WO2023201988A1 - 显示装置 - Google Patents

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Publication number
WO2023201988A1
WO2023201988A1 PCT/CN2022/121412 CN2022121412W WO2023201988A1 WO 2023201988 A1 WO2023201988 A1 WO 2023201988A1 CN 2022121412 W CN2022121412 W CN 2022121412W WO 2023201988 A1 WO2023201988 A1 WO 2023201988A1
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WO
WIPO (PCT)
Prior art keywords
voltage
switch
module
energy storage
light string
Prior art date
Application number
PCT/CN2022/121412
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English (en)
French (fr)
Other versions
WO2023201988A9 (zh
Inventor
庞震华
Original Assignee
海信视像科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Priority claimed from CN202210412214.4A external-priority patent/CN116963353A/zh
Priority claimed from CN202210415138.2A external-priority patent/CN116959379A/zh
Priority claimed from CN202210421396.1A external-priority patent/CN116978312A/zh
Application filed by 海信视像科技股份有限公司 filed Critical 海信视像科技股份有限公司
Publication of WO2023201988A1 publication Critical patent/WO2023201988A1/zh
Publication of WO2023201988A9 publication Critical patent/WO2023201988A9/zh

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits

Definitions

  • the present application relates to the technical field of display devices, and in particular, to a display device.
  • a resonant conversion circuit (LLC) module is used to output multiple DC voltages based on AC power to power the mainboard and the light string respectively.
  • each light string corresponds to a DC-DC voltage adjustment module, which adjusts the fixed DC voltage output by the LLC module to meet the voltage requirements of the light string.
  • two LLC modules are used to power the mainboard and the light string respectively.
  • the present application provides a display device to simplify the power supply circuit of the display device.
  • the present application provides a display device, including: a transformer, a voltage conversion module, a feedback module and a light string group; wherein the voltage conversion module corresponds to the light string group one-to-one, and the light string group includes a first light string and a second light string;
  • the first secondary coil and the second secondary coil of the transformer are coupled with the primary coil of the transformer; the first secondary coil is used to output the first voltage according to the power received by the primary coil; the second secondary coil is used to output the first voltage according to the power received by the primary coil.
  • the power received by the primary coil alternately outputs the second voltage from both ends of the second secondary coil; the second secondary coil corresponds to the light string group one-to-one; the voltage conversion module is used to generate a superimposed voltage according to the first voltage and The superimposed voltage is superimposed to the second voltage at both ends of the corresponding second secondary coil, and the superimposed third voltage is output; the feedback module is used to generate a feedback signal according to the output current of the light string group and send it to the voltage conversion module to feedback the signal It is used to instruct the voltage conversion module to adjust the third voltage; the first light string is connected to one end of the corresponding second secondary coil, and the second light string is connected to the other end of the corresponding second secondary coil for emitting light based on the third voltage.
  • Figure 1 is a schematic structural diagram of a display device equipped with an independent power board
  • Figure 2 is a schematic diagram of the connection relationship between the power board and the load of the display device
  • FIG. 3 is a schematic diagram of the TV power supply architecture
  • Figure 4 is a schematic diagram of a circuit structure that supplies power to the mainboard and LED light string
  • Figure 5 is a schematic diagram of another circuit structure that supplies power to the mainboard and LED light string
  • Figure 6 is a schematic diagram of another circuit structure that supplies power to the mainboard and LED light string
  • Figure 7 is a schematic circuit structure diagram of a two-way light string display device according to an embodiment of the present application.
  • Figure 8 is a schematic circuit structure diagram of a voltage conversion module according to an embodiment of the present application.
  • Figure 9 is a schematic circuit structure diagram of a voltage superposition module according to an embodiment of the present application.
  • Figure 10 is a schematic circuit structure diagram of a voltage adjustment module according to an embodiment of the present application.
  • Figure 11 is a schematic circuit structure diagram of another voltage adjustment module according to an embodiment of the present application.
  • Figure 12 is a schematic circuit structure diagram of a first switch circuit according to an embodiment of the present application.
  • Figure 13 is a schematic circuit structure diagram of a second switch circuit according to an embodiment of the present application.
  • Figure 14 is a schematic circuit structure diagram of a four-way light string display device according to an embodiment of the present application.
  • Figure 15 is a schematic circuit structure diagram of another four-way light string display device according to an embodiment of the present application.
  • Figure 16 is a schematic circuit structure diagram of yet another four-way light string display device according to an embodiment of the present application.
  • Figure 17 is a schematic circuit structure diagram of another four-way light string display device according to an embodiment of the present application.
  • Figure 18 is a schematic structural diagram of a power supply circuit that supplies power to the main board and LED light string;
  • Figure 19 is a schematic structural diagram of another power supply circuit that supplies power to the mainboard and LED light string;
  • Figure 20 is a schematic structural diagram of another power supply circuit that supplies power to the main board and LED light string;
  • Figure 21 is a schematic diagram of the power supply mode of an external adapter according to an embodiment of the present application.
  • Figure 22 is a schematic structural diagram of a power supply circuit of a display device according to an embodiment of the present application.
  • Figure 23 is a schematic structural diagram of a power supply circuit of another display device according to an embodiment of the present application.
  • Figure 24 is a schematic structural diagram of a power supply circuit of a charge pump module according to an embodiment of the present application.
  • Figure 25 is a schematic structural diagram of the power supply circuit of another display device according to an embodiment of the present application.
  • Figure 26 is a schematic structural diagram of the power supply circuit of a flyback isolation transformer module according to an embodiment of the present application.
  • Figure 27 is a schematic structural diagram of a level conversion circuit according to an embodiment of the present application.
  • Figure 28 is a schematic structural diagram of a level conversion circuit based on a charge pump module power supply circuit according to an embodiment of the present application
  • Figure 29 is a schematic structural diagram of a level conversion circuit based on a flyback isolation transformer module power supply circuit according to an embodiment of the present application.
  • Figure 30 is a schematic structural diagram of a circuit that supplies power to a mainboard according to an embodiment of the present application.
  • Figure 31 is a schematic structural diagram of another circuit that supplies power to a mainboard according to an embodiment of the present application.
  • Figure 32 is a schematic structural diagram of a power supply circuit of a display device according to an embodiment of the present application.
  • Figure 33 is a schematic structural diagram of the power supply circuit of another display device according to an embodiment of the present application.
  • Figure 34 is a schematic structural diagram of the power supply circuit of a charge pump module according to an embodiment of the present application.
  • Figure 35 is a schematic structural diagram of the power supply circuit of another charge pump module according to an embodiment of the present application.
  • Figure 36 is a schematic structural diagram of the power supply circuit of yet another charge pump module according to an embodiment of the present application.
  • Figure 37 is a schematic structural diagram of the power supply circuit of another charge pump module according to an embodiment of the present application.
  • Figure 38 is a schematic structural diagram of the power supply circuit of another display device according to an embodiment of the present application.
  • Figure 39 is a schematic structural diagram of the power supply circuit of a flyback isolation transformer module according to an embodiment of the present application.
  • Figure 40 is a schematic structural diagram of the power supply circuit of another flyback isolation transformer module according to an embodiment of the present application.
  • Figure 41 is a schematic structural diagram of a filter module according to an embodiment of the present application.
  • Figure 42 is a schematic structural diagram of a filter module based on a charge pump module power supply circuit according to an embodiment of the present application
  • Figure 43 is a schematic structural diagram of a filter module based on a flyback isolation transformer module power supply circuit according to an embodiment of the present application
  • Figure 44 is a schematic structural diagram of a circuit that supplies power to a mainboard according to an embodiment of the present application.
  • Figure 45 is a schematic structural diagram of another circuit that supplies power to a mainboard according to an embodiment of the present application.
  • the power supply circuit is one of the most important circuit structures in the display device.
  • the power supply circuit can provide power to the display device so that the display device can operate normally.
  • Some display devices are equipped with an independent power board, and some display devices combine the power board and the main board into one.
  • FIG. 1 is a schematic structural diagram of a display device equipped with an independent power supply board.
  • the display device includes Display panel 1, backlight assembly 2, motherboard 3, power board 4, rear case 5 and base 6.
  • the display panel 1 is used to present images to the user;
  • the backlight component 2 is located below the display panel 1 and is usually some optical components used to supply sufficient brightness and uniformly distributed light sources so that the display panel 1 can display images normally.
  • the component 2 also includes a back plate 20, on which the main board 3 and the power board 4 are arranged.
  • Some convex structures are usually punched on the back plate 20, and the main board 3 and the power board 4 are fixed on the convex structures through screws or hooks;
  • the back shell 5 is covered on the panel 1 to hide the backlight assembly 2, the motherboard 3, the power board 4 and other components of the display device, making the appearance more beautiful;
  • the base 6 is used to support the display device.
  • Figure 2 is a schematic diagram of the connection relationship between the power board and the load of the display device.
  • the power board 4 includes an input terminal 41 and an output terminal 42 (the figure shows a first output terminal 421, a first output terminal 421 and a second output terminal 42).
  • the second output terminal 422 and the third output terminal 423) wherein the input terminal 41 is connected to the mains, and the output terminal 42 is connected to the load.
  • the first output terminal 421 is connected to an LED light string used to light up the display screen.
  • the second output terminal 422 is connected to the speaker, and the third output terminal 423 is connected to the motherboard.
  • the power board 4 needs to convert the AC mains power into the DC power required by the load, and the DC power usually has different specifications, for example, the speaker requires 18V, the panel requires 12V, etc.
  • a TV is used as an example to introduce the power supply architecture of the display device.
  • Figure 3 is a schematic diagram of the power supply architecture of the TV.
  • the power board may specifically include: a rectifier bridge, a power factor correction (Power Factor Correction, PFC) module and a resonant converter (LLC) module, the LLC module includes a synchronous rectifier circuit (not shown in Figure 3), the PFC module is connected to the LLC module, and the LLC module is connected to the load.
  • PFC Power Factor Correction
  • LLC resonant converter
  • the rectifier bridge is used to rectify the input AC power and input full-wave signals to the PFC module.
  • An electromagnetic interference (EMI) filter (not shown in Figure 3) can be connected before the AC power is input to the PFC module to perform high-frequency filtering on the input AC power.
  • EMI electromagnetic interference
  • the PFC module can include a PFC inductor, switching power device and PFC control chip. It mainly performs power factor correction on the input AC power supply and outputs a stable DC bus voltage (such as 380V) to the LLC module.
  • the PFC module can effectively improve the power factor of the power supply and ensure that the voltage and current are in the same phase.
  • the PFC module may not be provided in the power supply architecture as shown in FIG. 3 .
  • the LLC module can use a dual MOS tube LLC resonant conversion circuit.
  • the synchronous rectification circuit is set up in the LLC module.
  • the synchronous rectification circuit mainly includes a transformer, a controller, two MOS tubes and a diode.
  • the LLC module can also include components such as pulse frequency modulation (PFM) circuits, capacitors, and inductors.
  • PFM pulse frequency modulation
  • the LLC module can step down or boost the DC bus voltage input by the PFC module and output a constant voltage to the load.
  • LLC modules can output a variety of different voltages to meet the needs of different loads.
  • the LLC module shown in Figure 3 can also be replaced by a flyback voltage conversion module, which steps down or boosts the voltage and outputs a constant voltage to the load.
  • FIG. 4 is a schematic structural diagram of a power supply circuit that supplies power to a mainboard and an LED light string.
  • the mains alternating current (100V-240V, 50-60Hz) obtained by the power supply circuit passes through the filter rectifier module (rectifier bridge), PFC module and LLC isolation voltage conversion module in sequence, and then supplies it to the mainboard of the display device, multi-channel LED light strings and other The load (not shown in Figure 4) is powered.
  • the first secondary winding in the LLC isolation voltage conversion module provides the first voltage (for example, 12V) to the main board
  • the second secondary winding provides the second voltage (for example, 18V) to the main board
  • the third secondary winding simultaneously Provide voltage to multiple LED light strings.
  • the LED light string is used to light up the display screen of the TV.
  • the LED components in the LED light string need to work within a certain voltage drop range to reach its rated current.
  • a multi-channel LED light string is a 16-channel LED light string.
  • the voltage range required by the multi-channel LED light string is 51.3V-58.5V, and the total current is 1.92A.
  • the power supply circuit is also provided with a voltage adjustment module (a buck circuit, a boost circuit, or a buck-boost circuit).
  • a voltage adjustment module (a buck circuit, a boost circuit, or a buck-boost circuit).
  • the working voltage or working current of the LED light string can be detected, and a feedback signal is sent to the voltage adjustment module according to the change of the working voltage or working current, so that the voltage adjustment module can adjust the voltage output to the LED light string according to the feedback signal. This maintains the stability of the operating current of the LED light string.
  • each LED light string is configured with a voltage adjustment module using a boost circuit as an example.
  • the voltage adjustment module can adjust the fixed voltage output by the third secondary winding according to the real-time current feedback result of each LED light string and then transmit it to each LED light string, so that each LED light string operates at the rated current to prevent over-current. High current flows through the LED components in the LED light string, causing damage to the components.
  • Figure 5 is a schematic structural diagram of another circuit that supplies power to the mainboard and LED light strings.
  • the mains alternating current (100V-240V, 50-60Hz) obtained by the power supply circuit passes through the filter rectifier module (rectifier bridge) in turn. , PFC module and LLC isolation voltage conversion module, then supply power to the mainboard of the display device, multi-channel LED light strings and other loads (not shown in Figure 5).
  • the first secondary winding in the LLC isolation voltage conversion module 1 provides the first voltage (for example, 12V) to the main board, and the second secondary winding provides the second voltage (for example, 18V) to the main board; the LLC isolation voltage conversion module 2 To provide voltage to two LED light strings at the same time.
  • the LLC isolation voltage conversion module 2 uses the characteristics of alternating current to alternately provide operating voltage for the two LED light strings. Among them, the controller of the LLC isolation voltage conversion module 2 receives the current feedback of the two LED light strings, then adjusts the voltage output by the LLC isolation voltage conversion module 2, and transmits the adjusted voltage to the two LED light strings, so that each Street LED light strings operate at rated current to prevent excessive current from flowing through the LED components in the LED light string and causing component damage.
  • a capacitor connected to an output end of the secondary winding of the LLC isolation voltage conversion module 2 plays a role in current sharing and is used to equalize the operating currents of the two LED light strings; the two output ends of the secondary winding are connected to the LED
  • the diodes connected in series between the light strings play a rectifying role based on the one-way conduction characteristics; the grounded diodes connected to the two output ends of the secondary winding play a voltage stabilizing role.
  • the output voltage range of the LLC isolation voltage conversion module 2 is limited.
  • the display device may have more than two LED light strings. According to the power supply circuit shown in Figure 5, for each additional two LED light strings, a secondary winding needs to be added to the LLC isolation voltage conversion module 2. Power the newly added LED string lights. A large number of secondary windings will make transformer design relatively difficult, and the cost of complex circuits will be high.
  • FIG. 6 is a schematic diagram of yet another circuit structure that supplies power to the mainboard and the LED light string.
  • the mains alternating current (100V-240V, 50-60Hz) obtained by the power supply circuit passes through the filter rectifier module (rectifier bridge), PFC module and LLC isolation voltage conversion module in sequence, and then supplies it to the mainboard of the display device, multi-channel LED light strings and other The load (not shown in Figure 6) is powered.
  • the LLC isolation voltage conversion module includes four secondary windings, the first secondary winding provides a first voltage (for example, 12V) to the mainboard, the second secondary winding provides a second voltage (for example, 18V) to the mainboard; the second secondary winding provides the mainboard with a first voltage (for example, 12V);
  • the first secondary winding and the third secondary winding jointly supply power to the second LED light string; the second secondary winding and the fourth secondary winding jointly supply power to the first LED light string.
  • the 18V voltage output by the second secondary winding passes through a voltage adjustment module taking a boost circuit as an example to generate a "fluctuating voltage", which is connected to one end of the third secondary winding and connected to the third secondary winding.
  • a fixed voltage 2 is generated for superposition, and the superimposed voltage supplies power to the second LED light string.
  • the 18V voltage output by the second secondary winding passes through the voltage adjustment module taking the boost circuit as an example to generate a "fluctuating voltage", which is connected to one end of the fourth secondary winding and connected with the fourth secondary winding.
  • a fixed voltage 1 is generated for superposition, and the superposed voltage supplies power to the first LED light string.
  • the superimposed power supply method of "variable voltage” and “fixed voltage” is called “ladder power supply”, which is beneficial to reducing the withstand voltage value of switching tubes, capacitors and other components in the voltage adjustment module. requirements, thereby reducing costs.
  • laser power supply the superimposed power supply method of "variable voltage” and “fixed voltage” is called “ladder power supply”, which is beneficial to reducing the withstand voltage value of switching tubes, capacitors and other components in the voltage adjustment module. requirements, thereby reducing costs.
  • laser power supply the superimposed power supply method of "variable voltage” and “fixed voltage” is called “ladder power supply”
  • two LED light strings share a secondary coil and a voltage conversion module, in which both ends of the secondary coil alternately output a "fixed voltage” and superimpose the “variable voltage” output by the voltage conversion module. , to achieve “ladder power supply” to two LED light strings. It can not only simplify the power supply circuit, but also reduce heat loss.
  • FIG. 7 is a schematic circuit structure diagram of a two-way light string display device according to an embodiment of the present application. As shown in Figure 7, it includes: a transformer, a voltage conversion module, a feedback module and a light string group; wherein the voltage conversion module corresponds to the light string group one-to-one, and the light string group includes a first light string 140 and a second light string 150;
  • the LLC isolation voltage conversion module is used as an example of the transformer.
  • the first secondary coil 110 and the second secondary coil 120 of the LLC isolation voltage conversion module are coupled with the primary coil 100 of the LLC isolation voltage conversion module; the first secondary coil 110, for outputting the first voltage according to the power received by the primary coil 100; the second secondary coil 120, for outputting the second voltage alternately from both ends of the second secondary coil 120 according to the power received by the primary coil 100;
  • the second secondary coil 120 corresponds to the light string group one-to-one;
  • the voltage conversion module is used to generate a superimposed voltage according to the first voltage and superimpose the superimposed voltage to the second voltage at both ends of the corresponding second secondary coil, and output the superimposed voltage.
  • the third voltage is used to generate a superimposed voltage according to the first voltage and superimpose the superimposed voltage to the second voltage at both ends of the corresponding second secondary coil, and output the superimposed voltage.
  • a feedback module is used to generate a feedback signal according to the output current of the light string group and send it to the voltage conversion module.
  • the feedback signal is used to instruct the voltage conversion module to adjust the third voltage;
  • the first light string 140 is connected to the corresponding second secondary coil 120
  • One end of the second light string 150 is connected to the other end of the corresponding second secondary coil 120 for emitting light based on the third voltage.
  • the power supply circuit shown in Figure 7 also includes a filter rectifier module (rectifier bridge) and a PFC module, which process the obtained mains alternating current, and then supply it to the mainboard of the display device and the multi-channel LED light string through the LLC isolation voltage conversion module. and other loads (not shown in Figure 7).
  • a filter rectifier module rectififier bridge
  • PFC module PFC module
  • first secondary coil 110 One end of the first secondary coil 110 is grounded, a middle tap of the first secondary coil 110 and the other end of the first secondary coil 110 are connected in series with a rectifier diode to output the first voltage.
  • the first voltage is 18V DC voltage as an example. Because the first secondary coil 110 is coupled with the primary coil 100 to induce alternating current, the AC-DC conversion needs to be performed through the above-mentioned rectifier circuit.
  • This embodiment uses the alternating current induced by the coupling between the second secondary coil 120 and the primary coil 100 to alternately output a second voltage from both ends of the second secondary coil, which is equivalent to a "fixed voltage”; the voltage conversion module converts the voltage according to the feedback signal.
  • the first voltage output by the first secondary coil is adjusted to generate a superimposed voltage, which is equivalent to a "variable voltage”; the voltage conversion module superimposes the superimposed voltage to a second voltage and outputs a superimposed third voltage.
  • the two light strings share the same power supply coil and voltage conversion module, which simplifies the circuit; at the same time, the voltage superposition of "fixed voltage” and “variable voltage” is used to realize ladder power supply, which is beneficial to reducing heat loss.
  • the feedback module can be a current feedback method or a voltage feedback method.
  • the feedback module can generate a feedback signal based on the current of a single light string, or can generate a feedback signal based on the current of multiple light strings.
  • the reference current value set in the feedback module is the required operating current of one light string.
  • the reference current value set in the feedback module is twice the required operating current of one light string.
  • the reference current value is used to compare with the actual current. If the actual current is higher than the reference current value, the output feedback signal instructs the voltage adjustment module to reduce the third voltage; if the actual current is equal to the reference current value, the output feedback signal indicates the voltage.
  • the adjustment module maintains the third voltage; if the actual current is lower than the reference current value, the output feedback signal instructs the voltage adjustment module to increase the third voltage.
  • Figure 7 adopts the method of common feedback between two light strings.
  • the feedback module generates a feedback signal according to the total current of the first light string 140 and the second light string 150 in the light string group, and sends it to the voltage conversion module to instruct the voltage conversion module to adjust the third voltage.
  • the first light string 140 and the second light string 150 may be directly grounded or grounded through a ground circuit Rn.
  • the grounding circuit Rn is conducive to releasing static electricity and avoiding the accumulation of static electricity.
  • FIG. 8 is a schematic circuit structure diagram of a voltage conversion module according to an embodiment of the present application.
  • the voltage conversion module includes: a voltage adjustment module and a voltage superposition module; the voltage adjustment module is connected to the output end of the first secondary coil and is used to generate a superimposed voltage according to the first voltage; the voltage superposition module receives the superimposed voltage and communicates it with the second The two ends of the primary coil are connected to superimpose the superimposed voltage to the second voltage at both ends of the corresponding second secondary coil, and output the superimposed third voltage; where the feedback signal is used to instruct the voltage adjustment module to adjust the superimposed voltage. Adjust the third voltage.
  • the second voltage is equivalent to the "fixed voltage”; the voltage adjustment module adjusts the first voltage according to the feedback signal and outputs a superimposed voltage, and the superimposed voltage is equivalent to the "variable voltage”.
  • the voltage superposition module superimposes the superimposed voltage to the second voltage, and outputs the superimposed third voltage to power the light string group.
  • the ladder power supply method is adopted, which is beneficial to reducing heat loss.
  • the voltage superposition module includes a first current sharing capacitor C1, a first rectifier diode D1, a second rectifier diode D2, a third rectifier diode D3, and a fourth rectifier diode D4;
  • One end of the first current sharing capacitor C1 is connected to one end of the second secondary coil; the other end of the first current sharing capacitor C1 is connected to the anode of the first rectifier diode D1 and the cathode of the second rectifier diode D2;
  • the positive electrode is connected to the superimposed voltage;
  • the negative electrode of the first rectifier diode D1 is connected to the positive electrode of the first light string 140; the negative electrode of the first light string 140 is connected to ground;
  • the anode of the third rectifier diode D3 is connected to the other end of the second secondary coil 120 and the cathode of the fourth rectifier diode D4.
  • the anode of the fourth rectifier diode D4 is connected to the superposed voltage; the cathode of the third rectifier diode D3 is connected to the second light string.
  • the positive terminal of 150 is connected; the negative terminal of the second light string 150 is grounded.
  • Figure 9 is a schematic circuit structure diagram of a voltage superposition module according to an embodiment of the present application.
  • the primary coil 100 is turned on and off under the internal control of the LLC isolation voltage conversion module, the first current sharing capacitor C1 performs charging and discharging processes respectively.
  • the current flows from the first end of the first current sharing capacitor C1 (that is, the left end of the first current sharing capacitor C1 shown in Figure 10) to the second end (that is, the first current sharing capacitor C1 shown in Figure 10). (the right end of the current capacitor C1) flows, and the electricity in the first current sharing capacitor C1 is released through the loop of the first light string 140.
  • the superimposed voltage output by the voltage adjustment module passes through the second rectifier diode D2 and is input to the anode of the first rectifier diode D1.
  • Current superposition occurs on the anode of the first rectifier diode D1, and is input to the cathode of the first rectifier diode D1. 140 for one light string.
  • the third rectifier diode D3 When the first current sharing capacitor C1 is charging, current flows from the second end of the first current sharing capacitor C1 to the first end, the third rectifier diode D3 is turned on, and the electricity in the first current sharing capacitor C1 passes through the second light string. 150 loop release. At the same time, the superimposed voltage output by the voltage adjustment module passes through the fourth rectifier diode D4 and is input to the anode of the third rectifier diode D3. Current superposition occurs at the anode of the third rectifier diode D3, and is input to the cathode of the third rectifier diode D3. 150 for two light strings.
  • the charges flowing through the two light strings are equal, which in turn makes the currents of the two light strings equal, thereby achieving current sharing for the two light strings. If the currents of the two light strings are not equal, a voltage difference will occur on the first current sharing capacitor C1, so that the loop voltage drops of the first light string 140 and the second light string 150 are the same, that is, the impedances are balanced. After a few cycles, the currents reach an equal equilibrium state again. Therefore, over a long period of time, the currents of the two LED strings are equal.
  • the loop where the first light string 140 is located includes the first rectifier diode D1, the first light string 140, the feedback module, the voltage adjustment module, the fourth rectifier diode D4, and the second side winding 120; the loop where the second light string 150 is located
  • the circuit includes the second side winding 120, the third rectifier diode D3, the second light string 150, the feedback module, the voltage adjustment module, and the second rectifier diode D2.
  • the two light strings share the same power supply coil (i.e., the second secondary coil 120) and the voltage adjustment module, which simplifies the circuit; at the same time, two rectifier diodes are used for voltage superposition to realize ladder power supply for each light string. , which is beneficial to reducing heat loss.
  • the voltage adjustment module may be a boost circuit.
  • the voltage adjustment module includes: a first inductor L1, a first transistor Q1, a first diode D5, and a first capacitor C2.
  • One end of the first inductor L1 is connected to the output end of the first secondary coil 110; the other end of the first inductor L1 is connected to one end of the first transistor Q1 and the anode of the first diode D5; the other end of the first transistor Q1 Grounded; the cathode of the first diode D5 is used as the output terminal of the voltage adjustment module to output the superimposed voltage;
  • one end of the first capacitor C2 is connected to the cathode of the first diode D5; the other end of the first capacitor C2 is grounded; the first The control electrode of the transistor Q1 is connected to the feedback module, and is used to adjust the switching frequency of the first transistor Q1 according to the feedback signal to adjust the superimposed voltage.
  • Figure 10 is a schematic circuit structure diagram of a voltage adjustment module according to an embodiment of the present application.
  • the output terminal of the first secondary coil 110 continues to output the first voltage to charge the first inductor L1, so that the current of the first inductor L1 increases linearly.
  • the first inductor L1 can only discharge through the first diode D5, and outputs a superimposed voltage from the cathode of the first diode D5 to the second rectifier diode D2 and the fourth rectifier diode D4. At the same time, The first capacitor C2 is charged; both ends of the capacitor rise and are higher than the input first voltage.
  • the first transistor Q1 When the first transistor Q1 is turned on again, the first inductor L1 is charged again; at the same time, due to the unidirectional conductivity of the first diode D5, the first capacitor C2 is discharged and rectified to the second rectifier diode D2 and the fourth rectifier diode D5. Diode D4 outputs the superimposed voltage.
  • the switching frequency of the first transistor Q1 By controlling the switching frequency of the first transistor Q1 or selecting the first capacitor C2 with a larger capacity, it is possible to continuously output a superimposed voltage, and the superimposed voltage is higher than the input first voltage.
  • the other end of the first transistor Q1 can be directly connected to the ground, or can also be connected to the ground resistor R1 to discharge static electricity and improve safety.
  • Figure 10 adopts a current feedback method.
  • the feedback module includes a first driver chip, which is used to collect the actual total current of the first light string 140 and the second light string 150 in real time and generate a feedback signal, so that the voltage adjustment module adjusts the voltage in a timely and effective manner. Adjust to prevent excessive current from flowing through the LED components in the first light string 140 and the second light string 150 and causing damage to the components.
  • the voltage adjustment module may be a buck circuit.
  • the voltage adjustment module includes: a second transistor Q2, a third transistor Q3, a second inductor L2, a second capacitor C2, and a second driver chip.
  • One end of the second transistor Q2 is connected to the output end of the first secondary coil 110; the other end of the second transistor Q2 is connected to one end of the third transistor Q3 and one end of the second inductor L2; the other end of the third transistor Q3 is connected to ground;
  • the other end of the second inductor L2 serves as the output end of the voltage adjustment module and outputs the superimposed voltage; one end of the second capacitor C2 is connected to the other end of the second inductor L2; the other end of the second capacitor C2 is connected to ground; the control of the second transistor Q2
  • the control electrode of the second transistor Q2 and the control electrode of the third transistor Q3 are both connected to the feedback module, which is used to adjust the switching frequency of the second transistor Q2 and the third transistor Q3 according to the feedback signal to adjust
  • FIG. 11 is a schematic circuit structure diagram of another voltage adjustment module according to an embodiment of the present application.
  • the voltage adjustment module is a synchronous rectifier buck circuit.
  • Using the third transistor Q3 instead of the rectifier diode is beneficial to improving the voltage conversion efficiency.
  • the output terminal of the first secondary coil 110 continues to output the first voltage to charge the second inductor L2, so that the current of the second inductor L2 increases linearly.
  • the second rectifier diode D2 and the fourth rectifier diode D4 output a superposed voltage and simultaneously charge the third capacitor C3.
  • the second inductor L2 freewheels and discharges through the third transistor Q3, and the current of the second inductor L2 decreases linearly. At this time, the current through the third capacitor C3 and the gradually decreasing The second inductor L2 outputs a superimposed voltage to the second rectifier diode D2 and the fourth rectifier diode D4.
  • the superimposed voltage can be continuously output, and the superimposed voltage is lower than the input first voltage.
  • the other end of the third transistor Q3 can be directly connected to the ground, or can also be connected to the ground resistor R2 to discharge static electricity and improve safety.
  • the voltage adjustment module when the synchronous rectification buck circuit shown in Figure 11 is used, the voltage adjustment module further includes a second diode D6; the cathode of the second diode D6 is connected to one end of the third capacitor C3; The anode of the second diode D6 is connected to the other end of the third capacitor C3.
  • the second transistor Q2 When the voltage adjustment module has no output, the second transistor Q2 is turned off, and the current of the light string group flows back to the second secondary coil 120 through the body diode of the third transistor Q3, the second inductor L2, and the fourth current sharing diode D4.
  • the current When the current is too large, it will cause more heat loss on the body diode of the third transistor Q3.
  • the second diode D6 is used to form a new current loop, so that the current of the light string group is passed through the second diode.
  • the diode D6 and the fourth current sharing diode D4 flow back to the second secondary coil 120 .
  • the second diode D6 is a low-power diode such as a Schottky diode.
  • the aforementioned buck topology and boost topology can be selected according to engineering needs.
  • the buck topology has the advantage of low cost, but the output voltage range is narrow; while the boost topology has the advantage of a wide output voltage range, but its cost is relatively high. .
  • the display device in some embodiments further includes a first switch circuit and a first ground resistor R3; the first switch circuit is located between the light string group and the first ground resistor R3; one end of the first switch circuit is connected to the first light string.
  • the negative electrode is connected to the negative electrode of the second light string, and the other end of the first switch circuit is connected to one end of the first ground resistor R3 and the input end of the feedback module; the other end of the first ground resistor R3 is connected to the ground; the first switch circuit, based on the The air ratio control signal is turned on or off.
  • FIG. 12 is a schematic circuit structure diagram of a first switch circuit according to an embodiment of the present application.
  • the voltages of multiple secondary coils may have cross-regulation issues.
  • the cross regulation rate refers to the impact on the output voltage of a certain channel when other channels are loaded. For example, when the load of the output voltage of the third secondary coil 130 is heavier, the output voltages of the first secondary coil 110 and the second secondary coil 120 will be increased. As a result, when the voltage conversion module is not working, the second voltage output by the second secondary coil 120 exceeds the operating voltage of the light string group, which causes the light string group to be naturally lit. That is, the lighting and turning off of the light string group are uncontrolled.
  • the display device when the display device is in the standby state, the display screen of the display device is usually turned off, that is, the light string group should be in the off state.
  • the duty cycle control signal ie, the PWM control signal shown in Figure 12
  • the control signal of the display device status can be synchronized, that is, when the display device is controlled to the standby state, the light string group is synchronously occupied.
  • the ratio control signal controls it to a non-luminous state.
  • the first switch circuit includes: a fourth transistor Q4; one end of the fourth transistor Q4 is connected to the negative electrode of the first light string 140 and the second light string 150; the other end of the fourth transistor Q4 is connected to the negative electrode of the first light string 140 and the second light string 150.
  • One end of a ground resistor R3 is connected to the input end of the feedback module; the gate of the fourth transistor Q4 is connected to the duty cycle control signal, and the fourth transistor is turned on or off based on the duty cycle control signal. Referring to Figure 12, when the PWM control signal is low level, the fourth transistor Q4 is turned off, so the light string group does not light up.
  • the display device of some embodiments further includes: a second switch circuit and a second ground resistor R4; the second switch circuit is located between the light string group and the second ground resistor R4; one end of the second switch circuit is connected to the first light string
  • the negative electrode of 140 is connected to the negative electrode of the second light string 150, and the other end of the second switch circuit is connected to one end of the second ground resistor R4; the other end of the second ground resistor R4 is grounded; the second switch circuit is used to change the loop current. , perform analog dimming.
  • FIG. 13 is a schematic circuit structure diagram of a second switch circuit according to an embodiment of the present application.
  • Analog dimming achieves the effect of changing the brightness of the light string group by changing the current in the light string group circuit.
  • the current of the light string group is smaller, the required working voltage of the light string group is smaller, and then the second voltage output by the second secondary coil 120 is more likely to exceed the required working voltage of the light string group.
  • the resistance value in the loop is adjusted through the second switch circuit to change the current in the loop.
  • the circuit design is simpler.
  • the second switch circuit includes: a fifth transistor Q5 and a comparator; one end of the fifth transistor Q5 is connected to the cathode of the first light string 140 and the cathode of the second light string 150 ; the other end of the fifth transistor Q5 One end is connected to one end of the second ground resistor R4 and the inverting input end of the comparator; the non-inverting input end of the comparator inputs the demand voltage of the light string group, and the output end of the comparator is connected to the gate of the fifth transistor Q5; adjust The resistance of the fifth transistor Q5 is used to change the loop current and perform analog dimming.
  • the inverting input terminal of the comparator receives the actual total current of the first light string 140 and the second light string 150.
  • the comparator compares voltage signals, so the current feedback signal needs to be converted into a voltage feedback signal.
  • the solution of converting the current feedback signal into the voltage feedback signal refers to the related technology.
  • the non-inverting input terminal of the comparator inputs a reference voltage, which is converted based on the reference current.
  • the solution of converting the reference current signal into the reference voltage signal refers to the related technology.
  • the fifth transistor Q5 can be set in a linear operating state to absorb the excess voltage on the fifth transistor Q5.
  • Figure 13 adopts voltage feedback method.
  • One end of the first feedback resistor R5 is connected to the negative electrode of the first light string 140 and the negative electrode of the second light string 150 , and the other end of the first feedback resistor R5 is connected to one end of the second feedback resistor R6 ; the other end of the second feedback resistor R6 One end is connected to ground; the second driver chip samples from the connection point of the first feedback resistor R5 and the second feedback resistor R6, and sends the voltage feedback signal to the voltage conversion module.
  • the second driver chip is used to collect the signal from the connection point of the first feedback resistor R5 and the second feedback resistor R6 in real time, and generate a feedback signal, so that the voltage conversion module can adjust the voltage in a timely and effective manner to prevent overshooting.
  • a large current flows through the LED components in the first light string 140 and the second light string 150, causing damage to the components.
  • the display device provided by this embodiment also includes a motherboard; the transformer also includes a third secondary coil 130 coupled with the primary coil; the third secondary coil 130 is used to generate power according to the power received by the primary coil.
  • a fourth voltage is output; the first voltage output by the first secondary coil 110 and the fourth voltage output by the third secondary coil 130 both supply power to the mainboard.
  • the first voltage is 18V and the fourth voltage is 12V.
  • the number of the second secondary coil 120, the voltage conversion module and the light string group is multiple; the display device also includes multiple current sharing inductors; one of the two adjacent second secondary coils has There are mutually coupled current sharing inductors between them.
  • FIG. 14 is a schematic circuit structure diagram of a four-way light string display device according to an embodiment of the present application, in which the voltage adjustment module takes a boost circuit as an example.
  • the voltage adjustment module takes a boost circuit as an example.
  • it includes two groups of light strings, four light strings: a first light string 140, a second light string 150, a third light string 160, and a fourth light string 170; two second secondary coils 120 and 121, corresponding to two sets of light strings.
  • mutually coupled current sharing inductors a third inductor L3 and a fourth inductor L4 are provided between the two second secondary coils 120 and 121 .
  • the current direction in the power supply circuit of the second light string 150 and the power supply circuit of the third light string 160 are opposite, thus creating impedance.
  • the third inductor L3 is connected in series in the power supply circuit of the second light string 150
  • the fourth inductor L4 is connected in series in the power supply circuit of the third light string 160.
  • the third inductor L3 and the fourth inductor L4 are coupled to each other for balancing the generated impedance.
  • the feedback module uses four light strings for common feedback, so the reference current value set in the feedback module is 4 times the required operating current of one light string.
  • the principle of the newly added second secondary coil 121 supplying power to the third light string 160 and the fourth light string 170 will not be described again.
  • FIG. 15 is a schematic circuit structure diagram of another four-way light string display device according to an embodiment of the present application.
  • the first switch circuit is located in the four-way light string (the first light string 140, the second light string 150, the third light string 160 and the fourth light string 170), which is the same as Figure 12. and ground resistor R3.
  • the voltages of multiple secondary coils may have cross-regulation issues. In order to avoid that when the voltage conversion module is not working, the second voltage output by the second secondary coil 120 or 121 exceeds the operating voltage of the light string group, causing the light string group to be lit, a third voltage is added to the circuit of the light string group.
  • the first switch circuit includes a fourth transistor Q4.
  • the fourth transistor Q4 When the PWM control signal is low level, the fourth transistor Q4 is turned off, so the light string group does not light up.
  • FIG. 16 is a schematic circuit structure diagram of yet another four-way light string display device according to an embodiment of the present application.
  • the second switch circuit is located between the light string group and the grounding resistor. Through the second switch circuit, the resistance value in the loop is adjusted, changing the current in the loop, and then adjusting the light string group. brightness. Specifically, when the actual voltage of the light string group exceeds the reference voltage, the transistor can be set in a linear operating state to share the excess voltage and avoid excessive partial voltage of the light string group, causing circuit damage.
  • the second switch circuit includes a fifth transistor Q5 and a comparator; the inverting input end of the comparator receives the actual total current of the first light string 140 and the second light string 150.
  • the comparator compares voltage signals. Therefore, the current feedback signal needs to be converted into a voltage feedback signal.
  • the solution of converting the current feedback signal into the voltage feedback signal refers to the related technology.
  • the non-inverting input terminal of the comparator inputs a reference voltage, which is converted based on the reference current.
  • the solution of converting the reference current signal into the reference voltage signal refers to the related technology.
  • the fifth transistor Q5 can be set in a linear operating state to absorb the excess voltage on the fifth transistor Q5.
  • FIG. 17 is a schematic circuit structure diagram of another four-way light string display device according to an embodiment of the present application.
  • the voltage adjustment circuit takes a buck step-down circuit as an example.
  • the synchronous rectification buck step-down circuit shown in Figure 11 is used, and a second diode D6 is provided at the same time.
  • the second transistor Q2 When the voltage adjustment module has no output, the second transistor Q2 is turned off, and the current of the light string group flows back to the second secondary coil 120 through the body diode of the third transistor Q3, the second inductor L2, and the fourth current sharing diode D4.
  • the current is too large, it will cause more heat loss on the body diode of the third transistor Q3.
  • the second diode D6 is used to form a new current loop, so that the current of the light string group is passed through the second diode.
  • the diode D6 and the fourth current sharing diode D4 flow back to the second secondary coil 120 .
  • the second diode D6 is a low-power diode such as a Schottky diode.
  • This embodiment also provides a display control method, which is applied to a display device.
  • the display device is shown in Figure 7 and includes: a transformer, a voltage conversion module, a feedback module and a light string group; the first secondary coil of the transformer and the second The secondary coil is coupled to the primary coil of the transformer; the first secondary coil is used to output the first voltage based on the power received by the primary coil; the second secondary coil is used to output the first voltage based on the power received by the primary coil.
  • Both ends of the coil output the second voltage alternately; the second secondary coil corresponds to the light string group one-to-one; the voltage conversion module is used to generate a superimposed voltage according to the first voltage and superimpose the superimposed voltage to the corresponding second secondary coil The second voltage at both ends outputs the superimposed third voltage.
  • a display control method provided by this embodiment includes: receiving a feedback signal, the feedback signal is generated by the feedback module according to the output current of the light string group; based on the feedback signal, adjusting the third voltage by adjusting the superimposed voltage; the third voltage is the light string group operating voltage.
  • the first voltage output by the first secondary coil is adjusted to generate a superimposed voltage.
  • the superimposed voltage is superimposed with the second voltage output by the second secondary coil. Then it is transmitted to each LED light string, so that each LED light string operates at the rated current to prevent excessive current from flowing through the LED components in the LED light string and causing damage to the components.
  • the superimposed voltage is equivalent to the "variable voltage”; the second voltage is equivalent to the "fixed voltage”.
  • the superposition of the two voltages realizes ladder power supply, which is beneficial to reducing heat loss; at the same time, the two light strings share the same power supply coil (i.e. the second stage coil) and voltage conversion module, which is helpful to simplify the circuit.
  • the display device includes a transformer, a voltage conversion module feedback module, and a light string group; wherein, the voltage conversion module corresponds to the light string group one-to-one, and the light string group includes a first light string and a second light string;
  • the first secondary coil and the second secondary coil are coupled with the primary coil of the transformer; the first secondary coil is used to output the first voltage according to the power received by the primary coil; the second secondary coil is used to output the first voltage according to the power received by the primary coil.
  • the received power supply alternately outputs the second voltage from both ends of the second secondary coil; the second secondary coil corresponds to the light string group one-to-one; the voltage conversion module is used to generate a superimposed voltage according to the first voltage and superimpose the voltage Superimpose the second voltage on both ends of the corresponding second secondary coil to output the superposed third voltage; the feedback module is used to generate a feedback signal according to the output current of the light string group and send it to the voltage conversion module, and the feedback signal is used for The voltage conversion module is instructed to adjust the third voltage; the first light string is connected to one end of the corresponding second secondary coil, and the second light string is connected to the other end of the corresponding second secondary coil for emitting light based on the third voltage.
  • the two light strings in this embodiment share the same power supply coil and voltage conversion module, which simplifies the circuit; at the same time, voltage superposition is used to realize ladder power supply, which is beneficial to reducing heat loss.
  • FIG. 18 is a schematic structural diagram of a power supply circuit that supplies power to the main board and the LED light string.
  • the mains alternating current (100V-240V, 50-60Hz) obtained by the power supply circuit passes through the filter rectifier module (rectifier bridge), PFC module and LLC isolation voltage conversion module in sequence, and then supplies it to the mainboard of the display device, multi-channel LED light strings and other The load is powered (not shown in Figure 18).
  • the first secondary winding in the LLC isolation voltage conversion module provides the fifth voltage (for example, 12V) to the main board
  • the second secondary winding provides the sixth voltage (for example, 18V) to the main board
  • the third secondary winding simultaneously supplies multiple voltages to the main board.
  • LED string lights provide voltage.
  • multi-channel LED light strings are used to light up the display screen of a TV.
  • the LED components in the multi-channel LED light strings need to work within a certain voltage drop range to reach the rated current of the LED components.
  • the multi-channel LED light strings are For a 16-channel LED light string, each light string includes 9 LED components. Under 120mA conditions, the required operating voltage range of the multi-channel LED light string is 51.3V-58.5V, and the total current is 1.92A.
  • the secondary winding in the LLC isolation voltage conversion module that supplies power to multiple LED light strings is additionally connected to a voltage adjustment module (such as a buck circuit or a boost circuit, the boost circuit is used as an example in Figure 18).
  • the voltage adjustment module can adjust the voltage according to the multiple
  • the real-time current feedback result of the LED light string is used to adjust the voltage directly output by the third secondary winding, so that the multi-channel LED drive module controls the multi-channel LED light string to operate at the rated current according to the received adjusted voltage to prevent overflow. Large current flows through the LED components in the multi-channel LED light string, causing damage to the components.
  • the voltage stress of the voltage adjustment module provided for the multi-channel LED light strings in the power supply circuit is relatively large.
  • the voltage adjustment module needs to step up or step down the voltage greater than 50V, which results in higher withstand voltage values of switching tubes, capacitors and other components in the voltage adjustment module, thus occupying a larger area of the PCB board where the power supply circuit is located. large, ultimately increasing the cost of the power supply circuit.
  • Figure 19 is a schematic structural diagram of another power supply circuit that supplies power to the main board and LED light string.
  • the difference from the power supply circuit shown in Figure 18 is that the form of "ladder power supply” is used in Figure 19, and the LLC isolation voltage conversion module Two different secondary windings power the LED string.
  • the power supply circuit includes three power supply branches.
  • the first power supply branch includes the first secondary winding in the LLC isolation voltage conversion module and is configured to output a fifth voltage (for example, 12V) to the motherboard.
  • the second power supply branch includes a second secondary winding in the LLC isolation voltage conversion module and is configured to output a sixth voltage as a fixed voltage.
  • the third power supply branch includes a third secondary winding in the LLC isolation voltage conversion module and is configured to output The seventh voltage (for example, 16V or 18V), and then the voltage adjustment module (low voltage buck/boost) converts the seventh voltage into the eighth voltage, and then provides the sum of the seventh voltage and the eighth voltage to the LED light string.
  • the voltage adjustment module only needs to adjust the secondary voltage of the smaller one.
  • the voltage output by the winding is adjusted, thereby reducing the requirements for the withstand voltage value of the switching tube, capacitor and other components in the voltage adjustment module, thereby reducing the area of the PCB board where the power supply circuit is located, and ultimately reducing the cost of the power supply circuit.
  • FIG 20 shows another schematic structural diagram of the power supply circuit that supplies power to the main board and LED light string.
  • the mains alternating current (100V-240V, 50-60Hz) obtained by the power supply circuit passes through the filter rectifier module (rectifier bridge), it is input separately.
  • an LLC isolation voltage conversion module is connected behind each PFC module.
  • One of the LLC isolation voltage conversion modules supplies power to the mainboard, providing 12V voltage, 18V voltage or 9.1V voltage in standby to the mainboard.
  • the mainboard can be controlled by adjusting the switching frequency or duty cycle of the transistors in the LLC isolation voltage conversion module. Available in different voltages.
  • Another LLC isolation voltage conversion module provides 10-15V voltage and 18A constant current to multiple or single LED loads, and adjusts the output voltage of the LLC module based on the feedback circuit.
  • the power supply structure of the display device is directly connected to the AC power of the city.
  • a special power supply circuit is configured in the power board of the display device to transform the AC power, convert it to DC, etc., and includes at least the following modules: Rectifier bridge, power factor correction (Power Factor Correction, PFC) module, resonant conversion circuit (LLC) isolation voltage conversion module.
  • PFC Power Factor Correction
  • LLC resonant conversion circuit isolation voltage conversion module.
  • a resonant conversion circuit (LLC) isolation voltage conversion module is used to generate multiple DC voltages to meet the power supply needs of the load in the display device.
  • the circuit structure of the power supply is relatively complex.
  • the complex The circuit is not conducive to improving integration.
  • FIG. 21 is a schematic diagram of an external adapter power supply mode according to an embodiment of the present application, showing a structural diagram of powering a display device, taking a television as an example, in the external adapter power supply mode. It can be seen that the display device (the television shown in Figure 21) is connected via a cable to a single fixed DC input voltage provided by the power adapter.
  • the display device provided by this application is equipped with a power supply interface connected to an external adapter to receive a DC input voltage to adapt to the external adapter power supply mode; the DC input voltage is used to generate a superimposed voltage, and the superimposed voltage is combined with the DC
  • the input voltages are superimposed to realize ladder power supply, which is beneficial to reducing heat loss; energy storage components are used to continuously supply power to the backlight control module; the power supply voltage of the backlight control module is adjusted in time through real-time feedback to stabilize the operation of the light-emitting diodes.
  • Figure 22 is a schematic structural diagram of a power supply circuit of a display device according to an embodiment of the present application, including: a backlight control module, a power supply interface, a first voltage conversion module, an energy storage element, and a feedback module.
  • the backlight control module is used to control the light emitting diode, and the light emitting diode is used to light up the screen of the display device;
  • the power supply interface is used to receive the DC input voltage provided by the external adapter;
  • the first voltage conversion module is used to generate a signal based on the DC input voltage.
  • the energy storage element is connected to the first voltage conversion module for storing the fifth voltage; the energy storage element and the first voltage conversion module alternately output the fifth voltage.
  • the negative electrode of the backlight control module is connected to the fifth voltage, and the fifth voltage is used as the negative reference voltage of the backlight control module; the positive electrode of the backlight control module is connected to the DC input voltage.
  • the feedback module is used to send the feedback signal generated by the backlight control module to the first voltage conversion module, and the feedback signal is used to instruct the first voltage conversion module to adjust the fifth voltage to adjust the demand voltage of the backlight control module.
  • the voltage on both sides of the backlight control module is the sum of the absolute value of the DC input voltage and the fifth voltage.
  • the DC input voltage is equivalent to the "fixed voltage”
  • the fifth voltage is equivalent to the "variable voltage”.
  • the above-mentioned circuit structure of using fixed voltage and variable voltage to power the backlight control module is called “ladder power supply”, which can reduce the voltage resistance value and other requirements of the electrical components in the first voltage conversion module to achieve the purpose of reducing costs and improving efficiency; at the same time, Can reduce heat loss on electrical components.
  • the external adapter receives mains alternating current (100V-240V, 50-60Hz).
  • the internal circuit of the external adapter can be shown in Figure 21, including at least a filter rectifier module, a PFC module, and an LLC isolation voltage conversion module.
  • This external adapter outputs a fixed DC voltage.
  • the display device is provided with a power supply interface connected to an external adapter for receiving DC input voltage to adapt to the external adapter power supply mode shown in Figure 21.
  • the energy storage component shown in Figure 22 may be a single energy storage capacitor or other energy storage circuit.
  • the energy storage element cooperates with the first voltage conversion module to alternately output the fifth voltage, continuously providing a negative reference voltage to the backlight control module, so that the light-emitting diode emits light stably.
  • the first voltage conversion module shown in FIG. 22 may be in the form of a charge pump.
  • FIG. 23 is a schematic structural diagram of a power supply circuit of another display device according to an embodiment of the present application. As shown in Figure 23, the first voltage conversion module includes: a charge pump module.
  • the charge pump module is used to generate a fifth voltage in the charging state; and to provide the fifth voltage to the negative electrode of the backlight control module in the discharging state; the first end of the energy storage element is connected to the positive output end of the charge pump module , and grounded; the second end of the energy storage element is connected to the negative output end of the charge pump module; the energy storage element is used to store the fifth voltage when the charge pump module is discharging; and, when the charge pump module is charging,
  • the negative electrode of the backlight control module provides a fifth voltage; wherein the feedback signal is used to instruct the charge pump module to adjust the fifth voltage to adjust the required voltage of the backlight control module.
  • the first voltage conversion module in the form of a charge pump in this embodiment is a non-inductive DC-DC power converter, that is, there is no inductive component in the voltage conversion in the charge pump form, so the voltage conversion principle does not involve high-speed transformation of the magnetic field, that is, electrical- Due to the high-speed conversion of magnetism and magnetism-electricity, the problem of electromagnetic interference can almost be ignored.
  • the principle of voltage conversion in the form of a charge pump utilizes high-speed charging and discharging of internal capacitive elements, so it has the advantage of low electromagnetic interference. In addition to low electromagnetic interference, it also has the advantages of wider adjustment range of output voltage, high efficiency, small size, low quiescent current, small minimum operating voltage, and low noise.
  • the integration of capacitors is easier and cheaper than the integration of inductors. Therefore, the first voltage conversion module in the form of a charge pump is easier to achieve high integration, and the cost of the overall application circuit is not high.
  • the energy storage component shown in Figure 23 may be a single energy storage capacitor or other energy storage circuit.
  • the energy storage element cooperates with the charge pump module to alternately output the fifth voltage to continuously supply power to the backlight control module so that the light-emitting diode emits light stably.
  • FIG. 24 is a schematic structural diagram of a power supply circuit of a charge pump module according to an embodiment of the present application, in which the energy storage element Cn is a single energy storage capacitor as an example.
  • the charge pump module includes: a first controller, a first storage capacitor C11, a first switch S11, a second switch S12, a third switch S13 and a fourth switch S14.
  • the first terminal of the first switch S11 is connected to the DC input voltage Vin, and the second terminal of the first switch S11 is connected to the first terminal of the second switch S12; the second terminal of the second switch S12 serves as the forward output terminal of the charge pump module, It is connected to the first end of the energy storage element Cn and grounded; the first end of the first energy storage capacitor C11 is connected to the second end of the first switch S11 and the first end of the second switch S12, and the first end of the first energy storage capacitor C11
  • the second terminal of is connected to the first terminal of the third switch S13 and the first terminal of the fourth switch S14; the second terminal of the fourth switch S14 is connected to ground; the second terminal of the third switch S13 serves as the negative output of the charge pump module terminal is connected to the second terminal of the energy storage element Cn, and the fifth voltage -Vo is output.
  • the first controller is connected to the control terminals of the first switch S11, the second switch S12, the third switch S13 and the fourth switch S14, and is used to control the first switch S11, the second switch S12 and the third switch S14 according to the feedback signal.
  • the switching frequency of the switch S13 and the fourth switch S14 is to adjust the fifth voltage -Vo; wherein the switching states of the first switch S11 and the second switch S12 are different, and the first switch S11 and the fourth switch S14 are turned off or turned on at the same time. ;
  • the second switch S12 and the third switch S13 are turned off or turned on at the same time.
  • the charge pump module and the energy storage element cooperate with each other to provide a negative reference voltage for the negative electrode of the backlight control module.
  • the principle is as follows:
  • Step (1) The first controller controls the first switch S11 and the fourth switch S14 to be closed at the same time, and the second switch S12 and the third switch S13 to be open at the same time.
  • the DC input voltage Vin charges the first energy storage capacitor C11 through the closed first switch S11, by controlling the opening time of the second switch S12 and the third switch S13, and the closing of the first switch S11 and the fourth switch S14.
  • time to control the charging time of the first energy storage capacitor C11 to control the energy storage voltage of the first energy storage capacitor C11. Assume that the energy storage voltage of the first energy storage capacitor C11 after charging is Vo. At this time, since the second terminal of the first energy storage capacitor C11 is grounded, the first terminal voltage of the first energy storage capacitor C11 is Vo.
  • Step (2) The first controller controls the first switch S11 and the fourth switch S14 to open at the same time, and the second switch S12 and the third switch S13 to close at the same time.
  • the first terminal of the first energy storage capacitor C11 is grounded, so the voltage at the second terminal of the first energy storage capacitor C11 is -Vo (ie, the fifth voltage), which is used to provide a negative reference voltage to the negative electrode of the backlight control module.
  • the first energy storage capacitor C11 charges the energy storage element Cn, so that the energy storage voltage of the energy storage element Cn after charging is Vo. Since the first terminal of the energy storage element Cn is also grounded, the second terminal of the energy storage element Cn is -Vo (that is, the fifth voltage).
  • Step (3) The first controller controls the first switch S11 and the fourth switch S14 to be closed at the same time, and the second switch S12 and the third switch S13 to be open at the same time. Repeat the charging process of the first energy storage capacitor C11 in step (1). At this time, the first end of the energy storage element Cn is grounded, and the second end of the energy storage element Cn provides a negative reference voltage, that is, the fifth voltage -Vo, to the negative electrode of the backlight control module.
  • the above power supply circuit shown in Figure 24 generates the fifth voltage -Vo based on the DC input voltage Vin, and connects the fifth voltage -Vo to the negative electrode of the backlight control module as the negative reference voltage of the backlight control module; combined with the backlight control module
  • the positive input DC input voltage Vin makes the voltage at both ends of the backlight control module be the sum of the DC input voltage Vin and the absolute value Vo of the fifth voltage, that is, the demand voltage Vled of the backlight control module is equal to Vin+Vo.
  • the first controller controls the amount of charge transmission by controlling the switching frequency or duty cycle of the first switch S11, the second switch S12, the third switch S13 and the fourth switch S14 based on the feedback signal, thereby achieving the requirement of controlling the backlight control module.
  • the purpose of voltage Vled is not limited to the power supply circuit shown in Figure 24, only the magnitude of the fifth voltage -Vo needs to be controlled to control changes in the demand voltage Vled of the backlight control module.
  • the first controller controls the amount of charge transmission by controlling the switching frequency or duty cycle of the first switch S11, the second switch S12, the third switch S13 and the fourth switch S14 based on the feedback signal, thereby achieving the requirement of controlling the backlight control module.
  • the purpose of voltage Vled is not limited to the switching frequency or duty cycle of the first switch S11, the second switch S12, the third switch S13 and the fourth switch S14 based on the feedback signal, thereby achieving the requirement of controlling the backlight control module.
  • the DC input voltage Vin is relatively stable and is equivalent to a "fixed voltage”; the fifth voltage -Vo is equivalent to a "variable voltage”. Since the DC input voltage Vin is relatively stable, the variation range of the output voltage of the fifth voltage -Vo depends on the variation range required by the demand voltage Vled of the backlight control module.
  • the above-mentioned circuit structure of using fixed voltage and variable voltage to power the backlight control module is called “ladder power supply", which can reduce the voltage resistance value and other requirements of the electrical components in the first voltage conversion module to achieve the purpose of reducing costs and improving efficiency; at the same time, Can reduce heat loss on electrical components.
  • the first voltage conversion module shown in FIG. 22 may be in a flyback isolation form.
  • FIG. 25 is a schematic structural diagram of a power supply circuit of another display device according to an embodiment of the present application. As shown in Figure 25, the first voltage conversion module includes: a flyback isolation transformer module.
  • the flyback isolation transformer module is used to generate the fifth voltage from the secondary winding when the primary winding is turned on and transmit it to the negative electrode of the backlight control module; the first end of the energy storage element is connected to the flyback isolation transformer module The positive output end is connected and grounded; the second end of the energy storage element is connected to the negative output end of the flyback isolation transformer module; the energy storage element is used to store the fifth voltage when the primary winding is turned on; and , when the primary winding is turned off, a fifth voltage is provided to the negative electrode of the backlight control module; the feedback signal is used to instruct the flyback isolation transformer module to adjust the fifth voltage to adjust the required voltage of the backlight control module.
  • the voltage conversion module in the form of flyback isolation used in this embodiment is electrically isolated through the primary winding and the secondary winding.
  • Flyback specifically means that when the switch tube is turned on, the secondary winding transformer acts as an inductor and the electrical energy is converted into magnetic energy. At this time, there is no current in the output loop; on the contrary, when the switch tube is turned off, the secondary winding transformer releases energy and the magnetic energy is converted into It is electrical energy, and there is current in the output circuit.
  • the secondary winding transformer also acts as an energy storage inductor, which has the characteristics of fewer components, simple circuit, low cost, and small size. At the same time, electrical isolation improves the safety of use.
  • the energy storage component shown in Figure 25 may be a single energy storage capacitor or other energy storage circuit.
  • the energy storage element cooperates with the flyback isolation transformer module to alternately output the fifth voltage, continuously providing a negative reference voltage for the backlight control module, so that the light-emitting diode emits light stably.
  • FIG. 26 is a schematic structural diagram of a power supply circuit of a flyback isolation transformer module according to an embodiment of the present application.
  • the flyback isolation transformer module includes: a primary winding, a secondary winding, a first diode D11, a second controller and a fifth switch S15.
  • the first end of the primary winding is connected to the DC input voltage Vin, the second end of the primary winding is connected to the first end of the fifth switch S15, and the second end of the fifth switch S15 is grounded; the secondary winding is coupled to the primary winding, and the secondary winding is coupled to the primary winding.
  • the first end of the side winding is connected to the anode of the first diode D11; the cathode of the first diode D11 serves as the forward output end of the flyback isolation transformer module and is connected to the first end of the energy storage element Cn. And grounded; the second end of the secondary winding serves as the negative output end of the flyback isolation transformer module, is connected to the second end of the energy storage element Cn, and outputs the fifth voltage -Vo.
  • the second controller is connected to the control end of the fifth switch S15 and is used to adjust the fifth voltage -Vo by controlling the switching frequency of the fifth switch S15 according to the feedback signal.
  • Step (1) The second controller controls the fifth switch S15 to turn on, the primary winding current increases linearly, and the inductor energy storage increases; the first diode D11 does not conduct.
  • the energy storage voltage of the primary winding can be controlled by controlling the switching frequency of the fifth switch S15.
  • Step (2) The second controller controls the fifth switch S15 to turn off, the primary winding current is cut off, and the first diode D11 is turned on.
  • the first end of the secondary winding is grounded through the first diode D11.
  • the second end of the secondary winding can output a fifth voltage -Vo, which is used to supply the backlight
  • the negative terminal of the control module provides the negative reference voltage.
  • the secondary winding charges the energy storage element Cn, so that the energy storage voltage of the energy storage element Cn after charging is Vo. Since the first terminal of the energy storage element Cn is also grounded, the second terminal of the energy storage element Cn is -Vo (that is, the fifth voltage).
  • Step (3) The second controller controls the fifth switch S15 to turn on, and repeats the energy storage process of the primary winding in step (1). At this time, the first end of the energy storage element Cn is grounded, and the second end of the energy storage element Cn provides a negative reference voltage, that is, the fifth voltage -Vo, to the negative electrode of the backlight control module.
  • the above power supply circuit shown in Figure 26 generates the fifth voltage -Vo based on the DC input voltage Vin, and connects the fifth voltage -Vo to the negative electrode of the backlight control module as the negative reference voltage of the backlight control module; combined with the backlight control module
  • the positive input DC input voltage Vin makes the voltage at both ends of the backlight control module be the sum of the DC input voltage Vin and the absolute value Vo of the fifth voltage, that is, the demand voltage Vled of the backlight control module is equal to Vin+Vo.
  • the second controller controls the amount of charge transmission by controlling the switching frequency or duty cycle of the fifth switch S15 based on the feedback signal, thereby achieving the purpose of controlling the demand voltage Vled of the backlight control module.
  • the DC input voltage Vin is relatively stable and is equivalent to a "fixed voltage”; the fifth voltage -Vo is equivalent to a "variable voltage”. Since the DC input voltage Vin is relatively stable, the variation range of the output voltage of the fifth voltage -Vo depends on the variation range required by the demand voltage Vled of the backlight control module.
  • the above-mentioned circuit structure of using fixed voltage and variable voltage to power the backlight control module is called “ladder power supply", which can reduce the voltage resistance value and other requirements of the electrical components in the first voltage conversion module to achieve the purpose of reducing costs and improving efficiency; at the same time, Can reduce heat loss on electrical components.
  • Figure 27 is a schematic structural diagram of a level conversion circuit according to an embodiment of the present application.
  • the feedback module includes level shifting circuitry.
  • the level conversion circuit receives the first feedback signal output by the backlight control module, converts the first feedback signal into a second feedback signal, and then outputs the second feedback signal to the first voltage conversion module; wherein the first feedback signal and the second feedback signal are The reference voltages of the feedback signals are different.
  • the circuit converts the first feedback signal with a reference low level of -Vo into a second feedback signal with a reference voltage of 0.
  • the level conversion circuit can refer to related technologies.
  • the display device further includes a first filtering module; the first filtering module is connected to the power supply interface and the first voltage conversion module, and is used to filter the DC input voltage.
  • the first filter module may be a filter circuit composed of one or more grounded capacitors, or may be a filter circuit composed of a capacitor and an inductor. As shown in Figure 27, the first filter module takes the first filter capacitor C13 as an example.
  • the first filter capacitor C13 is connected in parallel between the DC input voltage of the power supply interface and the ground. It is used to filter out the noise and AC components of the power supply, smooth the pulsating DC voltage, and store electrical energy.
  • the capacitance is related to the load current and the purity of the power supply. A larger-capacity filter capacitor is usually selected.
  • the first filter capacitor C13 may be the electrolytic capacitor shown in FIG. 27 .
  • Electrolytic capacitor is a type of capacitor.
  • the metal foil is the positive electrode (aluminum or tantalum).
  • the oxide film (aluminum oxide or tantalum pentoxide) close to the positive electrode is the dielectric.
  • the cathode is made of conductive material and electrolyte (the electrolyte can be liquid or solid) and other materials, because the electrolyte is the main part of the cathode. Its capacitance per unit volume is very large. Since the preparation materials are ordinary industrial materials and the preparation process is also ordinary industrial equipment, it can be mass produced, so the cost is relatively low. It should be noted that the positive and negative electrolytic capacitors cannot be connected incorrectly.
  • the first filter capacitor C13 can also be other types of capacitors, such as ceramic tape content, film capacitors, mica capacitors, etc. In actual circuits, selection can be made based on capacitance requirements.
  • the display device further includes a second filter module; the second filter module is disposed between the positive electrode and the negative electrode of the backlight control module.
  • the second filter module may be a filter circuit composed of one or more grounded capacitors, or may be a filter circuit composed of a capacitor and an inductor. As shown in Figure 27, the second filter module takes the second filter capacitor C14 as an example to stabilize the voltage at both ends of the backlight control module.
  • a third filtering module is further provided for filtering out noise in the positive DC input voltage Vin input to the backlight control module.
  • the third filter module takes the third filter capacitor C5 as an example.
  • One end of the third filter capacitor C5 is connected to the DC input voltage Vin, and the other end of the third filter capacitor C5 is connected to ground.
  • the display device further includes a second diode Dn; the anode of the second diode Dn is connected to the second end of the energy storage element Cn, and the cathode of the second diode Dn is connected to the second end of the energy storage element Cn.
  • the fourth diode Dn is used to form a current loop between the backlight control module and the negative electrode of the power supply interface to prevent the current from flowing through the first voltage conversion module and causing system malfunction or other abnormal situations when the first voltage conversion module is not working. Protect the first voltage conversion module.
  • FIG. 28 is a schematic structural diagram of a level conversion circuit based on a charge pump module power supply circuit according to an embodiment of the present application.
  • the charge pump module is shown in Figure 24 as an example, and the power supply principle will not be described again.
  • Figure 29 is a schematic structural diagram of a level conversion circuit based on a flyback isolation transformer module power supply circuit according to an embodiment of the present application.
  • the flyback isolation transformer module takes Figure 26 as an example. The power supply principle will not be described again.
  • the display device provided in this embodiment further includes: a mainboard; the mainboard is connected to the power supply interface, and the DC input voltage is used to supply power to the mainboard.
  • Figure 30 is a schematic structural diagram of a circuit that supplies power to a mainboard according to an embodiment of the present application. When the DC input voltage is equal to the required voltage of the motherboard, you can choose to use the DC input voltage to directly power the motherboard.
  • the display device further includes a second voltage conversion module; the second voltage conversion module is connected to the power supply interface and the main board, and is used to output a sixth voltage according to the DC input voltage, and the sixth voltage is the required voltage of the main board.
  • FIG. 31 is a schematic structural diagram of another circuit that supplies power to a mainboard according to an embodiment of the present application.
  • the second voltage conversion module can be used to perform DC-DC voltage conversion on the DC input voltage.
  • the second voltage conversion module may use a buck circuit, a boost-buck circuit, or the like.
  • Embodiments of the present application also provide a display control method, applied to the aforementioned display device.
  • the display control method includes: receiving a feedback signal, which is generated by the backlight control module and sent through the feedback module; based on the feedback signal, adjusting the fifth voltage to Adjust the demand voltage of the backlight control module.
  • the fifth voltage generated by the first voltage conversion module is adjusted according to the real-time current feedback signal output by the backlight control module, and then the demand voltage of the backlight control module is adjusted so that the backlight control module operates at the rated current to prevent overloading. High current flows through the LED components in the LED light string, causing damage to the components.
  • the display device includes: a backlight control module for controlling the light emitting of a light emitting diode, and the light emitting diode is used for lighting the screen of the display device; a power supply interface for receiving a DC input voltage provided by an external adapter; first The voltage conversion module is used to generate a fifth voltage according to the DC input voltage; the energy storage element is connected to the first voltage conversion module and is used to store the fifth voltage; the energy storage element and the first voltage conversion module alternately output the fifth voltage; The negative electrode of the backlight control module is connected to the fifth voltage, and the fifth voltage is used as the negative reference voltage of the backlight control module; the positive electrode of the backlight control module is connected to the DC input voltage; the sum of the absolute value of the DC input voltage and the absolute value of the fifth voltage is equal to the backlight control the demand voltage of the module; the feedback module is used to send the feedback signal generated by the backlight control module to the first voltage conversion module, and the feedback signal is used to instruct the first voltage conversion module to adjust the
  • the embodiment of the present application is provided with a power supply interface connected to an external adapter to receive a DC input voltage to adapt to the external adapter power supply mode; the fifth voltage generated by the DC input voltage is used as the negative reference voltage of the backlight control module, and the backlight control module
  • the DC input voltage connected to the positive pole forms a stepped power supply, which is beneficial to reducing heat loss; the energy storage element is used to continuously supply power to the backlight control module; the power supply voltage of the backlight control module is adjusted in time through real-time feedback to stabilize the operation of the light-emitting diode.
  • the display device provided by this application is provided with a power supply interface connected to an external adapter, receives a DC input voltage to adapt to the external adapter power supply mode; uses the DC input voltage to generate a superimposed voltage, and superimposes the superimposed voltage with the DC input voltage.
  • realizing ladder power supply which is beneficial to reducing heat loss; using energy storage components to continuously supply power to the backlight control module; adjusting the power supply voltage of the backlight control module in a timely manner through real-time feedback to stabilize the operation of the light-emitting diodes.
  • Figure 32 is a schematic structural diagram of a power supply circuit of a display device according to an embodiment of the present application, including: a backlight control module, a power supply interface, a third voltage conversion module, an energy storage element, and a feedback module.
  • the backlight control module is used to control the light emitting diode LED to light up the screen of the display device;
  • the power supply interface is used to receive the DC input voltage provided by the external adapter;
  • the third voltage conversion module is used to generate a superimposed signal based on the DC input voltage. voltage, and superpose the superimposed voltage with the DC input voltage to output the superposed ninth voltage.
  • the ninth voltage is the required voltage of the backlight control module;
  • the first end of the energy storage element is connected to the third voltage conversion module, and the energy storage element
  • the second terminal is connected to the DC input voltage for energy storage superimposed voltage, and alternately outputs the ninth voltage with the third voltage conversion module.
  • the feedback module is used to send the feedback signal generated by the backlight control module to the third voltage conversion module, and the feedback signal is used to instruct the third voltage conversion module to adjust the ninth voltage.
  • the external adapter receives mains alternating current (100V-240V, 50-60Hz).
  • the internal circuit of the external adapter can be shown in Figure 21, including at least a filter rectifier module, a PFC module, and an LLC isolation voltage conversion module.
  • This external adapter outputs a fixed DC voltage.
  • the display device is provided with a power supply interface connected to an external adapter for receiving DC input voltage to adapt to the external adapter power supply mode shown in Figure 21.
  • the energy storage component shown in Figure 32 may be a single energy storage capacitor or other energy storage circuit.
  • the energy storage element cooperates with the third voltage conversion module to alternately output the ninth voltage to continuously supply power to the backlight control module so that the light-emitting diode emits light stably.
  • the third voltage conversion module shown in FIG. 32 may be in the form of a charge pump.
  • FIG. 33 is a schematic structural diagram of a power supply circuit of another display device according to an embodiment of the present application. As shown in Figure 33, the third voltage conversion module includes: a charge pump module, used to generate a superimposed voltage in the charging state; in the discharging state, superimpose the superimposed voltage with the DC input voltage to generate a ninth voltage, and The ninth voltage obtained by superposition is output to the backlight control module.
  • the first end of the energy storage element is connected to the output end of the charge pump module; the energy storage element is used to store energy and superimpose the voltage when the charge pump module is discharging; and, when the charge pump module is charging, superimpose the superimposed voltage on the DC input voltage. , and output the superimposed ninth voltage to the backlight control module; wherein the feedback signal is used to instruct the charge pump module to adjust the ninth voltage by adjusting the superimposed voltage.
  • the third voltage conversion module in the form of a charge pump in this embodiment is a non-inductive DC-DC power converter, that is, there is no inductive component in the voltage conversion in the charge pump form, so the voltage conversion principle does not involve high-speed conversion of magnetic fields. That is, high-speed conversion of electricity-magnetism and magnetism-electricity, and the problem of electromagnetic interference can almost be ignored.
  • the principle of voltage conversion in the form of a charge pump utilizes high-speed charging and discharging of internal capacitive elements, so it has the advantage of low electromagnetic interference. In addition to low electromagnetic interference, it also has the advantages of wider adjustment range of output voltage, high efficiency, small size, low quiescent current, small minimum operating voltage, and low noise.
  • the integration of capacitors is easier and cheaper than the integration of inductors. Therefore, the third voltage conversion module in the form of a charge pump is easier to achieve high integration, and the cost of the overall application circuit is not high.
  • the energy storage component shown in Figure 33 may be a single energy storage capacitor or other energy storage circuit.
  • the energy storage element cooperates with the charge pump module to alternately output the ninth voltage to continuously supply power to the backlight control module so that the light-emitting diode emits light stably.
  • FIG. 34 is a schematic structural diagram of a power supply circuit of a charge pump module according to an embodiment of the present application.
  • the charge pump module includes: a first controller, a first storage capacitor C11, a first diode D11, a second diode D12, a first switch S1 and a second switch S2.
  • the anode of the first diode D11 is connected to the DC input voltage Vin
  • the cathode of the first diode D11 is connected to the anode of the second diode D12
  • the cathode of the second diode D12 serves as the output terminal of the charge pump module, and outputs the third Nine voltages Vled
  • the first terminal of the first switch S1 is connected to the anode of the first diode D11
  • the second terminal of the first switch S1 is connected to the first terminal of the second switch S2
  • the second terminal of the second switch S2 is grounded
  • the first terminal of the first energy storage capacitor C11 is connected to the cathode of the first diode D11
  • the second terminal of the first energy storage capacitor C11 is connected to the second terminal of the first switch S1.
  • the first controller is connected to the control terminals of the first switch S1 and the second switch S2, and is used to control the switching frequency of the first switch S1 and the second switch S2 according to the feedback signal to adjust the superimposed voltage; wherein, the first switch The switching states of S1 and the second switch S2 are different.
  • the energy storage component takes a single energy storage capacitor as an example.
  • the second terminal of the energy storage element Cn is connected to the DC input voltage Vin, that is, the DC input voltage Vin is applied to the second terminal of the energy storage element Cn.
  • a physical connection can be established between the second end of the energy storage element Cn and the power supply interface to apply the DC input voltage Vin to the second end of the energy storage element.
  • Step (1) The first controller controls the first switch S1 to open and the second switch S2 to close. At this time, the DC input voltage Vin charges the first energy storage capacitor C11 through the first diode D11, so that the first energy storage capacitor C11 is charged.
  • the first terminal of capacitor C11 is a positive voltage.
  • the charging time of the first energy storage capacitor C11 is controlled, thereby controlling the energy storage voltage of the first energy storage capacitor C11. Assume that the energy storage voltage of the first energy storage capacitor C11 after charging is Vo (that is, the superposition voltage). Since its second terminal is grounded, its first terminal voltage is Vo.
  • Step (2) The first controller controls the first switch S1 to close and the second switch S2 to open.
  • the DC input voltage Vin is connected to the second end of the first energy storage capacitor C11 through the first switch S1, and the first The energy storage capacitor C11 is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode.
  • the DC input voltage Vin connected to the lower end of the first energy storage capacitor C11 is equivalent to two batteries connected in series. Power supply, that is, voltage superposition is performed. Therefore, the first energy storage capacitor C11 outputs the superposed ninth voltage Vled through the cathode of the second diode D12, where Vled is equal to Vin+Vo.
  • the energy storage element Cn its first end is connected to the voltage Vled, and its second end is connected to the voltage Vin. Therefore, the energy storage element Cn is charged, and the Cn energy storage voltage difference is Vo (that is, the superimposed voltage).
  • Step (3) The first controller controls the first switch S1 to open, the second switch S2 to close, and repeats the charging process of the first energy storage capacitor C11 in step (1).
  • the energy storage element Cn is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode.
  • connecting the DC input voltage Vin to the second end of the energy storage element Cn is equivalent to a series connection.
  • the two power supplies perform voltage superposition. Therefore, the superposed ninth voltage Vled is output through the first terminal of the energy storage element Cn.
  • the anode voltage of the second diode D12 is Vin and the cathode voltage is Vled, it is not conductive.
  • the first controller controls the amount of charge transmission by controlling the switching frequency or duty cycle of the first switch S1 and the second switch S2 based on the feedback signal, thereby achieving the purpose of controlling the ninth voltage Vled.
  • the DC input voltage Vin is relatively stable and is equivalent to a "fixed voltage”; the superimposed voltage Vo is equivalent to a "varying voltage”. Since the DC input voltage Vin is relatively stable, the output voltage variation range of the superimposed voltage Vo depends on the required variation range of the ninth voltage Vled.
  • the above-mentioned circuit structure using a "fixed voltage” superimposed on a "variable voltage” is a "ladder power supply", which can achieve the purpose of reducing costs and improving efficiency.
  • the power supply circuit shown in Figure 34 is compared with a traditional DC-DC conversion scheme.
  • the traditional DC-DC conversion solution uses DC-DC circuit modules to convert the DC input voltage into the required voltage.
  • the DC-DC circuit module can be a boost circuit, a buck circuit, a boost-buck circuit, and other circuits with boost and reduction functions.
  • the operating voltage range is often around 11.4-12.6V.
  • the supply voltage range is: 45.6-50.4V. Assuming the input voltage is 42V, the voltage of Vled needs to be 50V, and the total output power is 100W.
  • the second end of the energy storage element Cn can also be grounded.
  • Figure 35 is a schematic structural diagram of a power supply circuit of another charge pump module according to an embodiment of the present application. The difference from Figure 34 is that the second end of the energy storage element Cn is grounded. Therefore, the difference between the power supply principles of Figure 35 and Figure 34 is that the energy storage voltage difference of the energy storage element Cn is different.
  • Step (1) The first controller controls the first switch S1 to open and the second switch S2 to close. At this time, the DC input voltage Vin charges the first energy storage capacitor C11 through the first diode D11, so that the first energy storage capacitor C11 is charged.
  • the first terminal of capacitor C11 is a positive voltage.
  • the charging time of the first energy storage capacitor C11 is controlled, thereby controlling the energy storage voltage of the first energy storage capacitor C11. Assume that the energy storage voltage of the first energy storage capacitor C11 after charging is Vo (that is, the superposition voltage). Since its second terminal is grounded, its first terminal voltage is Vo.
  • Step (2) The first controller controls the first switch S1 to close and the second switch S2 to open.
  • the DC input voltage Vin is connected to the second end of the first energy storage capacitor C11 through the first switch S1, and the first The energy storage capacitor C11 is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode.
  • the DC input voltage Vin connected to the lower end of the first energy storage capacitor C11 is equivalent to two batteries connected in series. Power supply, that is, voltage superposition is performed. Therefore, the first energy storage capacitor C11 outputs the superposed ninth voltage Vled through the cathode of the second diode D12, where Vled is equal to Vin+Vo.
  • the energy storage element Cn its first end is connected to the voltage Vled, and its second end is connected to the voltage 0. Therefore, the energy storage element Cn is charged, and the Cn energy storage voltage difference is Vled.
  • Step (3) The first controller controls the first switch S1 to open, the second switch S2 to close, and repeats the charging process of the first energy storage capacitor C11 in step (1).
  • the energy storage element Cn acts as the power output Vled to supply power to the backlight control module.
  • the anode voltage of the second diode D12 is Vin and the cathode voltage is Vled, it is not conductive.
  • FIG. 34 and FIG. 35 the first diode D11 and the second diode D12 can be replaced by switching elements.
  • Figure 36 is a schematic structural diagram of a power supply circuit of yet another charge pump module according to an embodiment of the present application.
  • the charge pump module includes: a second controller, a second energy storage capacitor C12, a third switch S3, a fourth switch S4, a fifth switch S5 and a sixth switch S6.
  • the first terminal of the third switch S3 is connected to the DC input voltage Vin
  • the second terminal of the third switch S3 is connected to the first terminal of the fourth switch S4.
  • the second terminal of the fourth switch S4 serves as the output terminal of the charge pump module, and outputs the third terminal of the charge pump module.
  • Nine voltages Vled the first terminal of the fifth switch S5 is connected to the first terminal of the third switch S3, the second terminal of the fifth switch S5 is connected to the first terminal of the sixth switch S6, and the second terminal of the sixth switch S6 is connected to ground;
  • the first terminal of the second energy storage capacitor C12 is connected to the second terminal of the third switch S3, and the second terminal of the second energy storage capacitor C12 is connected to the second terminal of the fifth switch S5.
  • the second controller is connected to the control terminals of the third switch S3, the fourth switch S4, the fifth switch S5 and the sixth switch S6, and is used to control the third switch S3, the fourth switch S4 and the fifth switch S6 according to the feedback signal.
  • the switching frequency of switch S5 and sixth switch S6 is to adjust the superimposed voltage; wherein, the switching states of the third switch S3 and the fourth switch S4 are different, and the third switch S3 and the sixth switch S6 are turned off or turned on at the same time; the fourth The switch S4 and the fifth switch S5 are turned off or turned on at the same time.
  • Step (1) The second controller controls the fourth switch S4 and the fifth switch S5 to open at the same time, and the third switch S3 and the sixth switch S6 to close at the same time.
  • the DC input voltage Vin charges the second energy storage capacitor C12 through the closed third switch S3, so that the first terminal of the second energy storage capacitor C12 is a positive voltage.
  • the opening time of the fourth switch S4 and the fifth switch S5, and the closing time of the third switch S3 and the sixth switch S6 the charging time of the second energy storage capacitor C12 is controlled, thereby controlling the storage time of the second energy storage capacitor C12. energy voltage.
  • Vo the energy storage voltage of the second energy storage capacitor C12 after charging
  • Vo that is, the superposition voltage
  • Step (2) The second controller controls the fourth switch S4 and the fifth switch S5 to close at the same time, and the third switch S3 and the sixth switch S6 to open.
  • the DC input voltage Vin passes through the fifth switch S5 and the second energy storage
  • the second end of the capacitor C12 is connected.
  • the second energy storage capacitor C12 is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode.
  • the DC input voltage Vin is connected to the second storage capacitor C12.
  • the lower end of capacitor C12 is equivalent to two power supplies connected in series, that is, the voltage is superimposed.
  • the second energy storage capacitor C12 outputs the superposed ninth voltage Vled through the fourth switch S4, where Vled is equal to Vin+Vo.
  • Vled is equal to Vin+Vo.
  • Step (3) The second controller controls the fourth switch S4 and the fifth switch S5 to open at the same time, the third switch S3 and the sixth switch S6 to close at the same time, and repeat the charging of the second energy storage capacitor C12 in step (1).
  • the energy storage element Cn is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode.
  • connecting the DC input voltage Vin to the second end of the energy storage element Cn is equivalent to a series connection.
  • the two power supplies perform voltage superposition. Therefore, the superposed ninth voltage Vin+Vo, that is, Vled, is output through the first terminal of the energy storage element Cn.
  • the second controller controls the amount of charge transmission by controlling the switching frequency or duty cycle of the third switch S3, the fourth switch S4, the fifth switch S5 and the sixth switch S6 based on the feedback signal, thereby controlling the ninth voltage Vled.
  • the DC input voltage Vin is relatively stable and is equivalent to a "fixed voltage”; the superimposed voltage Vo is equivalent to a "varying voltage”. Since the DC input voltage Vin is relatively stable, the output voltage variation range of the superimposed voltage Vo depends on the required variation range of the ninth voltage Vled.
  • the above-mentioned circuit structure using a "fixed voltage” superimposed on a "variable voltage” is a "ladder power supply", which can achieve the purpose of reducing costs and improving efficiency.
  • the second end of the energy storage element Cn can also be grounded.
  • Figure 37 is a schematic structural diagram of a power supply circuit of another charge pump module according to an embodiment of the present application. The difference from Figure 36 is that the second end of the energy storage element Cn is grounded. Therefore, the difference between the power supply principles of Figure 37 and Figure 36 is that the energy storage voltage difference of the energy storage element Cn is different.
  • Step (1) The second controller controls the fourth switch S4 and the fifth switch S5 to open at the same time, and the third switch S3 and the sixth switch S6 to close at the same time.
  • the DC input voltage Vin charges the second energy storage capacitor C12 through the closed third switch S3, so that the first terminal of the second energy storage capacitor C12 is a positive voltage.
  • the opening time of the fourth switch S4 and the fifth switch S5, and the closing time of the third switch S3 and the sixth switch S6 the charging time of the second energy storage capacitor C12 is controlled, thereby controlling the storage time of the second energy storage capacitor C12. energy voltage.
  • Vo the energy storage voltage of the second energy storage capacitor C12 after charging
  • Vo that is, the superposition voltage
  • Step (2) The second controller controls the fourth switch S4 and the fifth switch S5 to close at the same time, and the third switch S3 and the sixth switch S6 to open.
  • the DC input voltage Vin passes through the fifth switch S5 and the second energy storage
  • the second end of the capacitor C12 is connected.
  • the second energy storage capacitor C12 is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode.
  • the DC input voltage Vin is connected to the second storage capacitor C12.
  • the lower end of capacitor C12 is equivalent to two power supplies connected in series, that is, the voltage is superimposed.
  • the second energy storage capacitor C12 outputs the superposed ninth voltage Vled through the fourth switch S4, where Vled is equal to Vin+Vo.
  • Vled is equal to Vin+Vo.
  • Step (3) The fourth switch S4 and the fifth switch S5 of the second controller are opened at the same time, the third switch S3 and the sixth switch S6 are closed at the same time, and the charging process of the second energy storage capacitor C12 in step (1) is repeated. .
  • the energy storage element Cn acts as the power output Vled to supply power to the backlight control module.
  • the power supply circuit shown in FIG. 36 has lower energy storage requirements for the energy storage element Cn than the power supply circuit shown in FIG. 37 . Energy storage requirements are low and, accordingly, costs are low.
  • the third voltage conversion module shown in FIG. 32 may be in a flyback isolation form.
  • FIG. 38 is a schematic structural diagram of a power supply circuit of another display device according to an embodiment of the present application. As shown in Figure 38, the third voltage conversion module includes: a flyback isolation transformer module.
  • the flyback isolation transformer module is used to add the superimposed voltage generated by the secondary winding to the DC input voltage when the primary winding is cut off, and output the superimposed ninth voltage to the backlight control module; the first end of the energy storage element Connected to the output end of the flyback isolation transformer module; the energy storage element is used to store energy and superimpose the voltage when the primary winding is turned off; and when the primary winding is turned on, the superimposed voltage is superimposed on the DC input voltage, and the superimposed voltage
  • the final ninth voltage is output to the backlight control module; where the feedback signal is used to instruct the flyback isolation transformer module to adjust the ninth voltage by adjusting the superimposed voltage.
  • the voltage conversion module in the form of flyback isolation used in this embodiment is electrically isolated through the primary winding and the secondary winding, which can better complete voltage superposition.
  • Flyback specifically means that when the switch tube is turned on, the secondary winding transformer acts as an inductor and the electrical energy is converted into magnetic energy. At this time, there is no current in the output loop; on the contrary, when the switch tube is turned off, the secondary winding transformer releases energy and the magnetic energy is converted into It is electrical energy, and there is current in the output circuit.
  • the secondary winding transformer also acts as an energy storage inductor, which has the characteristics of fewer components, simple circuit, low cost, and small size. At the same time, electrical isolation improves the safety of use.
  • the energy storage component shown in Figure 38 may be a single energy storage capacitor or other energy storage circuit.
  • the energy storage element cooperates with the flyback isolation transformer module to alternately output the ninth voltage to continuously supply power to the backlight control module so that the light-emitting diode emits light stably.
  • the power supply principle of the third voltage conversion module and the energy storage element will be explained below based on the specific circuit structure schematic diagram of the flyback isolation transformer module and the energy storage element.
  • FIG. 39 is a schematic structural diagram of a power supply circuit of a flyback isolation transformer module according to an embodiment of the present application.
  • the flyback isolation transformer module includes: primary winding, secondary winding, third diode D13, third controller and seventh switch S7.
  • the first end of the primary winding is connected to the DC input voltage Vin
  • the second end of the primary winding is connected to the first end of the seventh switch S7, and the second end of the seventh switch S7 is grounded
  • the secondary winding is coupled to the primary winding
  • the secondary winding is coupled to the primary winding.
  • the first end of the side winding is connected to the anode of the third diode D13, and the second end of the secondary winding is connected to the DC input voltage Vin
  • the cathode of the third diode D13 serves as the output end of the flyback isolation transformer module.
  • the ninth voltage Vled is output.
  • the third controller is connected to the control end of the seventh switch S7 and is used to control the on and off of the primary winding by controlling the switching frequency S7 of the seventh switch according to the feedback signal to adjust the superimposed voltage.
  • the second end of the secondary winding is connected to the DC input voltage Vin, that is, the DC input voltage Vin is applied to the second end of the secondary winding.
  • the DC input voltage Vin can be applied to the second end of the secondary winding by establishing a physical connection between the second end of the secondary winding and the first end of the primary winding.
  • a physical connection can also be established between the second end of the secondary winding and the power supply interface to apply the DC input voltage Vin to the second end of the secondary winding, which is more conducive to electrical isolation.
  • Step (1) The third controller controls the seventh switch S7 to conduct, the primary winding conducts, the current in the primary winding increases linearly, and the inductor energy storage increases; the third diode D13 does not conduct, the secondary winding does not conduction.
  • the energy storage voltage of the primary winding can be controlled by controlling the switching frequency of the seventh switch S7.
  • Step (2) The third controller controls the seventh switch S7 to turn off, the primary winding is cut off, and the primary winding current is cut off; the third diode D13 is turned on, and the secondary winding is turned on.
  • the secondary winding can generate a superimposed voltage Vo; at the same time, since the second end of the secondary winding is connected to the DC input voltage Vin, after voltage superposition, the first end of the secondary winding
  • Step (3) The third controller controls the seventh switch S7 to turn on, and repeats the energy storage process of the primary winding in step (1).
  • the energy storage element Cn is regarded as a battery with the upper end (i.e. the first end) being the positive electrode and the lower end (i.e. the second end) being the negative electrode. Then connecting the DC input voltage Vin to the second end of the energy storage element Cn is equivalent to a series connection.
  • the two power supplies perform voltage superposition. Therefore, the superposed ninth voltage Vled is output through the first terminal of the energy storage element Cn.
  • the third controller controls the amount of charge transmission by controlling the switching frequency or duty cycle of the seventh switch S7 based on the feedback signal, thereby achieving the purpose of controlling the ninth voltage Vled.
  • the DC input voltage Vin is relatively stable and is equivalent to a "fixed voltage”; the superimposed voltage Vo is equivalent to a "varying voltage”. Since the DC input voltage Vin is relatively stable, the output voltage variation range of the superimposed voltage Vo depends on the required variation range of the ninth voltage Vled.
  • the above-mentioned circuit structure using a "fixed voltage” superimposed on a "variable voltage” is a "ladder power supply", which can achieve the purpose of reducing costs and improving efficiency.
  • the second end of the energy storage element Cn can also be grounded.
  • Figure 40 is a schematic structural diagram of the power supply circuit of another flyback isolation transformer module according to an embodiment of the present application. The difference from Figure 39 is that the second end of the energy storage element Cn is grounded. Therefore, the difference between the power supply principles of Figure 40 and Figure 39 is that the energy storage voltage difference of the energy storage element Cn is different.
  • Step (1) The third controller controls the seventh switch S7 to conduct, the primary winding conducts, the current in the primary winding increases linearly, and the inductor energy storage increases; the third diode D13 does not conduct, the secondary winding does not conduction.
  • the energy storage voltage of the primary winding can be controlled by controlling the switching frequency of the seventh switch S7.
  • Step (2) The third controller controls the seventh switch S7 to turn off, the primary winding is cut off, and the primary winding current is cut off; the third diode D13 is turned on, and the secondary winding is turned on.
  • the secondary winding can generate a superimposed voltage Vo; at the same time, since the second end of the secondary winding is connected to the DC input voltage Vin, after voltage superposition, the first end of the secondary winding
  • Step (3) The third controller controls the seventh switch S7 to turn on, and repeats the energy storage process of the primary winding in step (1).
  • the energy storage element Cn is regarded as a battery with the upper end (i.e., the first end) being the positive electrode and the lower end (i.e., the second end) being the negative electrode. It outputs Vled to power the backlight control module.
  • the display device provided in this embodiment further includes a first filtering module; the first filtering module is connected to the power supply interface and the third voltage conversion module, and is used to filter the DC input voltage.
  • the first filter module may be a filter circuit composed of one or more grounded capacitors, or may be a filter circuit composed of a capacitor and an inductor.
  • FIG. 41 is a schematic structural diagram of a filtering module according to an embodiment of the present application.
  • the first filter module takes a grounded capacitor as an example.
  • a first filter capacitor C13 is connected in parallel between the DC input voltage of the power supply interface and the ground. It is used to filter out the noise and AC components of the power supply, smooth the pulsating DC voltage, and store electrical energy.
  • the capacitance is related to the load current and the purity of the power supply. A larger-capacity filter capacitor is usually selected.
  • the first filter capacitor C13 may be the electrolytic capacitor shown in FIG. 41 .
  • Electrolytic capacitor is a type of capacitor.
  • the metal foil is the positive electrode (aluminum or tantalum).
  • the oxide film (aluminum oxide or tantalum pentoxide) close to the positive electrode is the dielectric.
  • the cathode is made of conductive material and electrolyte (the electrolyte can be liquid or solid) and other materials, because the electrolyte is the main part of the cathode. Its capacitance per unit volume is very large. Since the preparation materials are ordinary industrial materials and the preparation process is also ordinary industrial equipment, mass production can be carried out, so the cost is relatively low. It should be noted that the positive and negative electrolytic capacitors cannot be connected incorrectly.
  • the first filter capacitor C13 can also be other types of capacitors, such as ceramic tape content, film capacitors, mica capacitors, etc. In actual circuits, selection can be made based on capacitance requirements.
  • the display device provided in this embodiment further includes a second filtering module; the second filtering module is connected to the output end of the third voltage conversion module and is used to filter the ninth voltage.
  • the second filter module may be a filter circuit composed of one or more grounded capacitors, or may be a filter circuit composed of a capacitor and an inductor.
  • the second filter capacitor C14 that is grounded is used as an example for filtering.
  • the second end of the energy storage element Cn is connected to the DC input voltage Vin.
  • the charge pump module or flyback isolation transformer module cooperates with the energy storage element Cn to alternately output the ninth voltage Vled.
  • a filter module can also be provided to filter out noise in the DC input voltage Vin input to the energy storage element Cn.
  • the display device provided in this embodiment further includes a fourth diode Dn; the anode of the fourth diode Dn is connected to the second end of the energy storage element Cn, and the cathode of the fourth diode Dn is connected to the second end of the energy storage element Cn.
  • the first end of the energy storage element Cn is connected.
  • the fourth diode Dn is used to input the DC input voltage Vin to the backlight control module to form a current loop to prevent current from flowing through the third voltage conversion module and causing system malfunction or other abnormal conditions when the third voltage conversion module is not working. It plays the role of protecting the third voltage conversion module.
  • FIG. 42 is a schematic structural diagram of a filter module based on a charge pump module power supply circuit according to an embodiment of the present application.
  • the charge pump module is shown in Figure 36 as an example, and the power supply principle will not be described again.
  • Figure 43 is a schematic structural diagram of a filter module based on a flyback isolation transformer module power supply circuit according to an embodiment of the present application.
  • the flyback isolation transformer module takes Figure 39 as an example, where, By establishing a physical connection between the second end of the secondary winding and the first end of the primary winding, the DC input voltage Vin is applied to the second end of the secondary winding. The power supply principle will not be described again.
  • the display device provided in this embodiment further includes: a mainboard; the mainboard is connected to the power supply interface, and the DC input voltage is used to supply power to the mainboard.
  • Figure 44 is a schematic structural diagram of a third circuit that supplies power to a mainboard according to an embodiment of the present application. When the DC input voltage is equal to the required voltage of the motherboard, you can choose to use the DC input voltage to directly power the motherboard.
  • the display device provided in this embodiment further includes a fourth voltage conversion module; the fourth voltage conversion module is connected to the power supply interface and the mainboard, and is used to output a tenth voltage according to the DC input voltage, where the tenth voltage is The required voltage of the motherboard.
  • Figure 45 is a schematic structural diagram of a fourth circuit that supplies power to a mainboard according to an embodiment of the present application.
  • the fourth voltage conversion module can be used to perform DC-DC voltage conversion on the DC input voltage.
  • the fourth voltage conversion module may use a buck circuit, a boost-buck circuit, etc.
  • This embodiment also provides a display control method, applied to the aforementioned display device, including: receiving a feedback signal, the feedback signal is generated by the backlight control module and sent through the feedback module; based on the feedback signal, adjusting the superimposed voltage to adjust the ninth voltage; The ninth voltage is the required voltage of the backlight control module.
  • the superimposed voltage generated by the third voltage conversion module is adjusted according to the real-time current feedback signal output by the backlight control module, and then the ninth voltage is adjusted so that the backlight control module operates at the rated current to prevent excessive current from flowing.
  • the LED components in the LED light string cause damage to the components.
  • the superimposed voltage is equivalent to the "variable voltage”; the tenth voltage is equivalent to the "fixed voltage”.
  • the superposition of the two voltages realizes ladder power supply, which is beneficial to reducing heat loss.
  • the display device includes: a backlight control module for controlling the light emitting of a light emitting diode, and the light emitting diode is used for lighting the screen of the display device; a power supply interface for receiving a DC input voltage, the DC input voltage is provided by an external adapter Provide; a third voltage conversion module, used to generate a superimposed voltage according to the DC input voltage, superimpose the superimposed voltage with the DC input voltage, and output the superimposed ninth voltage; the ninth voltage is the demand voltage of the backlight control module; energy storage element, the first end of the energy storage element is connected to the output end of the third voltage conversion module, and the second end of the energy storage element is connected to the DC input voltage for energy storage superimposed voltage, and alternately outputs the ninth voltage with the third voltage conversion module. Voltage; feedback module, used to send the feedback signal generated by the backlight control module to the third voltage conversion module, and the feedback signal is used to instruct the third voltage conversion module to adjust the ninth voltage.
  • a power supply interface connected to an external adapter is provided to receive a DC input voltage to adapt to the external adapter power supply mode; the DC input voltage is used to generate a superimposed voltage, and the superimposed voltage is superimposed with the DC input voltage to achieve Ladder power supply is conducive to reducing heat loss; energy storage components are used to continuously supply power to the backlight control module; real-time feedback is used to adjust the power supply voltage of the backlight control module in a timely manner to stabilize the operation of the light-emitting diodes.

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Abstract

本申请提供一种显示装置，包括：变压器、电压变换模块、反馈模块及灯串组；电压变换模块与灯串组一一对应，灯串组包括第一灯串（140）和第二灯串（150）；变压器的第一次级线圈（110）输出第一电压；变压器的第二次级线圈（120）的两端交替输出第二电压；第二次级线圈（120）与灯串组一一对应；电压变换模块，根据第一电压生成叠加电压，并将叠加电压叠加至第二电压，输出第三电压；反馈模块，用于生成反馈信号并发送至电压变换模块，以对第三电压进行调整；第一灯串（140）连接至第二次级线圈（120）的一端，第二灯串（150）连接至第二次级线圈（120）的另一端，用于基于第三电压发光。本申请中两个灯串共用同一供电线圈和电压变换模块，简化了电路；同时利用电压叠加实现阶梯供电，降低了热损耗。

Description

显示装置
相关申请的交叉引用
本申请要求在2022年04月19日提交、申请号为202210412214.4；在2022年04月20日提交、申请号为202210415138.2；在2022年04月21日提交、申请号为202210421396.1的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及显示装置技术领域，尤其涉及一种显示装置。
背景技术
随着电子技术的发展，包括电视机等显示装置在内的电子设备的集成度越来越高，也就对显示装置的电源提出了越来越高的要求。
以电视为例，由于电视中存在主板供电和发光二极管(Light Emitting Diode，LED)灯串的背光驱动两种供电需求，所以系统设计比较复杂。具体的，一种相关设计中，采用谐振转换电路(LLC)模块基于交流电输出多个直流电压，分别为主板和灯串供电。其中，每路灯串对应一个直流-直流电压调整模块，对LLC模块输出的固定的直流电压进行电压调整，以满足灯串的电压需求。另一种相关设计中，采用两个LLC模块分别为主板和灯串供电。其中，通过调节灯串对应的LLC模块中原边绕组的交流电压，从而调节其副边绕组的输出电压，以满足灯串的电压需求。如何简化上述的供电电路，成为亟需解决的问题。
发明内容
本申请提供一种显示装置，用以简化显示装置的供电电路。
本申请提供一种显示装置，包括：变压器、电压变换模块、反馈模块以及灯串组；其中，电压变换模块与灯串组一一对应，灯串组包括第一灯串和第二灯串；变压器的第一次级线圈和第二次级线圈，与变压器的初级线圈耦合；第一次级线圈，用于根据初级线圈接收的电源，输出第一电压；第二次级线圈，用于根据初级线圈接收的电源，由第二次级线圈的两端交替输出第二电压；第二次级线圈与灯串组一一对应；电压变换模块，用于根据第一电压，生成叠加电压并将叠加电压叠加至对应的第二次级线圈两端的第二电压，输出叠加后的第三电压；反馈模块，用于根据灯串组的输出电流生成反馈信号，并发送至电压变换模块，反馈信号用于指示电压变换模块调整第三电压；第一灯串连接对应的第二次 级线圈的一端，第二灯串连接对应的第二次级线圈的另一端，用于基于第三电压发光。
附图说明
图1为设有独立电源板的显示装置的结构示意图；
图2为显示装置的电源板与负载的连接关系示意图；
图3为电视电源架构示意图；
图4为一种为主板以及LED灯串供电的电路结构示意图；
图5为另一种为主板以及LED灯串供电的电路结构示意图；
图6为再一种为主板以及LED灯串供电的电路结构示意图；
图7为根据本申请实施例的一种两路灯串的显示装置的电路结构示意图；
图8为根据本申请实施例的一种电压变换模块的电路结构示意图；
图9为根据本申请实施例的一种电压叠加模块的电路结构示意图；
图10为根据本申请实施例的一种电压调整模块的电路结构示意图；
图11为根据本申请实施例的另一种电压调整模块的电路结构示意图；
图12为根据本申请实施例的一种第一开关电路的电路结构示意图；
图13为根据本申请实施例的一种第二开关电路的电路结构示意图；
图14为根据本申请实施例的一种四路灯串的显示装置的电路结构示意图；
图15为根据本申请实施例的另一种四路灯串的显示装置的电路结构示意图；
图16为根据本申请实施例的再一种四路灯串的显示装置的电路结构示意图；
图17为根据本申请实施例的又一种四路灯串的显示装置的电路结构示意图；
图18为一种为主板以及LED灯串供电的供电电路结构示意图；
图19为另一种为主板以及LED灯串供电的供电电路结构示意图；
图20为再一种为主板以及LED灯串供电的供电电路结构示意图；
图21为根据本申请实施例的外置适配器供电模式的示意图；
图22为根据本申请实施例的一种显示装置的供电电路结构示意图；
图23为根据本申请实施例的另一种显示装置的供电电路结构示意图；
图24为根据本申请实施例的一种电荷泵模块的供电电路结构示意图；
图25为根据本申请实施例的又一种显示装置的供电电路结构示意图；
图26为根据本申请实施例的一种反激式隔离变压模块的供电电路结构示意图；
图27为根据本申请实施例的一种电平转换电路的结构示意图；
图28为根据本申请实施例的一种基于电荷泵模块供电电路的电平转换电路的结构示意图；
图29为根据本申请实施例的一种基于反激式隔离变压模块供电电路的电平转换电路 的结构示意图；
图30为根据本申请实施例的一种为主板供电的电路结构示意图；
图31为根据本申请实施例的另一种为主板供电的电路结构示意图；
图32为根据本申请实施例的一种显示装置的供电电路结构示意图；
图33为根据本申请实施例的另一种显示装置的供电电路结构示意图；
图34为根据本申请实施例的一种电荷泵模块的供电电路结构示意图；
图35为根据本申请实施例的另一种电荷泵模块的供电电路结构示意图；
图36为根据本申请实施例的再一种电荷泵模块的供电电路结构示意图；
图37为根据本申请实施例的又一种电荷泵模块的供电电路结构示意图；
图38为根据本申请实施例的又一种显示装置的供电电路结构示意图；
图39为根据本申请实施例的一种反激式隔离变压模块的供电电路结构示意图；
图40为根据本申请实施例的另一种反激式隔离变压模块的供电电路结构示意图；
图41为根据本申请实施例的一种滤波模块的结构示意图；
图42为根据本申请实施例的一种基于电荷泵模块供电电路的滤波模块的结构示意图；
图43为根据本申请实施例的一种基于反激式隔离变压模块供电电路的滤波模块的结构示意图；
图44为根据本申请实施例的一种为主板供电的电路结构示意图；
图45为根据本申请实施例的另一种为主板供电的电路结构示意图。
具体实施方式
这里将详细地对实施例进行说明。下面的描述涉及附图时，除非另有表示，不同附图中的相同数字表示相同或相似的要素。以下实施例中所描述的实施方式并不是本申请全部的而是部分实施方式。
随着人们获取信息的需求不断加深，各种类型的显示装置应运而生，比如电脑、电视机以及投影仪等。供电电路是显示装置中最为重要的电路结构之一，供电电路可以为显示装置提供电能，从而使显示装置得以正常运行。有的显示装置设置有独立电源板，有的显示装置将电源板和主板合二为一。
以设置有独立电源板的显示装置为例，对显示装置的结构进行说明，参见图1所示，图1为设有独立电源板的显示装置的结构示意图，如图1所示，显示装置包括显示面板1、背光组件2、主板3、电源板4、后壳5和基座6。其中，显示面板1用于给用户呈现画面；背光组件2位于显示面板1的下方，通常是一些光学组件，用于供应充足的亮度与分布均匀的光源，使显示面板1能正常显示影像，背光组件2还包括背板20，主板3和电源板4 设置于背板20上，通常在背板20上冲压形成一些凸包结构，主板3和电源板4通过螺钉或者挂钩固定在凸包上；后壳5盖设在面板1上，以隐藏背光组件2、主板3以及电源板4等显示装置的零部件，使得外观更美观；基座6，用于支撑显示装置。
在一些实施例中，图2为显示装置的电源板与负载的连接关系示意图，如图2所示，电源板4包括输入端41和输出端42(图中示出第一输出端421、第二输出端422、第三输出端423)，其中，输入端41与市电相连，输出端42与负载相连，比如，第一输出端421和用于点亮显示屏幕的LED灯串相连，第二输出端422和音响相连，第三输出端423和主板相连。电源板4需要将交流市电转换为负载所需求的直流电，并且，该直流电通常具有不同的规格，例如音响需要18V，面板需要12V等。
在一些实施例中，以电视为例介绍显示装置的电源架构，图3为电视电源架构示意图，如图3所示，电源板具体可以包括：整流桥、功率因数校正(Power Factor Correction，PFC)模块和谐振变换器(LLC)模块，LLC模块中包括同步整流电路(图3未示出)，PFC模块与LLC模块连接，LLC模块连接负载。
其中，整流桥用于对输入的市电交流电进行整流，向PFC模块输入全波信号。在交流电源输入PFC模块之前可以连接有电磁干扰(Electromagnetic Interference，EMI)滤波器(图3未示出)，对输入的交流电源进行高频滤波。
PFC模块可以包括PFC电感、开关功率器件和PFC控制芯片，主要对输入的交流电源进行功率因数校正，向LLC模块输出稳定的直流母线电压(如380V)。PFC模块可以有效提高电源的功率因数，保证电压和电流同相位。或者，而在一些实施例中，如图3所示的电源架构中也可以不设置PFC模块。
LLC模块可以采用双MOS管LLC谐振变换电路，通常同步整流电路设置在LLC模块中，同步整流电路主要可以包括变压器、控制器、两个MOS管以及二极管。另外，LLC模块还可以包括脉冲频率调整(Pulse frequency modulation，PFM)电路、电容以及电感等元器件。LLC模块具体可以对PFC模块输入的直流母线电压进行降压或升压，并输出恒定的电压给负载。通常，LLC模块能够输出多种不同的电压，以满足不同负载的需求。或者，在另一些实施例中，如图3所示的LLC模块还可以用反激电压变换模块代替，由反激励电压变换模块对电压进行降压或升压，并输出恒定的电压给负载。
更为具体地，同样以显示装置为电视机为例，图4为一种为主板以及LED灯串供电的供电电路结构示意图。供电电路所获取的市电交流电(100V-240V，50-60Hz)依次通过滤波整流模块(整流桥)、PFC模块和LLC隔离电压变换模块后，向显示装置的主板、多路LED灯串以及其他负载(图4中未示出)供电。其中，LLC隔离电压变换模块中的第一个副边绕组向主板提供第一电压(例如12V)，第二个副边绕组向主板提供第二电压(例如18V)，第三个副边绕组同时向多路LED灯串提供电压。
其中，LED灯串用于点亮电视机的显示屏幕，LED灯串内的LED组件需要在一定的压降范围内工作以达到其额定电流，例如多路LED灯串为16路的LED灯串，每路LED灯串包括9颗LED组件的情况下，在120mA条件下，多路LED灯串所需的电压范围为51.3V-58.5V，总电流为1.92A。
由于LED灯串的工作电压受到工作环境、LED组件的硬件特性及寿命等因素的影响，需要实时进行调整。因此，供电电路中还设置有电压调整模块(buck降压电路或者boost升压电路或者buck-boost升降压电路)。可以对LED灯串的工作电压或工作电流进行检测，并根据工作电压或工作电流的变化向电压调整模块发送反馈信号，使得电压调整模块可以根据反馈信号对输出给LED灯串的电压进行调整，进而保持LED灯串的工作电流的稳定。
如图4所示，以为主板及两路LED灯串供电为例，其中，为每路LED灯串对应配置了一个以boost升压电路为例的电压调整模块。电压调整模块能够根据每路LED灯串的实时电流反馈结果，对第三副边绕组输出的固定电压进行调整后传输至每路LED灯串，使得每路LED灯串以额定电流工作，防止过大电流流过LED灯串中的LED组件造成元件的损坏。
但是，在如图4所示的供电电路中，供电电路中为每路LED灯串设置的一个电压调整模块。即每增加一路LED灯串，需要相应的增加一个电压调整模块。因此，电路结构相对复杂，进而占用供电电路所在PCB板的面积较大，最终增加了供电电路的成本。
在一些实施例中，图5为另一种为主板以及LED灯串供电的电路结构示意图，供电电路所获取的市电交流电(100V-240V，50-60Hz)依次通过滤波整流模块(整流桥)、PFC模块和LLC隔离电压变换模块后，向显示装置的主板、多路LED灯串以及其他负载(图5中未示出)供电。其中，LLC隔离电压变换模块1中的第一个副边绕组向主板提供第一电压(例如12V)，第二个副边绕组向主板提供第二电压(例如18V)；LLC隔离电压变换模块2为同时为两路LED灯串提供电压。LLC隔离电压变换模块2利用交流电的特性交替为两路LED灯串提供工作电压。其中，LLC隔离电压变换模块2的控制器接收两路LED灯串的电流反馈，进而对LLC隔离电压变换模块2输出的电压进行调整，将调整后的电压传输至两路LED灯串，使得每路LED灯串以额定电流工作，防止过大电流流过LED灯串中的LED组件造成元件的损坏。
其中，LLC隔离电压变换模块2的副边绕组的一个输出端连接的电容起到均流的作用，用于使两路LED灯串的工作电流相等；该副边绕组的两个输出端与LED灯串之间串联的二极管，基于单向导通特性起到整流作用；该副边绕组的两个输出端所连接的接地二极管起到稳压作用。
但是，在图5所示的供电电路中，LLC隔离电压变换模块2的输出电压范围有限，当需要改变电流大小时，LLC隔离电压变换模块2的输出范围就受到较大的限制。另外，显 示装置可能具备大于两路的多路LED灯串，按照图5所示的供电电路，每增加两路LED灯串，相应的需要在LLC隔离电压变换模块2上增加一个副边绕组，为新增的LED灯串供电。数量较多的副边绕组会导致变压器设计相对困难，复杂的电路成本也较高。
在一些实施例中，图6为再一种为主板以及LED灯串供电的电路结构示意图。供电电路所获取的市电交流电(100V-240V，50-60Hz)依次通过滤波整流模块(整流桥)、PFC模块和LLC隔离电压变换模块后，向显示装置的主板、多路LED灯串以及其他负载(图6中未示出)供电。其中，LLC隔离电压变换模块包括四个副边绕组，第一个副边绕组向主板提供第一电压(例如12V)，第二个副边绕组向主板提供第二电压(例如18V)；第二个副边绕组及第三个副边绕组共同为第二LED灯串供电；第二个副边绕组及第四个副边绕组共同为第一LED灯串供电。
具体的，该第二副边绕组的输出的18V电压通过以boost升压电路为例的电压调整模块，生成“变动电压”，连接到该第三副边绕组的一端，与第三副边绕组生成固定电压2进行叠加，叠加后的电压为第二LED灯串供电。
同理，该第二副边绕组的输出的18V电压通过以boost升压电路为例的电压调整模块，生成“变动电压”，连接到该第四副边绕组的一端，与第四副边绕组生成固定电压1进行叠加，叠加后的电压为第一LED灯串供电。
在图6所示的供电电路中，“变动电压”与“固定电压”叠加供电的方式被称为“阶梯供电”，有利于降低了对电压调整模块中开关管、电容等元件的耐压值的要求，进而降低成本。但是，每增加一路LED灯串，相应的需要在LLC隔离电压变换模块上增加一个副边绕组，以及相应增加一个电压调整模块。数量较多的副边绕组会导致变压器设计相对困难；同时电路结构相对复杂，进而占用供电电路所在PCB板的面积较大，最终增加了供电电路的成本。
基于此，本申请提供的显示装置，两条LED灯串共用一个次级线圈和电压变换模块，其中，次级线圈的两端交替输出“固定电压”，叠加电压变换模块输出的“变动电压”，实现对两条LED灯串的“阶梯供电”。既能简化供电电路，又能降低热损耗。
下面以具体地实施例对本申请的内容以及本申请的内容如何解决上述技术问题进行详细说明。下面这几个具体的实施例可以相互结合。下面将结合附图，对本申请的实施例进行描述。
图7为根据本申请实施例的一种两路灯串的显示装置的电路结构示意图。如图7所示，包括：变压器、电压变换模块、反馈模块以及灯串组；其中，电压变换模块与灯串组一一对应，灯串组包括第一灯串140和第二灯串150；
图7中变压器以LLC隔离电压变换模块为例，LLC隔离电压变换模块的第一次级线圈110和第二次级线圈120，与LLC隔离电压变换模块的初级线圈100耦合；第一次级线 圈110，用于根据初级线圈100接收的电源，输出第一电压；第二次级线圈120，用于根据初级线圈100接收的电源，由第二次级线圈120的两端交替输出第二电压；第二次级线圈120与灯串组一一对应；电压变换模块，用于根据第一电压，生成叠加电压并将叠加电压叠加至对应的第二次级线圈两端的第二电压，输出叠加后的第三电压；
反馈模块，用于根据灯串组的输出电流生成反馈信号，并发送至电压变换模块，反馈信号用于指示电压变换模块调整第三电压；第一灯串140连接对应的第二次级线圈120的一端，第二灯串150连接对应的第二次级线圈120的另一端，用于基于第三电压发光。
其中，图7所示的供电电路还包括滤波整流模块(整流桥)和PFC模块，对所获取的市电交流电进行处理，再经由LLC隔离电压变换模块向显示装置的主板、多路LED灯串以及其他负载(图7中未示出)供电。
其中，第一次级线圈110的一端接地，第一次级线圈110中间抽头以及第一次级线圈110的另一端均串联一个整流二极管后输出第一电压。图7中该第一电压以18V直流电压为例。因为第一次级线圈110与初级线圈100耦合感生出交流电，所以需要通过上述的整流电路进行交流-直流的转换。
本实施例利用第二次级线圈120与初级线圈100耦合感生的交流电，由第二次级线圈的两端交替输出第二电压，相当于“固定电压”；电压变换模块根据反馈信号对将第一次级线圈输出的第一电压进行调整生成叠加电压，该叠加电压相当于“变动电压”；电压变换模块将该叠加电压叠加至第二电压，输出叠加后的第三电压。本实施例中，两个灯串共用同一供电线圈和电压变换模块，简化了电路；同时利用“固定电压”与“变动电压”的电压叠加实现阶梯供电，有利于降低热损耗。
其中，反馈模块可以为电流反馈方式，也可以为电压反馈方式。反馈模块可以根据单路灯串的电流生成反馈信号，也可以根据多路灯串的电流生成反馈信号。采用单路灯串进行反馈时，反馈模块中设定的参考电流值为一路灯串的需求工作电流。两路灯串共同反馈时，则反馈模块中设定的参考电流值为2倍的一路灯串的需求工作电流。该参考电流值用来与实际电流进行比较，若实际电流高于参考电流值，则输出的反馈信号指示电压调整模块降低第三电压；若实际电流等于参考电流值，则输出的反馈信号指示电压调整模块维持第三电压；若实际电流低于参考电流值，则输出的反馈信号指示电压调整模块提高第三电压。
图7采用两路灯串共同反馈的方式。具体的，反馈模块根据灯串组中第一灯串140和第二灯串150的总电流生成反馈信号，并发送至电压变换模块，用以指示电压变换模块调节第三电压。其中，第一灯串140和第二灯串150可以直接接地，或者通过接地电路Rn接地。接地电路Rn有利于释放静电，避免静电积累。
在一些实施例中，图8为根据本申请实施例的一种电压变换模块的电路结构示意图。 电压变换模块包括：电压调整模块和电压叠加模块；电压调整模块与第一次级线圈的输出端连接，用于根据第一电压，生成叠加电压；电压叠加模块接收叠加电压，并与第二次级线圈的两端连接，用于将叠加电压叠加至对应的第二次级线圈两端的第二电压，输出叠加后的第三电压；其中，反馈信号用于指示电压调整模块通过调整叠加电压来调整第三电压。
其中，第二电压相当于“固定电压”；电压调整模块根据反馈信号对第一电压进行调整输出叠加电压，该叠加电压相当于“变动电压”。电压叠加模块将该叠加电压叠加至第二电压，输出叠加后的第三电压，为灯串组进行供电。采用了阶梯供电方式，有利于降低热损耗。
在一些实施例中，电压叠加模块包括第一均流电容C1、第一整流二极管D1、第二整流二极管D2、第三整流二极管D3、第四整流二极管D4；
第一均流电容C1的一端与第二次级线圈的一端；第一均流电容C1的另一端与第一整流二极管D1的正极和第二整流二极管D2的负极连接；第二整流二极管D2的正极连接叠加电压；第一整流二极管D1的负极与第一灯串140的正极连接；第一灯串140的负极接地；
第三整流二极管D3的正极与第二次级线圈120的另一端和第四整流二极管D4的负极连接，第四整流二极管D4的正极连接叠加电压；第三整流二极管D3的负极与第二灯串150的正极连接；第二灯串150的负极接地。
图9为根据本申请实施例的一种电压叠加模块的电路结构示意图。初级线圈100在LLC隔离电压变换模块的内部控制下导通和断开时，第一均流电容C1分别进行充电和放电过程。
在第一均流电容C1放电时，电流由第一均流电容C1的第一端(即图10所示第一均流电容C1的左端)向第二端(即图10所示第一均流电容C1的右端)流动，第一均流电容C1中的电量经过第一灯串140的回路释放。同时，电压调整模块输出的叠加电压通过第二整流二极管D2，输入到第一整流二极管D1的正极，在第一整流二极管D1的正极发生电流叠加，并由第一整流二极管D1的负极输入至第一灯串140。
在第一均流电容C1充电时，电流由第一均流电容C1的第二端向第一端流动，第三整流二极管D3导通，第一均流电容C1中的电量经过第二灯串150的回路释放。同时，电压调整模块输出的叠加电压通过第四整流二极管D4，输入到第三整流二极管D3的正极，在第三整流二极管D3的正极发生电流叠加，并由第三整流二极管D3的负极输入至第二灯串150。
由于均流电容充电和放电的过程中电荷总数是相等的，因此分别流过两路灯串的电荷相等，进而使得两路灯串的电流相等，从而实现了两路灯串的均流。若两路灯串的电流不相等，则第一均流电容C1上会产生电压差，从而使第一灯串140和第二灯串150的环路 压降相同，即：平衡了阻抗。若干周期后，电流又达到相等的平衡状态。因此，在长时间的过程中，两条LED灯串的电流时相等的。
其中，第一灯串140所在环路包括第一整流二极管D1、第一灯串140、反馈模块、电压调整模块、第四整流二极管D4、第二次边绕组120；第二灯串150所在环路包括第二次边绕组120、第三整流二极管D3、第二灯串150、反馈模块、电压调整模块、第二整流二极管D2。
本申请实施例中，两个灯串共用同一供电线圈(即第二次级线圈120)和电压调整模块，简化了电路；同时利用两个整流二极管进行电压叠加，实现对每路灯串的阶梯供电，有利于降低热损耗。
一些实施例中，电压调整模块可以为boost升压电路。具体的，电压调整模块包括：第一电感L1、第一晶体管Q1、第一二极管D5、第一电容C2。第一电感L1的一端与第一次级线圈110的输出端连接；第一电感L1的另一端与第一晶体管Q1的一端和第一二极管D5的正极连接；第一晶体管Q1的另一端接地；第一二极管D5的负极作为电压调整模块的输出端，输出叠加电压；第一电容C2的一端与第一二极管D5的负极连接；第一电容C2的另一端接地；第一晶体管Q1的控制极与反馈模块连接，用于根据反馈信号，调节第一晶体管Q1的开关频率，以调节叠加电压。
图10为根据本申请实施例的一种电压调整模块的电路结构示意图。当第一晶体管Q1导通时，第一次级线圈110的输出端持续输出第一电压，为第一电感L1充电，使得第一电感L1的电流线性增加。
当第一晶体管Q1截止时，第一电感L1只能通过第一二极管D5放电，自第一二极管D5的负极向第二整流二极管D2和第四整流二极管D4输出叠加电压，同时为第一电容C2充电；电容两端升高，且高于输入的第一电压。
当第一晶体管Q1再次导通时，再次为第一电感L1充电；同时，由于第一二极管D5的单向导通性，使得第一电容C2放电，向第二整流二极管D2和第四整流二极管D4输出叠加电压。
通过控制第一晶体管Q1的开关频率，或者选择容量较大的第一电容C2，可以实现持续输出叠加电压，且该叠加电压高于输入的第一电压。其中，第一晶体管Q1的另一端可以直接接地，也可以连接接地电阻R1，用于释放静电，提高安全性。
一些实施例中，图10采用电流反馈方式。反馈模块包括第一驱动芯片，该第一驱动芯片用于实时地采集第一灯串140和第二灯串150的实际总电流，生成反馈信号，使电压调整模块对电压进行的及时、有效的调整，防止过大电流流过第一灯串140和第二灯串150中的LED组件造成元件的损坏。
一些实施例中，电压调整模块可以为buck降压电路。具体的，电压调整模块包括：第 二晶体管Q2、第三晶体管Q3、第二电感L2、第二电容C2、第二驱动芯片。第二晶体管Q2的一端与第一次级线圈110的输出端连接；第二晶体管Q2的另一端与第三晶体管Q3的一端和第二电感L2的一端连接；第三晶体管Q3的另一端接地；第二电感L2的另一端作为电压调整模块的输出端，输出叠加电压；第二电容C2的一端与第二电感L2的另一端连接；第二电容C2的另一端接地；第二晶体管Q2的控制极和第三晶体管Q3的控制极均与反馈模块连接，用于根据反馈信号，调节第二晶体管Q2和第三晶体管Q3的开关频率，以调节叠加电压。
图11为根据本申请实施例的另一种电压调整模块的电路结构示意图。该电压调整模块为同步整流buck降压电路。采用第三晶体管Q3代替整流二极管，有利于提高电压变换效率。
当第二晶体管Q2导通、第三晶体管Q3截止时，第一次级线圈110的输出端持续输出第一电压，为第二电感L2充电，使得第二电感L2的电流线性增加，此时向第二整流二极管D2和第四整流二极管D4输出叠加电压，同时给第三电容C3充电。当第二晶体管Q2截止、第三晶体管Q3导通时，第二电感L2续流通过第三晶体管Q3放电，第二电感L2的电流线性减少，此时，通过第三电容C3以及逐渐减小的第二电感L2向第二整流二极管D2和第四整流二极管D4输出叠加电压。
通过控制第二晶体管Q2和第三晶体管Q3的开关频率，可以持续输出叠加电压，且该叠加电压低于输入的第一电压。其中，第三晶体管Q3的另一端可以直接接地，也可以连接接地电阻R2，用于释放静电，提高安全性。
在一些实施例中，当采用图11所示的同步整流buck降压电路时，电压调整模块还包括第二二极管D6；第二二极管D6的负极与第三电容C3的一端连接；第二二极管D6的正极与第三电容C3的另一端连接。
当电压调整模块无输出时，第二晶体管Q2截止，灯串组的电流会通过第三晶体管Q3的体二极管、第二电感L2、第四均流二极管D4流回第二次级线圈120。当电流过大时，会在第三晶体管Q3的体二极管上造成较多的热损耗，为降低此损耗，利用第二二极管D6构成新的电流回路，使灯串组的电流由第二二极管D6、第四均流二极管D4流回第二次级线圈120。其中，第二二极管D6采用肖特基二极管等低功耗的二极管。
前述的buck拓扑和boost拓扑可以根据工程需要进行选择，例如，buck拓扑结构具有成本低的优势，但是输出电压范围较窄；而boost拓扑具有输出电压范围较宽的优势，但是其成本相对较高。
一些实施例的显示装置中，还包括第一开关电路和第一接地电阻R3；第一开关电路位于灯串组和第一接地电阻R3之间；第一开关电路的一端与第一灯串的负极和第二灯串的负极连接，第一开关电路的另一端与第一接地电阻R3的一端和反馈模块的输入端连接； 第一接地电阻R3的另一端接地；第一开关电路，基于占空比控制信号，进行导通或截止。
图12为根据本申请实施例的一种第一开关电路的电路结构示意图。如图12所示，对于多路输出电路，多个次级线圈的电压可能会存在交叉调整率的问题。交叉调整率是指当其他路带载时，对某一路输出电压的影响。例如，当第三次级线圈130的输出电压的负载较重时，第一次级线圈110和第二次级线圈120的输出电压会被提高。以至于，在电压变换模块不工作时，第二次级线圈120输出的第二电压就超过了灯串组的工作电压，此时会导致灯串组自然会被点亮。即，灯串组的发光和关闭不受控制了。
因此，需要在灯串组的回路内增加第一开关电路，以保证在不需要灯串组发光时，灯串组处于关闭状态。例如，比如显示装置为待机状态时，通常显示装置的显示屏幕是关闭的，即灯串组应该处于关闭状态。其中，该占空比控制信号(即图12所示的PWM控制信号)与显示装置状态的控制信号为可以为同步的，即当显示装置被控制为待机状态时，灯串组同步被占空比控制信号控制为不发光状态。
在一些实施例中，第一开关电路包括：第四晶体管Q4；第四晶体管Q4的一端与第一灯串140的负极和第二灯串150的负极连接；第四晶体管Q4的另一端与第一接地电阻R3的一端和反馈模块的输入端连接；第四晶体管Q4的栅极连接占空比控制信号，第四晶体管基于占空比控制信号，进行导通或截止。参照图12，当PWM控制信号为低电平时，第四晶体管Q4截止，因此灯串组不亮。
一些实施例的显示装置中，还包括：第二开关电路和第二接地电阻R4；第二开关电路位于灯串组和第二接地电阻R4之间；第二开关电路的一端与第一灯串140的负极和第二灯串150的负极连接，第二开关电路的另一端与第二接地电阻R4的一端连接；第二接地电阻R4的另一端接地；第二开关电路，用于改变回路电流，进行模拟调光。
图13为根据本申请实施例的一种第二开关电路的电路结构示意图。模拟调光是通过改变灯串组回路中电流大小达到改变灯串组亮度的效果。针对模拟调光的需求，如果灯串组电流较小，则灯串组的需求工作电压就越小，那么第二次级线圈120输出的第二电压就更容易超出灯串组的需求工作电压。在第二次级线圈120输出的第二电压不变时，通过第二开关电路，调节回路中的电阻值，改变回路中的电流。与调整第二次级线圈120输出的第二电压实现调光的方法相比，电路设计更简单。
在一些实施例中，第二开关电路包括：第五晶体管Q5、比较器；第五晶体管Q5的一端与第一灯串140的负极和第二灯串150的负极连接；第五晶体管Q5的另一端与第二接地电阻R4的一端和比较器的反相输入端连接；比较器的正相输入端输入灯串组的需求电压，比较器的输出端与第五晶体管Q5的栅极连接；调节第五晶体管Q5的阻值，用于改变回路电流，进行模拟调光。
参照图13，比较器的反相输入端接收第一灯串140和第二灯串150的实际总电流，一 般比较器是对电压信号进行比较，所以需要将电流反馈信号转换为电压反馈信号。其中，将电流反馈信号转换为电压反馈信号的方案参考相关技术。比较器的正相输入端输入参考电压，该参考电压是基于参考电流转换而来的。其中，将参考电流信号转换为参考电压信号的方案参考相关技术。当电压反馈信号，超出参考电压时，可将此第五晶体管Q5设定在线性工作状态，将多余的电压吸收在第五晶体管Q5上。
其中，图13采用电压反馈方式。第一反馈电阻R5的一端与第一灯串140的负极和第二灯串150的负极连接，第一反馈电阻R5的另一端与第二反馈电阻R6的一端连接；第二反馈电阻R6的另一端接地；第二驱动芯片自第一反馈电阻R5与第二反馈电阻R6的连接点进行采样，并将电压反馈信号发送至电压变换模块。
该第二驱动芯片用于实时的采集第一反馈电阻R5与第二反馈电阻R6的连接点的带你呀信号，生成反馈信号，使电压变换模块对电压进行的及时、有效的调整，防止过大电流流过第一灯串140和第二灯串150中的LED组件造成元件的损坏。
参照图7至图13，本实施例提供的显示装置，还包括主板；变压器还包括与初级线圈耦合的第三次级线圈130；第三次级线圈130，用于根据初级线圈接收的电源，输出第四电压；第一次级线圈110输出的第一电压，以及第三次级线圈130输出的第四电压均为主板供电。例如，第一电压为18V，第四电压为12V。
一些实施例的显示装置中，第二次级线圈120、电压变换模块和灯串组的数量均为多个；显示装置还包括多个均流电感；相邻的两个第二次级线圈之间设置有相互耦合的均流电感。
以四路灯串为例，图14为根据本申请实施例的一种四路灯串的显示装置的电路结构示意图，其中电压调整模块以boost升压电路为例。如图14所示，包括两组灯串组，四路灯串：第一灯串140、第二灯串150、第三灯串160、第四灯串170；两个第二次级线圈120和121，与两组灯串组对应。其中，两个第二次级线圈120和121之间设置有相互耦合的均流电感：第三电感L3和第四电感L4。
当两个第二次级线圈120和121的绕线方向、绕线匝数等均相同时，在供电过程中，第二灯串150的供电电路与第三灯串160的供电电路中电流方向是相反的，因此会产生阻抗。第三电感L3串联在第二灯串150的供电电路中，第四电感L4串联在第三灯串160的供电电路中，第三电感L3和第四电感L4相互耦合，用于平衡所产生的阻抗。
其中，反馈模块采用四路灯串共同反馈，因此反馈模块中设定的参考电流值为4倍的一路灯串的需求工作电流。另外，新增的第二次级线圈121为第三灯串160及第四灯串170供电的原理不再赘述。
图15为根据本申请实施例的另一种四路灯串的显示装置的电路结构示意图。针对四路灯串的显示装置的供电电路中，与图12相同，第一开关电路位于四路灯串(第一灯串 140、第二灯串150、第三灯串160及第四灯串170)和接地电阻R3之间。对于多路输出电路，多个次级线圈的电压可能会存在交叉调整率的问题。为了避免在电压变换模块不工作时，第二次级线圈120或121输出的第二电压超过了灯串组的工作电压，使导致灯串组被点亮，在灯串组的回路内增加第一开关电路，以保证在不需要灯串组发光时，灯串组处于关闭状态。具体的，第一开关电路包括第四晶体管Q4，当PWM控制信号为低电平时，第四晶体管Q4截止，因此灯串组不亮。
图16为根据本申请实施例的再一种四路灯串的显示装置的电路结构示意图。针对四路灯串的显示装置的供电电路中，第二开关电路位于灯串组和接地电阻之间，通过第二开关电路，调节回路中的电阻值，改变回路中的电流，进而调节灯串组亮度。具体的，当灯串组的实际电压超出参考电压时，可将此晶体管设定在线性工作状态，分担多余的电压，避免灯串组分压过大，造成电路损坏。具体的，第二开关电路包括第五晶体管Q5、比较器；比较器的反相输入端接收第一灯串140和第二灯串150的实际总电流，一般比较器是对电压信号进行比较，所以需要将电流反馈信号转换为电压反馈信号。其中，将电流反馈信号转换为电压反馈信号的方案参考相关技术。比较器的正相输入端输入参考电压，该参考电压是基于参考电流转换而来的。其中，将参考电流信号转换为参考电压信号的方案参考相关技术。当电压反馈信号，超出参考电压时，可将此第五晶体管Q5设定在线性工作状态，将多余的电压吸收在第五晶体管Q5上。
图17为根据本申请实施例的又一种四路灯串的显示装置的电路结构示意图。其中电压调整电路以buck降压电路为例，采用图11所示的同步整流buck降压电路，同时设置有第二二极管D6。当电压调整模块无输出时，第二晶体管Q2截止，灯串组的电流会通过第三晶体管Q3的体二极管、第二电感L2、第四均流二极管D4流回第二次级线圈120。当电流过大时，会在第三晶体管Q3的体二极管上造成较多的热损耗，为降低此损耗，利用第二二极管D6构成新的电流回路，使灯串组的电流由第二二极管D6、第四均流二极管D4流回第二次级线圈120。其中，第二二极管D6采用肖特基二极管等低功耗的二极管。
本实施例还提供一种显示控制方法，应用于显示装置，显示装置如图7所示，包括：变压器、电压变换模块、反馈模块以及灯串组；变压器的第一次级线圈和第二次级线圈，与变压器的初级线圈耦合；第一次级线圈，用于根据初级线圈接收的电源，输出第一电压；第二次级线圈，用于根据初级线圈接收的电源，由第二次级线圈的两端交替输出第二电压；第二次级线圈与灯串组一一对应；电压变换模块，用于根据第一电压，生成叠加电压并将叠加电压叠加至对应的第二次级线圈两端的第二电压，输出叠加后的第三电压。
本实施例提供的一种显示控制方法包括：接收反馈信号，反馈信号为反馈模块根据灯串组的输出电流生成；基于反馈信号，通过调整叠加电压调整第三电压；第三电压为灯串组的工作电压。本实施例中根据每路LED灯串输出的实时电流的反馈信号，对第一次级线 圈输出的第一电压进行调整生成叠加电压，该叠加电压与第二次级线圈的输出第二电压叠加后传输至每路LED灯串，使得每路LED灯串以额定电流工作，防止过大电流流过LED灯串中的LED组件造成元件的损坏。其中，叠加电压相当于“变动电压”；第二电压相当于“固定电压”，二者电压叠加实现了阶梯供电，有利于降低热损耗；同时两个灯串共用同一供电线圈(即第二次级线圈)和电压变换模块，有利于简化电路。
本实施例提供的显示装置，包括变压器、电压变换模块反馈模块以及灯串组；其中，电压变换模块与灯串组一一对应，灯串组包括第一灯串和第二灯串；变压器的第一次级线圈和第二次级线圈，与变压器的初级线圈耦合；第一次级线圈，用于根据初级线圈接收的电源，输出第一电压；第二次级线圈，用于根据初级线圈接收的电源，由第二次级线圈的两端交替输出第二电压；第二次级线圈与灯串组一一对应；电压变换模块，用于根据第一电压，生成叠加电压并将叠加电压叠加至对应的第二次级线圈两端的第二电压，输出叠加后的第三电压；反馈模块，用于根据灯串组的输出电流生成反馈信号，并发送至电压变换模块，反馈信号用于指示电压变换模块调整第三电压；第一灯串连接对应的第二次级线圈的一端，第二灯串连接对应的第二次级线圈的另一端，用于基于第三电压发光。本实施例的两个灯串共用同一供电线圈和电压变换模块，简化了电路；同时利用电压叠加实现阶梯供电，有利于降低热损耗。
为了利用外置适配器输出的直流电压满足显示装置内负载的供电需求，本申请还提供了如下实施例。
同样以显示装置为电视机为例，图18为一种为主板以及LED灯串供电的供电电路结构示意图。供电电路所获取的市电交流电(100V-240V，50-60Hz)依次通过滤波整流模块(整流桥)、PFC模块和LLC隔离电压变换模块后，向显示装置的主板、多路LED灯串以及其他负载供电(图18中未示出)。其中，LLC隔离电压变换模块中的第一副边绕组向主板提供第五电压(例如12V)，第二副边绕组向主板提供第六电压(例如18V)，第三副边绕组同时向多路LED灯串提供电压。
其中，多路LED灯串用于点亮电视机的显示屏幕，多路LED灯串内的LED组件需要在一定的压降范围内工作以达到LED组件的额定电流，例如多路LED灯串为16路的LED灯串，每路灯串包括9颗LED组件的情况下，在120mA条件下，多路LED灯串所需的工作电压范围为51.3V-58.5V，总电流为1.92A。
由于多路LED灯串所需的电压范围与多路LED灯串的工作环境、LED组件的硬件特性、寿命等因素有关，需要实时进行调整。因此，LLC隔离电压变换模块中为多路LED灯串供电的副边绕组还额外连接一个电压调整模块(例如buck电路或者boost电路，图18中以boost电路为例)，电压调整模块能够根据多路LED灯串的实时电流反馈结果，对第三副边绕组直接输出的电压进行调整，使得多路LED驱动模块根据接收到的调整后的电压 控制多路LED灯串以额定电流工作，防止过大电流流过多路LED灯串中的LED组件造成元件的损坏。
但是，在如图18所示的供电电路中，供电电路中为多路LED灯串设置的电压调整模块的电压应力较大，例如当多路LED灯串所需的电压范围为51.3V-58.5V时，电压调整模块需要对大于50V的电压进行升压或者降压的调整，导致了电压调整模块中开关管、电容等元件的耐压值较高，进而占用供电电路所在PCB板的面积较大，最终增加了供电电路的成本。
图19为另一种为主板以及LED灯串供电的供电电路结构示意图，其中，与图18所示供电电路所不同的是，图19中采用“阶梯供电”的形式，由LLC隔离电压变换模块中两个不同的副边绕组为LED灯串供电。具体地，该供电电路包括三个供电支路，第一供电支路包括LLC隔离电压变换模块中的第一副边绕组，被配置为向主板输出第五电压(例如12V)，第二供电支路包括LLC隔离电压变换模块中的第二副边绕组，被配置为输出作为固定电压的第六电压，第三供电支路包括LLC隔离电压变换模块中的第三副边绕组，被配置为输出第七电压(例如16V或18V)，随后，电压调整模块(低压buck/boost)将第七电压转换为第八电压后，向LED灯串提供第七电压和第八电压之和。在为LED灯串的供电过程中，由于通过灵活设置了第二副边绕组和第三副边绕组分别输出的两个不同的电压，而电压调整模块只需要对其中电压较小的一个副边绕组输出的电压进行调整，从而降低了对电压调整模块中开关管、电容等元件的耐压值的要求，进而减少了供电电路所在PCB板的面积，最终降低了供电电路的成本。
图20示出了再一种为主板以及LED灯串供电的供电电路结构示意图，供电电路所获取的市电交流电(100V-240V，50-60Hz)通过滤波整流模块(整流桥)后，分别输入至两个PFC模块，每个PFC模块后连接一个LLC隔离电压变换模块。其中一个LLC隔离电压变换模块为主板供电，向主板提供12V电压、18V电压或待机时的9.1V电压，可通过调节该LLC隔离电压变换模块中的晶体管的开闭频率或占空比实现对主板提供不同的电压。另一个LLC隔离电压变换模块向多路或单路LED负载提供10-15V的电压，18A的恒流电流，并基于反馈电路调节该LLC模块的输出电压。
随着电子技术的发展，包括电视机等显示装置在内的电子设备的集成度越来越高，也就对显示装置的电源提出了越来越高的要求。图18、图19和图20中，显示装置的电源架构直接与市电交流电连接，在显示装置电源板中配置有专门的供电电路对交流电进行变压、转直流等处理，至少包括以下模块：整流桥、功率因数校正(Power Factor Correction，简称：PFC)模块、谐振转换电路(LLC)隔离电压变换模块。其中，利用谐振转换电路(LLC)隔离电压变换模块生成多个直流电压，满足显示装置内负载的供电需求。由于电源架构中包含至少一个滤波整流模块、至少一个PFC模块以及至少一个LLC隔离电压变换模块， 以及LLC隔离电压变换模块包含至少一个副边绕组，所以电源的电路结构较为复杂，相应地，复杂的电路不利于提高集成度。
随着电源适配器的兴起和氮化镓器件的推广，显示装置的电源逐渐发展为外置形态，即利用外置的电源适配器完成对交流电进行变压、转直流等处理，输出一个固定的直流电压。图21为根据本申请实施例的外置适配器供电模式的示意图，展示了外置适配器供电模式下，为以电视机为例的显示装置进行供电的结构图。可见，显示装置(图21所示的电视)通过线缆连接电源适配器提供的单固定直流输入电压。
上述的如图18、图19和图20所示的显示装置电源架构中，利用LLC隔离电压变换模块的多个副边绕组输出多个电压，以为显示装置负载供电，并不适用于图21所示的外置适配器供电模式。如何利用外置适配器提供的单固定直流输入电压为显示装置负载供电是亟待解决的问题。
基于上述问题，本申请提供的显示装置，设置有与外置适配器连接的供电接口，接收直流输入电压，以适应外置适配器供电模式；利用直流输入电压生成叠加电压，并将该叠加电压与直流输入电压进行叠加，实现阶梯供电，有利于降低热损耗；利用储能元件实现为背光控制模块持续供电；通过实时反馈及时调整背光控制模块的供电电压，使发光二极管工作稳定。
下面以具体地实施例对本申请的内容以及本申请的内容如何解决上述技术问题进行详细说明。下面这几个具体的实施例可以相互结合。下面将结合附图，对本申请的实施例进行描述。
图22为根据本申请实施例的一种显示装置的供电电路结构示意图，包括：背光控制模块、供电接口、第一电压变换模块、储能元件、反馈模块。
背光控制模块，用于控制发光二极管发光，发光二极管用于点亮显示装置的屏幕；供电接口，用于接收外置适配器提供的直流输入电压；第一电压变换模块，用于根据直流输入电压生成第五电压；储能元件，与第一电压变换模块连接，用于储能第五电压；储能元件与第一电压变换模块交替输出第五电压。
背光控制模块的负极连接第五电压，第五电压作为背光控制模块的负参考电压；背光控制模块的正极连接直流输入电压。反馈模块，用于将背光控制模块生成的反馈信号发送至第一电压变换模块，反馈信号用于指示第一电压变换模块调整第五电压以调整背光控制模块的需求电压。
其中，背光控制模块两侧的电压为直流输入电压与第五电压的绝对值之和。该直流输入电压相当于“固定电压”，该第五电压相当于“变动电压”。上述采用固定电压与变动电压为背光控制模块供电的电路结构即为“阶梯供电”，可降低第一电压变换模块内电器元件的耐压值等要求，以达到降低成本、提高效率的目的；同时可降低电器元件上的热损耗。
如图22所示，外置适配器接收市电交流电(100V-240V，50-60Hz)，该外置适配器的内部电路可如图21所示，至少包括滤波整流模块、PFC模块、LLC隔离电压变换模块。该外置适配器输出固定直流电压。显示装置设置有与外置适配器连接的供电接口，用于接收直流输入电压，以适应图21所示的外置适配器供电模式。相比于图18至图20，无需将滤波整流模块、PFC模块、LLC隔离电压变换模块设置在显示装置电源板上，有利于简化电路。
在一些实施例中，图22所示的储能元件可以为单个储能电容或者其他储能电路。该储能元件与第一电压变换模块共同配合，交替输出第五电压，为背光控制模块持续提供负参考电压，使发光二极管稳定发光。
在一些实施例中，图22所示的第一电压变换模块可以为电荷泵形式。图23为根据本申请实施例的另一种显示装置的供电电路结构示意图。如图23所示，第一电压变换模块，包括：电荷泵模块。电荷泵模块，用于在充电状态下，产生第五电压；以及在放电状态下，向背光控制模块的负极提供第五电压；储能元件的第一端与电荷泵模块的正向输出端连接，并接地；储能元件的第二端与电荷泵模块的负向输出端连接；储能元件用于在电荷泵模块放电时，储能第五电压；以及，在电荷泵模块充电时，向背光控制模块的负极提供第五电压；其中，反馈信号用于指示电荷泵模块调整第五电压以调整背光控制模块的需求电压。
本实施例的电荷泵形式的第一电压变换模块为无感式DC-DC电源变换器，即电荷泵形式的电压变换中没有电感元件，因此电压变换原理不涉及磁场的高速变换，即电-磁、磁-电的高速变换，电磁干扰问题几乎可以忽略。电荷泵形式的电压变换原理是利用内部电容元件的高速充电和放电，因此具有低电磁干扰的优点。除了低电磁干扰外，还具有输出电压的调节范围更大、高效率、体积小、低静态电流、最低工作电压小、低噪声等优点。另外，电容的集成比电感的集成更为容易和廉价，因此电荷泵形式的第一电压变换模块也就更容易实现高度集成，对整体应用电路而言成本也不高。
在一些实施例中，图23所示的储能元件可以为单个储能电容或者其他储能电路。该储能元件与电荷泵模块共同配合，交替输出第五电压，为背光控制模块持续供电，使发光二极管稳定发光。
下面结合电荷泵模块及储能元件具体的电路结构示意图，对第一电压变换模块与储能元件配合供电的原理进行说明。
在一些实施例中，图24为根据本申请实施例的一种电荷泵模块的供电电路结构示意图，其中，储能元件Cn以单个储能电容为例。电荷泵模块包括：第一控制器、第一储能电容C11、第一开关S11、第二开关S12、第三开关S13以及第四开关S14。
第一开关S11的第一端连接直流输入电压Vin，第一开关S11的第二端连接第二开关S12的第一端；第二开关S12的第二端作为电荷泵模块的正向输出端，与储能元件Cn的 第一端连接，并接地；第一储能电容C11的第一端与第一开关S11的第二端及第二开关S12的第一端连接，第一储能电容C11的第二端与第三开关S13的第一端及第四开关S14的第一端连接；第四开关S14的第二端接地；第三开关S13的第二端作为电荷泵模块的负向输出端，与储能元件Cn的第二端连接，输出第五电压-Vo。
第一控制器，与第一开关S11、第二开关S12、第三开关S13以及第四开关S14的控制端连接，用于根据反馈信号，通过控制第一开关S11、第二开关S12、第三开关S13以及第四开关S14的开关频率，以调整第五电压-Vo；其中，第一开关S11和第二开关S12的开关状态不同，第一开关S11与第四开关S14同时断开或导通；第二开关S12与第三开关S13同时断开或导通。
基于图24所示的供电电路，电荷泵模块与储能元件相互配合为背光控制模块的负极提供负参考电压的原理如下：
步骤(1)：第一控制器控制第一开关S11与第四开关S14同时闭合，第二开关S12与第三开关S13同时断开。此时直流输入电压Vin经过闭合的第一开关S11为第一储能电容C11充电，通过控制第二开关S12与第三开关S13的断开时间，及第一开关S11与第四开关S14的闭合时间，控制对第一储能电容C11充电时间，以控制第一储能电容C11的储能电压。假设充电后第一储能电容C11的储能电压为Vo，此时，由于第一储能电容C11的第二端接地，所以第一储能电容C11的第一端电压为Vo。
步骤(2)：第一控制器控制第一开关S11与第四开关S14同时断开，第二开关S12与第三开关S13同时闭合。此时，第一储能电容C11的第一端接地，所以第一储能电容C11的第二端电压为-Vo(即第五电压)，用于向背光控制模块的负极提供负参考电压。同时，第一储能电容C11为储能元件Cn充电，使充电后储能元件Cn的储能电压为Vo。由于储能元件Cn的第一端也接地，因此储能元件Cn的第二端为-Vo(即第五电压)。
步骤(3)：第一控制器控制第一开关S11与第四开关S14同时闭合，第二开关S12与第三开关S13同时断开。重复步骤(1)中为第一储能电容C11的充电过程。此时，储能元件Cn的第一端接地，由储能元件Cn的第二端向背光控制模块的负极提供负参考电压，即第五电压-Vo。
上述通过图24所示的供电电路基于直流输入电压Vin生成第五电压-Vo，并将第五电压-Vo连接至背光控制模块的负极，以作为背光控制模块的负参考电压；结合背光控制模块的正极输入的直流输入电压Vin，使得背光控制模块两端电压为直流输入电压Vin与第五电压的绝对值Vo之和，即背光控制模块的需求电压Vled等于Vin+Vo。
对于图24所示的供电电路中，只需要控制第五电压-Vo的大小，就可以控制背光控制模块的需求电压Vled的变化。第一控制器基于反馈信号通过控制第一开关S11、第二开关S12、第三开关S13以及第四开关S14的开关频率或者占空比来控制电荷的传输数量，从 而达到控制背光控制模块的需求电压Vled的目的。
直流输入电压Vin比较稳定，相当于“固定电压”；第五电压-Vo，相当于“变动电压”。由于直流输入电压Vin比较稳定，第五电压-Vo的输出电压变化范围取决于背光控制模块的需求电压Vled所需的变化范围。上述采用固定电压与变动电压为背光控制模块供电的电路结构即为“阶梯供电”，可降低第一电压变换模块内电器元件的耐压值等要求，以达到降低成本、提高效率的目的；同时可降低电器元件上的热损耗。
在一些实施例中，图22所示的第一电压变换模块可以为反激隔离形式。图25为根据本申请实施例的又一种显示装置的供电电路结构示意图。如图25所示，第一电压变换模块，包括：反激式隔离变压模块。
反激式隔离变压模块，用于在原边绕组导通时，由副边绕组生成第五电压，并输送至背光控制模块的负极；储能元件的第一端与反激式隔离变压模块的正向输出端连接并接地；储能元件的第二端与反激式隔离变压模块的负向输出端连接；储能元件用于在原边绕组导通时，储能第五电压；以及，在原边绕组截止时，向背光控制模块的负极提供第五电压；其中，反馈信号用于指示反激式隔离变压模块调整第五电压以调整背光控制模块的需求电压。
具体的，本实施例采用的反激隔离形式的电压变换模块，通过原边绕组和副边绕组进行了电气隔离。“反激”具体指当开关管接通时，副边绕组变压器充当电感，电能转化为磁能，此时输出回路无电流；相反，当开关管关断时，副边绕组变压器释放能量，磁能转化为电能，输出回路中有电流。反激式电压变换模块中，副边绕组变压器同时充当储能电感，具有元器件少，电路简单，成本低，体积小等特点，同时电气隔离提高了使用安全性。
在一些实施例中，图25所示的储能元件可以为单个储能电容或者其他储能电路。该储能元件与反激式隔离变压模块共同配合，交替输出第五电压，为背光控制模块持续提供负参考电压，使发光二极管稳定发光。
下面结合反激式隔离变压模块及储能元件具体的电路结构示意图，对第一电压变换模块与储能元件配合供电的原理进行说明。
在一些实施例中，图26为根据本申请实施例的一种反激式隔离变压模块的供电电路结构示意图。反激式隔离变压模块包括：原边绕组、副边绕组、第一二极管D11、第二控制器以及第五开关S15。
原边绕组的第一端连接直流输入电压Vin，原边绕组的第二端连接第五开关S15的第一端，第五开关S15的第二端接地；副边绕组与原边绕组耦合，副边绕组的第一端与第一二极管D11的正极连接；第一二极管D11的负极作为反激式隔离变压模块的正向输出端，与储能元件Cn的第一端连接，并接地；副边绕组的第二端作为反激式隔离变压模块的负向输出端，与储能元件Cn的第二端连接，输出第五电压-Vo。
第二控制器，与第五开关S15的控制端连接，用于根据反馈信号，通过控制第五开关S15的开关频率，以调整第五电压-Vo。
基于图26所示的供电电路，反激式隔离变压模块与储能元件相互配合为背光控制模块的负极提供负参考电压的原理如下：
步骤(1)：第二控制器控制第五开关S15接通，原边绕组电流线性增长，电感储能增加；第一二极管D11不导通。通过控制第五开关S15的开关频率可控制原边绕组的储能电压。
步骤(2)：第二控制器控制第五开关S15关断，原边绕组电流切断，第一二极管D11导通。副边绕组的第一端通过第一二极管D11接地，通过设置原边绕组与副边绕组的匝数比，可使副边绕组的第二端输出第五电压-Vo，用于向背光控制模块的负极提供负参考电压。同时，副边绕组为储能元件Cn充电，使充电后储能元件Cn的储能电压为Vo。由于储能元件Cn的第一端也接地，因此储能元件Cn的第二端为-Vo(即第五电压)。
步骤(3)：第二控制器控制第五开关S15接通，重复步骤(1)原边绕组的储能过程。此时，储能元件Cn的第一端接地，由储能元件Cn的第二端向背光控制模块的负极提供负参考电压，即第五电压-Vo。
上述通过图26所示的供电电路基于直流输入电压Vin生成第五电压-Vo，并将第五电压-Vo连接至背光控制模块的负极，以作为背光控制模块的负参考电压；结合背光控制模块的正极输入的直流输入电压Vin，使得背光控制模块两端电压为直流输入电压Vin与第五电压的绝对值Vo之和，即背光控制模块的需求电压Vled等于Vin+Vo。
对于图26所示的供电电路中，只需要控制第五电压-Vo的大小，就可以控制背光控制模块的需求电压Vled的变化。第二控制器基于反馈信号通过控制第五开关S15、的开关频率或者占空比来控制电荷的传输数量，从而达到控制背光控制模块的需求电压Vled的目的。
直流输入电压Vin比较稳定，相当于“固定电压”；第五电压-Vo，相当于“变动电压”。由于直流输入电压Vin比较稳定，第五电压-Vo的输出电压变化范围取决于背光控制模块的需求电压Vled所需的变化范围。上述采用固定电压与变动电压为背光控制模块供电的电路结构即为“阶梯供电”，可降低第一电压变换模块内电器元件的耐压值等要求，以达到降低成本、提高效率的目的；同时可降低电器元件上的热损耗。
图27为根据本申请实施例的一种电平转换电路的结构示意图。在一些实施例中，反馈模块包括电平转换电路。电平转换电路，接收背光控制模块输出的第一反馈信号，将第一反馈信号转换为第二反馈信号后，向第一电压变换模块输出第二反馈信号；其中，第一反馈信号和第二反馈信号的参考电压不同。
由于背光控制模块的参考电压为-Vo，第一电压变换模块的参考电压为0，导致了背光控制模块所产生的第一反馈信号无法直接发送到第一电压变换模块，因此，利用电平转换 电路将参考低电平为-Vo的第一反馈信号转换为参考电压为0的第二反馈信号。其中，电平转换电路可参照相关技术。
在一些实施例的显示装置中，还包括第一滤波模块；第一滤波模块，与供电接口和第一电压变换模块连接，用于对直流输入电压进行滤波。第一滤波模块可以为一个或多个接地电容组成的滤波电路、也可以为电容与电感组成的滤波电路。如图27所示，第一滤波模块以第一滤波电容C13为例，供电接口的直流输入电压及接地之间并联有第一滤波电容C13。用于滤除电源的杂波和交流成分，平滑脉动直流电压，储存电能。其电容容量与负载电流和电源的纯净度有关，通常选取较大容量的滤波电容。
在一些实施例中，该第一滤波电容C13可以为图27所示的电解电容。电解电容是电容的一种，金属箔为正极(铝或钽)，与正极紧贴金属的氧化膜(氧化铝或五氧化二钽)是电介质，阴极由导电材料、电解质(电解质可以是液体或固体)和其他材料共同组成，因电解质是阴极的主要部分。其单位体积的电容量非常大，由于制备材料为普通工业材料，制备工艺也是普通工业设备，因此可进行批量生产，所以成本也相对较低。需要注意的是，电解电容正负不可接错。
在一些实施例中，该第一滤波电容C13也可以为其他类型的电容，例如陶瓷带内容、薄膜电容、云母电容等。在实际电路中，可根据电容容量需求进行选择。
在一些实施例的显示装置中，还包括第二滤波模块；第二滤波模块，设置在背光控制模块的正极与负极之间。第二滤波模块可以为一个或多个接地电容组成的滤波电路、也可以为电容与电感组成的滤波电路。如图27所示，第二滤波模块以第二滤波电容C14为例，用于稳定背光控制模块两端的电压。
在一些实施例的显示装置中，还设置由第三滤波模块，用于滤除输入至背光控制模块的正极的直流输入电压Vin中的杂波。如图27所示，第三滤波模块以第三滤波电容C5为例，第三滤波电容C5的一端连接直流输入电压Vin，第三滤波电容C5的另一端接地。
在一些实施例的显示装置中，还包括第二二极管Dn；第二二极管Dn的正极与储能元件Cn的第二端连接，第二二极管Dn的负极与储能元件Cn的第一端连接。利用第四二极管Dn使背光控制模块与供电接口的负极构成电流回路，防止第一电压变换模块不工作时，电流流经第一电压变换模块而造成系统误动作或者其他异常情况，起到保护第一电压变换模块的作用。
在一些实施例中，图28为根据本申请实施例的一种基于电荷泵模块供电电路的电平转换电路的结构示意图。该电荷泵模块以图24为例，供电原理不再赘述。在一些实施例中，图29为根据本申请实施例的一种基于反激式隔离变压模块供电电路的电平转换电路的结构示意图，该反激式隔离变压模块以图26为例，供电原理不再赘述。
在一些实施例中，本实施例提供的显示装置还包括：主板；主板与供电接口连接，直 流输入电压用于向主板供电。图30为根据本申请实施例的一种为主板供电的电路结构示意图。当直流输入电压等于主板的需求电压时，可以选择由直流输入电压为主板直接进行供电。
在一些实施例的显示装置中，还包括第二电压变换模块；第二电压变换模块，与供电接口和主板连接，用于根据直流输入电压，输出第六电压，第六电压为主板的需求电压。图31为根据本申请实施例的另一种为主板供电的电路结构示意图。当直流输入电压不满足主板的需求电压时，可采用第二电压变换模块对直流输入电压进行DC-DC的电压变换。当电视功率较大时，为了降低线缆的损耗，可通过提高电压而降低电流，因此直流输入电压会高于主板的需求电压。在一些实施例中，由于主板通常需要固定电压，所以第二电压变换模块可以采用buck降压电路、boost-buck升压降压电路等。
本申请实施例还提供一种显示控制方法，应用于前述的显示装置，显示控制方法包括：接收反馈信号，反馈信号由背光控制模块生成并通过反馈模块发送；基于反馈信号，调整第五电压以调整背光控制模块的需求电压。本实施例中根据背光控制模块输出的实时电流的反馈信号，对第一电压变换模块生成的第五电压进行调整，进而调整背光控制模块的需求电压，使得背光控制模块以额定电流工作，防止过大电流流过LED灯串中的LED组件造成元件的损坏。
根据本申请实施例的显示装置，包括：背光控制模块，用于控制发光二极管发光，发光二极管用于点亮显示装置的屏幕；供电接口，用于接收外置适配器提供的直流输入电压；第一电压变换模块，用于根据直流输入电压生成第五电压；储能元件，与第一电压变换模块连接，用于储能第五电压；储能元件与第一电压变换模块交替输出第五电压；背光控制模块的负极连接第五电压，第五电压作为背光控制模块的负参考电压；背光控制模块的正极连接直流输入电压；直流输入电压的绝对值与第五电压的绝对值之和等于背光控制模块的需求电压；反馈模块，用于将背光控制模块生成的反馈信号发送至第一电压变换模块，反馈信号用于指示第一电压变换模块调整第五电压以调整背光控制模块的需求电压。
本申请实施例设置有与外置适配器连接的供电接口，接收直流输入电压，以适应外置适配器供电模式；利用直流输入电压生成的第五电压作为背光控制模块的负参考电压，与背光控制模块的正极连接的直流输入电压，构成阶梯式供电，有利于降低热损耗；利用储能元件实现为背光控制模块持续供电；通过实时反馈及时调整背光控制模块的供电电压，使发光二极管工作稳定。
为了利用外置适配器输出的直流电压满足显示装置内负载的供电需求，本申请还提供了如下实施例。
本申请提供的显示装置，设置有与外置适配器连接的供电接口，接收直流输入电压，以适应外置适配器供电模式；利用直流输入电压生成叠加电压，并将该叠加电压与直流输 入电压进行叠加，实现阶梯供电，有利于降低热损耗；利用储能元件实现为背光控制模块持续供电；通过实时反馈及时调整背光控制模块的供电电压，使发光二极管工作稳定。
下面以具体地实施例对本申请的内容以及本申请的内容如何解决上述技术问题进行详细说明。下面这几个具体的实施例可以相互结合。下面将结合附图，对本申请的实施例进行描述。
图32为根据本申请实施例的一种显示装置的供电电路结构示意图，包括：背光控制模块、供电接口、第三电压变换模块、储能元件、反馈模块。
其中，背光控制模块，用于控制发光二极管LED发光以点亮显示装置的屏幕；供电接口，用于接收外置适配器提供的直流输入电压；第三电压变换模块，用于根据直流输入电压生成叠加电压，并将叠加电压与直流输入电压进行叠加，输出叠加后的第九电压，第九电压为背光控制模块的需求电压；储能元件的第一端与第三电压变换模块连接，储能元件的第二端连接直流输入电压，用于储能叠加电压，并与第三电压变换模块交替输出第九电压。反馈模块，用于将背光控制模块生成的反馈信号发送至第三电压变换模块，反馈信号用于指示第三电压变换模块调整第九电压。
如图32所示，外置适配器接收市电交流电(100V-240V，50-60Hz)，该外置适配器的内部电路可如图21所示，至少包括滤波整流模块、PFC模块、LLC隔离电压变换模块。该外置适配器输出固定直流电压。显示装置设置有与外置适配器连接的供电接口，用于接收直流输入电压，以适应图21所示的外置适配器供电模式。相比于图18至图20，无需将滤波整流模块、PFC模块、LLC隔离电压变换模块设置在显示装置电源板上，有利于简化电路。
在一些实施例中，图32所示的储能元件可以为单个储能电容或者其他储能电路。该储能元件与第三电压变换模块共同配合，交替输出第九电压，为背光控制模块持续供电，使发光二极管稳定发光。
在一些实施例中，图32所示的第三电压变换模块可以为电荷泵形式。图33为根据本申请实施例的另一种显示装置的供电电路结构示意图。如图33所示，第三电压变换模块，包括：电荷泵模块，用于在充电状态下产生叠加电压；在放电状态下，将该叠加电压与直流输入电压进行叠加生成第九电压，并将叠加所得的第九电压输出至背光控制模块。储能元件的第一端与电荷泵模块的输出端连接；储能元件用于在电荷泵模块放电时，储能叠加电压；以及，在电荷泵模块充电时，向直流输入电压叠加该叠加电压，并将叠加后的第九电压输出至背光控制模块；其中，反馈信号用于指示电荷泵模块通过调整叠加电压来调整第九电压。
具体的，本实施例的电荷泵形式的第三电压变换模块为无感式DC-DC电源变换器，即电荷泵形式的电压变换中没有电感元件，因此电压变换原理不涉及磁场的高速变换，即 电-磁、磁-电的高速变换，电磁干扰问题几乎可以忽略。电荷泵形式的电压变换原理是利用内部电容元件的高速充电和放电，因此具有低电磁干扰的优点。除了低电磁干扰外，还具有输出电压的调节范围更大、高效率、体积小、低静态电流、最低工作电压小、低噪声等优点。另外，电容的集成比电感的集成更为容易和廉价，因此电荷泵形式的第三电压变换模块也就更容易实现高度集成，对整体应用电路而言成本也不高。
在一些实施例中，图33所示的储能元件可以为单个储能电容或者其他储能电路。该储能元件与电荷泵模块共同配合，交替输出第九电压，为背光控制模块持续供电，使发光二极管稳定发光。
下面结合电荷泵模块及储能元件具体的电路结构示意图，对第三电压变换模块与储能元件配合供电的原理进行说明。
在一些实施例中，图34为根据本申请实施例的一种电荷泵模块的供电电路结构示意图。电荷泵模块包括：第一控制器、第一储能电容C11、第一二极管D11、第二二极管D12、第一开关S1以及第二开关S2。
第一二极管D11的正极连接直流输入电压Vin，第一二极管D11的负极连接第二二极管D12的正极；第二二极管D12的负极作为电荷泵模块的输出端，输出第九电压Vled；第一开关S1的第一端连接第一二极管D11的正极，第一开关S1的第二端连接第二开关S2的第一端，第二开关S2的第二端接地；第一储能电容C11的第一端与第一二极管D11的负极连接，第一储能电容C11的第二端与第一开关S1的第二端连接。
第一控制器，与第一开关S1及第二开关S2的控制端连接，用于根据反馈信号，控制第一开关S1及第二开关S2的开关频率，以调整叠加电压；其中，第一开关S1和第二开关S2的开关状态不同。
如图34所示，储能元件以单个储能电容为例。该储能元件Cn的第二端连接直流输入电压Vin，即向储能元件的第二端施加直流输入电压Vin。可以通过储能元件Cn的第二端与供电接口建立物理连接，实现对储能元件的第二端施加直流输入电压Vin。
基于图34所示的供电电路，第三电压变换模块与储能元件配合供电的原理如下：
步骤(1)：第一控制器控制第一开关S1断开，第二开关S2闭合，此时直流输入电压Vin经过第一二极管D11为第一储能电容C11充电，使第一储能电容C11的第一端为正压。通过控制第一开关S1断开时间及第二开关S2闭合时间控制对第一储能电容C11充电时间，进而控制第一储能电容C11的储能电压。假设充电后第一储能电容C11的储能电压为Vo(即叠加电压)，由于其第二端接地，所以其第一端电压为Vo。
步骤(2)：第一控制器控制第一开关S1闭合，第二开关S2断开，此时直流输入电压Vin经过第一开关S1与第一储能电容C11的第二端连接，将第一储能电容C11看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接 到第一储能电容C11的下端相当于串联的两个电源，即进行了电压叠加。因此，第一储能电容C11通过第二二极管D12的负极输出叠加后的第九电压Vled，其中Vled等于Vin+Vo。此时，对于储能元件Cn，其第一端连接电压Vled，其第二端连接电压Vin，因此，储能元件Cn被充电，Cn储能压差为Vo(即叠加电压)。
步骤(3)：第一控制器控制第一开关S1断开，第二开关S2闭合，重复步骤(1)中为第一储能电容C11的充电过程。同时，将储能元件Cn看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接到储能元件Cn的第二端相当于串联的两个电源，即进行了电压叠加。因此，通过储能元件Cn的第一端输出叠加后的第九电压Vled。其中，由于第二二极管D12正极电压为Vin、负极电压为Vled，所以不导通。
对于图34所示的供电电路中，只需要控制叠加电压Vo的大小，就可以控制第九电压Vled的变化。第一控制器基于反馈信号通过控制第一开关S1和第二开关S2的开关频率或者占空比来控制电荷的传输数量，从而达到控制第九电压Vled的目的。直流输入电压Vin比较稳定，相当于“固定电压”；叠加电压Vo，相当于“变动电压”。由于直流输入电压Vin比较稳定，叠加电压Vo的输出电压变化范围取决于第九电压Vled所需的变化范围。上述采用一个“固定电压”叠加一个“变动电压”的电路结构即为“阶梯供电”，可达到降低成本、提高效率的目的。
在一些实施例中，将图34所示的供电电路与传统的直流-直流变换方案进行比较。其中，传统的直流-直流变换方案即采用DC-DC电路模块将直流输入电压变换为需求电压。具体的，DC-DC电路模块可以为boost升压电路、buck降压电路、boost-buck升压降压电路以及其他具有升压降低功能的电路。
针对规格为12V的LED组件，其工作电压变化范围往往在11.4-12.6V左右。对于一串具有4颗LED组件的灯串，供电电压的变动范围为：45.6-50.4V。假设输入电压为42V，Vled的电压需要50V，总计输出功率为100W。
传统的直流-直流变换方案以采用boost升压电路为例，假设boost升压电路的效率为95％，则有输入功率为100W/0.95＝105.2W，热损耗为5.2W。
基于图34所示的供电电路：假设叠加电压Vo为8V，输入为42V，输出电流为2A。假设电荷泵模块的效率为90％，则输出功率为16W，输入功率为16W/0.9＝17.8W，因此热损耗为1.8W。总体转换效率为：100W/(42V×2A+17.8W)＝98.2％。效率提升了98.2％-95％＝3.2％。同时，由于变换器的转换功率大大下降，也降低了成本。
在一些实施例中，图34所示的供电电路中，储能元件Cn的第二端也可以接地。图35为根据本申请实施例的另一种电荷泵模块的供电电路结构示意图。与图34不同的是：储能元件Cn的第二端接地。因此，图35与图34供电原理中不同的是储能元件Cn的储能压 差不同。
基于图35所示的供电电路，第三电压变换模块与储能元件配合供电的原理如下：
步骤(1)：第一控制器控制第一开关S1断开，第二开关S2闭合，此时直流输入电压Vin经过第一二极管D11为第一储能电容C11充电，使第一储能电容C11的第一端为正压。通过控制第一开关S1断开时间及第二开关S2闭合时间控制对第一储能电容C11充电时间，进而控制第一储能电容C11的储能电压。假设充电后第一储能电容C11的储能电压为Vo(即叠加电压)，由于其第二端接地，所以其第一端电压为Vo。
步骤(2)：第一控制器控制第一开关S1闭合，第二开关S2断开，此时直流输入电压Vin经过第一开关S1与第一储能电容C11的第二端连接，将第一储能电容C11看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接到第一储能电容C11的下端相当于串联的两个电源，即进行了电压叠加。因此，第一储能电容C11通过第二二极管D12的负极输出叠加后的第九电压Vled，其中Vled等于Vin+Vo。此时，对于储能元件Cn，其第一端连接电压Vled，其第二端连接电压0，因此，储能元件Cn被充电，Cn储能压差为Vled。
步骤(3)：第一控制器控制第一开关S1断开，第二开关S2闭合，重复步骤(1)中为第一储能电容C11的充电过程。此时，储能元件Cn充当电源输出Vled，为背光控制模块供电。其中，由于第二二极管D12正极电压为Vin、负极电压为Vled，所以不导通。
将图34与图35相比，采用图34所示的供电电路对储能元件Cn的储能要求低于图11所示的供电电路。储能要求低，相应地，成本也较低。
在一些实施例中，图34及图35所示的供电电路中，第一二极管D11和第二二极管D12可以替换为开关元件。图36为根据本申请实施例的再一种电荷泵模块的供电电路结构示意图。电荷泵模块包括：第二控制器、第二储能电容C12、第三开关S3、第四开关S4、第五开关S5及第六开关S6。
第三开关S3的第一端连接直流输入电压Vin，第三开关S3的第二端连接第四开关S4的第一端；第四开关S4的第二端作为电荷泵模块的输出端，输出第九电压Vled；第五开关S5的第一端连接第三开关S3的第一端，第五开关S5的第二端连接第六开关S6的第一端，第六开关S6的第二端接地；第二储能电容C12的第一端与第三开关S3的第二端连接，第二储能电容C12的第二端与第五开关S5的第二端连接。
第二控制器，与第三开关S3、第四开关S4、第五开关S5及第六开关S6的控制端连接，用于根据反馈信号，通过控制第三开关S3、第四开关S4、第五开关S5及第六开关S6的开关频率，以调整叠加电压；其中，第三开关S3和第四开关S4的开关状态不同，第三开关S3与第六开关S6同时断开或导通；第四开关S4与第五开关S5同时断开或导通。
基于图36所示的供电电路，第三电压变换模块与储能元件配合供电的原理如下：
步骤(1)：第二控制器控制第四开关S4与第五开关S5同时断开，第三开关S3与第六开关S6同时闭合。此时直流输入电压Vin经过闭合的第三开关S3为第二储能电容C12充电，使第二储能电容C12的第一端为正压。通过控制第四开关S4与第五开关S5的断开时间，及三开关S3与第六开关S6的闭合时间，控制对第二储能电容C12充电时间，进而控制第二储能电容C12的储能电压。假设充电后第二储能电容C12的储能电压为Vo(即叠加电压)，由于其第二端接地，所以其第一端电压为Vo。
步骤(2)：第二控制器控制第四开关S4与第五开关S5同时闭合，第三开关S3与第六开关S6断开，此时直流输入电压Vin经过第五开关S5与第二储能电容C12的第二端连接，将第二储能电容C12看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接到第二储能电容C12的下端相当于串联的两个电源，即进行了电压叠加。因此，第二储能电容C12通过第四开关S4输出叠加后的第九电压Vled，其中Vled等于Vin+Vo。此时，对于储能元件Cn，其第一端连接电压Vled，其第二端连接电压Vin，因此，储能元件Cn被充电，Cn储能压差为Vo。
步骤(3)：第二控制器控制第四开关S4与第五开关S5同时断开，第三开关S3与第六开关S6同时闭合，重复步骤(1)中为第二储能电容C12的充电过程。同时，将储能元件Cn看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接到储能元件Cn的第二端相当于串联的两个电源，即进行了电压叠加。因此，通过储能元件Cn的第一端输出叠加后的第九电压Vin+Vo，即Vled。
对于图36所示的电路中，只需要控制叠加电压Vo的大小，就可以控制第九电压Vled的变化。第二控制器基于反馈信号通过控制第三开关S3、第四开关S4、第五开关S5及第六开关S6的开关频率或者占空比来控制电荷的传输数量，从而达到控制第九电压Vled的目的。直流输入电压Vin比较稳定，相当于“固定电压”；叠加电压Vo，相当于“变动电压”。由于直流输入电压Vin比较稳定，叠加电压Vo的输出电压变化范围取决于第九电压Vled所需的变化范围。上述采用一个“固定电压”叠加一个“变动电压”的电路结构即为“阶梯供电”，可达到降低成本、提高效率的目的。
在一些实施例中，图36所示的供电电路中，储能元件Cn的第二端也可以接地。图37为根据本申请实施例的又一种电荷泵模块的供电电路结构示意图。与图36不同的是：储能元件Cn的第二端接地。因此，图37与图36供电原理中不同的是储能元件Cn的储能压差不同。
基于图37所示的供电电路，第三电压变换模块与储能元件配合供电的原理如下：
步骤(1)：第二控制器控制第四开关S4与第五开关S5同时断开，第三开关S3与第六开关S6同时闭合。此时直流输入电压Vin经过闭合的第三开关S3为第二储能电容C12充电，使第二储能电容C12的第一端为正压。通过控制第四开关S4与第五开关S5的断开 时间，及三开关S3与第六开关S6的闭合时间，控制对第二储能电容C12充电时间，进而控制第二储能电容C12的储能电压。假设充电后第二储能电容C12的储能电压为Vo(即叠加电压)，由于其第二端接地，所以其第一端电压为Vo。
步骤(2)：第二控制器控制第四开关S4与第五开关S5同时闭合，第三开关S3与第六开关S6断开，此时直流输入电压Vin经过第五开关S5与第二储能电容C12的第二端连接，将第二储能电容C12看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接到第二储能电容C12的下端相当于串联的两个电源，即进行了电压叠加。因此，第二储能电容C12通过第四开关S4输出叠加后的第九电压Vled，其中Vled等于Vin+Vo。此时，对于储能元件Cn，其第一端连接电压Vled，其第二端连接电压0，因此，储能元件Cn被充电，Cn储能压差为Vled。
步骤(3)：第二控制器第四开关S4与第五开关S5同时断开，第三开关S3与第六开关S6同时闭合，重复步骤(1)中为第二储能电容C12的充电过程。此时，储能元件Cn充当电源输出Vled，为背光控制模块供电。
将图37与图36相比，采用图36所示的供电电路对储能元件Cn的储能要求低于图37所示的供电电路。储能要求低，相应地，成本也较低。
在一些实施例中，图32所示的第三电压变换模块可以为反激隔离形式。图38为根据本申请实施例的又一种显示装置的供电电路结构示意图。如图38所示，第三电压变换模块包括：反激式隔离变压模块。反激式隔离变压模块，用于在原边绕组截止时，向直流输入电压叠加副边绕组生成的叠加电压，并将叠加后的第九电压输出至背光控制模块；储能元件的第一端与反激式隔离变压模块的输出端连接；储能元件用于在原边绕组截止时，储能叠加电压；以及，在原边绕组导通时，向直流输入电压叠加该叠加电压，并将叠加后的第九电压输出至背光控制模块；其中，反馈信号用于指示反激式隔离变压模块通过调整叠加电压来调整第九电压。
具体的，本实施例采用的反激隔离形式的电压变换模块，通过原边绕组和副边绕组进行了电气隔离，可以更好地完成电压叠加。“反激”具体指当开关管接通时，副边绕组变压器充当电感，电能转化为磁能，此时输出回路无电流；相反，当开关管关断时，副边绕组变压器释放能量，磁能转化为电能，输出回路中有电流。反激式电压变换模块中，副边绕组变压器同时充当储能电感，具有元器件少，电路简单，成本低，体积小等特点，同时电气隔离提高了使用安全性。
在一些实施例中，图38所示的储能元件可以为单个储能电容或者其他储能电路。该储能元件与反激式隔离变压模块共同配合，交替输出第九电压，为背光控制模块持续供电，使发光二极管稳定发光。
下面结合反激式隔离变压模块及储能元件具体的电路结构示意图，对第三电压变换模 块与储能元件的供电原理进行说明。
在一些实施例中，图39为根据本申请实施例的一种反激式隔离变压模块的供电电路结构示意图。反激式隔离变压模块包括：原边绕组、副边绕组、第三二极管D13、第三控制器以及第七开关S7。
原边绕组的第一端连接直流输入电压Vin，原边绕组的第二端连接第七开关S7的第一端，第七开关S7的第二端接地；副边绕组与原边绕组耦合，副边绕组的第一端与第三二极管D13的正极连接，副边绕组的第二端连接直流输入电压Vin；第三二极管D13的负极作为反激式隔离变压模块的输出端，输出第九电压Vled。
第三控制器，与第七开关S7的控制端连接，用于根据反馈信号，通过控制第七开关的开关频率S7，控制原边绕组的导通与截止，以调整叠加电压。
其中，副边绕组的第二端连接直流输入电压Vin即向副边绕组的第二端施加直流输入电压Vin。在一些实施例中，可以通过副边绕组的第二端与原边绕组的第一端建立物理连接，实现对副边绕组的第二端施加直流输入电压Vin。在一些实施例中，也可以通过副边绕组的第二端与供电接口建立物理连接，实现对副边绕组的第二端施加直流输入电压Vin，更有利于实现电气隔离。
基于图39所示的供电电路，第三电压变换模块与储能元件配合供电的原理如下：
步骤(1)：第三控制器控制第七开关S7导通，原边绕组导通，原边绕组内电流线性增长，电感储能增加；第三二极管D13不导通，副边绕组不导通。通过控制第七开关S7的开关频率可控制原边绕组的储能电压。
步骤(2)：第三控制器控制第七开关S7关断，原边绕组截止，原边绕组电流切断；第三二极管D13导通，副边绕组导通。通过设置原边绕组与副边绕组的匝数比，可使副边绕组产生叠加电压Vo；同时由于副边绕组的第二端连接直流输入电压Vin，经过电压叠加，副边绕组的第一端输出叠加的第九电压Vled，其中Vled＝Vin+Vo。此时，对于储能元件Cn，其第一端连接电压Vled，其第二端连接电压Vin，因此，储能元件Cn被充电，Cn储能压差为Vo。
步骤(3)：第三控制器控制第七开关S7导通，重复步骤(1)原边绕组的储能过程。同时，将储能元件Cn看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，则直流输入电压Vin连接到储能元件Cn的第二端相当于串联的两个电源，即进行了电压叠加。因此，通过储能元件Cn的第一端输出叠加后的第九电压Vled。
对于图39所示的供电电路中，只需要控制叠加电压Vo的大小，就可以控制第九电压Vled的变化。第三控制器基于反馈信号通过控制第七开关S7的开关频率或者占空比来控制电荷的传输数量，从而达到控制第九电压Vled的目的。直流输入电压Vin比较稳定，相当于“固定电压”；叠加电压Vo，相当于“变动电压”。由于直流输入电压Vin比较稳定，叠 加电压Vo的输出电压变化范围取决于第九电压Vled所需的变化范围。上述采用一个“固定电压”叠加一个“变动电压”的电路结构即为“阶梯供电”，可达到降低成本、提高效率的目的。
在一些实施例中，图39所示的供电电路中，储能元件Cn的第二端也可以接地。图40为根据本申请实施例的另一种反激式隔离变压模块的供电电路结构示意图。与图39不同的是：储能元件Cn的第二端接地。因此，图40与图39供电原理中不同的是储能元件Cn的储能压差不同。
基于图40所示的供电电路，第三电压变换模块与储能元件配合供电的原理如下：
步骤(1)：第三控制器控制第七开关S7导通，原边绕组导通，原边绕组内电流线性增长，电感储能增加；第三二极管D13不导通，副边绕组不导通。通过控制第七开关S7的开关频率可控制原边绕组的储能电压。
步骤(2)：第三控制器控制第七开关S7关断，原边绕组截止，原边绕组电流切断；第三二极管D13导通，副边绕组导通。通过设置原边绕组与副边绕组的匝数比，可使副边绕组产生叠加电压Vo；同时由于副边绕组的第二端连接直流输入电压Vin，经过电压叠加，副边绕组的第一端输出叠加的第九电压Vled，其中Vled＝Vin+Vo。此时，对于储能元件Cn，其第一端连接电压Vled，其第二端连接电压0，因此，储能元件Cn被充电，Cn储能压差为Vled。
步骤(3)：第三控制器控制第七开关S7接通，重复步骤(1)原边绕组的储能过程。此时，将储能元件Cn看作为一个上端(即第一端)为正极、下端(即第二端)为负极的电池，输出Vled，为背光控制模块供电。
将图40与图39相比，采用图39所示的供电电路对储能元件Cn的储能要求低于图39所示的供电电路。储能要求低，相应地，成本也较低。
在一些实施例中，本实施例提供的显示装置还包括第一滤波模块；第一滤波模块，与供电接口和第三电压变换模块连接，用于对直流输入电压进行滤波。第一滤波模块可以为一个或多个接地电容组成的滤波电路、也可以为电容与电感组成的滤波电路。
示例性的，图41为根据本申请实施例的一种滤波模块的结构示意图。第一滤波模块以一个接地电容为例。具体的，供电接口的直流输入电压及接地之间并联有第一滤波电容C13。用于滤除电源的杂波和交流成分，平滑脉动直流电压，储存电能。其电容容量与负载电流和电源的纯净度有关，通常选取较大容量的滤波电容。
在一些实施例中，该第一滤波电容C13可以为图41所示的电解电容。电解电容是电容的一种，金属箔为正极(铝或钽)，与正极紧贴金属的氧化膜(氧化铝或五氧化二钽)是电介质，阴极由导电材料、电解质(电解质可以是液体或固体)和其他材料共同组成，因电解质是阴极的主要部分。其单位体积的电容量非常大，由于制备材料为普通工业材料， 制备工艺也是普通工业设备，因此可进行批量生产，所以成本也相对较低。需要注意的是，电解电容正负不可接错。
在一些实施例中，该第一滤波电容C13也可以为其他类型的电容，例如陶瓷带内容、薄膜电容、云母电容等。在实际电路中，可根据电容容量需求进行选择。
在一些实施例中，本实施例提供的显示装置还包括第二滤波模块；第二滤波模块，与第三电压变换模块的输出端连接，用于对第九电压进行滤波。第二滤波模块可以为一个或多个接地电容组成的滤波电路、也可以为电容与电感组成的滤波电路。示例性的，如图41所示，以接地的第二滤波电容C14为例进行滤波。
如图41所示，储能元件Cn的第二端连接直流输入电压Vin。在供电过程中，电荷泵模块或反激式隔离变压模块与储能元件Cn配合，交替输出第九电压Vled。其中，在直流输入电压Vin与储能元件Cn的第二端连接处，也可以设置滤波模块，用于滤除输入至储能元件Cn的直流输入电压Vin中的杂波等。
在一些实施例中，本实施例提供的显示装置还包括第四二极管Dn；第四二极管Dn的正极与储能元件Cn的第二端连接，第四二极管Dn的负极与储能元件Cn的第一端连接。利用第四二极管Dn使直流输入电压Vin输入至背光控制模块，构成电流回路，防止第三电压变换模块不工作时，电流流经第三电压变换模块而造成系统误动作或者其他异常情况，起到保护第三电压变换模块的作用。
在一些实施例中，图42为根据本申请实施例的一种基于电荷泵模块供电电路的滤波模块的结构示意图。该电荷泵模块以图36为例，供电原理不再赘述。在一些实施例中，图43为根据本申请实施例的一种基于反激式隔离变压模块供电电路的滤波模块的结构示意图，该反激式隔离变压模块以图39为例，其中，通过副边绕组的第二端与原边绕组的第一端建立物理连接，实现对副边绕组的第二端施加直流输入电压Vin，供电原理不再赘述。
在一些实施例中，本实施例提供的显示装置还包括：主板；主板与供电接口连接，直流输入电压用于向主板供电。图44为根据本申请实施例的第三种为主板供电的电路结构示意图。当直流输入电压等于主板的需求电压时，可以选择由直流输入电压为主板直接进行供电。
在一些实施例中，本实施例提供的显示装置还包括第四电压变换模块；第四电压变换模块，与供电接口和主板连接，用于根据直流输入电压，输出第十电压，第十电压为主板的需求电压。图45为根据本申请实施例的第四种为主板供电的电路结构示意图。当直流输入电压不满足主板的需求电压时，可采用第四电压变换模块对直流输入电压进行DC-DC的电压变换。当电视功率较大时，为了降低线缆的损耗，往往提高电压而降低电流，因此直流输入电压会高于主板的需求电压。在一些实施例中，由于主板通常需要固定电压，所 以第四电压变换模块可以采用buck降压电路、boost-buck升压降压电路等。
本实施例还提供一种显示控制方法，应用于前述的显示装置，包括：接收反馈信号，反馈信号由背光控制模块生成并通过反馈模块发送；基于反馈信号，调整叠加电压以调整第九电压；第九电压为背光控制模块的需求电压。
本实施例中根据背光控制模块输出的实时电流的反馈信号，对第三电压变换模块生成的叠加电压进行调整，进而调整第九电压，使得背光控制模块以额定电流工作，防止过大电流流过LED灯串中的LED组件造成元件的损坏。其中，叠加电压相当于“变动电压”；第十电压相当于“固定电压”，二者电压叠加实现了阶梯供电，有利于降低热损耗。
根据本申请实施例的显示装置，包括：背光控制模块，用于控制发光二极管发光，发光二极管用于点亮显示装置的屏幕；供电接口，用于接收直流输入电压，直流输入电压由外置适配器提供；第三电压变换模块，用于根据直流输入电压生成叠加电压，并将叠加电压与直流输入电压进行叠加，输出叠加后的第九电压；第九电压为背光控制模块的需求电压；储能元件，储能元件的第一端与第三电压变换模块的输出端连接，储能元件的第二端连接直流输入电压，用于储能叠加电压，并与第三电压变换模块交替输出第九电压；反馈模块，用于将背光控制模块生成的反馈信号发送至第三电压变换模块，反馈信号用于指示第三电压变换模块调整第九电压。
本申请实施例中设置有与外置适配器连接的供电接口，接收直流输入电压，以适应外置适配器供电模式；利用直流输入电压生成叠加电压，并将该叠加电压与直流输入电压进行叠加，实现阶梯供电，有利于降低热损耗；利用储能元件实现为背光控制模块持续供电；通过实时反馈及时调整背光控制模块的供电电压，使发光二极管工作稳定。
应当理解的是，本申请并不局限于上面已经描述并在附图中示出的精确结构，并且可以在不脱离其范围进行各种修改和改变。本申请的范围仅由所附的权利要求书来限制。

Claims (27)

  1. 一种显示装置，包括：变压器、电压变换模块、反馈模块以及灯串组；其中，所述电压变换模块与所述灯串组一一对应，所述灯串组包括第一灯串和第二灯串；
    所述变压器的第一次级线圈和第二次级线圈，与所述变压器的初级线圈耦合；所述第一次级线圈，用于根据所述初级线圈接收的电源，输出第一电压；
    所述第二次级线圈，用于根据所述初级线圈接收的电源，由所述第二次级线圈的两端交替输出第二电压；所述第二次级线圈与所述灯串组一一对应；
    所述电压变换模块，用于根据所述第一电压，生成叠加电压并将所述叠加电压叠加至对应的所述第二次级线圈两端的第二电压，输出叠加后的第三电压；
    所述反馈模块，用于根据所述灯串组的输出电流生成反馈信号，并发送至所述电压变换模块，所述反馈信号用于指示所述电压变换模块调整所述第三电压；
    所述第一灯串连接对应的所述第二次级线圈的一端，所述第二灯串连接对应的所述第二次级线圈的另一端，用于基于所述第三电压发光。
  2. 根据权利要求1所述的显示装置，所述电压变换模块包括：电压调整模块和电压叠加模块；
    所述电压调整模块与所述第一次级线圈的输出端连接，用于根据所述第一电压，生成叠加电压；
    所述电压叠加模块接收所述叠加电压，并与所述第二次级线圈的两端连接，用于将所述叠加电压叠加至对应的所述第二次级线圈两端的第二电压，输出叠加后的所述第三电压；
    其中，所述反馈信号用于指示所述电压调整模块通过调整所述叠加电压来调整所述第三电压。
  3. 根据权利要求2所述的显示装置，所述电压叠加模块包括第一均流电容、第一整流二极管、第二整流二极管、第三整流二极管、第四整流二极管；
    所述第一均流电容的一端与所述第二次级线圈的一端；所述第一均流电容的另一端与所述第一整流二极管的正极和所述第二整流二极管的负极连接；所述第二整流二极管的正极连接所述叠加电压；所述第一整流二极管的负极与所述第一灯串的正极连接；所述第一灯串的负极接地；
    所述第三整流二极管的正极与所述第二次级线圈的另一端和所述第四整流二极管的负极连接，所述第四整流二极管的正极连接所述叠加电压；所述第三整流二极管的负极与所述第二灯串的正极连接；所述第二灯串的负极接地。
  4. 根据权利要求2所述的显示装置，所述电压调整模块包括：第二晶体管、第三晶体管、第二电感、第二电容；
    所述第二晶体管的一端与所述第一次级线圈的输出端连接；所述第二晶体管的另一端与所述第三晶体管的一端和所述第二电感的一端连接；所述第三晶体管的另一端接地；
    所述第二电感的另一端作为所述电压调整模块的输出端，输出所述叠加电压；
    所述第二电容的一端与所述第二电感的另一端连接；所述第二电容的另一端接地；
    所述第二晶体管的控制极和所述第三晶体管的控制极均与所述反馈模块连接，用于根据所述反馈信号，调节所述第二晶体管和所述第三晶体管的开关频率，以调节所述叠加电压。
  5. 根据权利要求4所述的显示装置，所述电压调整模块还包括第二二极管；
    所述第二二极管的负极与所述第二电容的一端连接；所述第二二极管的正极与所述第二电容的另一端连接。
  6. 根据权利要求1所述的显示装置，所述显示装置还包括第一开关电路和第一接地电阻；
    所述第一开关电路位于所述灯串组和所述第一接地电阻之间；
    所述第一开关电路的一端与所述第一灯串的负极和所述第二灯串的负极连接，所述第一开关电路的另一端与所述第一接地电阻的一端和所述反馈模块的输入端连接；所述第一接地电阻的另一端接地；所述第一开关电路，基于占空比控制信号，进行导通或截止。
  7. 根据权利要求1所述的显示装置，所述显示装置还包括：第二开关电路和第二接地电阻；
    所述第二开关电路位于所述灯串组和所述第二接地电阻之间；
    所述第二开关电路的一端与所述第一灯串的负极和所述第二灯串的负极连接，所述第二开关电路的另一端与所述第二接地电阻的一端连接；所述第二接地电阻的另一端接地；
    所述第二开关电路，用于改变回路电流，进行模拟调光。
  8. 根据权利要求7所述的显示装置，所述第二开关电路包括：第五晶体管、比较器；
    所述第五晶体管的一端与所述第一灯串的负极和所述第二灯串的负极连接；所述第五晶体管的另一端与所述第二接地电阻的一端和所述比较器的反相输入端连接；
    所述比较器的正相输入端输入所述灯串组的需求电压，所述比较器的输出端与所述第五晶体管的栅极连接；
    调节所述第五晶体管的阻值，用于改变回路电流，进行模拟调光。
  9. 根据权利要求1所述的显示装置，所述第二次级线圈、所述电压变换模块和所述灯串组的数量均为多个；
    所述显示装置还包括多个均流电感；
    相邻的两个第二次级线圈之间设置有相互耦合的所述均流电感。
  10. 根据权利要求1所述的显示装置，还包括：
    背光控制模块，用于控制发光二极管发光，所述发光二极管用于点亮所述显示装置的屏幕；
    供电接口，用于接收外置适配器提供的直流输入电压；
    第一电压变换模块，用于根据所述直流输入电压生成第五电压；储能元件，与所述第一电压变换模块连接，用于储能所述第五电压；所述储能元件与所述第一电压变换模块交替输出所述第五电压；
    所述背光控制模块的负极连接所述第五电压，所述第五电压作为所述背光控制模块的负参考电压；所述背光控制模块的正极连接所述直流输入电压；所述直流输入电压的绝对值与所述第五电压的绝对值之和等于所述背光控制模块的需求电压；
    反馈模块，用于将所述背光控制模块生成的反馈信号发送至所述第一电压变换模块，所述反馈信号用于指示所述第一电压变换模块调整所述第五电压以调整所述背光控制模块的需求电压。
  11. 根据权利要求10所述的显示装置，所述第一电压变换模块，包括：电荷泵模块；
    所述电荷泵模块，用于在充电状态下，产生所述第五电压；以及在放电状态下，向所述背光控制模块的负极提供所述第五电压；
    所述储能元件的第一端与所述电荷泵模块的正向输出端连接，并接地；所述储能元件的第二端与所述电荷泵模块的负向输出端连接；所述储能元件用于在所述电荷泵模块放电时，储能所述第五电压；以及，在所述电荷泵模块充电时，向所述背光控制模块的负极提供所述第五电压；
    其中，所述反馈信号用于指示所述电荷泵模块调整所述第五电压以调整所述背光控制模块的需求电压。
  12. 根据权利要求10所述的显示装置，所述第一电压变换模块，包括：反激式隔离变压模块；
    所述反激式隔离变压模块，用于在原边绕组导通时，由副边绕组生成所述第五电压，并输送至所述背光控制模块的负极；
    所述储能元件的第一端与所述反激式隔离变压模块的正向输出端连接并接地；所述储能元件的第二端与所述反激式隔离变压模块的负向输出端连接；所述储能元件用于在所述原边绕组导通时，储能所述第五电压；以及，在所述原边绕组截止时，向所述背光控制模块的负极提供所述第五电压；
    其中，所述反馈信号用于指示所述反激式隔离变压模块调整所述第五电压以调整所述背光控制模块的需求电压。
  13. 根据权利要求11所述的显示装置，所述电荷泵模块包括：第一控制器、第一储能电容、第一开关、第二开关、第三开关及第四开关；
    所述第一开关的第一端连接所述直流输入电压，所述第一开关的第二端连接所述第二开关的第一端；所述第二开关的第二端作为所述电荷泵模块的正向输出端，与所述储能元件的第一端连接，并接地；
    所述第一储能电容的第一端与所述第一开关的第二端及所述第二开关的第一端连接，所述第一储能电容的第二端与所述第三开关的第一端及所述第四开关的第一端连接；所述第四开关的第二端接地；
    所述第三开关的第二端作为所述电荷泵模块的负向输出端，与所述储能元件的第二端连接，输出所述第五电压；
    所述第一控制器，与所述第一开关、所述第二开关、所述第三开关及所述第四开关的控制端连接，用于根据所述反馈信号，通过控制所述第一开关、所述第二开关、所述第三开关及所述第四开关的开关频率，以调整所述第五电压；
    其中，所述第一开关和所述第二开关的开关状态不同，所述第一开关与所述第四开关同时断开或导通；所述第二开关与所述第三开关同时断开或导通。
  14. 根据权利要求12所述的显示装置，所述反激式隔离变压模块包括：原边绕组、副边绕组、第一二极管、第二控制器以及第五开关；
    所述原边绕组的第一端连接所述直流输入电压，所述原边绕组的第二端连接所述第五开关的第一端，所述第五开关的第二端接地；
    所述副边绕组与所述原边绕组耦合，所述副边绕组的第一端与所述第一二极管的正极连接；所述第一二极管的负极作为所述反激式隔离变压模块的正向输出端，与所述储能元件的第一端连接，并接地；
    所述副边绕组的第二端作为所述反激式隔离变压模块的负向输出端，与所述储能元件的第二端连接，输出所述第五电压；
    所述第二控制器，与所述第五开关的控制端连接，用于根据所述反馈信号，通过控制所述第五开关的开关频率，以调整所述第五电压。
  15. 根据权利要求11-14中任一项所述的显示装置，所述反馈模块包括电平转换电路；
    所述电平转换电路，接收所述背光控制模块输出的第一反馈信号，将第一反馈信号转换为第二反馈信号后，向所述第一电压变换模块输出所述第二反馈信号；其中，所述第一反馈信号和所述第二反馈信号的参考电压不同。
  16. 根据权利要求10所述的显示装置，所述显示装置还包括：第二二极管；
    所述第二二极管的正极与所述储能元件的第二端连接，所述第二二极管的负极与所述储能元件的第一端连接。
  17. 根据权利要求10所述的显示装置，所述显示装置还包括：主板；
    所述主板与所述供电接口连接，所述直流输入电压用于向所述主板供电。
  18. 根据权利要求17所述的显示装置，所述显示装置还包括第二电压变换模块；
    所述第二电压变换模块，与所述供电接口和所述主板连接，用于根据所述直流输入电压，输出第六电压，所述第六电压为所述主板的需求电压。
  19. 根据权利要求1所述的显示装置，还包括：
    背光控制模块，用于控制发光二极管发光，所述发光二极管用于点亮所述显示装置的屏幕；
    供电接口，用于接收直流输入电压，所述直流输入电压由外置适配器提供；
    第三电压变换模块，用于根据所述直流输入电压生成叠加电压，并将所述叠加电压与所述直流输入电压进行叠加，输出叠加后的第九电压；所述第九电压为所述背光控制模块的需求电压；
    储能元件的第一端与所述第三电压变换模块连接，所述储能元件的第二端连接所述直流输入电压，用于储能所述叠加电压，并与所述第三电压变换模块交替输出所述第九电压；
    反馈模块，用于将所述背光控制模块生成的反馈信号发送至所述第三电压变换模块，所述反馈信号用于指示所述第三电压变换模块调整所述第九电压。
  20. 根据权利要求19所述的显示装置，所述第三电压变换模块，包括：电荷泵模块；
    所述电荷泵模块，用于在充电状态下产生所述叠加电压；以及在放电状态下，向所述直流输入电压叠加所述叠加电压，并将叠加后的所述第九电压输出至所述背光控制模块；
    所述储能元件的第一端与所述电荷泵模块的输出端连接；所述储能元件用于在所述电荷泵模块放电时，储能所述叠加电压；以及，在所述电荷泵模块充电时，向所述直流输入电压叠加所述叠加电压，并将叠加后的所述第九电压输出至所述背光控制模块；
    其中，所述反馈信号用于指示所述电荷泵模块通过调整所述叠加电压来调整所述第九电压。
  21. 根据权利要求19所述的显示装置，所述第三电压变换模块，包括：反激式隔离变压模块；
    所述反激式隔离变压模块，用于在原边绕组截止时，向所述直流输入电压叠加所述副边绕组生成的所述叠加电压，并将叠加后的所述第九电压输出至所述背光控制模块；
    所述储能元件的第一端与所述反激式隔离变压模块的输出端连接；所述储能元件用于在所述原边绕组截止时，储能所述叠加电压；以及，在所述原边绕组导通时，向所述直流输入电压叠加所述叠加电压，并将叠加后的所述第九电压输出至所述背光控制模块；
    其中，所述反馈信号用于指示所述反激式隔离变压模块通过调整所述叠加电压来调整所述第九电压。
  22. 根据权利要求20所述的显示装置，所述电荷泵模块包括：第一控制器、第一储能电容、第一二极管、第二二极管、第一开关以及第二开关；
    所述第一二极管的正极连接所述直流输入电压，所述第一二极管的负极连接所述第二二极管的正极；所述第二二极管的负极作为所述电荷泵模块的输出端，输出所述第九电压；
    所述第一开关的第一端连接所述第一二极管的正极，所述第一开关的第二端连接所述第二开关的第一端，所述第二开关的第二端接地；
    所述第一储能电容的第一端与所述第一二极管的负极连接，所述第一储能电容的第二端与所述第一开关的第二端连接；
    所述第一控制器，与所述第一开关及所述第二开关的控制端连接，用于根据所述反馈信号，控制所述第一开关及所述第二开关的开关频率，以调整所述叠加电压；
    其中，所述第一开关和所述第二开关的开关状态不同。
  23. 根据权利要求20所述的显示装置，所述电荷泵模块包括：第二控制器、第二储能电容、第三开关、第四开关、第五开关及第六开关；
    所述第三开关的第一端连接所述直流输入电压，所述第三开关的第二端连接所述第四开关的第一端；所述第四开关的第二端作为所述电荷泵模块的输出端，输出所述第九电压；
    所述第五开关的第一端连接所述第三开关的第一端，所述第五开关的第二端连接所述第六开关的第一端，所述第六开关的第二端接地；
    所述第二储能电容的第一端与所述第三开关的第二端连接，所述第二储能电容的第二端与所述第五开关的第二端连接；
    所述第二控制器，与所述第三开关、所述第四开关、所述第五开关及所述第六开关的控制端连接，用于根据所述反馈信号，通过控制所述第三开关、所述第四开关、所述第五开关及所述第六开关的开关频率，以调整所述叠加电压；
    其中，所述第三开关和所述第四开关的开关状态不同，所述第三开关与所述第六开关同时断开或导通；所述第四开关与所述第五开关同时断开或导通。
  24. 根据权利要求21所述的显示装置，所述反激式隔离变压模块包括：原边绕组、副边绕组、第三二极管、第三控制器以及第七开关；
    所述原边绕组的第一端连接所述直流输入电压，所述原边绕组的第二端连接所述第七开关的第一端，所述第七开关的第二端接地；
    所述副边绕组与所述原边绕组耦合，所述副边绕组的第一端与所述第三二极管的正极连接，所述副边绕组的第二端连接所述直流输入电压；所述第三二极管的负极作为所述反激式隔离变压模块的输出端，输出所述第九电压；
    所述第三控制器，与所述第七开关的控制端连接，用于根据所述反馈信号，通过控制所述第七开关的开关频率，以调整所述叠加电压。
  25. 根据权利要求19所述的显示装置，所述显示装置还包括：第四二极管；
    所述第四二极管的正极与所述储能元件的第二端连接，所述第四二极管的负极与所述 储能元件的第一端连接。
  26. 根据权利要求19所述的显示装置，所述显示装置还包括：主板；
    所述主板与所述供电接口连接，所述直流输入电压用于向所述主板供电。
  27. 根据权利要求26所述的显示装置，所述显示装置还包括第四电压变换模块；
    所述第四电压变换模块，与所述供电接口和所述主板连接，用于根据所述直流输入电压，输出第十电压，所述第十电压为所述主板的需求电压。
PCT/CN2022/121412 2022-04-19 2022-09-26 显示装置 WO2023201988A1 (zh)

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CN202210415138.2 2022-04-20
CN202210415138.2A CN116959379A (zh) 2022-04-20 2022-04-20 显示装置及显示控制方法
CN202210421396.1A CN116978312A (zh) 2022-04-21 2022-04-21 显示装置及显示控制方法
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040246226A1 (en) * 2003-05-23 2004-12-09 Seung-Hwan Moon Inverter and liquid crystal display including inverter
CN109560710A (zh) * 2018-12-29 2019-04-02 惠州华科电器有限公司 正极直流叠加电路
CN113763868A (zh) * 2020-06-01 2021-12-07 海信视像科技股份有限公司 显示装置及供电设备

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040246226A1 (en) * 2003-05-23 2004-12-09 Seung-Hwan Moon Inverter and liquid crystal display including inverter
CN109560710A (zh) * 2018-12-29 2019-04-02 惠州华科电器有限公司 正极直流叠加电路
CN113763868A (zh) * 2020-06-01 2021-12-07 海信视像科技股份有限公司 显示装置及供电设备

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