Display device and power supply feedback method

Abstract

The display device and power supply feedback method provided by this application include: obtaining a minimum feedback signal for the light string based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; obtaining a maximum feedback signal for the light string based on the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string; comparing the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and sending a corresponding adjustment feedback signal to the power supply circuit based on the comparison result, so that the power supply circuit adjusts the supply voltage of the light string based on the adjustment feedback signal. This solution can improve the accuracy of the limited range of the light string feedback voltage, thereby improving the reliability of the output feedback signal.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a display device and a power supply feedback method. Background Art

[0002] The power supply circuit is usually used to provide power supply voltage for electrical equipment to ensure the normal operation of the electrical equipment. The power supply circuit can supply power to the backlight component of the display device, where the display device can be a sub-millimeter light emitting diode (Minilight Emitting Diode, referred to as MiniLED), a liquid crystal display (Liquid Crystal Display, referred to as LCD), etc. The backlight component includes a light board, and the power supply circuit is used to supply power to the light string in the light board. In actual applications, the power supply circuit adjusts the output power supply voltage based on the feedback signal to ensure the stability of the power supply voltage of the light string. However, in some scenarios, the collected feedback signal is easily distorted, which causes the output power supply voltage to be unstable, and thus the reliability of the power supply circuit cannot be guaranteed.

[0003] To this end, in related art, an upper limit for the feedback signal is set based on the maximum operating voltage of the light string. If the feedback signal exceeds the upper limit, it is considered to be a distorted signal and the feedback signal is adjusted accordingly. However, the setting range of the feedback signal in related art is inaccurate, and distorted feedback signals cannot be accurately identified, resulting in low reliability of the output feedback signal. Summary of the Invention

[0004] The present application provides a display device and a power supply feedback method, aiming to solve the technical problem in the related art that the limited range of the feedback signal is inaccurate, resulting in low reliability of the output feedback signal.

[0005] In a first aspect, the present application provides a display device, comprising: a light board, comprising at least one light string, configured to provide backlight through the light string; a power supply circuit, connected to the light board, configured to provide a power supply voltage to the light string in the light board; a controller, connected to the light board and the power supply circuit, configured to: obtain a power supply feedback signal of the light string in the light board; obtain a minimum feedback signal of the light string based on a reference supply voltage of the light string at a current current and a line loss voltage of the light string; and obtain a maximum feedback signal of the light string based on a reference supply voltage of the light string at a current current and a temperature compensation voltage of the light string; compare the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and send a corresponding adjustment feedback signal to the power supply circuit based on the comparison result, so that the power supply circuit adjusts the supply voltage of the light string based on the adjustment feedback signal.

[0006] In some embodiments, when obtaining the minimum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; and obtaining the maximum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string, the controller is specifically configured as follows: obtaining the reference supply voltage of the light string at the current current based on a calculation formula of the reference supply voltage and current of the light string; obtaining a reference feedback signal corresponding to the reference supply voltage of the light string at the current current based on the correspondence between the supply voltage and the feedback signal; obtaining the minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage; and obtaining the maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage.

[0007] In some embodiments, when the minimum feedback signal of the light string is obtained based on the reference feedback signal of the light string and the line loss voltage, the controller is specifically configured to: obtain the corresponding relationship between the line loss voltage and current of the light string according to the line loss voltage of the light string under a predetermined current; obtain the line loss voltage under the current current according to the corresponding relationship between the line loss voltage and current of the light string, and obtain the first corrected feedback signal of the light string under the current current according to the line loss voltage under the current current and the corresponding relationship between the power supply voltage and the feedback signal; and obtain the minimum feedback signal of the light string under the current current by subtracting the reference feedback signal from the first corrected feedback signal.

[0008] In some embodiments, when the maximum feedback signal of the light string is obtained based on the reference feedback signal of the light string and the temperature compensation voltage, the controller is further specifically configured to: obtain the current temperature of the light string, and obtain the compensation coefficient of the light string at the current temperature based on the correspondence between the temperature and the compensation coefficient; obtain the temperature compensation voltage of the light string at the current temperature based on the compensation coefficient and the compensation experience value, and obtain the second corrected feedback signal of the light string at the current temperature based on the temperature compensation voltage of the light string at the current temperature and the correspondence between the supply voltage and the feedback signal; add the reference feedback signal and the second corrected feedback signal to obtain the maximum feedback signal of the light string under the current current.

[0009] In some embodiments, when obtaining the minimum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; and obtaining the maximum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string, the controller is specifically configured as follows: obtaining the reference supply voltage of the light string at the current current based on a calculation formula of the reference supply voltage and current of the light string; adding the reference supply voltage to the line loss voltage to obtain the maximum supply voltage; and subtracting the reference supply voltage from the temperature compensation voltage to obtain the minimum supply voltage; obtaining the minimum feedback signal corresponding to the maximum supply voltage based on the correspondence between the supply voltage and the feedback signal, and obtaining the maximum feedback signal corresponding to the minimum supply voltage.

[0010] In some embodiments, the controller is further configured to compare the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and when sending a corresponding adjustment feedback signal to the power supply circuit based on the comparison result, the controller is specifically further configured to: detect whether the power supply feedback signal is within a first range; the upper limit value of the first range is the maximum feedback signal, and the lower limit value of the first range is the minimum feedback signal; if the power supply feedback signal is not within the first range and the feedback signal is greater than the maximum feedback signal, then the maximum feedback signal is used as the adjustment feedback signal; if the power supply feedback signal is not within the first range and the feedback signal is less than the minimum feedback signal, then the minimum feedback signal is used as the adjustment feedback signal.

[0011] In a second aspect, the present application provides a power supply feedback method for a display device, wherein the display device includes a controller, a power supply circuit and a lamp board, and the method includes: the controller obtains a power supply feedback signal of a light string in the lamp board; the controller obtains a minimum feedback signal of the light string based on a reference supply voltage of the light string at a current current and a line loss voltage of the light string; and obtains a maximum feedback signal of the light string based on a reference supply voltage of the light string at a current current and a temperature compensation voltage of the light string; the controller compares the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and sends a corresponding adjustment feedback signal to the power supply circuit based on the comparison result, so that the power supply circuit outputs the power supply voltage of the light string based on the adjustment feedback signal.

[0012] In some embodiments, the controller obtains the minimum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; and obtains the maximum feedback signal of the light string based on the temperature compensation voltage of the light string and the reference supply voltage of the light string at the current current, including: the controller obtains the reference supply voltage of the light string at the current current based on a calculation formula of the reference supply voltage and current of the light string; the controller obtains the correspondence between the supply voltage and the feedback signal, and obtains the reference feedback signal corresponding to the reference supply voltage of the light string at the current current based on the correspondence between the supply voltage and the feedback signal; the controller obtains the minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage; and, based on the reference feedback signal of the light string, obtains the maximum feedback signal of the light string.

[0013] In some embodiments, the controller obtains the minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage, including: the controller obtains the correspondence between the line loss voltage and the current of the light string according to the line loss voltage of the light string under a predetermined current; the controller obtains the line loss voltage under the current current based on the correspondence between the line loss voltage and the current of the light string, and obtains the first corrected feedback signal of the light string under the current current based on the line loss voltage under the current current and the correspondence between the power supply voltage and the feedback signal; the controller subtracts the reference feedback signal from the first corrected feedback signal to obtain the minimum feedback signal of the light string under the current current.

[0014] In some embodiments, the controller obtains the maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage, including: the controller obtains the current temperature of the light string, and obtains the compensation coefficient of the light string at the current temperature based on the correspondence between the temperature and the compensation coefficient; the controller obtains the temperature compensation voltage of the light string at the current temperature based on the compensation coefficient and the compensation experience value, and obtains the second corrected feedback signal of the light string at the current temperature based on the temperature compensation voltage of the light string at the current temperature and the correspondence between the power supply voltage and the feedback signal; the controller adds the reference feedback signal and the second corrected feedback signal to obtain the maximum feedback signal of the light string under the current current.

[0015] In a third aspect, the present application provides an electronic device comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; and the processor executes the computer-executable instructions stored in the memory to implement the method described above.

[0016] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to implement the method as described above when executed by a processor.

[0017] In the display device and power supply feedback method provided in this application, a minimum feedback signal of the light string is obtained based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; and a maximum feedback signal of the light string is obtained based on the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string, and a corresponding adjustment feedback signal is output based on the maximum feedback signal and the minimum feedback signal. Compared with the scheme in the related art that sets a limited range without considering the characteristics of the light string and the circuit in which it is located, this scheme considers the influence of the linear loss and temperature compensation of the light string on the feedback signal of the light string, and obtains the maximum feedback signal and the minimum feedback signal based on these two influencing factors. This is more in line with the actual scenario of light string power supply, and thus this scheme can improve the accuracy of the limited range of the light string feedback voltage, thereby improving the reliability of the output feedback signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the embodiments of the present application, and together with the description, are used to explain the principles of the embodiments of the present application.

[0019] The above drawings illustrate specific embodiments of the present invention, which will be described in more detail below. These drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concepts of the present invention for those skilled in the art by reference to specific embodiments.

[0020] Figure 1 A schematic diagram of the structure of a display device equipped with an independent power supply board;

[0021] Figure 2 This is a schematic diagram of the connection relationship between the power board and the light board in an example;

[0022] Figure 3 A schematic structural diagram of a display device provided in an embodiment of the present application;

[0023] Figure 4 This is a flow chart of a power supply feedback method provided in one embodiment of the present application;

[0024] Figure 5 This is a flow chart of another power supply feedback method provided in one embodiment of the present application;

[0025] Figure 6 This is a flow chart of another power supply feedback method provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0027] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the numbers used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] The following first describes the application scenarios and existing problems of this application with reference to the accompanying drawings.

[0031] As people's demand for information continues to grow, various types of display devices have emerged, such as computers, televisions, and projectors. The power supply circuit is one of the most important circuit structures in a display device, providing electrical energy to the display device and ensuring its normal operation. Some display devices have a separate power supply board, while others combine the power supply board with the mainboard.

[0032] Taking a display device with an independent power board as an example, the structure of the display device is described. Figure 1 As shown, Figure 1 A schematic diagram of the structure of a display device with an independent power supply board is shown in FIG. Figure 1As shown, the display device includes a display panel 1, a backlight assembly 2, a mainboard 3, a power board 4, a rear cover 5, and a base 6. The display panel 1 is used to present images to the user; the backlight assembly 2 is located below the display panel 1 and typically includes a light board equipped with multiple light strings, which is used to supply sufficient brightness and evenly distributed light sources so that the display panel 1 can display images normally. The backlight assembly 2 also includes a back panel 20, on which the mainboard 3 and the power board 4 are disposed. Typically, some convex structures are stamped on the back panel 20, and the mainboard 3 and the power board 4 are fixed to the convex structures by screws or hooks; the rear cover 5 is provided on the display panel 1 to conceal the components of the display device, such as the backlight assembly 2, the mainboard 3, and the power board 4, for an aesthetically pleasing effect; and the base 6 is used to support the display device.

[0033] In some embodiments, Figure 2 This is a schematic diagram of the connection relationship between the power board and the light board in an example. Figure 2 As shown, the power board, that is, the power supply circuit 4, the input end of the power supply circuit 4 is connected to the mains, and the output end of the power supply circuit is connected to the light string in the light board 50. The power supply circuit 4 is used to provide a power supply voltage to the light string in the light board 50. The power supply circuit also receives a power supply feedback signal and adjusts the power supply voltage according to the power supply feedback signal to keep the power supply voltage stable.

[0034] However, in the specific implementation process, the power supply feedback signal may be affected by various factors and distorted. For example, the feedback signal may be affected by electromagnetic interference during transmission, causing signal damage and distortion. For another example, in the example of obtaining the feedback signal through an amplifier, if the gain of the amplifier is too high or too low, the signal may not be amplified correctly, resulting in signal distortion. When the feedback signal is distorted, the power supply voltage output by the power supply circuit will become unstable, and the power supply voltage may even exceed the safe voltage of the light string, because the safety of the power supply to the display device cannot be guaranteed.

[0035] In some technologies, an upper limit for the feedback signal is set based on the maximum operating voltage of the light string. If the feedback signal exceeds this upper limit, it is considered to be distorted and the feedback signal is adjusted accordingly. However, the feedback signal setting range in this technology is inaccurate, and distorted feedback signals cannot be accurately identified, resulting in low reliability of the output feedback signal.

[0036] Therefore, the present application provides a display device and a control method thereof, aiming to solve the above technical problems of the related art. The present application can improve the accuracy of the setting range of the feedback signal to accurately identify the distorted feedback signal, thereby improving the reliability of the output feedback signal.

[0037] The technical solutions of the present application and the technical solutions of the present application are described in detail below with reference to specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in certain embodiments. In the description of the present application, unless otherwise clearly specified and limited, each term should be understood in a broad sense within the art. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0038] In some embodiments, Figure 3 This is a schematic structural diagram of a display device provided in an embodiment of the present application. Figure 3 FIG1 shows part of the circuits in the display device, and other circuits not related to this application are not shown. Figure 3 As shown, in the display device provided by this embodiment, the power supply circuit 4 is connected to the light string in the light board 50 to provide a power supply voltage to the light string. A controller 30 is also provided between the light board and the power supply circuit. The controller 30 obtains the current or voltage signal of the light string as the power supply feedback signal of the light string. The controller 30 generates an adjustment feedback signal based on the power supply feedback signal, the maximum feedback signal, and the minimum feedback signal, and sends the adjustment feedback signal to the power supply circuit 4. The power supply circuit 4 outputs the power supply signal to the light string in the light board 50 based on the adjustment feedback signal.

[0039] Among them, the maximum feedback signal can be considered as the upper limit value of the power supply feedback signal, and the minimum feedback signal can be considered as the lower limit value of the power supply feedback signal. If it exceeds the upper and lower limits, the power supply feedback signal can be considered as a distorted signal and needs to be adjusted to generate an adjusted feedback signal, thereby improving the safety of power supply.

[0040] In some examples, the controller can be integrated into the power supply circuit as part of the power supply circuit, such as the controller can be an MCU; the controller can also be integrated on the motherboard as part of the motherboard; it can also be installed in the display device as an independent unit.

[0041] In some examples, the display device may be a MinLED or MicroLED. In these display devices, the light board includes multiple driver chips, each corresponding to at least one light string. Each driver chip is connected to a Bcon circuit, which can send driving data to the driver chip so that the driver chip drives the corresponding light string based on the driving data. In this scenario, the controller can be the Bcon circuit. The controller can obtain the power supply feedback signal of the light string corresponding to the driver chip by reading the data in the driver chip.

[0042] It should be noted that, when the light panel includes multiple light strings, the controller may use the feedback signal with the smallest value among the feedback signals of the multiple light strings as the power supply feedback signal.

[0043] In some examples, the controller can obtain the minimum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; and obtain the maximum feedback signal of the light string based on the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string.

[0044] Among them, the reference supply voltage of the light string is the voltage required for the light string to reach a predetermined current without considering the influence of other factors. However, in actual applications, there is a line loss voltage in the circuit where the light string is located, and the line loss voltage is related to the current of the light string and the resistance of the line. When the supply voltage of the light string is constant, the greater the line loss voltage, the smaller the current of the light string, and the smaller the feedback signal. Therefore, the line loss voltage affects the feedback signal of the power supply circuit of the light string (hereinafter referred to as the feedback signal of the light string); in addition, when the supply voltage of the light string is constant, the higher the temperature of the light string, the greater the current of the light string, which leads to a larger feedback signal. It can be understood that under normal working conditions, the feedback signal of the light string should be affected by two factors, and the influence of these two factors is opposite. Therefore, the normal feedback signal of the light string should be between the feedback signals considering the influence of a single factor. Therefore, the minimum feedback signal determined based on the reference supply voltage and the line loss voltage, and the maximum feedback signal determined based on the reference supply voltage and the temperature compensation voltage, can improve the accuracy of the limited range of the feedback signal, and then accurately identify the distorted feedback signal, thereby improving the reliability of the output feedback signal.

[0045] In some embodiments, in a specific implementation of the present application, based on Figure 3 In the embodiment shown, the controller 30 may:

[0046] Based on the calculation formula of the reference supply voltage and current of the light string, the reference supply voltage of the light string under the current current is obtained; based on the corresponding relationship between the supply voltage and the feedback signal, the reference feedback signal corresponding to the reference supply voltage of the light string under the current current is obtained; the controller obtains the minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage; and, based on the reference feedback signal of the light string and the temperature compensation voltage, the maximum feedback signal of the light string is obtained.

[0047] The calculation formula for the reference supply voltage and current of the light string is determined by the characteristics of the light string itself, and is usually an exponential operation model. For example, U = U1 + aln(I1 / I), where I is the target current, U is the reference supply voltage at the target current, I1 is the set initial current value, and U1 is the initial voltage at the initial current value. Different light strings have different corresponding values ​​for the coefficient a. I1 can be set according to the brightness of the display device that the light string provides backlight for. I1 can be understood as the current when the brightness is moderate. U1 can be obtained by collecting the voltage across the light string when the current is I1. For example, I can be set to 24mA. Then, by collecting Un corresponding to different currents In, the collection point is obtained. In practical applications, the coefficients in the initial model can be determined based on one collection point (In, Un). Of course, the corresponding coefficient a can also be obtained through multiple collection points, and then the multiple a values ​​are averaged to confirm the calculation formula for the reference supply voltage and current of the light string.

[0048] The controller 30 obtains the reference supply voltage of the light string under the current current based on the above formula. The controller can also obtain the power supply feedback signal corresponding to the reference supply voltage based on the corresponding relationship between the supply voltage and the feedback signal.

[0049] In some examples, the controller can obtain the supply voltage under multiple feedback signals; based on the multiple feedback signals and the corresponding supply voltage, the corresponding relationship between the supply voltage and the feedback signal is fitted. Usually, the supply voltage and the feedback signal are linearly negatively correlated. For example, U = A-k2FB, where U is the supply voltage, A is the initial value, and k2 is the coefficient. Therefore, the controller can determine the coefficients in the above functional relationship based on multiple test points, and thus can obtain the baseline feedback signal of the light string under the current based on this corresponding relationship.

[0050] In some embodiments, continue to refer to Figure 3 In the embodiment of the present invention, when obtaining the minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage, the controller may:

[0051] According to the line loss voltage of the light string under a predetermined current, the corresponding relationship between the line loss voltage and the current of the light string is obtained; according to the corresponding relationship between the line loss voltage and the current of the light string, the line loss voltage under the current current is obtained, and according to the line loss voltage under the current current and the corresponding relationship between the power supply voltage and the feedback signal, the first corrected feedback signal of the light string under the current current is obtained; the controller subtracts the reference feedback signal from the first corrected feedback signal to obtain the minimum feedback signal of the light string under the current current.

[0052] The line loss voltage is related to the line resistance and the current, and the line loss voltage can be linear. The predetermined current can be set within the allowable operating current of the light string. For example, if the predicted current is set to 24mA and the corresponding line loss voltage is measured to be 500mV, then ΔU1 = 20.8I.

[0053] The line loss voltage and temperature compensation voltage are also part of the supply voltage and have the same corresponding relationship with the feedback signal as the supply voltage. Therefore, based on the corresponding relationship between the supply voltage and the feedback signal, the first corrected feedback signal of the light string under the current can be obtained.

[0054] The following is an example based on a specific scenario: Based on the above example, the line loss voltage under the current is:

[0055] ΔU1=k1I Formula (1)

[0056] Wherein, ΔU1 is the line loss voltage, I is the current current, and k1 is the constant coefficient (the acquisition method refers to the above example).

[0057] Based on the corresponding relationship between the supply voltage and the feedback signal, we can get:

[0058] ΔU1=-k2ΔFB1 formula (2)

[0059] Wherein, ΔFB1 is the first corrected feedback signal corresponding to the line loss voltage, and k2 is a constant.

[0060] Since the loss voltage is a negative value, we take |ΔFB1| and combine formula (1) and formula (2) to obtain the first corrected feedback signal under the current:

[0061]

[0062] Based on the above example, the reference supply voltage is:

[0063] U=U1+aln(I1 / I) Formula (4)

[0064] The corresponding reference feedback signal is:

[0065]

[0066] Wherein FB is the reference feedback signal, and FB1 is the feedback signal corresponding to the supply voltage U1.

[0067] The first modified feedback signal generated based on the line loss voltage will cause the feedback signal to become smaller. Therefore, based on the above formulas (1) to (5), the minimum feedback signal can be obtained as follows:

[0068]

[0069] Thus, the minimum feedback signal can be obtained through the above formula (VI).

[0070] In this embodiment, the controller obtains the line loss voltage at the current current according to the corresponding relationship between the line loss voltage and the current of the lamp string, obtains the first corrected feedback signal of the lamp string at the current current according to the corresponding relationship between the supply voltage and the feedback signal, and subtracts the reference feedback signal from the first corrected feedback signal to obtain the minimum feedback signal, thereby improving the accuracy of the lower limit value of the feedback signal.

[0071] In some other embodiments, when the controller obtains the maximum feedback signal of the lamp string based on the reference feedback signal and the temperature compensation voltage of the lamp string, the controller may further:

[0072] Obtain the current temperature of the lamp string, obtain the compensation coefficient of the lamp string at the current temperature according to the corresponding relationship between the temperature and the compensation coefficient; obtain the temperature compensation voltage of the lamp string at the current temperature based on the compensation coefficient and the compensation experience value, and obtain the second corrected feedback signal of the lamp string at the current temperature according to the corresponding relationship between the temperature compensation voltage of the lamp string at the current temperature and the supply voltage and the feedback signal; add the reference feedback signal and the second corrected feedback signal to obtain the maximum feedback signal of the lamp string at the current current.

[0073] An exemplary description of this solution is given in combination with a specific scenario:

[0074] The temperature compensation voltage is: ΔU2 = b × B (Formula VII)

[0075] Among them, the compensation coefficient is b, and B is the standard voltage compensation value. The controller can set the corresponding relationship between the temperature and the compensation coefficient based on relevant technical standards. For example, when T ≤ 0, the compensation coefficient b is 1; when 0 ≤ T ≤ 50, the compensation coefficient b is 2; when 50 < T, the compensation coefficient b is 3. The compensation experience value is a standard voltage compensation value. For example, the standard voltage compensation value can be 200. If the current temperature is 30 °C, then ΔU2 = 2 × 200 = 400 mV.

[0076] The temperature compensation voltage is positive, and the corresponding second corrected feedback signal:

[0077]

[0078] Among them, ΔFB2 is the second corrected feedback coefficient, b is the compensation coefficient, B is the compensation experience value, and k2 is a constant coefficient.

[0079] The second corrected feedback signal generated based on the temperature compensation voltage will cause the feedback signal to increase. Based on the foregoing formula, the maximum feedback signal can be obtained:

[0080]

[0081] In this embodiment, the controller obtains the temperature compensation voltage of the lamp string at the current temperature based on the compensation coefficient and the compensation experience value, and the correspondence between the temperature compensation voltage and the power supply voltage and the feedback signal, and obtains the second corrected feedback signal of the lamp string at the current temperature, and adds the reference feedback signal and the second corrected feedback signal to obtain the maximum feedback signal, thereby improving the accuracy of the upper limit value of the feedback signal.

[0082] In some other embodiments, in another specific implementation of the present application, based on the following Figure 3 In the embodiment shown, the controller may:

[0083] Based on the calculation formula of the reference supply voltage and current of the lamp string, the reference supply voltage of the lamp string under the current current is obtained; the reference supply voltage is added to the line loss voltage to obtain the maximum supply voltage; and the reference supply voltage is subtracted from the temperature compensation voltage to obtain the minimum supply voltage; based on the correspondence between the supply voltage and the feedback signal, the minimum feedback signal corresponding to the maximum supply voltage is obtained, and the maximum feedback signal corresponding to the minimum supply voltage is obtained.

[0084] The controller's workflow is illustrated below: Based on the above example, the calculation formula for the reference supply voltage under the current current is formula (4), and the calculation formula for the line loss voltage is formula (1). Based on formulas (1) and (4), the controller obtains the maximum supply voltage under the current current:

[0085] U max =U+ΔU1=U1+aln(I1 / I n )+k1I; Formula (10)

[0086] The minimum supply voltage is:

[0087] U min =U-ΔU2=U1+aln(I1 / I n )-b×B Formula (XI)

[0088] The controller is based on the above-mentioned relationship between the supply voltage and the feedback signal, that is, formula (2)

[0089] ΔU1=-k2ΔFB1

[0090] The minimum feedback signal obtained in the above formula (VI) is:

[0091]

[0092] And the maximum feedback signal obtained as in the above formula (8) is:

[0093]

[0094] Based on this, the maximum feedback signal and the minimum feedback signal under the current current can be obtained.

[0095] In this example, by first obtaining the maximum power supply voltage and the minimum power supply voltage, and then obtaining the maximum feedback signal and the minimum feedback signal based on the corresponding relationship between the power supply voltage and the feedback signal, compared with the S1021-S1023 scheme, the calculation steps are reduced, thereby increasing the speed of feedback signal feedback.

[0096] The controller in this embodiment first obtains the maximum supply voltage and the minimum supply voltage, and then obtains the maximum feedback signal and the minimum feedback signal based on the corresponding relationship between the supply voltage and the feedback signal. Compared with the above-mentioned controller using the reference feedback signal and the first corrected feedback signal and the second corrected feedback signal, the controller reduces the number of calculation steps and thus reduces the processing pressure of the controller, thereby increasing the speed at which the controller generates the adjustment feedback signal.

[0097] In another embodiment, Figure 4 This is a flow chart of a power supply feedback method provided in one embodiment of the present application. The power supply feedback method provided in the embodiment of the present application is applied to a display device, which includes a light board, a power supply circuit and a controller. The light board includes at least one light string. Figure 4 As shown, the method includes:

[0098] S101: The controller obtains a power supply feedback signal of the light string in the light panel;

[0099] S102: The controller obtains a minimum feedback signal of the light string based on a reference supply voltage of the light string at a current current and a line loss voltage of the light string; and obtains a maximum feedback signal of the light string based on the reference supply voltage of the light string at a current current and a temperature compensation voltage of the light string;

[0100] S103: The controller compares the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and sends a corresponding adjustment feedback signal to the power supply circuit according to the comparison result, so that the power supply circuit outputs the power supply voltage of the light string based on the adjustment feedback signal.

[0101] The power supply feedback signal in this embodiment can be a voltage feedback signal or a current feedback signal. Taking the current feedback signal as an example, when obtaining the feedback signal, a sampling resistor can be set at the negative end of the light string. By obtaining the voltage across the sampling resistor, the current feedback signal of the power supply circuit in which the light string is located is obtained.

[0102] The reference supply voltage of the light string is the voltage required for the light string to reach a predetermined current without considering the influence of other factors. However, in actual applications, there is a line loss voltage in the circuit where the light string is located, and the line loss voltage is related to the current of the light string and the resistance of the line. When the supply voltage of the light string is constant, the greater the line loss voltage, the smaller the current of the light string, and the smaller the feedback signal. Therefore, the line loss voltage affects the feedback signal of the power supply circuit of the light string (hereinafter referred to as the feedback signal of the light string); in addition, when the supply voltage of the light string is constant, the higher the temperature of the light string, the greater the current of the light string, which leads to a larger feedback signal. It can be understood that under normal working conditions, the feedback signal of the light string should be affected by two factors, and the influence of these two factors is opposite. Therefore, the normal feedback signal of the light string should be between the feedback signals considering the influence of a single factor. Therefore, the minimum feedback signal determined based on the reference supply voltage and the line loss voltage, and the maximum feedback signal determined based on the reference supply voltage and the temperature compensation voltage, can improve the accuracy of the limited range of the feedback signal, and then accurately identify the distorted feedback signal, thereby improving the reliability of the output feedback signal.

[0103] In order to further ensure the accuracy of the feedback signal limit range, Figure 5 This is a flow chart of another power supply feedback method provided in Example 1 of the present application, as shown in FIG. Figure 5 As shown, in one example, S102 may include:

[0104] S1021. The controller obtains a reference supply voltage of the light string under a current based on a calculation formula of the reference supply voltage and current of the light string;

[0105] S1022. The controller obtains a correspondence between the supply voltage and the feedback signal, and obtains a reference feedback signal corresponding to the reference supply voltage of the light string under the current current based on the correspondence between the supply voltage and the feedback signal.

[0106] S1023. The controller obtains a minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage; and obtains a maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage.

[0107] This example describes a method for obtaining maximum and minimum feedback signals. The specific relationship between the supply voltage and the feedback signal is negatively correlated in a power supply circuit using negative feedback regulation. Based on this relationship, the reference supply voltage of the light string at the current current can be converted into a reference feedback signal. The maximum and minimum feedback signals are then derived based on the reference feedback signal, line loss voltage, and temperature compensation voltage, thereby accurately defining the feedback signal's range.

[0108] In the method for obtaining the reference supply voltage, as an implementation, S1021 may include:

[0109] Obtaining an initial calculation model of the reference supply voltage and current of the light string;

[0110] Obtaining a calculation model of a reference supply voltage and current of the light string according to the initial calculation model, a predetermined current, and a test voltage corresponding to the predetermined current;

[0111] Based on the calculation model, a reference supply voltage of the light string under the current is obtained.

[0112] In practical applications, the correspondence between the reference supply voltage and current of the light string is determined by the characteristics of the light string itself. Usually, the initial model of the light string is an exponential operation model, for example, U=U1+aln(I1 / I), where I is the current current, U is the reference supply voltage under the current current, I1 is the set initial current value, and U1 is the initial voltage under the initial current value.

[0113] Among them, I1 can be set according to the brightness of the display device that provides backlight for the light string, and I1 can be understood as the current when the brightness is moderate. U1 can be obtained by collecting the voltage at both ends of the light string when the current is I1. For example, I can be set to 24mA. Then, by collecting Un corresponding to different currents In, the collection point is obtained. In practical applications, the coefficients in the initial model can be determined based on one collection point (In, Un). Of course, the corresponding coefficients a can also be obtained through multiple collection points, and then the multiple a's can be averaged to obtain the coefficients of the final initial calculation model, thereby determining the calculation model. Based on the calculation model, the reference supply voltage of the light string under the current current can be obtained.

[0114] This embodiment determines the calculation model of the reference supply voltage and current of the light string by voltage fitting. Based on this model, the reference supply voltage under the current current can be accurately obtained, thereby providing a guarantee for subsequently obtaining the maximum feedback signal and the minimum feedback signal based on the reference supply voltage.

[0115] For S1022, the corresponding relationship between the supply voltage and the feedback signal can be obtained by referring to the following example:

[0116] Obtaining the supply voltage under multiple feedback signals;

[0117] According to the plurality of feedback signals and the corresponding supply voltages, a corresponding relationship between the supply voltages and the feedback signals is fitted.

[0118] In practical applications, the relationship between the supply voltage and the feedback signal can be set based on hardware such as an MCU within the power supply circuit. Typically, the supply voltage and feedback signal are linearly and negatively correlated. For example, U = A - k²FB, where U is the supply voltage, A is the initial value, and k² is the coefficient. Therefore, the coefficients in this functional relationship can be determined based on multiple test points, allowing the baseline feedback signal of the light string to be obtained based on this relationship at the current current.

[0119] In S1023, based on the reference feedback signal of the light string and the line loss voltage, the minimum feedback signal of the light string is obtained. As an example, the minimum feedback signal of the light string can be obtained based on the following scheme:

[0120] The controller obtains a corresponding relationship between the line loss voltage and the current of the light string according to the line loss voltage of the light string under a predetermined current;

[0121] The controller obtains the line loss voltage at the current current based on the corresponding relationship between the line loss voltage and the current of the light string, and obtains a first corrected feedback signal of the light string at the current current based on the corresponding relationship between the line loss voltage at the current current and the power supply voltage and the feedback signal;

[0122] The controller calculates the difference between the reference feedback signal and the first corrected feedback signal to obtain a minimum feedback signal of the light string under the current.

[0123] In this example, the line loss voltage is related to the line resistance and the current, and can be considered a linear relationship. The predetermined current can be set within the allowable operating current of the light string. For example, if the predicted current is set to 24mA and the corresponding line loss voltage is measured to be 500mV, then ΔU1 = 20.8I.

[0124] The line loss voltage and temperature compensation voltage are also part of the supply voltage and have the same corresponding relationship with the feedback signal as the supply voltage. Therefore, based on the corresponding relationship between the supply voltage and the feedback signal, the first corrected feedback signal of the light string under the current can be obtained.

[0125] This example obtains the line loss voltage under the current current based on the correspondence between the line loss voltage and the current of the lamp string, obtains the first corrected feedback signal of the lamp string under the current current based on the correspondence between the power supply voltage and the feedback signal, and subtracts the reference feedback signal from the first corrected feedback signal to obtain the minimum feedback signal, thereby improving the accuracy of the lower limit value of the feedback signal.

[0126] In another example, obtaining the maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage in S1023 includes:

[0127] The controller obtains the current temperature of the light string, and obtains the compensation coefficient of the light string at the current temperature according to the corresponding relationship between the temperature and the compensation coefficient;

[0128] The controller obtains a temperature compensation voltage of the light string at a current temperature based on the compensation coefficient and the compensation empirical value, and obtains a second corrected feedback signal of the light string at the current temperature based on a correspondence between the temperature compensation voltage of the light string at the current temperature and the supply voltage and the feedback signal;

[0129] The controller adds the reference feedback signal and the second corrected feedback signal to obtain a maximum feedback signal of the light string under a current current.

[0130] This example obtains the temperature compensation voltage of the light string at the current temperature based on the compensation coefficient and the compensation experience value, and the correspondence between the temperature compensation voltage and the power supply voltage and the feedback signal, and obtains the second corrected feedback signal of the light string at the current temperature. The reference feedback signal and the second corrected feedback signal are added to obtain the maximum feedback signal, thereby improving the accuracy of the upper limit value of the feedback signal.

[0131] Figure 6 This is a flow chart of another power supply feedback method provided in an embodiment of the present application, such as Figure 6 As shown, in another example, S102 may further include:

[0132] S1024. The controller obtains a reference supply voltage of the light string under a current current;

[0133] S1025. The controller adds the reference supply voltage to the line loss voltage to obtain a maximum supply voltage; and subtracts the reference supply voltage from the temperature compensation voltage to obtain a minimum supply voltage.

[0134] S1026. The controller obtains a correspondence between the power supply voltage and the feedback signal, and based on the correspondence between the power supply voltage and the feedback signal, obtains a minimum feedback signal corresponding to the maximum power supply voltage, and obtains a maximum feedback signal corresponding to the minimum power supply voltage.

[0135] This example provides another method for obtaining the maximum and minimum feedback signals based on the reference supply voltage, line loss voltage, and temperature compensation voltage. By first obtaining the maximum and minimum supply voltages, and then determining the maximum and minimum feedback signals based on the corresponding relationship between the supply voltages and the feedback signals, this method reduces the number of calculation steps compared to the solutions in S1021-S1023, thereby increasing the speed of feedback signal generation.

[0136] In this example, S1024 and S1021 are the same steps, so the specific solution of S1024 can refer to the solution of S1021. Similarly, the method of obtaining the line loss voltage and temperature compensation voltage in S1025 can refer to the above example and will not be repeated here.

[0137] In this example, by first obtaining the maximum power supply voltage and the minimum power supply voltage, and then obtaining the maximum feedback signal and the minimum feedback signal based on the corresponding relationship between the power supply voltage and the feedback signal, compared with the S1021-S1023 scheme, the calculation steps are reduced, thereby increasing the speed of feedback signal feedback.

[0138] After obtaining the maximum and minimum feedback signals based on the above-described execution of S102, S103 is executed. It can be understood that the maximum and minimum feedback signals serve as the upper and lower limits of the defined range of the light string feedback signal. If the feedback signal exceeds this range, it can be determined to be distorted and cannot be directly output. Otherwise, the light string will not reach the predetermined current, or even cause damage to the light string. Therefore, the feedback signal is compared with the maximum and minimum feedback signals, and corresponding adjustments are made based on the comparison results to output a corresponding regulated feedback signal.

[0139] The following is an exemplary introduction to the feedback signal adjustment process. In one example, S103 may include:

[0140] detecting whether the feedback signal is within a first range; an upper limit value of the first range being the maximum feedback signal, and a lower limit value of the first range being the minimum feedback signal;

[0141] If the feedback signal is not within the first range and the feedback signal is greater than the maximum feedback signal, then using the maximum feedback signal as the adjustment feedback signal;

[0142] If the feedback signal is not within the first range and the feedback signal is smaller than the minimum feedback signal, the minimum feedback signal is used as the adjustment feedback signal.

[0143] In this example, when the feedback signal is greater than the maximum feedback signal, it can be considered that the feedback signal may be an erroneous feedback signal or a distorted feedback signal. In this scenario, the maximum feedback signal is used as the adjustment feedback signal. When the feedback signal is less than the minimum feedback signal, it may also be an erroneous feedback signal or a distorted feedback signal. In this scenario, the minimum feedback signal is used as the adjustment feedback signal. This can avoid the impact of the distorted feedback signal on the power supply circuit, thereby improving the reliability of the power supply circuit.

[0144] In the power supply feedback method provided in this embodiment, the minimum feedback signal of the light string is obtained based on the reference supply voltage of the light string at the current current and the line loss voltage of the light string; the maximum feedback signal of the light string is obtained based on the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string, and a corresponding adjustment feedback signal is output based on the maximum feedback signal and the minimum feedback signal. Compared with the related art scheme that sets a limited range without considering the characteristics of the light string and the circuit in which it is located, this scheme considers the impact of the linear loss and temperature compensation of the light string on the feedback signal of the light string, and obtains the maximum feedback signal and the minimum feedback signal based on these two influencing factors. This is more in line with the actual scenario of light string power supply, and thus this scheme can improve the accuracy of the limited range of the light string feedback voltage, thereby improving the reliability of the output feedback signal.

[0145] In some embodiments, Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Figure 7 As shown, the electronic device includes:

[0146] The electronic device includes a processor 291 and a memory 292. It may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via bus 294. Communication interface 293 can be used for information transmission. The processor 291 can invoke logic instructions in memory 292 to execute the methods of the above embodiments.

[0147] In addition, when the logic instructions in the memory 292 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0148] Memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of the present application. Processor 291 executes the software programs, instructions, and modules stored in memory 292 to perform functional applications and data processing, thereby implementing the methods in the above-mentioned method embodiments.

[0149] Memory 292 may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data generated based on the use of the terminal device. Memory 292 may also include high-speed random access memory and non-volatile memory.

[0150] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in any embodiment.

[0151] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0152] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A display device, characterized in that: include: a light panel comprising at least one light string, configured to provide backlighting through the light string; a power supply circuit, connected to the light board and configured to provide a power supply voltage to the light string in the light board; A controller is connected to the light board and the power supply circuit and is configured to: Obtaining a power supply feedback signal of the light string in the light board; Obtaining a minimum feedback signal of the light string according to a reference supply voltage of the light string at a current current and a line loss voltage of the light string; and obtaining a maximum feedback signal of the light string according to a reference supply voltage of the light string at a current current and a temperature compensation voltage of the light string; The power supply feedback signal is compared with the maximum feedback signal and the minimum feedback signal, and a corresponding adjustment feedback signal is sent to the power supply circuit according to the comparison result, so that the power supply circuit adjusts the power supply voltage of the light string based on the adjustment feedback signal.

2. The display device according to claim 1, wherein obtaining a minimum feedback signal of the light string according to the reference supply voltage of the light string at the current current and the line loss voltage of the light string; When obtaining the maximum feedback signal of the light string according to the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string, the controller is specifically configured as follows: Obtaining a reference supply voltage of the light string at a current based on a calculation formula of the reference supply voltage and current of the light string; Obtaining a reference feedback signal corresponding to the reference supply voltage of the light string under the current current according to the corresponding relationship between the supply voltage and the feedback signal; Obtaining a minimum feedback signal of the light string based on a reference feedback signal of the light string and the line loss voltage; Furthermore, a maximum feedback signal of the light string is obtained based on the reference feedback signal of the light string and the temperature compensation voltage.

3. The display device according to claim 2, wherein When obtaining the minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage, the controller is specifically configured to: Obtaining a corresponding relationship between the line loss voltage and the current of the light string according to the line loss voltage of the light string under a predetermined current; Obtaining the line loss voltage at the current current based on a correspondence between the line loss voltage and the current of the light string, and obtaining a first corrected feedback signal of the light string at the current current based on a correspondence between the line loss voltage at the current current and the supply voltage and a feedback signal; The reference feedback signal is subtracted from the first corrected feedback signal to obtain a minimum feedback signal of the light string under the current.

4. The display device according to claim 2, wherein When obtaining the maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage, the controller is further configured to: Obtaining the current temperature of the light string, and obtaining the compensation coefficient of the light string at the current temperature based on the corresponding relationship between the temperature and the compensation coefficient; Based on the compensation coefficient and the compensation experience value, a temperature compensation voltage of the light string at the current temperature is obtained, and according to a correspondence between the temperature compensation voltage of the light string at the current temperature and the supply voltage and the feedback signal, a second corrected feedback signal of the light string at the current temperature is obtained; The reference feedback signal and the second modified feedback signal are added to obtain a maximum feedback signal of the light string under the current.

5. The display device according to claim 1, wherein obtaining a minimum feedback signal of the light string according to the reference supply voltage of the light string at the current current and the line loss voltage of the light string; When obtaining the maximum feedback signal of the light string according to the reference supply voltage of the light string at the current current and the temperature compensation voltage of the light string, the controller is specifically configured as follows: Obtaining a reference supply voltage of the light string at a current based on a calculation formula of the reference supply voltage and current of the light string; Adding the reference supply voltage to the line loss voltage to obtain a maximum supply voltage; and subtracting the reference supply voltage from the temperature compensation voltage to obtain a minimum supply voltage; Based on the corresponding relationship between the supply voltage and the feedback signal, a minimum feedback signal corresponding to the maximum supply voltage is obtained, and a maximum feedback signal corresponding to the minimum supply voltage is obtained.

6. The display device according to any one of claims 1 to 5, characterized in that: The controller is further configured to compare the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and send a corresponding adjustment feedback signal to the power supply circuit according to the comparison result. Specifically, the controller is further configured to: detecting whether the power supply feedback signal is within a first range; an upper limit value of the first range is the maximum feedback signal, and a lower limit value of the first range is the minimum feedback signal; If the power supply feedback signal is not within the first range and the feedback signal is greater than the maximum feedback signal, the maximum feedback signal is used as the adjustment feedback signal; If the power supply feedback signal is not within the first range and the feedback signal is smaller than the minimum feedback signal, the minimum feedback signal is used as the adjustment feedback signal.

7. A power supply feedback method, characterized in that: The method is applied to a display device, the display device including a light board, a power supply circuit, and a controller, the light board including at least one light string, and the method comprising: The controller obtains a power supply feedback signal of the light string in the light panel; The controller obtains a minimum feedback signal of the light string based on a reference supply voltage of the light string at a current current and a line loss voltage of the light string; and obtains a maximum feedback signal of the light string based on the reference supply voltage of the light string at a current current and a temperature compensation voltage of the light string; The controller compares the power supply feedback signal with the maximum feedback signal and the minimum feedback signal, and sends a corresponding adjustment feedback signal to the power supply circuit according to the comparison result, so that the power supply circuit outputs the power supply voltage of the light string based on the adjustment feedback signal.

8. The power supply feedback method according to claim 7, characterized in that: The controller obtains a minimum feedback signal of the light string according to a reference supply voltage of the light string at a current current and a line loss voltage of the light string; and obtaining a maximum feedback signal of the light string according to the temperature compensation voltage of the light string and the reference supply voltage of the light string under the current current, including: The controller obtains the reference supply voltage of the light string under the current based on a calculation formula of the reference supply voltage and current of the light string; The controller obtains a reference feedback signal corresponding to the reference supply voltage of the light string under the current current according to the corresponding relationship between the supply voltage and the feedback signal; The controller obtains a minimum feedback signal of the light string based on the reference feedback signal of the light string and the line loss voltage; and obtains a maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage.

9. The power supply feedback method according to claim 8, characterized in that: The controller obtains a minimum feedback signal of the light string based on a reference feedback signal of the light string and the line loss voltage, including: The controller obtains a corresponding relationship between the line loss voltage and the current of the light string according to the line loss voltage of the light string under a predetermined current; The controller obtains the line loss voltage at the current current based on the corresponding relationship between the line loss voltage and the current of the light string, and obtains a first corrected feedback signal of the light string at the current current based on the corresponding relationship between the line loss voltage at the current current and the power supply voltage and the feedback signal; The reference feedback signal is subtracted from the first corrected feedback signal to obtain a minimum feedback signal of the light string under the current.

10. The power supply feedback method according to claim 8, characterized in that: The controller obtains a maximum feedback signal of the light string based on the reference feedback signal of the light string and the temperature compensation voltage, including: The controller obtains the current temperature of the light string, and obtains the compensation coefficient of the light string at the current temperature according to the corresponding relationship between the temperature and the compensation coefficient; The controller obtains a temperature compensation voltage of the light string at a current temperature based on the compensation coefficient and the compensation empirical value, and obtains a second corrected feedback signal of the light string at the current temperature based on a correspondence between the temperature compensation voltage of the light string at the current temperature and the supply voltage and the feedback signal; The controller adds the reference feedback signal and the second corrected feedback signal to obtain a maximum feedback signal of the light string under a current current.

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