.

[0059] In some embodiments, such as Figure 3 As shown, communicator 220 is a component used to communicate with external devices or servers according to various communication protocol types.

[0060] For example, the communicator may include at least one of the following: a Wi-Fi module, a Bluetooth module, a wired Ethernet module, other network communication protocol chips or near-field communication protocol chips, and an infrared receiver. The display device 200 can establish the transmission and reception of control signals and data signals with the external control device 100 or the server 400 through the communicator 220.

[0061] In some embodiments, such as Figure 3 As shown, the user interface can be used to receive control signals from the control device 100 (such as an infrared remote control).

[0062] In some embodiments, such as Figure 3 As shown, detector 230 is used to collect signals from the external environment or to interact with the outside world.

[0063] For example, detector 230 may include a light receiver, a sensor for acquiring ambient light intensity; or, detector 230 may include an image acquisition device, such as a camera, for acquiring external environmental scenes, user attributes, or user interaction gestures; or, detector 230 may include a sound acquisition device, such as a microphone, for receiving external sounds.

[0064] In some embodiments, the external device interface 240 may include, but is not limited to, one or more of the following interfaces: High Definition Multimedia Interface (HDMI), analog or data high-definition component input interface (component), composite video input interface (CVBS), USB input interface (USB), RGB port, etc. It may also be a composite input / output interface formed by multiple interfaces mentioned above.

[0065] In some embodiments, the signal converter 210 receives broadcast television signals via wired or wireless reception, and demodulates audio and video signals, such as EPG data signals, from multiple wireless or wired broadcast television signals.

[0066] In some embodiments, the controller 250 and the signal converter 210 may be located in different separate devices, that is, the signal converter 210 may also be located in an external device of the main device where the controller 250 is located, such as an external digital video converter box.

[0067] In some embodiments, the controller 250 controls the operation of the display device and responds to user operations via various software control programs stored in memory. The controller 250 controls the overall operation of the display device 200. For example, in response to receiving a user command to select a UI object to display on the display 260, the controller 250 can perform operations related to the object selected by the user command.

[0068] In some embodiments, the controller may include at least one of a central processing unit (CPU), a video processor, an audio processor, a graphics processing unit (GPU), RAM (random access memory), ROM (read-only memory), a first to an nth interface for input / output, a communication bus, etc.

[0069] In some embodiments, a user can input user commands through a graphical user interface (GUI) displayed on a display 260, and the user input interface receives user input commands through the graphical user interface (GUI).

[0070] In other embodiments, users can input user commands by inputting specific sounds or gestures. The user input interface then uses sensors to recognize the sounds or gestures to receive the user input commands.

[0071] The "user interface" is the medium through which applications or operating systems interact and exchange information with users. It converts information from its internal form to a form that users can accept. A common form of user interface is the graphical user interface (GUI), which refers to a user interface related to computer operation displayed graphically. It can be an icon, window, control, or other interface element displayed on the screen of an electronic device. Controls can include visual interface elements such as icons, buttons, menus, tabs, text boxes, dialog boxes, status bars, navigation bars, and widgets.

[0072] In some embodiments, the display device may include a backlight assembly, wherein the backlight assembly is coupled to a power supply circuit.

[0073] In some embodiments, the backlight assembly may be configured to provide backlighting to the display panel.

[0074] In some embodiments, the display device may include a motherboard 80, which may include at least one of a signal converter, a communicator, a detector, an external device interface, a controller, an audio output interface, a memory, and a user interface.

[0075] In some embodiments, Figure 4 This is a schematic diagram showing the connection relationship between the power supply circuit and the load provided in this application, as shown below. Figure 4 As shown, the power supply circuit 10 includes an input terminal 10a and output terminals (first output terminal 10b, second output terminal 10c, and third output terminal 423d are shown in the figure). The input terminal 10a is connected to AC mains power, and the output terminal 423d is connected to the load. For example, the first output terminal 10b is connected to an LED strip used to light the display screen, the second output terminal 10c is connected to speakers, and the third output terminal 423d is connected to the motherboard. The power supply circuit 10 needs to convert AC mains power into DC power required by the load, and this DC power typically has different specifications; for example, speakers require 18V, and the panel requires 12V.

[0076] Specifically, the power architecture of display devices will be introduced using a television as an example. Figure 5 The schematic diagram of the television power supply architecture provided in this application is as follows: Figure 5 As shown, the display device may include: a power supply circuit and a load, wherein the power supply circuit includes: a rectifier bridge, a power factor correction (PFC) module and a resonant converter (LLC) module, and the LLC module includes a synchronous rectification circuit (…). Figure 3 (Not shown). The PFC module is connected to the LLC module. The LLC module can be an asymmetric half-bridge circuit, and outputs the corresponding power supply voltage to the motherboard and the backlight assembly respectively through the two secondary windings of the transformer (not shown) in the asymmetric half-bridge circuit. The asymmetric half-bridge circuit realizes dual-channel closed-loop output through time-division control.

[0077] However, during time-sharing control, it is necessary to switch from one load power to another. Due to limitations such as the operating frequency of the asymmetric half-bridge circuit and the utilization rate of the magnetic core in the transformer, the power of the two loads cannot differ too much. The power of the motherboard is relatively stable, which limits the power of the backlight component, thus making the power supply circuit only suitable for display devices with lower power.

[0078] To address the aforementioned issues, the power supply circuit in the display device of this application includes three secondary winding circuits. The first secondary winding circuit supplies power to the motherboard, and the second secondary winding circuit is connected to the third secondary winding circuit, with both winding circuits jointly supplying power to the backlight assembly. This reduces the voltage difference between the first and second primary windings. Effectively, it is equivalent to superimposing the output power of the second secondary winding circuit onto the third secondary winding circuit, thereby increasing the output power supplied to the backlight. Meanwhile, the output power of the first and second secondary winding circuits can be relatively similar. Therefore, this application can increase the output power of the backlight path while maintaining a balance between the output power of the two windings, thus improving the adaptability of the power supply circuit under the asymmetric half-bridge circuit.

[0079] The technical solutions of this application will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. In the description of this application, unless otherwise expressly specified and limited, the terms should be broadly understood within the art. The embodiments of this application will now be described with reference to the accompanying drawings.

[0080] Figure 6 A schematic diagram of the structure of a display device provided in an embodiment of this application. Figure 1 ,like Figure 6 As shown, it includes: motherboard 30, backlight assembly 20 and power supply circuit 10.

[0081] The power supply circuit 10 includes: a primary winding circuit 11, a first secondary winding circuit 12, a second secondary winding circuit 13, and a third secondary winding circuit 14.

[0082] In some embodiments, the primary winding circuit 11 is configured to output the first primary voltage and the second primary voltage in a time-sharing manner, that is, to output using asymmetric half-bridge technology.

[0083] As an example, the power supply circuit 10 may include an LLC circuit, with the primary winding circuit 11, the first secondary winding circuit 12, and the second secondary winding circuit 13 being part of the LLC circuit.

[0084] In some embodiments, such as Figure 7 In the display device shown, the primary winding circuit 11 may include a first driving switch Q1, a second driving switch Q2, a first storage capacitor C1', a first inductor L1, and the primary winding 111 of a transformer.

[0085] In some embodiments, the first secondary winding circuit 12 is coupled to the primary winding circuit 11 and connected to the motherboard 30, and is configured to output a first supply voltage to the motherboard 30 based on the first primary voltage.

[0086] For example, such as Figure 7 As shown, the first secondary winding circuit 12 may include: the first secondary winding 121 of the transformer, the seventh diode D7, and the second storage capacitor C2'.

[0087] In some embodiments, the following continues: Figure 7 As shown, the second secondary winding circuit 13 may include: the second secondary winding 131 of the transformer, the eighth diode D8 and the third storage capacitor C3', and the same-name terminals of the first secondary winding 121 and the second secondary winding 131 are opposite.

[0088] During operation, the power supply processor 17 outputs a first drive signal and a second drive signal to drive the first drive switch Q1 and the second drive switch Q2, and realizes the time-sharing conduction of the first drive switch Q1 and the second drive switch Q2. The duty cycles of the first drive signal and the second drive signal can be different, that is, the conduction time of the first drive switch Q1 and the second drive switch Q2 can be different. Based on this, the first primary voltage and the second primary voltage can be controlled separately. For the secondary side, the two capacitors are controlled by diodes with different directions to store charge in a time-sharing manner, thereby realizing the control of the output voltage of the first secondary winding circuit 12 and the second secondary winding circuit 13.

[0089] In some embodiments, the third secondary winding circuit 14 is coupled to the primary winding circuit 11 and connected to the second secondary winding circuit 13 and the backlight assembly 20. It is configured to generate a third supply voltage based on the second primary voltage and supply power to the backlight assembly 20 based on the second supply voltage VO2 and the third supply voltage.

[0090] To illustrate, consider the following examples: Figure 6 , Figure 7 As shown, since the motherboard 30 is powered by a constant voltage, the first voltage is a constant 12V. With the motherboard 30 having a power of 36W, the load of the second secondary winding circuit 13 is set to no more than 100W. It is known that in related technologies, only one second secondary winding circuit 13 powers the backlight assembly 20, thus the maximum power of the backlight assembly 20 is 100W. However, in this embodiment, a third secondary winding circuit 14 is also included. The third secondary winding circuit 141 can provide 50W of power, so the power of the backlight assembly 20 can be 150W. It can be understood that the second secondary winding circuit 13 and the third secondary winding circuit 14 can be equivalent to two power sources, jointly powering the backlight assembly 20. That is, the third secondary winding circuit 14 shares a portion of the power, thus reducing the load imbalance between the first secondary winding circuit 12 and the second secondary winding circuit 13, thereby increasing the output power of the power supply circuit 10.

[0091] It should be noted that in this embodiment, the number of third secondary winding circuits 14 can be one or more. When there are multiple circuits, the multiple third secondary winding circuits 14 are connected in parallel and jointly supply power to the backlight assembly 20, so as to further improve the power supply power of the power supply circuit 10 to the backlight assembly 20.

[0092] It should also be noted that, continuing to refer to Figure 4 The power supply circuit 10 may also include a fourth secondary winding circuit, which is used to supply power to audio components such as speakers. However, the power supply requirements of audio components are relatively low. The fourth secondary winding circuit adopts an open-loop power supply. The inventive point of this solution does not involve the improvement of this part, so it will not be described in detail in this application.

[0093] The third secondary winding circuit 14 will be described below as an example.

[0094] In one embodiment, such as Figure 7 As shown, the third secondary winding circuit 14 includes: a third secondary winding 141, a charging and discharging unit 142, and a path control unit 143.

[0095] In some embodiments, such as Figure 7 As shown, the charging / discharging unit 142 may include a balancing capacitor Cb.

[0096] In some embodiments, such as Figure 7 As shown, the third secondary winding 141 is coupled to the primary winding circuit 11 and connected in series with the charging and discharging unit 142, and is configured to output a third supply voltage based on the second primary voltage.

[0097] In some embodiments, such as Figure 7 As shown, the path control unit 143 is connected to the third secondary winding 141, the second secondary winding circuit 13, and the backlight assembly 20.

[0098] In some embodiments, such as Figure 7 As shown, the path control unit 143 is configured to connect the charging and discharging unit 142 to the first path when the primary winding circuit 11 outputs the first primary voltage, so as to supply power to the backlight assembly 20 through the third power supply voltage and the second power supply voltage VO2 provided by the charging and discharging unit 142.

[0099] In some embodiments, such as Figure 7 As shown, the path control unit 143 is also configured to connect the charging and discharging unit 142 to the second path when the primary winding circuit 11 outputs the second primary voltage, so as to charge the charging and discharging unit 142 based on the third power supply voltage provided by the third secondary winding 141, and to supply power to the backlight assembly 20 through the second power supply voltage VO2 and the third power supply voltage provided by the third winding.

[0100] Among them, the same-name terminal of the third secondary winding 141 can be the same as the same-name terminal of the second secondary winding 131, and opposite to the same-name terminal of the first secondary winding 121.

[0101] In this embodiment, when the primary winding circuit 11 outputs different voltages, the charging and discharging unit 142 is connected to different paths through the path control unit 143, so as to achieve the effect of supplying power to the backlight assembly 20 based on the second power supply voltage VO2 and the third power supply voltage, thereby reducing the load imbalance between the first secondary winding circuit 12 and the second secondary winding circuit 13.

[0102] The path control unit 143 has various structures.

[0103] In one implementation, Figure 8 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 3 ,like Figure 8 As shown, the path control unit 143 includes: a first diode D1, the positive terminal of the first diode D1 is connected to one end of the charging and discharging unit 142, and the negative terminal is connected to the backlight assembly 20; the other end of the charging and discharging unit 142 is connected to one end of the third secondary winding 141.

[0104] In some examples, the path control unit 143 may also include: a second diode D2, the positive terminal of which is connected to the output terminal of the second secondary winding circuit 13 and the other end of the third secondary winding 141, and the negative terminal is connected to the backlight assembly 20.

[0105] In some examples, the path control unit 143 may also include: a third diode D3, the positive terminal of which is connected to the output terminal of the second secondary winding circuit 13, and the negative terminal is connected to one end of the charging and discharging unit 142 and the positive terminal of the first diode D1;

[0106] In some examples, the path control unit 143 may also include a fourth diode D4, the positive terminal of which is connected to the output terminal of the second secondary winding circuit 13, and the negative terminal of which is connected to the other end of the third secondary winding 141 and the positive terminal of the second diode D2.

[0107] Combination Figure 8 The working process of this embodiment is described by way of example:

[0108] When the first drive switch is turned on, the clockwise voltage generated by the third secondary winding 141 turns on the first diode D1, the fourth diode D4, and the seventh diode, while the second diode D2, the third diode D3, and the eighth diode are turned off. The balancing capacitor Cb is connected to the first path, which is: point A at the upper end of the third secondary winding 141 → balancing capacitor Cb (charging) → first diode D1 → backlight assembly 20 → negative terminal (ground) → point B' at the lower end of the second secondary winding 131 → point B at the upper end of the second secondary winding 131 → seventh diode → fourth diode D4 → point A' at the lower end of the third secondary winding 141, forming a loop. The second supply voltage VO2 (voltage at point M) of the second secondary winding circuit 13, based on the bootstrap principle of the capacitor, increases the voltage at the other end (output terminal N) of the balancing capacitor Cb. This can be understood as superimposing the second supply voltage VO2 onto the third supply voltage.

[0109] When the second drive switch is turned on, the counterclockwise voltage generated by the third secondary winding 141 causes the second diode D2, the third diode D3, and the eighth diode to be cut off, while the first diode D1, the fourth diode D4, and the seventh diode are turned on. The balancing capacitor Cb is connected to the second path, which is: lower end A' of the third secondary winding 141 → second diode D2 → backlight assembly 20 → negative terminal (ground) → third diode D3 → balancing capacitor Cb → upper end A of the third secondary winding 141, forming a loop. The balancing capacitor Cb discharges, and similarly, power is supplied to the backlight assembly 20 based on the second supply voltage VO2 and the third supply voltage.

[0110] In another implementation, Figure 9 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 4 ,like Figure 9 As shown, the positive terminal of the third diode D3 can also be grounded, and the negative terminal is connected to one end of the charging and discharging unit 142 and the positive terminal of the first diode D1.

[0111] Its working principle and Figure 8 Similar examples exist, so they will not be repeated here.

[0112] In some embodiments, such as Figure 8 , Figure 9 As shown, the backlight assembly 20 includes a first LED string 1 and a second LED string 2;

[0113] The negative terminal of the first diode D1 is connected to the positive terminal of the first LED string LED1, and the negative terminal of the second diode D2 is connected to the positive terminal of the second LED string LED2.

[0114] In this embodiment, the number of the first LED string (LED1) and the second LED string (LED2) can be one or more. That is, the third secondary winding unit 141 can simultaneously output two power supply signals to supply power to different LED strings, thereby improving the brightness of the backlight.

[0115] In this embodiment, the third secondary winding circuit containing the balancing capacitor is a current balancing circuit (C-balance). In a steady-state system, according to the capacitor ampere-second balance principle (charge conservation), the product of the charging and discharging currents on the capacitor multiplied by the time should be equal (equal charge) in a complete switching cycle. That is, under the action of the balancing capacitor Cb, as long as the duty cycles of the first driving switch Q1 and the second driving switch Q2 are the same and the positive and negative half-cycle times are equal, the current on the two LED strings should be the same. This forms the current sharing of the two LED loads.

[0116] According to the capacitance-voltage relationship

[0117]

[0118] Among them, i c (t) The current flowing through the balancing capacitor, V C (t) Voltage across the balancing capacitor. In a step-down circuit, integrating the above formula over a complete switching cycle yields the voltage change across the capacitor over one cycle:

[0119]

[0120] Under steady state, the net change in capacitor voltage over one switching cycle must be zero. Therefore, we have

[0121]

[0122] This indicates that the area between the capacitor current curve and the time axis (i.e., the "charge") of the buck circuit under steady-state conditions is zero; or, in other words, the average value of the capacitor current is zero.

[0123] In some embodiments, continue to refer to Figure 8 , Figure 9 The path control unit 143 also includes: a first capacitor C1 and a second capacitor C2.

[0124] One end of the first capacitor C1 is connected to the negative terminal of the first diode D1 and the positive terminal of the first LED string LED1, and the other end is grounded;

[0125] One end of the second capacitor C2 is connected to the negative terminal of the second diode D2 and the positive terminal of the second LED string LED2, while the other end is grounded.

[0126] Combination Figure 9The working principle of this embodiment is illustrated by way of example: When the first drive switch is turned on, the first capacitor C1 charges, and the output terminal of the third secondary winding circuit 14 supplies power to the first LED string (LED1); the second capacitor C2 discharges, supplying power to the second LED string (LED2). When the second drive switch is turned on, the first capacitor C1 charges and discharges, supplying power to the first LED string (LED1); the output terminal of the third secondary winding circuit 14 supplies power to the second LED string (LED2).

[0127] It should be noted that, to improve the stability of the power supply to the display device, the motherboard 30 requires a constant voltage power supply, and the backlight assembly requires a constant current power supply. Therefore, in some embodiments, Figure 10 Schematic diagram of the structure of the display device provided in the embodiments of this application Figure 5 ,like Figure 10 As shown, the power supply circuit 10 also includes: a first feedback circuit 15, a second feedback circuit 16, and a power supply processor 17.

[0128] In some embodiments, the input terminal of the first feedback circuit 15 is connected to the output terminal of the first secondary winding circuit 12, and the output terminal is connected to the power supply processor 17. It is configured to output a first feedback signal to the power supply processor 17 based on a first power supply voltage.

[0129] In some embodiments, the input terminal of the second feedback circuit 16 is connected to the output terminal of the first secondary winding circuit 12 and the backlight assembly 20, and the output terminal is connected to the power supply processor 17. It is configured to output a second feedback signal to the power supply processor 17 based on the second power supply voltage VO2 and the current flowing through the backlight assembly 20.

[0130] In some embodiments, the power supply processor 17 is connected to the primary winding circuit 11 and is configured to output a first drive signal and a second drive signal to the primary winding circuit 11 based on a first feedback signal and a second feedback signal, so that the primary winding circuit 11 controls the first primary voltage and the second primary voltage based on the first drive signal and the second drive signal.

[0131] This embodiment provides two feedback circuits. The first feedback circuit 15 outputs a first feedback signal based on a first supply voltage, so that the power supply processor 17 issues a corresponding drive signal to adjust the output voltage of the first secondary winding circuit 12, thereby achieving constant voltage output. The second feedback circuit 16 outputs a second feedback signal based on a second supply voltage VO2 and the current flowing through the backlight component 20, so as to achieve constant voltage output of the second secondary winding circuit 13 and constant current output of the third secondary winding circuit 14.

[0132] Among them, the power supply processor 17 is a processor with computing capabilities, for example, it can be a microcontroller unit (MCU).

[0133] The first feedback circuit 15 and the second feedback circuit 16 will be described in an exemplary manner below.

[0134] In some embodiments, Figure 11 This is a schematic diagram of the first feedback circuit, as shown below. Figure 11 As shown, the first feedback circuit 15 includes: a first optocoupler N1, a second three-terminal regulator N2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0135] One end of the third resistor R3 receives the second reference voltage signal, and the other end of the third resistor R3 is connected to the primary input terminal of the first optocoupler N1.

[0136] One end of the fourth resistor R4 is connected to the primary input terminal of the first optocoupler N1, and the other end of the fourth resistor R4 is connected to the primary output terminal of the first optocoupler N1.

[0137] The primary output terminal of the first optocoupler N1 is connected to the negative terminal of the second three-terminal regulator N2, the secondary input terminal of the first optocoupler N1 is connected to the power supply processor 17, and the secondary output terminal of the first optocoupler N1 is grounded.

[0138] The reference terminal of the second three-terminal regulator N2 is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6, and the positive terminal of the second three-terminal regulator N2 is grounded.

[0139] The other end of the fifth resistor R5 receives the second reference level signal; the other end of the sixth resistor R6 is grounded.

[0140] In this example, resistors R5, R6, R3, and R4 are all voltage divider resistors. The second reference voltage signal is a reference power supply signal. As an example, one end of resistor R5 can be connected to power supply circuit 10 to receive the first power supply voltage and use it as the second reference voltage signal. This eliminates the need for a separate reference voltage, thus simplifying the structure of power supply circuit 10 in this example.

[0141] During operation, when the first power supply voltage increases, the voltage of the reference terminal 2 of the second three-terminal regulator N2 increases, the current flowing from the negative terminal to the positive terminal of the second three-terminal regulator N2 increases, the impedance of the secondary side of the first optocoupler N1 increases, and the voltage at the input terminal of the secondary side of the first optocoupler N1 increases, thereby isolating and transmitting the first feedback signal to the power supply processor 17.

[0142] In this example, the first feedback signal can be isolated and transmitted to the power supply processor 17 through the first optocoupler N1, the second three-terminal regulator N2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6.

[0143] In one implementation, such as Figure 11 As shown, the first feedback circuit 15 further includes a seventh resistor R7 and a seventh capacitor C7; one end of the seventh resistor R7 is connected to one end of the fifth resistor R5; the other end of one end of the seventh resistor R7 is connected to one end of the seventh capacitor C7, and the other end of the seventh capacitor C7 is connected to the negative terminal of the second three-terminal regulator N2. The seventh resistor R7 and the seventh capacitor C7 are used for filtering to reduce the influence of interference signals on the first supply voltage.

[0144] In another implementation, continue to refer to Figure 11 The first feedback circuit 15 further includes an eighth capacitor C8. One end of the eighth capacitor C8 is connected to the secondary input terminal of the first optocoupler N1, and the other end of the eighth capacitor C8 is connected to the secondary output terminal of the first optocoupler N1 and grounded. In this embodiment, the eighth capacitor C8 is a filter capacitor used to filter out interference signals in the first feedback signal FB1 to ensure the reliability of the first feedback signal FB1.

[0145] In some embodiments, Figure 12 Here is a schematic diagram of the second feedback circuit in an example, such as Figure 12 As shown, the second feedback circuit 16 includes: a dimming unit 161, a current feedback unit 162, a voltage feedback unit 163, and an isolation transmission unit 164.

[0146] In some embodiments, the dimming unit 161 receives a dimming signal and a first reference voltage signal, and is configured to generate a first reference signal based on the dimming signal and the first reference voltage signal.

[0147] In some embodiments, the current feedback unit 162 is connected to the dimming unit 161 and the backlight assembly 20, and receives a first reference signal, and is configured to output a first signal based on the comparison result between the current flowing through the backlight assembly 20 and the first reference signal.

[0148] In some embodiments, the voltage feedback unit 163 is connected to the second secondary winding circuit 13 and receives the second reference signal, and is configured to output a second signal based on the comparison result between the second supply voltage VO2 and the second reference signal.

[0149] In some embodiments, the isolation transmission unit 164, connected to the current feedback unit 162 and the voltage feedback unit 163, is configured to generate a second feedback signal based on the first signal and the second signal.

[0150] In this embodiment, the dimming unit 161 receives a dimming signal and a first reference voltage signal, and is configured to generate a first reference signal based on the dimming signal and the first reference voltage signal. That is, the first reference signal can be adjusted based on the dimming signal, thereby achieving backlight brightness adjustment, wherein the dimming signal can be output based on user selection. The current feedback unit 162 outputs a first signal based on the comparison result between the current of the backlight component 20 and the first reference signal, wherein the current of the backlight component 20 can be a voltage signal representing the corresponding current during sampling, and the first reference signal can also be a voltage signal.

[0151] In this embodiment, the current feedback unit 162 outputs a first signal based on the comparison result of the current flowing through the backlight component 20 and the first reference signal; the voltage feedback unit 163 outputs a second signal based on the comparison result of the second power supply voltage VO2 and the second reference signal; and the isolation transmission unit 164 generates a second feedback signal based on the first signal and the second signal.

[0152] In some embodiments, Figure 13 Here is a schematic diagram of the second feedback circuit in another example, such as Figure 13 As shown, the dimming unit 161 includes: an eighth resistor R8, a ninth resistor R9, a ninth capacitor C9, and a first switching element V1.

[0153] In some embodiments, one end of the eighth resistor R8 receives a first reference voltage signal and is connected to one end of the ninth resistor R9. The other end of the eighth resistor R8 is connected to one end of the first switching element V1, and the other end of the first switching element V1 is grounded. The control terminal of the first switching element V1 receives a dimming signal. The other end of the ninth resistor R9 is connected to the current feedback unit 162.

[0154] One end of the ninth capacitor C9 is connected to one end of the ninth resistor R9 and one end of the eighth resistor R8, and the other end of the ninth capacitor C9 is grounded.

[0155] In this embodiment, the switching element can be a field-effect transistor or a transistor; for example, it can be an N-MOS transistor or a P-MOS transistor. For ease of explanation, the embodiments of this application all use a P-MOS transistor as an example. During operation, when the dimming signal is high, the first switching element V1 is turned on, the eighth resistor R8 is connected to the first reference level signal, the ninth capacitor C9 is charged, and one end of the eighth resistor R8 outputs the first reference signal. When the dimming signal is low, the first switching element V1 is turned off, the first resistor R1 is not connected to the first reference level signal, the fourth capacitor C4 is discharged, and one end of the first resistor R1 outputs the first reference signal released by the fourth capacitor C4. When it is necessary to increase the brightness, taking the dimming signal as a PWM signal as an example, the duty cycle of the PWM signal increases, the charging time of the fourth capacitor C4 increases, and the output first reference signal increases. Conversely, when it is necessary to increase the brightness, the duty cycle of the PWM signal decreases, the charging time of the fourth capacitor C4 decreases, and the output first reference signal decreases.

[0156] In some embodiments, continue to refer to Figure 13 The dimming unit 161 may also include: a tenth resistor R10 and a tenth capacitor C10;

[0157] One end of the tenth resistor R10 is connected to one end of the ninth resistor R9 and one end of the ninth capacitor C9, and the other end of the tenth resistor R10 is connected to the other end of the ninth capacitor C9 and grounded.

[0158] One end of the tenth capacitor C10 is connected to the other end of the tenth resistor R10, and the other end of the tenth capacitor C10 is grounded.

[0159] In this example, the tenth resistor R10 is used to release the charge of the tenth capacitor C10 or the signal of the first reference level signal when the dimming unit 161 malfunctions and stops operating. The tenth resistor R10 is a voltage divider resistor, and the tenth capacitor C10 is a filter capacitor.

[0160] In one example, continue to refer to Figure 13 The dimming unit 161 further includes an eleventh resistor R11 and a twelfth resistor R12. One end of the eleventh resistor R11 receives the first reference level signal, and the other end of the eleventh resistor R11 is connected to one end of the twelfth resistor R12 and the reference terminal of the first three-terminal regulator N1. The other end of the twelfth resistor R12 is connected to one end of the first resistor R1 and the third resistor R3. In this example, both the eleventh resistor R11 and the twelfth resistor R12 are voltage divider resistors. The eleventh resistor R11 is used to prevent the first reference level signal from being directly grounded, thereby preventing a short circuit.

[0161] In one example, continue to refer to Figure 13The dimming unit 161 further includes a thirteenth resistor R13; one end of the thirteenth resistor R13 is connected to the control terminal of the first switching element V1, and the other end of the thirteenth resistor R13 is grounded. In this example, the thirteenth resistor R13 is a pull-down resistor, which is used to pull down the voltage of the control terminal of the first switching element V1 to a low level when the dimming signal is not connected, so as to prevent the control terminal of the first switching element V1 from being in a floating state.

[0162] In one example, continue to refer to Figure 13 The dimming unit 161 further includes a fourteenth resistor R14; one end of the fourteenth resistor R14 receives the dimming signal, and the other end of the fourteenth resistor R14 is connected to the control terminal of the first switching element V1. The fourteenth resistor R14 is a voltage divider resistor to prevent the input level of the dimming signal from being too high and damaging the first switching element V1.

[0163] In some embodiments, continue to refer to Figure 13 The current feedback unit 162 includes: a first operational amplifier N3, a fifth diode D5, a third capacitor C3, a fourth capacitor C4, and a first resistor R1;

[0164] The non-inverting input of the first operational amplifier N3 is connected to the backlight assembly 20, the inverting input is connected to the dimming unit 161, one end of the third capacitor C3 and one end of the first resistor R1, and the output is connected to the positive terminal of the fifth diode D5, the other end of the third capacitor C3 and the other end of the fourth capacitor C4.

[0165] The negative terminal of the fifth diode D5 is connected to the isolation transmission unit 164 and the voltage feedback unit 163; the other end of the first resistor R1 is connected to one end of the fourth capacitor C4.

[0166] In this embodiment, the first operational amplifier N3 has operational functions and can generate a first signal based on the written algorithm and the sampled signal representing the backlight component 20 and the first reference signal. Once one of the signals changes, the first signal output by the first operational amplifier N3 will also change accordingly, so as to quickly regulate the constant current power supply signal output by the power supply circuit 10.

[0167] The fifth diode, D5, is used to prevent reverse current flow, thereby improving the reliability of the circuit.

[0168] The third capacitor C3, the fourth capacitor C4, and the first resistor R1 form the negative feedback loop of the first operational amplifier N3, enabling the first operational amplifier N3 to output a stable voltage, so as to avoid the influence of the fluctuation of the output signal on the entire adjustment process.

[0169] Therefore, this example can use hardware such as operational amplifiers to realize the output of a first signal based on the current of the backlight component 20 and the first reference signal. In addition, the hardware processing method in this example is reliable and has a fast response speed, which can improve the generation speed of the first drive signal, so as to quickly regulate the constant current power supply signal and thus ensure the effectiveness of the regulation of the constant current power supply signal.

[0170] In some examples, continue to refer to Figure 13 The current feedback unit 162 includes: an eleventh capacitor C11 and a sixteenth resistor R16;

[0171] One end of the eleventh capacitor C11 is connected to the non-inverting input of the first operational amplifier N3, and the other end is grounded;

[0172] One end of the sixteenth resistor R16 is connected to the backlight assembly 20, and the other end is connected to one end of the eleventh capacitor C11 and the non-inverting input of the first operational amplifier N3.

[0173] In this embodiment, the eleventh capacitor C11 is a filter capacitor used to improve the stability of the sampled signal representing the current of the backlight component 20. The sixteenth resistor R16 is a voltage divider resistor used to adjust the signal input to the non-inverting input of the first operational amplifier N3 to prevent excessive voltage from damaging the first operational amplifier N3.

[0174] The voltage feedback unit 163 will now be described as an example.

[0175] In some embodiments, the voltage feedback unit 163 includes: a second operational amplifier N4, a sixth diode D6, a second resistor R2, a fifth capacitor C5, and a sixth capacitor C6;

[0176] In some embodiments, the non-inverting input of the second operational amplifier N4 is connected to the second secondary winding circuit 13, the inverting input receives the second reference signal and is connected to one end of the second resistor R2 and one end of the fifth capacitor C5, and the output is connected to the positive terminal of the sixth diode D6, the other end of the fifth capacitor C5 and the other end of the sixth capacitor C6; the negative terminal of the sixth diode D6 is connected to the isolation transmission unit 164 and the current feedback unit 162.

[0177] In some embodiments, the other end of the second resistor R2 is connected to the other end of the sixth capacitor C6.

[0178] In this embodiment, the second operational amplifier N4, similar to the first operational amplifier N3, has operational functions and can generate a second signal based on the written algorithm and a signal representing the second supply voltage VO2 and a second reference signal. The second reference signal can be a fixed voltage. During operation, if the signal representing the second supply voltage VO2 is less than the second reference signal, the second signal is reduced; conversely, if the signal representing the second supply voltage VO2 is greater than the second reference signal, the second signal is reduced.

[0179] Similarly, the sixth diode D6 is used to prevent reverse current to improve circuit reliability.

[0180] Among them, the fifth capacitor C5, the sixth capacitor C6, and the second resistor R2 constitute the negative feedback loop of the second operational amplifier N4, which enables the second operational amplifier N4 to output a stable voltage, so as to avoid the influence of the fluctuation of the output signal on the entire adjustment process.

[0181] In other examples, continue to refer to Figure 13 The voltage feedback unit 163 may include a fifteenth resistor R15 and a first three-terminal regulator N1.

[0182] In some embodiments, reference continues to be made to Figure 13 One end of the fifteenth resistor R15 is connected to the inverting input of the second operational amplifier N4, and the other end is connected to the positive terminal of the first three-terminal regulator N1 and grounded.

[0183] In some embodiments, the positive terminal of the first three-terminal regulator N1 receives a first reference voltage signal, and the negative terminal of the first three-terminal regulator N1 is connected to the reference terminal.

[0184] In this example, when the first three-terminal regulator N1 is powered on, the voltage of its reference terminal is set to a fixed value. Taking the voltage setting as 2.5V as an example, in this example, the reference terminal of the first three-terminal regulator N1 is connected to the negative terminal, so that the voltage of the negative terminal will remain at 2.5V, that is, the second reference voltage signal is increased to the inverting input terminal of the second operational amplifier N4.

[0185] In some embodiments, continue to refer to Figure 13 The isolation transmission unit 164 includes a second optocoupler N5 and a sixteenth resistor R16, wherein the primary input terminal of the second optocoupler N5 is connected to the power supply processor 17, and the primary output terminal is grounded; the primary input terminal of the second optocoupler N5 is connected to the output terminal of the second feedback circuit 16 and one end of the sixteenth resistor R16, and receives the first signal and the second signal, and the primary output terminal is connected to the other end of the sixteenth resistor R16 and grounded.

[0186] In this embodiment, the second optocoupler element N5 can be an optocoupler, and the second optocoupler element N5 generates a second feedback signal based on the first signal and the second signal.

[0187] During operation, the first and second signals can be current signals. When the sum of the first and second signals increases, the voltage across the sixteenth resistor R16 increases, and the voltage at the secondary input of the second optocoupler N5N2 increases, thus increasing FB2. Based on FB2, the power supply processor 17 adjusts the duty cycle of the second drive signal to decrease. Conversely, when the sum of the first and second signals decreases, the voltage across the sixteenth resistor R16 decreases, and the voltage at the secondary input of the second optocoupler N5N2 decreases, which can be interpreted as decreasing FB2. Based on FB2, the power supply processor 17 adjusts the duty cycle of the second drive signal to increase.

[0188] In this example, the first signal and the second signal are isolated and transmitted to the power supply processor 17 through the second optocoupler N5 and the sixteenth resistor R16. This avoids mutual interference between the module on the primary winding side of the transformer and the module on the secondary winding side of the transformer, thereby further ensuring that the power supply circuit 10 outputs a constant current power supply signal.

[0189] Based on the above embodiments, continue to refer to Figure 13 In another embodiment, the power supply circuit 10 further includes a standby control module 18, which is connected between the backlight assembly 20 and ground. The standby control module 18 is used to control the backlight assembly 20 to be grounded or disconnected from ground according to the standby signal.

[0190] In this embodiment, when the display device is in standby mode, the path of the backlight assembly 20 is disconnected, so that the backlight assembly 20 no longer generates current, and thus the backlight assembly 20 no longer consumes power. Therefore, in this embodiment, the standby control module 18 can realize the on / off control of the backlight assembly 20, so that the backlight assembly 20 does not consume power in standby mode, thereby reducing the power consumption of the display device.

[0191] In one example, such as Figure 9 As shown, the standby control module 18 includes: a second switching element V2, a third switching element V3, a fourth switching element V4, and a seventeenth resistor R17;

[0192] The control terminal of the second switching element V2 receives the standby signal. The first terminal of the second switching element V2 is connected to one end of the seventeenth resistor R17, and the other end of the second switching element V2 is grounded. The second switching element V2 is used to turn on when the standby signal is in the first state and to turn off when the standby signal is in the second state.

[0193] The other end of the seventeenth resistor R17 is connected to the control terminal of the third switching element V3; the first terminal of the third switching element V3 receives the third reference voltage signal, and the second terminal of the third switching element V3 is connected to the control terminal of the fourth switching element V4; the third switching element V3 is used to turn on when the second switching element V2 is turned on, and to turn off when the second switching element V2 is turned off.

[0194] The first end of the fourth switching element V4 is connected to the backlight assembly 20, and the second end of the fourth switching element V4 is grounded. The fourth switching element V4 is used to turn on when the third switching element V3 is turned on, and to turn off when the third switching element V3 is turned off.

[0195] In this example, the third reference voltage signal is a reference power supply signal. As an example, the first terminal of the third switching element V3 can be connected to the power supply circuit 10 to receive the first power supply voltage and use it as the third reference voltage signal. It should be noted that when the second terminal of the fourth switching element V4 is grounded, in one embodiment, the fourth switching element V4 can be directly grounded. In another embodiment, in conjunction with the example of the second feedback circuit 16 including a current sampling unit, such as... Figure 9 As shown, the second terminal of the fourth switching element V4 can be connected to the current sampling unit, and the second terminal of the fourth switching element V4 is grounded through the current sampling unit.

[0196] The working principle of this example will be illustrated below: Continuing with the example of the first state being high and the second state being low, as follows... Figure 9 As shown, when the standby signal is in the first state, the second switching element V2 is turned on, and the first supply voltage VO2 provides a second reference level signal to the first terminal of the second switching element V2 through the first terminal and control terminal of the third switching element V3. The second switching element V2 is turned on, the control terminal of the third switching element V3 is at a high level, the third switching element V3 is turned on, the control terminal of the fourth switching element V4 is at a high level, the fourth switching element V4 is turned on, and the backlight assembly 20 is grounded. When the standby signal is in the second state, the second switching element V2 is turned off, the control terminal of the third switching element V3 is at a low level, the third switching element V3 is turned off, the control terminal of the fourth switching element V4 is at a low level, the fourth switching element V4 is turned off, and the backlight assembly 20 is disconnected from ground.

[0197] This example demonstrates the ability to control the connection between the backlight assembly and ground based on the standby signal, thereby reducing the power consumption of the display device. Furthermore, the standby signal is smaller than the second reference level signal, thus enabling the control of a large voltage component by a small voltage component.

[0198] In one example, continue to refer to Figure 9The standby control module 18 also includes an eighteenth resistor R18. One end of the eighteenth resistor R18 receives the standby signal, and the other end of the eighteenth resistor R18 is connected to the control terminal of the second switching element V2. The eighteenth resistor R18 is a voltage divider resistor used to limit the voltage at the control terminal of the second switching element V2.

[0199] In one example, continue to refer to Figure 9 The standby control module 18 further includes: a twelfth capacitor C12 and a nineteenth resistor R19. One end of the nineteenth resistor R19 is connected to the control terminal of the second switching element V2, and the other end of the nineteenth resistor R19 is connected to the second terminal of the second switching element V2 and grounded. One end of the twelfth capacitor C12 is connected to one end of the nineteenth resistor R19, and the other end of the twelfth capacitor C12 is connected to the other end of the nineteenth resistor R19 and grounded. In this example, the nineteenth resistor R19 is used to pull down the voltage of the second terminal of the second switching element V2 to prevent the second terminal of the second switching element V2 from being in a floating state when the second switching element V2 is turned off. The twelfth capacitor C12 is used to filter higher frequency signals to avoid interference signals affecting the input standby signal.

[0200] In one example, continue to refer to Figure 9 Standby control module 18: Twentieth resistor R20; one end of the twentieth resistor R20 is connected to the first terminal of the third switching element V3, and the other end of the twentieth resistor R20 is connected to the control terminal of the fourth switching element V4. In this example, the twentieth resistor R20 is a voltage divider resistor used to limit the voltage at the control terminal of the fourth switching element V4.

[0201] In the display device and power supply circuit provided in this application, the first secondary winding circuit is used to supply power to the motherboard, the second secondary winding circuit outputs a second supply voltage based on the second primary voltage, and the third secondary winding circuit and the second secondary winding circuit generate a third supply voltage based on the second primary voltage, and supply power to the backlight assembly based on the second supply voltage and the third supply voltage. In effect, it is equivalent to the second secondary winding circuit and the third secondary winding circuit jointly supplying power to the backlight assembly. This can reduce the difference in output power between the first secondary winding circuit and the second secondary winding circuit. Therefore, this solution can improve the output power supplied to the backlight assembly.

[0202] In other embodiments, this application also provides a power supply circuit, including: a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit, and a third secondary winding circuit;

[0203] The primary winding circuit is configured to output the first primary voltage and the second primary voltage in a time-division manner;

[0204] The first secondary winding circuit is coupled to the primary winding circuit and connected to the motherboard, and is configured to output a first supply voltage to the motherboard based on the first primary voltage;

[0205] The second secondary winding circuit is coupled to the primary winding circuit and is configured to output a second supply voltage based on the second primary voltage.

[0206] The third secondary winding circuit is coupled to the primary winding circuit and connected to the second secondary winding circuit and the backlight assembly. It is configured to generate a third supply voltage based on the second primary voltage and supply power to the backlight assembly based on the second supply voltage and the third supply voltage.

[0207] The working principle of the power supply circuit in this embodiment and the power supply circuit of the display device in any of the above examples are the same as those in the above embodiments, and will not be repeated here.

[0208] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0209] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0210] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0211] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A display device, characterized in that, include: Motherboard, backlight assembly and power supply circuit; The power supply circuit includes: a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit, and a third secondary winding circuit; The primary winding circuit is configured to output the first primary voltage and the second primary voltage in a time-division manner; The first secondary winding circuit is coupled to the primary winding circuit and connected to the motherboard, and is configured to output a first supply voltage to the motherboard based on the first primary voltage; The second secondary winding circuit is coupled to the primary winding circuit and is configured to output a second supply voltage based on the second primary voltage. The third secondary winding circuit is coupled to the primary winding circuit and connected to the second secondary winding circuit and the backlight assembly. It is configured to generate a third supply voltage based on the second primary voltage and supply power to the backlight assembly based on the second supply voltage and the third supply voltage.

2. The display device according to claim 1, characterized in that, The third secondary winding circuit includes: a third secondary winding, a charging and discharging unit, and a path control unit; The third secondary winding is coupled to the primary winding circuit and connected in series with the charging and discharging unit, and is configured to output the third supply voltage based on the second primary voltage; The path control unit, connected to the third secondary winding, the second secondary winding circuit, and the backlight assembly, is configured to connect the charging and discharging unit to the first path when the primary winding circuit outputs a first primary voltage, so as to supply power to the backlight assembly through the second power supply voltage and the third power supply voltage provided by the charging and discharging unit; and to connect the charging and discharging unit to the second path when the primary winding circuit outputs a second primary voltage, so as to charge the charging and discharging unit based on the third power supply voltage provided by the third secondary winding, and supply power to the backlight assembly through the second power supply voltage and the third power supply voltage provided by the third secondary winding.

3. The display device according to claim 2, characterized in that, The path control unit includes: The first diode has its positive terminal connected to one end of the charging / discharging unit and its negative terminal connected to the backlight assembly; the other end of the charging / discharging unit is connected to one end of the third secondary winding. The second diode has its positive terminal connected to the output terminal of the second secondary winding circuit and the other end of the third secondary winding, and its negative terminal connected to the backlight assembly. The third diode has its anode connected to the output terminal of the second secondary winding circuit, and its cathode connected to one end of the charging / discharging unit and the anode of the first diode. The fourth diode has its anode connected to the output terminal of the second secondary winding circuit, and its cathode connected to the other end of the third secondary winding and the anode of the second diode.

4. The display device according to claim 2, characterized in that, The path control unit includes: The first diode has its positive terminal connected to one end of the charging / discharging unit and its negative terminal connected to the backlight assembly; the other end of the charging / discharging unit is connected to one end of the third secondary winding. The second diode has its positive terminal connected to the output terminal of the second secondary winding circuit and the other end of the third secondary winding, and its negative terminal connected to the backlight assembly. The third diode has its positive terminal grounded and its negative terminal connected to one end of the charging / discharging unit and the positive terminal of the first diode. The fourth diode has its anode connected to the output terminal of the second secondary winding circuit, and its cathode connected to the other end of the third secondary winding and the anode of the second diode.

5. The display device according to claim 3 or 4, characterized in that, The backlight assembly includes a first LED string and a second LED string; The cathode of the first diode is connected to the anode of the first light string, and the cathode of the second diode is connected to the anode of the second light string. The path control unit further includes: a first capacitor and a second capacitor. One end of the first capacitor is connected to the negative terminal of the first diode and the positive terminal of the first lamp string, and the other end is grounded; One end of the second capacitor is connected to the negative terminal of the second diode and the positive terminal of the second lamp string, and the other end is grounded.

6. The display device according to any one of claims 1-4, characterized in that, The power supply circuit also includes: a first feedback circuit, a second feedback circuit, and a power supply processor. The input terminal of the first feedback circuit is connected to the output terminal of the first secondary winding circuit, and the output terminal is connected to the power supply processor. It is configured to output a first feedback signal to the power supply processor based on the first power supply voltage. The input terminal of the second feedback circuit is connected to the output terminal of the first secondary winding circuit and the backlight assembly, and the output terminal is connected to the power supply processor. It is configured to output a second feedback signal to the power supply processor based on the second power supply voltage and the current flowing through the backlight assembly. The power supply processor, connected to the primary winding circuit, is configured to output a first drive signal and a second drive signal to the primary winding circuit based on the first feedback signal and the second feedback signal, so that the primary winding circuit controls the first primary voltage and the second primary voltage based on the first drive signal and the second drive signal.

7. The display device according to claim 6, characterized in that, The second feedback circuit includes: a dimming unit, a current feedback unit, a voltage feedback unit, and an isolation transmission unit; The dimming unit receives a dimming signal and a first reference voltage signal, and is configured to generate a first reference signal based on the dimming signal and the first reference voltage signal; The current feedback unit is connected to the dimming unit and the backlight assembly, and receives a first reference signal. It is configured to output a first signal based on the comparison result between the current flowing through the backlight assembly and the first reference signal. The voltage feedback unit is connected to the second secondary winding circuit and receives the second reference signal. It is configured to output the second signal based on the comparison result between the second supply voltage and the second reference signal. The isolated transmission unit, connected to the current feedback unit and the voltage feedback unit, is configured to generate the second feedback signal based on the first signal and the second signal.

8. The display device according to claim 7, characterized in that, The current feedback unit includes: a first operational amplifier, a fifth diode, a third capacitor, a fourth capacitor, and a first resistor; The non-inverting input of the first operational amplifier is connected to the backlight assembly, the inverting input is connected to the dimming unit, one end of the third capacitor and one end of the first resistor, and the output is connected to the positive terminal of the fifth diode, the other end of the third capacitor and the other end of the fourth capacitor; the negative terminal of the fifth diode is connected to the isolation transmission unit and the voltage feedback unit. The other end of the first resistor is connected to one end of the fourth capacitor.

9. The display device according to claim 6, characterized in that, The voltage feedback unit includes: a second operational amplifier, a sixth diode, a second resistor, a fifth capacitor, and a sixth capacitor; The non-inverting input of the second operational amplifier is connected to the second secondary winding circuit, the inverting input receives the second reference signal and is connected to one end of the second resistor and one end of the fifth capacitor, and the output is connected to the positive terminal of the sixth diode, the other end of the fifth capacitor and the other end of the sixth capacitor; the negative terminal of the sixth diode is connected to the isolation transmission unit and the current feedback unit. The other end of the second resistor is connected to the other end of the sixth capacitor.

10. A power supply circuit, characterized in that, include: Primary winding circuit, first secondary winding circuit, second secondary winding circuit and third secondary winding circuit; The primary winding circuit is configured to output the first primary voltage and the second primary voltage in a time-division manner; The first secondary winding circuit is coupled to the primary winding circuit and connected to the motherboard, and is configured to output a first supply voltage to the motherboard based on the first primary voltage; The second secondary winding circuit is coupled to the primary winding circuit and is configured to output a second supply voltage based on the second primary voltage. The third secondary winding circuit is coupled to the primary winding circuit and connected to the second secondary winding circuit and the backlight assembly. It is configured to generate a third supply voltage based on the first primary voltage and supply power to the backlight assembly based on the second supply voltage and the third supply voltage.

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