Power supply circuit and display device

Abstract

A power supply circuit (10) and a display device (200). The power supply circuit (10) comprises: a primary winding circuit (11), a first secondary winding circuit (12), a second secondary winding circuit (13), and a third secondary winding circuit (14). The primary winding circuit (11) may be configured to output a first primary voltage and a second primary voltage at different times; the first secondary winding circuit (12) is coupled to the primary winding circuit (11), is connected to a first load, and can be configured to output a first power supply voltage to the first load on the basis of the first primary voltage; the second secondary winding circuit (13) is coupled to the primary winding circuit (11) and can be configured to output a second power supply voltage on the basis of the second primary voltage; and the third secondary winding circuit (14) can be coupled to the primary winding circuit (11), can be connected to the second secondary winding circuit (13) and a second load, and can be configured to generate a third power supply voltage on the basis of the second primary voltage and to supply power to the second load on the basis of the second power supply voltage and the third power supply voltage.

Description

Power supply circuit and display device

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202411105103.4, filed on August 12, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of display devices, and in particular to a power supply circuit and a display device. BACKGROUND

[0004] With the development of electronic technology and Internet technology, display devices such as laser televisions and smart displays have been widely used in people's daily life. The display device is configured with a power supply circuit, which is used to supply power to the display device. The power-consuming elements of the display device include a mainboard and a backlight assembly. In related technologies, the power supply circuit includes an asymmetric half-bridge circuit, and two secondary winding groups of a transformer in the asymmetric half-bridge circuit are used to output corresponding power supply voltages to the mainboard and the backlight assembly, respectively. The asymmetric half-bridge circuit realizes double-loop output through time-sharing control. However, the power supply circuit in related technologies can only adapt to display devices with low power. SUMMARY

[0005] According to some embodiments of the present application, a power supply circuit can include: a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit, and a third secondary winding circuit; the primary winding circuit can be configured to output a first primary voltage and a second primary voltage in time-sharing manner; the first secondary winding circuit is coupled to the primary winding circuit and connected with a first load, and can be configured to output a first power supply voltage to the first load based on the first primary voltage; the second secondary winding circuit is coupled to the primary winding circuit and can be 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 with the second secondary winding circuit and a second load, and can be configured to generate a third power supply voltage based on the second primary voltage, and supply power to the second load based on the second power supply voltage and the third power supply voltage.

[0006] According to some embodiments of the present application, a display device can include a first load, a second load, and the above-mentioned power supply circuit. BRIEF DESCRIPTION OF DRAWINGS

[0007] FIG. 1 is a schematic diagram of an operating scenario between a display device and a control device according to some embodiments of the present application;

[0008] FIG. 2 is a configuration block diagram of a control device according to some embodiments of the present application;

[0009] FIG. 3 is a structural schematic diagram of a display device according to some embodiments of the present application;

[0010] FIG. 4 is a schematic diagram of a connection relationship between a power supply circuit and a load according to some embodiments of the present application;

[0011] FIG. 5 is a power supply architecture schematic diagram of a display device according to some embodiments of the present application;

[0012] FIG. 6 is a structural schematic diagram one of a display device according to some embodiments of the present application;

[0013] FIG. 7 is a structural schematic diagram two of a display device according to some embodiments of the present application;

[0014] FIG. 8 is a structural schematic diagram three of a display device according to some embodiments of the present application;

[0015] FIG. 9 is a structural schematic diagram four of a display device according to some embodiments of the present application;

[0016] FIG. 10 is a structural schematic diagram five of a display device according to some embodiments of the present application;

[0017] FIG. 11 is a structural schematic diagram of a first feedback circuit according to some embodiments of the present application;

[0018] FIG. 12 is a structural schematic diagram of a second feedback circuit according to some embodiments of the present application;

[0019] FIG. 13 is a structural schematic diagram of a second feedback circuit according to some other embodiments of the present application. DETAILED DESCRIPTION

[0020] Some embodiments will now be described in detail in the following description, with reference to the drawings. The following description, while including specific embodiments, is not meant to limit the present application to these embodiments. Rather, the following description is meant to provide examples of apparatus and methods consistent with some aspects of the present application as detailed in the following claims. The following drawings and description are not meant to limit the scope of the present application to any particular embodiment, but rather the scope of the present application is to be afforded the full breadth that such embodiments encompass.

[0021] It should be noted that the brief description of terms in the present application is only for the convenience of understanding the following described embodiments, and is not intended to limit the embodiments of the present application. Unless otherwise specified, these terms should be understood according to their ordinary and common meanings.

[0022] The terms "first", "second", and the like in the description and in the claims of the present application and above-described drawings are used for distinguishing between similar or identical objects and do not necessarily indicate a specific order or sequence, unless otherwise indicated (Unless otherwise indicated). It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the application are capable of operating according to either order or sequence.

[0023] Furthermore, the terms "comprise", "comprising", "have", "having", "include", "including", "contain", "containing", "provide", "providing", and the like, are used in the detailed description and in the claims of this application and are intended to be construed as inclusive or open-ended, unless otherwise indicated (Unless otherwise indicated). It will be understood by those within the art that any term used herein in the singular can also be interpreted as plural, and vice versa, as appropriate and / or according to particular circumstances and / or as otherwise indicated (Unless otherwise indicated). By way of example, a component can refer to components that can function either separately or in combination. In the description and in the claims of the application, the phrases "at least one", "one or more" and "and / or" are open-ended expressions that are intended to be affording the possibility that there can be zero, one, two, three, four, five, or more than five of the recited elements or steps, depending on the intent of the present application as set forth in the description and / or claims. In the description and in the claims of the application, the term "about" preceding a number or a numerical range means that the value of the number or the numerical range is "approximately" the value stated, for example, within 10%, 5%, 1%, or 0.5% of the stated value. In the description and in the claims of the application, the term "coupled" means that two or more elements are in some way currently directly or indirectly connected together (e.g., mechanically, electrically, communicatively, via a wireless interface, etc.), whether or not they are described as being actuated together at a given point in time, unless otherwise indicated (Unless otherwise indicated). In the description and in the claims of the application, the term "circuitry" refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software and / or firmware and / or artificial intelligence and / or fuzzy logic that can perform the functionality described in this element.

[0024] The display device provided by the embodiments of the present application can have various implementation forms, for example, can be a television, a laser projection device, a monitor, an electronic bulletin board, an electronic table, and the like. FIG. 1 and FIG. 2 are a specific embodiment of the display device of the present application.

[0025] FIG. 1 is a schematic diagram of an operating scenario between a display device and a control device according to some embodiments of the present application. As shown in FIG. 1, a user can operate the display device 200 through the smart device 300 or the control device 100.

[0026] In some embodiments, the control device 100 can be a remote controller, and the communication between the remote controller and the display device can include infrared protocol communication or Bluetooth protocol communication, and other short-distance communication modes, to control the display device 200 in a wireless or wired manner. The user can input a user instruction through a button on the remote controller, voice input, control panel input, and the like, to control the display device 200.

[0027] In some embodiments, the smart device 300 (such as a mobile terminal, a tablet computer, a computer, a notebook computer, and the like) can also be used to control the display device 200. For example, an application running on the smart device is used to control the display device 200.

[0028] In some embodiments, the display device can not receive instructions using the above-described smart device or control device, but can receive user control through touch or gesture, and the like.

[0029] In some embodiments, the display device 200 can also be controlled in a manner other than the control device 100 and the smart device 300, for example, the user's voice instruction control can be received directly through the module configured inside the display device 200 to acquire voice instructions, and the user's voice instruction control can also be received through the voice control device arranged outside the display device 200.

[0030] In some embodiments, the display device 200 can also communicate data with the server 400. The display device 200 can be communicatively coupled through a local area network (LAN), a wireless local area network (WLAN), and other networks.

[0031] In some embodiments, the server 400 can provide various content and interaction to the display device 200. The server 400 can be a cluster or multiple clusters, and can include one or more types of servers.

[0032] FIG. 2 is a configuration block diagram of a control device according to some embodiments of the present application.

[0033] In some embodiments, as shown in FIG. 2, the control device 100 can include at least one processor 110.

[0034] In some embodiments, the processor can include at least one of a central processing unit (CPU), a video processor, an audio processor, a graphics processing unit (GPU), a random access memory (RAM), a read-only memory (ROM), a first interface to an n-th interface for input / output, a communication bus, and the like.

[0035] In some embodiments, as shown in FIG. 2, the control device 100 can include a communication interface 130.

[0036] In some embodiments, the communication interface 130, under the control of the at least one processor 110, realizes communication of control signals and data signals with the display device 200. The communication interface 130 can include at least one of a WiFi chip, a Bluetooth module, a near field communication (NFC) module, and other near field communication modules.

[0037] In some embodiments, as shown in FIG. 2, the control device 100 can include a user input / output interface 140.

[0038] In some embodiments, the user input / output interface 140, wherein the input interface can include at least one of a microphone, a touchpad, a sensor, a key, and other input interfaces.

[0039] In some embodiments, as shown in FIG. 2, the control device 100 can include a memory.

[0040] In some embodiments, the memory can be used to store various running programs, data and applications for driving and controlling the control device 100 under the control of the control device. The memory 190 can store various control signal instructions input by the user. In some embodiments, as shown in FIG. 2, the control device 100 can include a power supply circuit; the power supply can be used to provide operating power support for the elements of the control device 100 under the control of the control device.

[0041] In some embodiments, the control device 100 can receive the input operation instructions of the user, and convert the operation instructions into instructions that can be recognized and responded by the display device 200, and play the role of intermediary in the interaction between the user and the display device 200.

[0042] FIG. 3 is a structural schematic diagram of a display device in some embodiments of the present application.

[0043] In some embodiments, as shown in FIG. 3, the display device 200 can include a signal converter 210.

[0044] In some embodiments, the signal converter 210 can receive broadcast signals through wired or wireless receiving mode, and demodulate audio and video signals and Electrical Program Guide (EPG) data signals from a plurality of wireless or wired broadcast signals.

[0045] In some embodiments, the at least one processor 250 and the signal converter 210 can be located in different split devices, that is, the signal converter 210 can also be in an external device of the main device where the at least one processor 250 is located, such as an external digital video converter box.

[0046] In some embodiments, as shown in FIG. 3, the display device 200 can include a communication device 220.

[0047] In some embodiments, as shown in FIG. 3, the communication device 220 is a component that can be used to communicate with external devices or servers according to various communication protocol types.

[0048] For example, the communication device can include at least one of a Wifi 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 communication device 220.

[0049] In some embodiments, as shown in FIG. 3, the display device 200 can include a detector 230.

[0050] In some embodiments, as shown in FIG. 3, the detector 230 can be used to collect signals of the external environment or interaction with the outside.

[0051] For example, the detector 230 can include a light receiver, which can be used to collect a sensor of ambient light intensity; or the detector 230 can include an image collector, such as a camera, which can be used to collect an external environment scene, a user's attribute, or a user interaction gesture; or the detector 230 can include a sound collector, such as a microphone, which can be used to receive external sound.

[0052] In some embodiments, as shown in FIG. 3, the display device 200 can include an external device interface 240.

[0053] In some embodiments, the external device interface 240 can include, but is not limited to, any one or more of the following: a High Definition Multimedia Interface (HDMI), an analog or digital High Definition Component input interface (component), a Composite Video input interface (Composite Video Broadcast Signal or Composite Video Blanking and Sync, CVBS), a Universal Serial Bus (USB) input interface (referred to as USB), an RGB port, etc. It can also be a composite input / output interface formed by the above multiple interfaces.

[0054] In some embodiments, as shown in FIG. 3, the display device 200 can include at least one processor 250.

[0055] In some embodiments, as shown in FIG. 3, the processor can include at least one of a central processing unit (CPU), a video processor, an audio processor, a graphics processing unit (GPU), a random access memory (RAM), a read-only memory (ROM), a first interface to an n-th interface for input / output, a communication bus, and the like.

[0056] In some embodiments, as shown in FIG. 3, the display device 200 can include a display 260.

[0057] In some embodiments, as shown in FIG. 3, the display 260 can include a display screen component for presenting a picture.

[0058] In some embodiments, as shown in FIG. 3, the display 260 can include a driving component for driving an image display, and can be used for receiving an image signal output from at least one processor, and for displaying video content, image content, and a menu operation interface component, and a user operation UI interface.

[0059] In some embodiments, as shown in FIG. 3, the display 260 can be a liquid crystal display, an organic light-emitting diode (OLED) display, and a projection display.

[0060] In some other embodiments, as shown in FIG. 3, the display 260 can be a projection device and a projection screen.

[0061] In some embodiments, as shown in FIG. 3, the display device 200 can include an audio output interface 270.

[0062] In some embodiments, the audio output device 270 can be a native loudspeaker of the display device 200, or can be an audio output device externally connected to the display device 200. For the audio output device externally connected to the display device 200, the display device 200 can further be provided with an external audio output terminal, and the audio output device can be connected to the display device 200 through the external audio output terminal to output sound of the display device 200.

[0063] In some embodiments, as shown in FIG. 3, the display device 200 can include a memory.

[0064] In some embodiments, the at least one processor 250 can control the operation of the display device and respond to user operations by various software control programs stored in the memory. The at least one processor 250 controls the overall operation of the display device 200. For example, in response to receiving a user command for selecting a UI object displayed on the display 260, the at least one processor 250 can perform an operation related to the object selected by the user command.

[0065] In some embodiments, as shown in FIG. 3, the display device 200 can include at least one of a user interface.

[0066] In some embodiments, as shown in FIG. 3, the user interface can be configured to receive a control signal of a control apparatus 100 (e.g., an infrared remote controller, etc.).

[0067] In some embodiments, a user can input a user command through a graphical user interface (GUI) displayed on the display 260, and the user input interface receives the user input command through the graphical user interface (GUI).

[0068] In some embodiments, as shown in FIG. 3, the display device 200 can include a power supply circuit for providing power support for loads of the display device 200.

[0069] In some embodiments, the display device can include a first load and a second load, and the first load and the second load can be any specific load such as a main board, a power amplifier, a backlight assembly, etc.

[0070] For convenience of explanation in subsequent embodiments, the first load is taken as the main board and the second load is taken as the backlight assembly.

[0071] In some embodiments, the display device includes a main board coupled to the power supply circuit, and the main board can include at least one of a signal converter, a communicator, a detector, an external device interface, at least one processor, an audio output interface, a memory, and a user interface.

[0072] In some embodiments, the display device includes a backlight assembly coupled to the power supply circuit, and the backlight assembly can be configured to provide backlight to a display panel.

[0073] In some embodiments, FIG. 4 is a schematic diagram of a connection relationship between a power supply circuit and loads according to some embodiments of the present application. As shown in FIG. 4, the power supply circuit 10 can include an input end 10a and output ends (e.g., a first output end 10b, a second output end 10c, and a third output end 423d). The input end 10a is connected to a commercial power supply, and the output ends are connected to loads, such as the first output end 10b connected to the backlight assembly 20 (e.g., an LED light bar for lighting a display screen), the second output end 10c connected to the audio assembly 40 (e.g., a speaker), and the third output end 423d connected to the main board 30. The power supply circuit 10 needs to convert the alternating current of the commercial power supply into direct current required by the loads, and the direct current usually has different specifications, for example, the speaker requires 18V, and the panel requires 12V.

[0074] FIG. 5 is a schematic diagram of a power supply architecture of a display device according to some embodiments of the present application. As shown in FIG. 5, the display device can include a power supply circuit 10 and loads. The power supply circuit 10 can include a rectifier bridge 101, a power factor correction (PFC) module 102, and a resonant converter (LLC) module 103. The LLC module 103 can include a synchronous rectification circuit (not shown in FIG. 5). The PFC module 102 is connected to the LLC module 103. The LLC module 103 can be an asymmetric half-bridge circuit, and the asymmetric half-bridge circuit can output corresponding power supply voltages to the main board 30 and the backlight assembly 20 through two secondary winding of a transformer (not shown in FIG. 5) in the asymmetric half-bridge circuit by time-sharing control to achieve double-loop output.

[0075] However, in the time-sharing control process, the power needs to be switched from one load to another. Due to the factors such as the working 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 be too different. The power of the main board is relatively stable, which limits the power of the backlight assembly, and thus the power supply circuit can only be adapted to display devices with low power.

[0076] According to some embodiments of the present application, the power supply circuit of the display device can include three secondary winding circuits. The first secondary winding circuit can be configured to supply power to the main board. The second secondary winding circuit and the third secondary winding circuit can be connected to supply power to the backlight assembly. In this way, the difference between the first primary voltage and the second primary voltage can be reduced. In effect, the output power of the second secondary winding circuit is added to the third secondary winding circuit to increase the output power supplied to the backlight. The output power of the first secondary winding circuit and the second secondary winding circuit can be similar. Therefore, the output power of the backlight circuit can be increased under the premise of balancing the output power of the two winding circuits, thereby improving the adaptive power of the power supply circuit under the asymmetric half-bridge circuit.

[0077] The scheme of the present application and the scheme of the present application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described in detail in some embodiments. In the description of the present application, unless otherwise specified and limited, each term should be understood in a broad sense within the art. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0078] FIG. 6 is a structural schematic diagram of a display device according to some embodiments of the present application. As shown in FIG. 6, the display device can include a main board 30, a backlight assembly 20, and a power supply circuit 10.

[0079] The power supply circuit 10 can include a primary winding circuit 11, a first secondary winding circuit 12, a second secondary winding circuit 13, and a third secondary winding circuit 14.

[0080] In some embodiments, the primary winding circuit 11 can be configured to output a first primary voltage and a second primary voltage in time division, i.e., using asymmetric half-bridge technology for output.

[0081] As an example, the power supply circuit 10 can include an LLC circuit, and the primary winding circuit 11, the first secondary winding circuit 12, and the second secondary winding circuit 13 can be part of the LLC circuit.

[0082] In some embodiments, as shown in FIG. 7, the primary winding circuit 11 can include a first drive switch Q1, a second drive switch Q2, a first storage capacitor C1', a first inductor L1, and a primary winding 111 of a transformer.

[0083] In some embodiments, the first secondary winding circuit 12 is coupled to the primary winding circuit 11 and connected to the main board 30, and can be configured to output a first power supply voltage to the main board 30 based on the first primary voltage.

[0084] In a possible implementation, as shown in FIG. 7, the first secondary winding circuit 12 can include the first secondary winding 121 of the transformer, the seventh diode D7, and the second storage capacitor C2'.

[0085] In some embodiments, as shown in FIG. 7, the second secondary winding circuit 13 can include the second secondary winding 131 of the transformer, the eighth diode D8, and the third storage capacitor C3', and the like ends of the first secondary winding 121 and the second secondary winding 131 are opposite.

[0086] In operation, the power supply processor 17 outputs the first driving signal and the second driving signal to drive the first driving switch Q1 and the second driving switch Q2, and realize the time-sharing conduction of the first driving switch Q1 and the second driving switch Q2, and the duty cycles of the first driving signal and the second driving signal can be different, that is, the conduction time of the first driving switch Q1 and the second driving switch Q2 can be different, based on which the first primary voltage and the second primary voltage can be controlled respectively, and for the secondary side, the diodes with different current directions are used to control the two capacitors to store the electric quantity at different times, thereby realizing the control of the output voltages of the first secondary winding circuit 12 and the second secondary winding circuit 13.

[0087] In some embodiments, the third secondary winding circuit 14 can be coupled to the primary winding circuit 11, and connected with the second secondary winding circuit 13 and the backlight assembly 20, and can be 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.

[0088] By way of example, as shown in FIGS. 6 and 7, since the mainboard 30 supplies power at a constant voltage, the first voltage is a constant 12V, and the power of the mainboard 30 is 36W, and the load of the second secondary winding circuit 13 is set to be no more than 100W. It can be seen that in the related art, only one second secondary winding circuit 13 is used to supply power to the backlight assembly 20, and thus the maximum power of the backlight assembly 20 is 100W. In the present embodiment, the third secondary winding circuit 14 can also be included, and the third secondary winding 141 can provide a power of 50W, and thus 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 supplies, and supply power to the backlight assembly 20 together, that is, the third secondary winding circuit 14 shares a part of the power, and thus the load imbalance of the first secondary winding circuit 12 and the second secondary winding circuit 13 can be reduced, thereby the output power of the power supply circuit 10 can be improved.

[0089] It should be noted that the number of the third auxiliary winding circuit 14 in the embodiment can be one or multiple. When the number is multiple, the multiple third auxiliary winding circuits 14 are connected in parallel and supply power to the backlight assembly 20 together, so as to further improve the power supply power of the power supply circuit 10 to the backlight assembly 20.

[0090] It should be further noted that, continuing to refer to FIG. 4, the power supply circuit 10 can further include a fourth auxiliary winding circuit, which can be used to supply power to the audio assembly 40 such as a sound system, but the audio assembly 40 has relatively low power supply requirements, and the fourth auxiliary winding circuit can adopt open-loop power supply. The improvement of this part is not involved in the present application, and thus the present application does not make too much description on this.

[0091] The third auxiliary winding circuit 14 will be described illustratively below.

[0092] As shown in FIG. 7, in some embodiments, the third auxiliary winding circuit 14 can include a third auxiliary winding 141, a charge-discharge unit 142, and a path control unit 143.

[0093] In some embodiments, as shown in FIG. 7, the charge-discharge unit 142 can include a balancing capacitor Cb.

[0094] In some embodiments, as shown in FIG. 7, the third auxiliary winding 141 is coupled with the primary winding circuit 11 and connected in series with the charge-discharge unit 142, and can be configured to output a third supply voltage based on the second primary voltage.

[0095] In some embodiments, as shown in FIG. 7, the path control unit 143 is connected with the third auxiliary winding 141, the second auxiliary winding circuit 13, and the backlight assembly 20.

[0096] In some embodiments, as shown in FIG. 7, the path control unit 143 can be configured to connect the charge-discharge 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 by the third supply voltage and the second supply voltage VO2 provided by the charge-discharge unit 142.

[0097] In some embodiments, as shown in FIG. 7, the path control unit 143 can be further configured to connect the charge-discharge unit 142 to the second path when the primary winding circuit 11 outputs the second primary voltage, so as to charge the charge-discharge unit 142 based on the third supply voltage provided by the third auxiliary winding 141, and supply power to the backlight assembly 20 by the second supply voltage VO2 and the third supply voltage provided by the third winding.

[0098] In the third auxiliary winding 141, the same-named end can be the same as the same-named end of the second auxiliary winding 131 and opposite to the same-named end of the first auxiliary winding 121.

[0099] 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 realize the effect of supplying power to the backlight assembly 20 based on the second supply voltage V02 and the third supply voltage, and further reduce the load imbalance of the first secondary winding circuit 12 and the second secondary winding circuit 13.

[0100] The structure of the path control unit 143 can include various structures.

[0101] In an implementation manner, FIG. 8 is a structural schematic diagram of a display device according to some embodiments of the present application, as shown in FIG. 8, the path control unit 143 can include: a first diode D1, a positive electrode of the first diode D1 is connected with one end of the charging and discharging unit 142, and a negative electrode is connected with the backlight assembly 20; the other end of the charging and discharging unit 142 is connected with one end of the third secondary winding 141.

[0102] In some examples, the path control unit 143 can further include: a second diode D2, a positive electrode of the second diode D2 is connected with an output end of the second secondary winding circuit 13 and the other end of the third secondary winding 141, and a negative electrode is connected with the backlight assembly 20;

[0103] In some examples, the path control unit 143 can further include: a third diode D3, a positive electrode of the third diode D3 is connected with the output end of the second secondary winding circuit 13, and a negative electrode is connected with one end of the charging and discharging unit 142 and the positive electrode of the first diode D1;

[0104] In some examples, the path control unit 143 can further include: a fourth diode D4, a positive electrode of the fourth diode D4 is connected with the output end of the second secondary winding circuit 13, and a negative electrode is connected with the other end of the third secondary winding 141 and the positive electrode of the second diode D2.

[0105] The working process of this embodiment is schematically explained in combination with FIG. 8:

[0106] When the first driving switch tube Q1 is turned on, the current direction generated by the third secondary winding 141 is clockwise, the first diode D1, the fourth diode D4 and the eighth diode D8 are turned on, the second diode D2, the third diode D3 and the seventh diode D7 are turned off, the balancing capacitor Cb is connected to the first path, the first path is: the upper end A point of the third secondary winding 141→the balancing capacitor Cb (charging)→the first diode D1→the backlight assembly 20→the negative end (ground)→the lower end B' point of the second secondary winding 131→the upper end B point of the second secondary winding 131→the eighth diode D8→the fourth diode D4→the lower end A' point of the third secondary winding 141, forming a complete loop. Among them, the second supply voltage VO2 (the voltage of point M) of the second secondary winding circuit 13 and one end of the balancing capacitor Cb are based on the bootstrap principle of the capacitor, thereby increasing the voltage of the other end (output end N) of the balancing capacitor Cb. It can be understood that it is equivalent to superimposing the second supply voltage VO2 on the third supply voltage VO3.

[0107] When the second driving switch tube Q2 is turned on, the current direction generated by the third secondary winding 141 is counterclockwise, the second diode D2, the third diode D3 and the seventh diode D7 are turned on, the first diode D1, the fourth diode D4 and the eighth diode D8 are turned off, and the balancing capacitor Cb is connected to the second path, wherein the second path is: the lower end A' point of the third secondary winding 141→the second diode D2→the backlight assembly 20→the negative end (ground)→the third storage capacitor C3'→the third diode D3→the balancing capacitor Cb→the upper end A point of the third secondary winding 141, forming a loop. Among them, the balancing capacitor Cb is discharged, and for the same reason, the second supply voltage VO2 and the third supply voltage VO3 supply power to the backlight assembly 20. Another loop is: the lower end of the first secondary winding 121→the seventh diode D7→the main board 30→the negative end (ground)→the upper end of the first secondary winding 121, forming a complete loop.

[0108] In the related art, the power of the main board is relatively stable, while the power of the backlight assembly is related to many factors, such as light source type, backlight technology, etc., and the power is large, resulting in a large difference between the two powers. Through the two secondary windings in the asymmetric half-bridge circuit, the corresponding supply voltages are output to the main board and the backlight assembly, respectively. Because there is no third secondary winding circuit 14, when the first driving switch tube Q1 is turned on, the first supply voltage VO1 output by the first secondary winding circuit 12 supplies power to the main board 30, and when the second driving switch tube Q2 is turned on, VO2 output by the second secondary winding circuit 13 supplies power to the backlight assembly 30.

[0109] In this embodiment, based on the above, the third auxiliary winding circuit 14, when the first drive switch Q1 is turned on, can be understood as adding the second supply voltage VO2 to the third supply voltage VO3, when the second drive switch Q2 is turned on, the second supply voltage VO2 and the third supply voltage VO3 are supplied to the backlight assembly, that is, the first auxiliary winding circuit 12 supplies power to the main board, and the second auxiliary winding circuit 13 and the third auxiliary winding circuit 14 supply power to the backlight assembly together, so that the difference between the first primary voltage and the second primary voltage can be reduced, thereby balancing the output power of the first auxiliary winding 121 and the second auxiliary winding 131, improving the output power of the backlight circuit, and improving the adaptive power of the power supply circuit under the asymmetric half-bridge circuit.

[0110] In another implementation, FIG. 9 is a structural schematic diagram of a display device according to some embodiments of the present application, as shown in FIG. 9, the anode of the third diode D3 can also be grounded, and the cathode is connected to one end of the charge and discharge unit 142 and the anode of the first diode D1.

[0111] The working principle is similar to the example in FIG. 8, as shown in FIG. 9, when the first drive switch Q1 is turned on, the current direction generated by the third auxiliary winding 141 is clockwise, the first diode D1, the fourth diode D4 and the eighth diode D8 are turned on, the second diode D2, the third diode D3 and the seventh diode D7 are turned off, and the balancing capacitor Cb is connected to the first path. The first path is: the upper end A point of the third auxiliary winding 141→the balancing capacitor Cb (charging)→the first diode D1→the backlight assembly 20→the fourth switch element V4→R7'→the negative end (ground)→the lower end B' point of the second auxiliary winding 131→the upper end B point of the second auxiliary winding 131→the eighth diode D8→the fourth diode D4→the lower end A' point of the third auxiliary winding 141, forming a complete loop. Among them, the second supply voltage VO2 (the voltage of point M) of the second auxiliary winding circuit 13 and one end of the balancing capacitor Cb, based on the bootstrap principle of the capacitor, then the voltage of the other end (output end N) of the balancing capacitor Cb is improved. It can be understood that the second supply voltage VO2 is added to the third supply voltage VO3.

[0112] When the second driving switch Q2 is turned on, the current direction generated by the third secondary winding 141 is counterclockwise, the second diode D2, the third diode D3 and the seventh diode D7 are turned on, the first diode D1, the fourth diode D4 and the eighth diode D8 are turned off, and the balancing capacitor Cb is connected to the second path, where the second path is: the lower end A' point of the third secondary winding 141→the second diode D2→the backlight assembly 20→the fourth switch element V4→R7'→the negative terminal (ground)→the third diode D3→the balancing capacitor Cb→the upper end A point of the third secondary winding 141, forming a loop. At this time, the balancing capacitor Cb is discharged, and the second supply voltage VO2 and the third supply voltage VO3 are supplied to the backlight assembly 20 based on the same principle. Another loop is: the lower end of the first secondary winding 121→the seventh diode D7→the main board 30→the negative terminal (ground)→the upper end of the first secondary winding 121, forming a complete loop.

[0113] The beneficial effects are similar to those shown in FIG. 8, and will not be repeated here.

[0114] In some embodiments, as shown in FIGS. 8 and 9, the backlight assembly 20 can include a first lamp string LED1 and a second lamp string LED2.

[0115] The negative electrode of the first diode D1 is connected to the positive electrode of the first lamp string LED1, and the negative electrode of the second diode D2 is connected to the positive electrode of the second lamp string LED2.

[0116] In this embodiment, the number of the first lamp string LED1 and the second lamp string LED2 can be one or more. That is, the third secondary winding 141 unit can output two supply signals at the same time, and supply power to different lamp strings, thereby improving the brightness of the backlight.

[0117] In this embodiment, the third secondary winding circuit in which the balancing capacitor Cb is located is a current balance circuit (C-balance). In a steady-state system, according to the principle of capacitor ampere-second balance (charge conservation), the product of the charging and discharging currents of the capacitor in a complete switching cycle should be equal (the amount of charge is equal). 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 currents on the two lamp strings should be the same, thereby forming current sharing of the two LED loads.

[0118] According to the capacitor volt-ampere relationship,

[0119] Where i c (t) is the current flowing through the balancing capacitor, V C(t) the voltage across the balancing capacitor. Integrating the above equation over a complete switching cycle in a buck circuit, the change in voltage across the capacitor over a cycle is

[0120] At steady state, the net change in capacitor voltage over a switching cycle must be zero. So there is

[0121] This states that the area (i.e. the "charge") between the capacitor current curve and the time axis over a switching cycle at steady state is zero; or, in other words, the average value of the capacitor current is zero.

[0122] In some embodiments, continuing to refer to FIG. 8, FIG. 9, the path control unit 143 can further include: a first capacitor C1 and a second capacitor C2,

[0123] One end of the first capacitor C1 is connected with the negative electrode of the first diode D1 and the positive electrode of the first lamp string LED1, and the other end is grounded;

[0124] One end of the second capacitor C2 is connected with the negative electrode of the second diode D2 and the positive electrode of the second lamp string LED2, and the other end is grounded.

[0125] The working principle of the present embodiment is schematically described in combination with FIG. 9:

[0126] When the first driving switch tube Q1 is turned on, the first capacitor C1 is charged, and the output end of the third auxiliary winding circuit 14 supplies power to the first lamp string LED1; the second capacitor C2 is discharged, and supplies power to the second lamp string LED2. When the second driving switch tube Q2 is turned on, the first capacitor C1 is discharged, and supplies power to the first lamp string LED1; the output end of the third auxiliary winding circuit 14 supplies power to the second lamp string LED2.

[0127] It should be noted that, in order to improve the stability of the power supply of the display device, the mainboard 30 needs to be supplied with constant voltage, and the backlight assembly needs to be supplied with constant current. Therefore, in some embodiments, FIG. 10 is a structural schematic diagram five of a display device provided by some embodiments of the present application, as shown in FIG. 10, the power supply circuit 10 can further include: a first feedback circuit 15, a second feedback circuit 16 and a power supply processor 17.

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

[0129] In some embodiments, the input terminal of the second feedback circuit 16 is connected with the output terminal of the third auxiliary winding circuit 14 and the backlight component 20, and the output terminal is connected with the power supply processor 17, which can be configured to output a second feedback signal to the power supply processor 17 based on the second power supply voltage V02 and the current flowing through the backlight component 20.

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

[0131] In the present embodiment, two feedback circuits are provided, wherein the first feedback circuit 15 outputs a first feedback signal based on the first power supply voltage, so that the power supply processor 17 sends a corresponding driving signal to adjust the output voltage of the first auxiliary winding circuit 12, thereby realizing constant voltage output. The second feedback circuit 16 outputs a second feedback signal based on the second power supply voltage V02 and the current flowing through the backlight component 20, so as to realize constant voltage output of the second auxiliary winding circuit 13 and constant current output of the third auxiliary winding circuit 14.

[0132] In some embodiments, the power supply processor 17 can be a processor with operation processing capability, and as a possible implementation, can be a microcontroller unit (MCU).

[0133] In the following, the first feedback circuit 15 and the second feedback circuit 16 will be introduced schematically.

[0134] In some embodiments, FIG. 11 is a structural schematic diagram of the first feedback circuit according to some embodiments of the present application, as shown in FIG. 11, the first feedback circuit 15 can include a first optocoupler element N1, a second three-terminal voltage 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 a second reference voltage signal, and the other end of the third resistor R3 is connected with the primary input terminal of the first optocoupler element N1.

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

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

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

[0139] The other end of the fifth resistor R5 receives a second reference voltage signal, and the other end of the sixth resistor R6 is grounded.

[0140] In the example, the fifth resistor R5, the sixth resistor R6, the third resistor R3 and the fourth resistor R4 are all voltage dividing resistors. The second reference voltage signal is a reference supply signal. As an example, one end of the fifth resistor R5 can be connected with the supply circuit 10 to receive a first supply voltage, and the first supply voltage is taken as the second reference voltage signal. In this way, there is no need to additionally provide a reference voltage, and the structure of the supply circuit 10 can be simplified.

[0141] During operation, when the first supply voltage increases, the voltage of the reference electrode 2 of the second three-terminal voltage regulator N2 increases, the current flowing from the negative electrode to the positive electrode of the second three-terminal voltage regulator N2 increases, the impedance of the secondary side of the first optocoupler element N1 increases, and the voltage of the input end of the secondary side of the first optocoupler element N1 increases, so as to isolate and transmit the first feedback signal to the supply processor 17.

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

[0143] In one implementation, as shown in FIG. 11, the first feedback circuit 15 can further include a seventh resistor R7 and a seventh capacitor C7. One end of the seventh resistor R7 is connected with one end of the fifth resistor R5. The other end of the one end of the seventh resistor R7 is connected with one end of the seventh capacitor C7, and the other end of the seventh capacitor C7 is connected with the negative electrode of the second three-terminal voltage 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, still referring to FIG. 11, the first feedback circuit 15 can further include an eighth capacitor C8. One end of the eighth capacitor C8 is connected with the input end of the secondary side of the first optocoupler element N1, and the other end of the eighth capacitor C8 is connected with the output end of the secondary side of the first optocoupler element N1 and grounded. In the implementation, the eighth capacitor C8 is a filtering capacitor, which can be 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, FIG. 12 is a schematic diagram of a structure of a second feedback circuit according to some embodiments of the present application. As shown in FIG. 12, the second feedback circuit 16 can include a dimming unit 161, a current feedback unit 162, a voltage feedback unit 163, and an isolation transmission unit 164. The second feedback circuit is configured to superimpose a constant current power supply signal ISEN and a second reference signal VSEN to form a second feedback signal FB2 to participate in feedback together, so as to stabilize the current and the second power supply voltage of the backlight assembly 20.

[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. The dimming signal is used to adjust the reference voltage signal in the current feedback unit 162 through the dimming unit 161, so as to realize current regulation.

[0147] In some embodiments, the current feedback unit 162 is connected to the dimming unit 161 and the backlight assembly 20, and receives the first reference signal, and is configured to output a first signal based on a comparison result of 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 VSEN, and is configured to output a second signal based on a comparison result of the second power supply voltage VO2 and the second reference signal VSEN.

[0149] In some embodiments, the isolation transmission unit 164 is connected to the current feedback unit 162 and the voltage feedback unit 163, and 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, so as to realize adjustment of the brightness of the backlight. The dimming signal can be output based on the selection of a user. The current feedback unit 162 outputs a first signal based on a comparison result of the current of the backlight assembly 20 and the first reference signal. The current of the backlight assembly 20 can be a voltage signal representing the corresponding current at the time of sampling, and the first reference signal can also be a voltage signal.

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

[0152] In some embodiments, FIG. 13 is a structural schematic diagram of a second feedback circuit according to some embodiments of the present application. As shown in FIG. 13, the dimming unit 161 can include 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, the other end of the first switching element V1 is grounded, and the control end 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 tube or a triode. As a possible implementation, it can be an N-MOS tube or a P-MOS tube. For the convenience of introducing the scheme, the P-MOS tube is taken as an example for description in the embodiments of the present application.

[0156] In operation, when the dimming signal is at a high level, 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.

[0157] When the dimming signal is at a low level, 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.

[0158] When it is necessary to increase the brightness, taking the dimming signal as a PWM signal as an example, the duty ratio of the PWM signal becomes larger, the charging time of the fourth capacitor C4 becomes longer, and the output first reference signal becomes larger. Conversely, when it is necessary to increase the darkness, the duty ratio of the PWM signal becomes smaller, the charging time of the fourth capacitor C4 becomes shorter, and the output first reference signal becomes smaller.

[0159] In some embodiments, continuing to refer to FIG. 13, the dimming unit 161 can further include a tenth resistor R10 and a tenth capacitor C10.

[0160] 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.

[0161] One end of the tenth resistor R10 is connected to the other end of the tenth capacitor C10, and the other end of the tenth capacitor C10 is grounded.

[0162] In this example, the tenth resistor R10 is used to release the electric quantity of the tenth capacitor C10 or the signal of the first reference level signal when the dimming unit 161 fails to operate. The tenth resistor R10 is a voltage dividing resistor, and the tenth capacitor C10 is a filter capacitor.

[0163] In one example, continuing to refer to FIG. 13, the dimming unit 161 can further include 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 voltage 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, the eleventh resistor R11 and the twelfth resistor R12 can both be voltage dividing resistors, and the eleventh resistor R11 is used to avoid the first reference level signal being directly grounded, thereby avoiding short circuit.

[0164] In one example, continuing to refer to FIG. 13, the dimming unit 161 can further include 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, and the thirteenth resistor R13 is used to pull down the voltage at the control terminal of the first switching element V1 to a low level when the dimming signal is not connected, so as to avoid the control terminal of the first switching element V1 being in a floating state.

[0165] In one example, continuing to refer to FIG. 13, the dimming unit 161 can further include 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 dividing resistor, which prevents the input level of the dimming signal from being too high and damaging the first switching element V1.

[0166] In some embodiments, continuing to refer to FIG. 13, the current feedback unit 162 can include a first operational amplifier N3, a fifth diode D5, a third capacitor C3, a fourth capacitor C4, and a first resistor R1.

[0167] The non-inverting input terminal of the first operational amplifier N3 is connected to the backlight assembly 20, the inverting input terminal 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 terminal is connected to the anode of the fifth diode D5, the other end of the third capacitor C3, and the other end of the fourth capacitor C4.

[0168] The negative electrode of the fifth diode D5 is connected with the isolation transmission unit 164 and the voltage feedback unit 163; the other end of the first resistor R1 is connected with one end of the fourth capacitor C4.

[0169] In this embodiment, the first operational amplifier N3 has an operational function, and can generate the first signal based on the written algorithm and according to the sampled signal representing the backlight assembly 20 and the first reference signal. Once one of the signals changes, the output first signal of the first operational amplifier N3 will also change immediately, so as to be able to quickly regulate the constant current power supply signal ISEN output by the power supply circuit 10.

[0170] The fifth diode D5 is used to prevent current from reversing, so as to improve the reliability of the circuit.

[0171] The third capacitor C3, the fourth capacitor C4 and the first resistor R1 constitute a negative feedback loop of the first operational amplifier N3, so that the first operational amplifier N3 can output a stable voltage, so as to avoid the influence of the fluctuation of the output signal on the entire regulation process.

[0172] Therefore, the present example can output the first signal based on the current of the backlight assembly 20 and the first reference signal by using the operational amplifier and other hardware. In addition, the hardware processing method in the present example is reliable and has a fast response speed, so as to improve the generation speed of the first driving signal, quickly regulate the constant current power supply signal, and further ensure the effectiveness of the regulation of the constant current power supply signal.

[0173] In some examples, continuing to refer to FIG. 13, the current feedback unit 162 can include an eleventh capacitor C11 and a sixteenth resistor R16;

[0174] One end of the eleventh capacitor C11 is connected with the non-inverting input terminal of the first operational amplifier N3, and the other end is grounded;

[0175] One end of the sixteenth resistor R16 is connected with the backlight assembly 20, and the other end is connected with one end of the eleventh capacitor C11 and the non-inverting input terminal of the first operational amplifier N3.

[0176] In this embodiment, the eleventh capacitor C11 is a filter capacitor, which can be used to improve the stability of the sampled signal representing the current of the backlight assembly 20. The sixteenth resistor R16 is a voltage dividing resistor, which can be used to regulate the signal input to the non-inverting input terminal of the first operational amplifier N3, so as to prevent the input voltage from being too large to damage the first operational amplifier N3.

[0177] The voltage feedback unit 163 will be described illustratively below.

[0178] In some embodiments, the voltage feedback unit 163 can include a second operational amplifier N4, a sixth diode D6, a second resistor R2, a fifth capacitor C5, and a sixth capacitor C6.

[0179] In some embodiments, the non-inverting input terminal of the second operational amplifier N4 is connected with the second secondary winding circuit 13, the inverting input terminal receives a second reference signal, and is connected with one end of the second resistor R2 and one end of the fifth capacitor C5, and the output terminal is connected with the anode of the sixth diode D6, the other end of the fifth capacitor C5, and the other end of the sixth capacitor C6; the cathode of the sixth diode D6 is connected with the isolation transmission unit 164 and the current feedback unit 162.

[0180] In some embodiments, the other end of the second resistor R2 is connected with the other end of the sixth capacitor C6.

[0181] In the present embodiment, the second operational amplifier N4 is similar to the first operational amplifier N3, has an operation function, and can generate a second signal based on a written algorithm and based on a signal representing the second supply voltage VO2 and a second reference signal. The second reference signal can be a fixed voltage. When the signal representing the second supply voltage VO2 is less than the second reference signal, the second signal can be reduced; otherwise, when the signal representing the second supply voltage VO2 is greater than the second reference signal, the second signal can be reduced.

[0182] Similarly, the sixth diode D6 can be used to prevent current reversal to improve the reliability of the circuit.

[0183] The fifth capacitor C5 and the sixth capacitor C6 and the second resistor R2 form a negative feedback loop of the second operational amplifier N4, so that the second operational amplifier N4 can output a stable voltage to avoid the influence of the fluctuation of the output signal on the entire adjustment process.

[0184] In other examples, continuing to refer to FIG. 13, the voltage feedback unit 163 can include a fifteenth resistor R15 and a first three-terminal voltage regulator N1'.

[0185] In some embodiments, continuing to refer to FIG. 13, one end of the fifteenth resistor R15 is connected with the inverting input terminal of the second operational amplifier N4, and the other end is connected with the anode of the first three-terminal voltage regulator N1' and grounded.

[0186] In some embodiments, the anode of the first three-terminal voltage regulator N1' receives a first reference voltage signal, and the cathode of the first three-terminal voltage regulator N1' is connected with the reference electrode.

[0187] In the example, when the first three-terminal voltage regulator N1' is powered on, the voltage of the reference electrode is set to a constant value. For example, the voltage is set to 2.5V. In the example, the reference electrode of the first three-terminal voltage regulator N1' is connected to the negative electrode. Thus, the voltage of the negative electrode is maintained at 2.5V, i.e., the second reference voltage signal is applied to the inverting input terminal of the second operational amplifier N4.

[0188] In some embodiments, still referring to FIG. 13, the isolation transmission unit 164 can include a second optocoupler element N5 and a sixteenth resistor R16. The primary input terminal of the second optocoupler element N5 is connected to the power supply processor 17, and the primary output terminal is grounded. The primary input terminal of the second optocoupler element 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. The primary output terminal is connected to the other end of the sixteenth resistor R16 and grounded.

[0189] In the example, the second optocoupler element N5 can be an optocoupler. The second optocoupler element N5 can generate a second feedback signal based on the first signal and the second signal.

[0190] In the working process, the first signal and the second signal can be current signals. When the sum of the first signal and the second signal increases, the voltage across the sixteenth resistor R16 increases, the voltage at the secondary input terminal of the second optocoupler element N5 increases, and the second feedback signal FB2 increases. The power supply processor 17 adjusts the duty cycle of the second drive signal based on the second feedback signal FB2. Conversely, when the sum of the first signal and the second signal decreases, the voltage across the sixteenth resistor R16 decreases, the voltage at the secondary input terminal of the second optocoupler element N5 decreases, and the second feedback signal FB2 decreases. It can be understood that the second feedback signal FB2 decreases, and the power supply processor 17 adjusts the duty cycle of the second drive signal based on the second feedback signal FB2.

[0191] In the example, the first signal and the second signal are transmitted to the power supply processor 17 through the second optocoupler element N5 and the sixteenth resistor R16. Thus, the module on the primary side of the transformer and the module on the secondary side of the transformer can be prevented from interfering with each other, and the power supply circuit 10 can further output a constant-current current supply signal.

[0192] On the basis of the above-described embodiments, still referring to FIG. 9, in another example, the power supply circuit 10 can further include a standby control module 18. The standby control module 18 is connected between the backlight assembly 20 and the ground. The standby control module 18 can be used to control the backlight assembly 20 to be grounded or disconnected from the ground based on a standby signal.

[0193] In the embodiment, when the display device is in the standby state, the path of the backlight assembly 20 is disconnected, so that the backlight assembly 20 does not generate a circulating current at this time, and the backlight assembly 20 does not consume power. Thus, in the embodiment, the on-off control of the backlight assembly 20 can be realized by the standby control module 18, so that the backlight assembly 20 can not consume power in the standby state, thereby reducing the energy consumption of the display device.

[0194] In an example, as shown in FIG. 9, the standby control module 18 can include a second switching element V2, a third switching element V3, a fourth switching element V4, and a seventeenth resistor R17.

[0195] The control end of the second switching element V2 receives the standby signal, the first end 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 can be used to be turned on when the standby signal is in the first state, and be turned off when the standby signal is in the second state.

[0196] The other end of the seventeenth resistor R17 is connected to the control end of the third switching element V3; the first end of the third switching element V3 receives the third reference voltage signal, and the second end of the third switching element V3 is connected to the control end of the fourth switching element V4; the third switching element V3 can be used to be turned on when the second switching element V2 is turned on, and be turned off when the second switching element V2 is turned off.

[0197] 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 be turned on when the third switching element V3 is turned on, and be turned off when the third switching element V3 is turned off.

[0198] In the example, the third reference voltage signal is a reference power supply signal. As an example, the first end of the third switching element V3 can be connected to the power supply circuit 10 to receive the first power supply voltage VO2, and the first power supply voltage VO2 is used as the third reference voltage signal. It should be noted that when the second end of the fourth switching element V4 is grounded, in one embodiment, the fourth switching element V4 can be directly grounded. In another embodiment, in combination with the example that the second feedback circuit 16 includes a current sampling unit, as shown in FIG. 9, the second end of the fourth switching element V4 can be connected to the current sampling unit, and the second end of the fourth switching element V4 is grounded through the current sampling unit.

[0199] The working principle of the present example will be described as follows: continuing to take the first state as high level and the second state as low level as an example, as shown in FIG. 9, when the standby signal is in the first state, the second switch element V2 is turned on, the first supply voltage VO2 provides the second reference level signal to the first end of the second switch element V2 through the first end and the control end of the third switch element V3, the second switch element V2 is turned on, the control end of the third switch element V3 is at high level, the third switch element V3 is turned on, the control end of the fourth switch element V4 is at high level, the fourth switch element V4 is turned on, and the backlight assembly 20 is grounded. When the standby signal is in the second state, the second switch element V2 is turned off, the control end of the third switch element V3 is at low level, the third switch element V3 is turned off, the control end of the fourth switch element V4 is at low level, the fourth switch element V4 is turned off, and the backlight assembly 20 is disconnected from the ground.

[0200] In the present example, the connection between the backlight assembly and the ground can be controlled according to the standby signal, thereby reducing the power consumption of the display device. In addition, the standby signal is smaller than the second reference level signal, thereby realizing the control of the small voltage element on the large voltage element.

[0201] In one example, continuing to refer to FIG. 9, the standby control module 18 can further include an eighteenth resistor R18, one end of the eighteenth resistor R18 receiving the standby signal, and the other end of the eighteenth resistor R18 being connected to the control end of the second switch element V2, wherein the eighteenth resistor R18 is a voltage dividing resistor for limiting the voltage of the control end of the second switch element V2.

[0202] In one example, continuing to refer to FIG. 9, the standby control module 18 can further include a twelfth capacitor C12 and a nineteenth resistor R19, one end of the nineteenth resistor R19 being connected to the control end of the second switch element V2, and the other end of the nineteenth resistor R19 being connected to the second end of the second switch element V2 and grounded; one end of the twelfth capacitor C12 being connected to one end of the nineteenth resistor R19, and the other end of the twelfth capacitor C12 being connected to the other end of the nineteenth resistor R19 and grounded. In the present example, the nineteenth resistor R19 can be used to pull down the voltage of the second end of the second switch element V2, so as to avoid the second end of the second switch element V2 being in a floating state when the second switch element V2 is turned off. The twelfth capacitor C12 can be used to filter the signal of higher frequency, so as to avoid the influence of the interference signal on the input standby signal.

[0203] In one example, continuing to refer to FIG. 9, the standby control module 18 can include: a twentieth resistor R20; one end of the twentieth resistor R20 is connected with the first end of the third switch element V3, and the other end of the twentieth resistor R20 is connected with the control end of the fourth switch element V4. In this example, the twentieth resistor R20 is a voltage dividing resistor, which can be used to limit the voltage of the control end of the fourth switch element V4.

[0204] In some embodiments, the standby control module 18 can also be included in FIG. 8, which works similarly to the example in FIG. 9, and will not be described here.

[0205] According to some embodiments of the present application, the first secondary winding circuit can be used to supply power to the main board, the second secondary winding circuit can output a second supply voltage based on the second primary voltage, and the third secondary winding circuit and the second secondary winding circuit can 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, the second secondary winding circuit and the third secondary winding circuit supply power to the backlight assembly together, which can reduce the difference between the output power of the first secondary winding circuit and the second secondary winding circuit, thereby improving the output power of the backlight assembly.

[0206] In other embodiments, according to some embodiments of the present application, a power supply circuit is provided, which can include: a primary winding circuit, a first secondary winding circuit, a second secondary winding circuit, and a third secondary winding circuit; the primary winding circuit can be configured to output a first primary voltage and a second primary voltage in time; the first secondary winding circuit can be coupled to the primary winding circuit and connected with a first load, and can be configured to output a first supply voltage to the first load based on the first primary voltage; the second secondary winding circuit can be coupled to the primary winding circuit and can be 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 with the second secondary winding circuit and a second load, and can be configured to generate a third supply voltage based on the second primary voltage and supply power to the second load based on the second supply voltage and the third supply voltage.

[0207] The power supply circuit in this embodiment works similarly to the power supply circuit of the display device in any of the above examples, and specific reference is made to any of the above embodiments, which will not be described here.

[0208] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as illustrative only, with the true scope and spirit of the application being indicated by the following claims.

[0209] It is to be understood that the application is not limited to the precise construction herein disclosed and shown in the drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. A power supply circuit, comprising: a primary winding circuit configured to output a first primary voltage and a second primary voltage in time division manner; a first secondary winding circuit coupled to the primary winding circuit and connected to a first load, and configured to output a first power supply voltage to the first load based on the first primary voltage; a second secondary winding circuit coupled to the primary winding circuit, and configured to output a second power supply voltage based on the second primary voltage; a third secondary winding circuit coupled to the primary winding circuit and connected to the second secondary winding circuit and a second load, and configured to generate a third power supply voltage based on the second primary voltage, and supply power to the second load based on the second power supply voltage and the third power supply voltage. 2.The power supply circuit of claim 1, wherein the third secondary winding circuit comprises: a charge-discharge unit; a third secondary winding coupled to the primary winding circuit and connected in series to the charge-discharge unit, and configured to output the third power supply voltage based on the second primary voltage; a path control unit coupled to the third secondary winding, the second secondary winding circuit and the second load, and configured to: connect the charge-discharge unit to a first path to supply power to the second load through the second power supply voltage and the third power supply voltage provided by the charge-discharge unit when the primary winding circuit outputs the first primary voltage; and connect the charge-discharge unit to a second path to charge the charge-discharge unit based on the third power supply voltage provided by the third secondary winding, and supply power to the second load through the second power supply voltage and the third power supply voltage provided by the third secondary winding when the primary winding circuit outputs the second primary voltage. 3.The power supply circuit of claim 2, wherein the path control unit comprises: a first diode having a positive electrode connected to one end of the charge-discharge unit and a negative electrode connected to the second load, and the other end of the charge-discharge unit connected to one end of the third secondary winding; a second diode having a positive electrode connected to an output end of the second secondary winding circuit and the other end of the third secondary winding, and a negative electrode connected to the second load; a third diode having a positive electrode connected to the output end of the second secondary winding circuit, and a negative electrode connected to one end of the charge-discharge unit and the positive electrode of the first diode; a fourth diode having a positive electrode connected to the output end of the second secondary winding circuit, and a negative electrode connected to the other end of the third secondary winding and the positive electrode of the second diode. 4.The power supply circuit of claim 2, wherein the path control unit comprises: a first diode having a positive electrode connected to one end of the charge-discharge unit and a negative electrode connected to the second load, and the other end of the charge-discharge unit connected to one end of the third secondary winding; a second diode, a positive electrode of the second diode being connected with an output end of the second auxiliary winding circuit and the other end of the third auxiliary winding, and a negative electrode of the second diode being connected with the second load; a third diode, a positive electrode of the third diode being grounded, and a negative electrode of the third diode being connected with one end of the charging and discharging unit and a positive electrode of the first diode; a fourth diode, a positive electrode of the fourth diode being connected with the output end of the second auxiliary winding circuit, and a negative electrode of the fourth diode being connected with the other end of the third auxiliary winding and a positive electrode of the second diode.

5. The power supply circuit according to claim 3 or 4, the second load comprising: a first light string, a negative electrode of the first diode being connected with a positive electrode of the first light string; a second light string, a negative electrode of the second diode being connected with a positive electrode of the second light string; the path control unit further comprising: a first capacitor, one end of the first capacitor being connected with the negative electrode of the first diode and the positive electrode of the first light string, and the other end of the first capacitor being grounded; a second capacitor, one end of the second capacitor being connected with the negative electrode of the second diode and the positive electrode of the second light string, and the other end of the second capacitor being grounded.

6. The power supply circuit according to any one of claims 1-4, the power supply circuit further comprising: a first feedback circuit, an input end of the first feedback circuit being connected with the output end of the first auxiliary winding circuit, and an output end of the first feedback circuit being connected with the power supply processor, the first feedback circuit being configured to output a first feedback signal to the power supply processor based on the first power supply voltage; a second feedback circuit, an input end of the second feedback circuit being connected with the output end of the first auxiliary winding circuit and the second load, and an output end of the second feedback circuit being connected with the power supply processor, the second feedback circuit being configured to output a second feedback signal to the power supply processor based on the second power supply voltage and a current flowing through the second load; a power supply processor, the power supply processor being connected with the primary winding circuit, and the power supply processor being configured to output a first driving signal and a second driving signal to the output of 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 driving signal and the second driving signal.

7. The power supply circuit according to claim 6, the second feedback circuit comprising: a dimming unit, the dimming unit receiving a dimming signal and a first reference voltage signal, and the dimming unit being configured to generate a first reference signal based on the dimming signal and the first reference voltage signal; a current feedback unit, the current feedback unit being connected with the dimming unit and the second load, and the current feedback unit receiving the first reference signal, and the current feedback unit being configured to output a first signal based on a comparison result of a current flowing through the second load and the first reference signal; a voltage feedback unit, the voltage feedback unit being connected with the second auxiliary winding circuit, and the voltage feedback unit receiving a second reference signal, and the voltage feedback unit being configured to output a second signal based on a comparison result of the second power supply voltage and the second reference signal. An isolation transmission unit, connected with the current feedback unit and the voltage feedback unit, configured to generate the second feedback signal based on the first signal and the second signal.

8. The power supply circuit of claim 7, the current feedback unit comprising: a first operational amplifier, a fifth diode, a third capacitor, a fourth capacitor and a first resistor; a non-inverting input terminal of the first operational amplifier is connected with the second load, an inverting input terminal is connected with the dimming unit, one end of the third capacitor and one end of the first resistor, and an output terminal is connected with a positive electrode of the fifth diode, the other end of the third capacitor and the other end of the fourth capacitor; a negative electrode of the fifth diode is connected with the isolation transmission unit and the voltage feedback unit; the other end of the first resistor is connected with one end of the fourth capacitor.

9. The power supply circuit of claim 6, the voltage feedback unit comprising: a second operational amplifier, a sixth diode, a second resistor, a fifth capacitor and a sixth capacitor; a non-inverting input terminal of the second operational amplifier is connected with the second secondary winding circuit, an inverting input terminal receives a second reference signal and is connected with one end of the second resistor and one end of the fifth capacitor, and an output terminal is connected with a positive electrode of the sixth diode, the other end of the fifth capacitor and the other end of the sixth capacitor; a negative electrode of the sixth diode is connected with the isolation transmission unit and the current feedback unit; the other end of the second resistor is connected with the other end of the sixth capacitor.

10. A display device comprising: a first load, a second load and the power supply circuit according to any one of claims 1-9.

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