Backlight module and display device

Abstract

The present application discloses a backlight module and a display device. The backlight module includes N power chips, N first driver chips, at least one second driver chip, and N voltage regulation modules, where N is an integer greater than or equal to 2. Each of the power chips includes an output terminal and a reference voltage regulation terminal; each of the first driver chips includes a first feedback terminal, the first driver chip is connected to the output terminal in a one-to-one correspondence, and the first feedback terminal is connected to the reference voltage regulation terminal in a one-to-one correspondence; the second driver chip includes a second feedback terminal, the second driver chip is respectively connected to the output terminal of the M power chips; the second feedback terminal is respectively connected to the reference voltage regulation terminal of the M power chips; M is an integer greater than or equal to 1 and less than or equal to N. The present application can ensure the normal application of the feedback function of the first driver chip and the second driver chip, while reducing the number of power chips and reducing costs.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a backlight module and a display device. Background Art

[0002] With the continuous development of display technology and the panel industry, MLED (Micro / Mini Light-Emitting Diode) backlight technology has emerged in the public eye. Compared to traditional LED (Light-Emitting Diode) backlights, MLED backlights have a local dimming function, which allows for precise control of extremely small areas, achieving display effects comparable to OLED (Organic Light-Emitting Diode).

[0003] Backlight drivers typically include a power chip (DC-DC) and an LED driver chip (LED Driver IC). The power chip is used to convert the input voltage into the driving voltage required by the LED driver chip. The LED driver chip provides different currents for each LED partition to display various grayscale brightness. The LED driver chip has a feedback function that can dynamically adjust the driving voltage output by the power chip by collecting the voltage at the negative pole of the LED, thereby avoiding the LED driver chip heating caused by excessive voltage at the negative pole of the LED. Due to the application of the LED driver chip feedback function, each LED driver chip requires a power chip. However, since the power of the LED light string is not high, the power chip specifications are excessive, resulting in cost redundancy. Summary of the Invention

[0004] The present application provides a backlight module and a display device, which can reduce the number of power chips and lower costs while ensuring the normal application of the feedback function of the driver chip.

[0005] The present application provides a backlight module, which includes:

[0006] N power chips, each of the power chips comprising an output terminal and a reference voltage regulating terminal, the output terminal being used to output an initial driving voltage; N is an integer greater than or equal to 2;

[0007] N first driver chips, each of which is connected to the output terminal in a one-to-one correspondence; each of the first driver chips includes a first feedback terminal, which is connected to the reference voltage regulating terminal in a one-to-one correspondence, and the first feedback terminal is used to output a first feedback signal;

[0008] at least one second driver chip, the second driver chip being respectively connected to the output terminals of the M power supply chips; the second driver chip comprising a second feedback terminal, the second feedback terminal being respectively connected to the reference voltage regulating terminals of the M power supply chips, the second feedback terminal being configured to output a second feedback signal; M being an integer greater than or equal to 1 and less than or equal to N; and

[0009] N voltage regulating modules, each of which is arranged in a one-to-one correspondence with the power supply chip; each of the voltage regulating modules is connected to the output end, the reference voltage regulating end and the ground end, and each of the voltage regulating modules is used to adjust the initial driving voltage according to the first feedback signal and / or the second feedback signal.

[0010] Optionally, in some embodiments of the present application, the backlight module further includes a plurality of first light-emitting units connected to the first driver chip and a plurality of second light-emitting units connected to the second driver chip;

[0011] The second driver chip has multiple first control terminals, the anode of the second light-emitting unit is connected to the corresponding output terminal, and the cathode of the second light-emitting unit is connected to the corresponding first control terminal; the second light-emitting units connected to the same second driver chip are divided into M groups, and the M groups of second light-emitting units are connected one-to-one to the output terminals of the M power chips.

[0012] Optionally, in some embodiments of the present application, in M ​​groups of the second light-emitting units, the number of the second light-emitting units in each group is equal.

[0013] Optionally, in some embodiments of the present application, each of the first light-emitting units and each of the second light-emitting units includes one or more light-emitting diodes.

[0014] Optionally, in some embodiments of the present application, at least one of the voltage regulating modules includes a first resistor and a second resistor;

[0015] One end of the first resistor is connected to the output end, the other end of the first resistor and one end of the second resistor are both connected to the reference voltage regulating end, and the other end of the second resistor is connected to the ground end.

[0016] Optionally, in some embodiments of the present application, a first unidirectional diode is provided between the reference voltage regulating terminal and the corresponding first feedback terminal; an anode of the first unidirectional diode is connected to the first feedback terminal, and a cathode of the first unidirectional diode is connected to the reference voltage regulating terminal;

[0017] A second unidirectional diode is provided between the reference voltage regulating terminal and the corresponding second feedback terminal; the anode of the second unidirectional diode is connected to the second feedback terminal, and the cathode of the second unidirectional diode is connected to the reference voltage regulating terminal.

[0018] Optionally, in some embodiments of the present application, when at least one of the first driver chips is in a working state and the second driver chip is in a non-working state, the voltage regulation module corresponding to the first driver chip in the working state is used to adjust the initial driving voltage according to the first feedback signal.

[0019] Optionally, in some embodiments of the present application, when N first driver chips are in a non-working state and the second driver chip is in a working state, the voltage regulation module corresponding to the M power supply chips is used to adjust the initial driving voltage according to the second feedback signal.

[0020] Optionally, in some embodiments of the present application, when N of the first driver chips are in a working state and the second driver chip is in a working state, the voltage regulating module corresponding to the M power supply chips is used to adjust the initial driving voltage according to the first feedback signal and the second feedback signal, and the voltage regulating module corresponding to the other (NM) power supply chips is used to adjust the initial driving voltage according to the first feedback signal.

[0021] Optionally, in some embodiments of the present application, each of the first driver chip and each of the second driver chip includes at least one current source, and the current source has a current adjustment order. Every time the current source is adjusted one order, the current value of the first feedback signal or the second feedback signal changes by a preset value.

[0022] Optionally, in some embodiments of the present application, the current adjustment order range is 0-255, and the preset value is 1 microampere.

[0023] Correspondingly, the present application also provides a display device, which includes a display panel and a backlight module as described in any one of the above items.

[0024] The present application provides a backlight module and a display device. The backlight module includes N power chips, N first driver chips, at least one second driver chip and N voltage regulating modules, where N is an integer greater than or equal to 2. The present application ensures the normal operation of the first driver chips and the normal application of the feedback function by setting N first driver chips and N power chips in a one-to-one correspondence, and connecting the N first driver chips to the output ends of the N power chips in a one-to-one correspondence, and connecting the first feedback ends of the N first driver chips to the reference voltage regulating ends of the N power chips in a one-to-one correspondence. Then, the second driver chip is set to be connected to the output ends of the M power chips respectively, and the second feedback end of the second driver chip is connected to the reference voltage regulating ends of the M power chips respectively, where M is an integer greater than or equal to 1 and less than or equal to N, thereby ensuring the normal operation of the second driver chip and the normal application of the feedback function; thereby, the number of power chips is reduced, the excessive specifications of the power chips are avoided, and the cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a first structural diagram of the backlight module provided by this application;

[0027] Figure 2 This is a second structural diagram of the backlight module provided by this application;

[0028] Figure 3 This is a third structural diagram of the backlight module provided by this application;

[0029] Figure 4 This is a structural schematic diagram of the display device provided in this application. DETAILED DESCRIPTION

[0030] 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 those skilled in the art without making creative efforts are within the scope of protection of this application.

[0031] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" etc. may explicitly or implicitly include one or more of the said features, and therefore cannot be understood as limitations on the present application. In addition, it should be noted that, unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The present application provides a backlight module and a display device, which are described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application.

[0033] See also Figure 1 , Figure 1 1 is a first structural diagram of a backlight module provided by the present application. The present application provides a backlight module 100 . The backlight module 100 includes N power chips 10 , N first driver chips 20 , at least one second driver chip 30 , and N voltage regulating modules 40 .

[0034] Each power chip 10 includes an output terminal A and a reference voltage regulating terminal B. The output terminal A is used to output the initial driving voltage VLED. N is an integer greater than or equal to 2.

[0035] The N first driver chips 20 are connected in a one-to-one correspondence to the output terminals A of the N power chips 10. Each first driver chip 20 includes a first feedback terminal F1. The first feedback terminals F1 of the N first driver chips 20 are connected in a one-to-one correspondence to the reference voltage regulating terminals B of the N power chips 10. The first feedback terminals F1 are used to output a first feedback signal FB1.

[0036] The second driver chip 30 is connected to the output terminals A of the M power chips 10. The second driver chip 30 includes a second feedback terminal F2. The second feedback terminal F2 is connected to the reference voltage regulator terminals B of the M power chips. The second feedback terminal F2 is configured to output a second feedback signal FB2. M is an integer greater than or equal to 1 and less than or equal to N.

[0037] N voltage regulating modules 40 are provided in a one-to-one correspondence with the N power chips 10. Each voltage regulating module 40 is connected to the output terminal A, the reference voltage regulating terminal B, and the ground terminal GND. Each voltage regulating module 40 is configured to adjust the corresponding initial driving voltage VLED based on the first feedback signal FB1 and / or the second feedback signal FB2.

[0038] In the embodiment of the present application, N first driver chips 20 are provided in a one-to-one correspondence with N power supply chips 10, and the N first driver chips 20 are connected in a one-to-one correspondence to the output terminals A of the N power supply chips 10, and the first feedback terminals F1 of the N first driver chips 20 are connected in a one-to-one correspondence to the reference voltage regulating terminals B of the N power supply chips 10. This allows each first driver chip 20 to operate normally under the corresponding initial drive voltage VLED, while ensuring the normal application of the feedback function of the first driver chip 20. Then, a second driver chip 30 is provided to be connected to the output terminals A of the M power supply chips 10, and the second feedback terminals F2 of the second driver chip 30 are connected to the reference voltage regulating terminals B of the M power supply chips 10. This allows the second driver chip 30 to operate normally under the simultaneous drive of the M initial drive voltages VLED, while ensuring the normal application of the feedback function of the second driver chip 30. Thus, the number of power supply chips 10 is reduced, over-specification of power supply chips 10 is avoided, and production costs are reduced.

[0039] In the embodiment of the present application, the power chip 10 further includes an input terminal C. The input terminal C is used to receive an initial voltage Vin. The power chip 10 is used to convert the initial voltage Vin into an initial driving voltage VLED.

[0040] In the embodiment of the present application, the power chip 10 is a direct current (DC-DC) power converter. The reference voltage regulator terminal B is used to output a reference voltage FB. Reference voltage FB is the voltage regulation reference value of the power chip 10 and is determined by the internal current source 201. Reference voltage FB is used to initially adjust the voltage value of the initial driving voltage VLED. The voltage value of reference voltage FB is fixed, typically 0.6V or 0.8V, and can be set according to actual needs.

[0041] The number of power chips 10 depends on the specifications of the backlight module 100 and the load current that the power chip 10 can output. For example, N can be 2, 3, 4, 5, 6, etc., which are not listed here one by one.

[0042] In the embodiment of the present application, the N first driver chips 20 and the second driver chip 30 can be the same DC-DC chip. Ideally, the specifications of the same DC-DC chip are the same and the load current it can provide is the same. Of course, the N first driver chips 20 and the second driver chip 30 can also be different DC-DC chips; the specific setting can be based on the actual needs of the backlight module 100. The first driver chip 20 (the second driver chip 30) can also include a ground pin GND, a brightness information receiving pin SPI, a power pin VCC, etc., which are not detailed here.

[0043] Among them, the total number of the first driver chip 20 and the second driver chip 30 depends on the specification requirements of the backlight module 100 and the number of channels of each driver chip (first driver chip 20 / second driver chip 30). For example, most driver chips include 48 channels (CH1-CH48). If the backlight requirement is 192 partitions, 4 driver chips are required. Furthermore, the number of each of the first driver chip 20 and the second driver chip 30 depends on the load current of the power chip 10, so as to avoid excessive specifications of the power chip 10 while ensuring the normal application of the feedback function of the first driver chip 20 and the second driver chip 30. For example, the first driver chip 20 can be set to 3, and the second driver chip 30 can be set to 1; in this case, N is 3, and M can be 1, 2 or 3.

[0044] In the embodiment of the present application, the backlight module 100 further includes a plurality of first light-emitting units 51 connected to the first driver chip 20 and a plurality of second light-emitting units 52 connected to the second driver chip 30. The second driver chip 30 has a plurality of first control terminals 30a. Each first control terminal 30a corresponds to a channel of the second driver chip 30. The anode of the second light-emitting unit 52 is connected to the corresponding output terminal A. The cathode of the second light-emitting unit 52 is connected to the corresponding first control terminal 30a. The second light-emitting units 52 connected to the same second driver chip 30 are divided into M groups. The M groups of second light-emitting units 52 are connected one-to-one to the output terminals A of the M power supply chips 10. The first driver chip 20 has a plurality of second control terminals 20a. Each second control terminal 20a corresponds to a channel of the first driver chip 20. The anode of the first light-emitting unit 51 is connected to the corresponding output terminal A; the cathode of the first light-emitting unit 51 is connected to the corresponding second control terminal 20a.

[0045] It is understandable that the power of each first light-emitting unit 51 or second light-emitting unit 52 is not high. If each power chip 10 can provide a large load current, and each driver chip is equipped with a power chip 10, it is easy to cause the specifications of the power chip 10 to be excessive. In this embodiment of the application, the output terminal A of M power chips 10 is connected to the first light-emitting unit 51 connected to the first driver chip 20 and to at least a portion of the second light-emitting unit 52 connected to the second driver chip 30, which can fully utilize the load capacity of the power chip 10.

[0046] Each first light-emitting unit 51 and each second light-emitting unit 52 may include at least one light-emitting device. The light-emitting device may be a mini light-emitting diode, a micro light-emitting diode, or an organic light-emitting diode. When the first light-emitting unit 51 or the second light-emitting unit 52 includes two or more light-emitting devices, the multiple light-emitting devices may be arranged in series or in parallel, which is not specifically limited in this application.

[0047] Among them, M can be less than or equal to N. M depends on the load current required by the first driver chip 20 and the second driver chip 30 and the load current that the power chip 10 can provide. For example, if a power chip 10 can only output 4A current, and the load current required by a driver chip is 4A, then one power chip 10 can only drive one driver chip. The embodiment of the present application is aimed at the load current provided by one power chip 10 being greater than the load current required by one driver chip. For example, if one power chip 10 can output 8A current, and the load current required by one driver chip is 4A, then one power chip 10 can drive two driver chips; at this time, M=1, which is equivalent to one power chip 10 driving one first driver chip 20 and one second driver chip 30 at the same time. For example, if a power chip 10 can output a current of 4A, and a driver chip requires a load current of 3A, three power chips 10, three first driver chips 20, and one second driver chip 30 can be set; at this time, M=3, that is, one second driver chip 30 is driven by three power chips 10 simultaneously, which can maximize the load capacity of the power chip 10.

[0048] In some embodiments, in the M groups of second light-emitting units 52 , the number of second light-emitting units 52 in each group is equal.

[0049] It is understood that when the N power chips 10 have the same specifications, evenly dividing the number of channels ensures that each power chip 10 needs to output the same current, maximizing the load capacity of the power chip 10. If the number of channels is not evenly divided, as the current fed back by the second driver chip 30 continues to increase, the power chip 10 connected to a larger number of second light-emitting units 52 may reach its maximum output current prematurely, which is not conducive to adjusting the overall brightness of the second light-emitting units 52.

[0050] Of course, if the specifications of the N power chips 10 are different, that is, if the load currents that the N power chips 10 can output are different, the number of second light-emitting units 52 in each group can also be divided according to the load capacity of the N power chips 10. For example, the stronger the load capacity of the power chip 10, the more second light-emitting units 52 can be connected to it.

[0051] In some embodiments, when the first driver chip 20 is in operation and the second driver chip 30 is in non-operation, the voltage regulating module 40 corresponding to the first driver chip 20 in operation is configured to adjust the corresponding initial driving voltage VLED according to the first feedback signal FB1.

[0052] Here, "in working state" means that at least one first light-emitting unit 51 connected to the first driver chip 20 (second driver chip 30) emits light, and the driver chip 20 (second driver chip 30) has a channel output. "In non-working state" means that none of the first light-emitting units 51 connected to the first driver chip 20 (second driver chip 30) emit light, and the driver chip 20 (second driver chip 30) has a channel output.

[0053] It is understood that when the second light-emitting unit 52 connected to the second driver chip 30 is not emitting light, the second driver chip 30 does not need to adjust the light-emitting current, and therefore does not need to adjust the initial driving voltage VLED output by the power chip 10. Therefore, the second driver chip 30 does not output the second feedback signal FB2, and the voltage regulator module 40 corresponding to the first driver chip 20 in an active state adjusts the initial driving voltage VLED only based on the first feedback signal FB1. Similarly, the first driver chip 20 in an inactive state does not output the first feedback signal FB1. Therefore, the voltage regulator module 40 corresponding to the first driver chip 20 in an inactive state does not need to operate.

[0054] In some embodiments, when the N first driver chips 20 are in a non-operating state and the second driver chip 30 is in an operating state, the voltage regulating modules 40 corresponding to the M power chips 10 are used to adjust the corresponding initial driving voltage VLED according to the second feedback signal FB2.

[0055] It is understood that when the first light-emitting unit 51 connected to the first driver chip 20 is not emitting light, the first driver chip 20 does not output the first feedback signal FB1. Therefore, the voltage regulating module 40 adjusts the corresponding initial driving voltage VLED only based on the second feedback signal FB2. At this time, the second feedback terminal F2 of the second driver chip 30 is connected to the reference voltage regulating terminal B of the M power supply chips 10. Therefore, the corresponding M voltage regulating modules 40 can adjust the initial driving voltage VLED of the M first driver chips 20 based on the second feedback signal FB2.

[0056] Specifically, since the second feedback signal FB2 is a current signal and is output to the reference voltage regulating terminals B of the M power chips 10 respectively, according to the current shunt principle, the feedback signal received by a voltage regulating module 40 is one-Mth of the second feedback signal FB.

[0057] In some embodiments, when N first driver chips 20 are in working state and the second driver chip 30 is also in working state, the voltage regulating module 40 corresponding to the M power supply chips 10 is used to adjust the initial driving voltage VLED according to the first feedback signal FB1 and the second feedback signal FB2; the voltage regulating module 40 corresponding to the other (NM) power supply chips 10 is used to adjust the initial driving voltage VLED according to the first feedback signal FB1.

[0058] Specifically, the voltage regulating modules 40 corresponding to the M power chips 10 each receive one-Mth of the corresponding first feedback signal FB1 and second feedback signal FB2. Therefore, the voltage regulating modules 40 corresponding to the M power chips 10 adjust the corresponding initial driving voltage VLED based on one-Mth of the first feedback signal FB1 and second feedback signal FB2.

[0059] Of course, in some embodiments, when only some of the first driver chips 20 and the second driver chips 30 are in the working state, for the first driver chips 20 in the working state, the corresponding voltage regulation module 40 adjusts its initial driving voltage VLED according to the first feedback signal FB1 and the second feedback signal FB2; for the first driver chips 20 in the non-working state, the corresponding voltage regulation module 40 adjusts its initial driving voltage VLED only according to the second feedback signal FB2.

[0060] In the examples of this application, please refer to Figure 2 , Figure 2 This is a second structural diagram of the backlight module provided by this application. Figure 1 The difference between the backlight module 100 shown is that the voltage regulating module 40 can include a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the output terminal A. The other end of the first resistor R1 and one end of the second resistor R2 are both connected to the reference voltage regulating terminal B. The other end of the second resistor R2 is connected to the ground terminal GND.

[0061] The resistance values ​​of the first resistors R1 in the multiple voltage regulating modules 40 may be the same or different, and the resistance values ​​of the second resistors R2 in the multiple voltage regulating modules 40 may be the same or different.

[0062] Initially, the first driver chip 20 and the second driver chip 30 are not working, and the power chip 10 does not receive the first feedback signal FB1 and the second feedback signal FB2. The calculation formula for the initial driving voltage output by each power chip 10 is: VLED = FB(R1+R2)R2.

[0063] Wherein, VLED is the voltage value of the initial driving voltage VLED, FB is the voltage value of the reference voltage FB, R1 is the resistance value of the first resistor R1, and R2 is the resistance value of the second resistor R2. Since the reference voltage FB is a fixed value, the voltage value of the initial driving voltage VLED output by each power chip 10 can be adjusted by adjusting the resistance values ​​of the first resistor R1 and the second resistor R2.

[0064] In the embodiment of the present application, the resistance values ​​of the first resistors R1 in the N voltage regulating modules 40 are all equal, and the resistance values ​​of the second resistors R2 in the N voltage regulating modules 40 are all equal. Then, the voltage values ​​of the initial driving voltages VLED output by the N power chips 10 are all the same.

[0065] It can be understood that the first feedback signal FB1 and the second feedback signal FB2 are current signals. When the first feedback signal FB1 and / or the second feedback signal FB2 are output to the reference voltage terminal B, since the reference voltage FB is fixed, the voltage change caused by the changing current passing through the first resistor R1 is the voltage change of the initial driving voltage VLED.

[0066] Specifically, in the embodiment of the present application, each first driver chip 20 and each second driver chip 30 includes at least one current source 201. The current source 201 has a current adjustment step. Each time the current source 201 adjusts one step, the current value of the first feedback signal FB1 or the second feedback signal FB2 changes by a predetermined value.

[0067] Specifically, the detection circuit within the first driver chip 20 (second driver chip 30) can detect the cathode voltage of the first light-emitting unit 51 (second light-emitting unit 52). When the cathode voltage is too high, it indicates that the initial drive voltage VLED is too high, and the voltage value of the initial drive voltage VLED needs to be reduced. The first driver chip 20 (second driver chip 30) will reduce the voltage value of the initial drive voltage VLED by reducing the current adjustment step. Conversely, when the voltage of the initial drive voltage VLED is too low, the voltage value of the initial drive voltage VLED will be increased by increasing the current adjustment step.

[0068] It should be noted that when it is detected that the cathode voltages of multiple first light-emitting units 51 (second light-emitting units 52) are different, the current adjustment order of the current source 201 can be comprehensively considered to adjust the brightness of multiple first light-emitting units 51 (second light-emitting units 52).

[0069] Specifically, in some embodiments, the current adjustment step range is 0-255, with a preset value of 1 μA. That is, for each step adjustment of the current source 201, the current value of the first feedback signal FB1 or the second feedback signal FB2 changes by 1 μA. As analyzed in the above embodiment, when the first feedback signal FB1 changes by 1 μA, the corresponding initial driving voltage VLED changes by 1R1. When the second feedback signal FB2 changes by 1 μA, the corresponding initial driving voltage VLED changes by 1R1 / M.

[0070] In some embodiments of the present application, a first unidirectional diode D1 is provided between the reference voltage regulating terminal B and the corresponding first feedback terminal F1. The anode of the first unidirectional diode D1 is connected to the first feedback terminal F1. The cathode of the first unidirectional diode D1 is connected to the reference voltage regulating terminal B. A second unidirectional diode D2 is provided between the reference voltage regulating terminal B and the corresponding second feedback terminal F2. The anode of the second unidirectional diode D2 is connected to the second feedback terminal F2. The cathode of the second unidirectional diode D2 is connected to the reference voltage regulating terminal B.

[0071] In the embodiment of the present application, a first unidirectional diode D1 is provided between the reference voltage terminal B and the first feedback terminal F1, and a second unidirectional diode D2 is provided between the reference voltage terminal B and the second feedback terminal F2, thereby avoiding the formation of a current backflow path, thereby avoiding mutual influence between the first driver chip 20 and the second driver chip 30.

[0072] In the embodiment of the present application, N power chips 10 can output multiple initial driving voltages VLED1, such as the first initial driving voltage VLED1, the Mth initial driving voltage VLED M , Nth initial driving voltage VLED N The following describes the technical solution of the present application in detail by taking N=M=3 and only one second driving chip 30 as an example, but this should not be construed as limiting the present application.

[0073] See also Figure 3 , Figure 3This is a third structural schematic diagram of the backlight module provided in this application. The backlight module 100 includes three power chips 10, three first driver chips 20, and one second driver chip 30. From left to right in the figure, the first power chip 11 outputs a first initial drive voltage VLED1 to the first first driver chip 21; the first first driver chip 21 outputs a first feedback signal FB11 to the first power chip 11. The second power chip 12 outputs a second initial drive voltage VLED2 to the second first driver chip 22; the second first driver chip 22 outputs a first feedback signal FB12 to the second power chip 12. The third power chip 13 outputs a third initial drive voltage VLED3 to the third first driver chip 23; the third first driver chip 23 outputs a first feedback signal FB13 to the third power chip 13. The second driver chip 30 receives the first initial drive voltage VLED1, the second initial drive voltage VLED2, and the third initial drive voltage VLED3, and the second driver chip 30 outputs a second feedback signal FB2 to the three power chips 10.

[0074] In this embodiment, the initial voltage values ​​of the first initial driving voltage VLED1 , the second initial driving voltage VLED2 , and the third initial driving voltage VLED3 are equal.

[0075] The first feedback signal FB11 adjusts only the first initial driving voltage VLED1, the first feedback signal FB12 adjusts only the second initial driving voltage VLED2, and the third feedback signal FB13 adjusts only the third initial driving voltage VLED3. The first feedback signal FB13 adjusts the first initial driving voltage VLED1, the second initial driving voltage VLED2, and the third initial driving voltage VLED3 simultaneously.

[0076] Specifically, the backlight module 100 has the following working modes:

[0077] In the first working mode, when only the first driver chip 21 is in working state, the voltage value of the first initial driving voltage VLED1 is controlled and adjusted by the corresponding voltage regulating module 40 according to the first feedback signal FB11; the second initial driving voltage VLED2 and the third initial driving voltage VLED3 do not change.

[0078] In the second working mode, when only the second first driver chip 22 is in working state, the voltage of the second initial driving voltage VLED2 is controlled and adjusted by the corresponding voltage regulating module 40 according to the first feedback signal FB12; the first initial driving voltage VLED1 and the third initial driving voltage VLED3 do not change.

[0079] In the third working mode, when only the third first driving chip 23 is in working state, the voltage of the third initial driving voltage VLED3 is controlled and adjusted by the corresponding voltage regulating module 40 according to the first feedback signal FB13; the first initial driving voltage VLED1 and the second initial driving voltage VLED2 do not change.

[0080] In the fourth operating mode, when only the second driver chip 30 is in operation, the voltage values ​​of the first initial driving voltage VLED1, the second initial driving voltage VLED2, and the third initial driving voltage VLED3 are simultaneously adjusted by the corresponding voltage regulation module 40 based on the second feedback signal FB2. After the adjustment, VLED1 = VLED2 = VLED3. Because the three first driver chips 20 are in an inactive state and do not consume current, the power consumption and heat generation of the three first driver chips 20 are not affected.

[0081] In the fifth working mode, when the second driver chip 30 is in a non-working state and the three first driver chips 20 are all in a working state, the first initial driving voltage VLED1, the second initial driving voltage VLED2, and the third initial driving voltage VLED3 are independent of each other and are independently adjusted by the corresponding first feedback signal FB11, the first feedback signal FB12, or the first feedback signal FB13.

[0082] In the sixth working mode, only the first driving chip 20 and the second driving chip 30 are in working state.

[0083] For example, when only the first driver chip 21 and the second driver chip 30 are in the working state, the voltage value change of the first initial driving voltage VLED1 is (R1*nI FB11 +R1*mI FB2 / 3); the voltage value change of the second initial driving voltage VLED2 is R1*mI FB2 / 3; the voltage value change of the third initial driving voltage VLED3 is R1*mI FB2 / 3.

[0084] Wherein, n is the current adjustment step number of the first driver chip 20 in the sixth working mode, and m is the current adjustment step number of the second driver chip 30 in the sixth working mode. As can be seen from the above embodiment, when the current source 201 adjusts one step, the current value of the first feedback signal FB1 or the second feedback signal FB2 changes by 1 microampere. Therefore, nI FB11 mI represents the current change fed back by the first driver chip 21; FB2 Indicates the current change fed back by the second driver chip 30.

[0085] In the sixth operating mode, the voltage values ​​of the second initial driving voltage VLED2 and the third initial driving voltage VLED3 may increase slightly, but remain lower than the voltage value of the first initial driving voltage VLED1. Because the second first driver chip 22 and the third first driver chip 23 are both in a non-operating state and consume no current, power consumption and heat generation are not affected.

[0086] Similarly, when only the second first driver chip 22 and the second driver chip 30 have channel outputs, or when only the third first driver chip 23 and the second driver chip 30 have channel outputs, refer to the situation when only the first first driver chip 21 and the second driver chip 30 are in the working state, and are not described in detail here.

[0087] In the seventh working mode, only the first driving chip 20 and the second driving chip 30 are in working state.

[0088] For example, when the first driving chip 21, the second driving chip 22 and the second driving chip 30 are in the working state, the voltage value change of the first initial driving voltage VLED1 is (R1*xI FB11 +R1*yI FB2 / 3); the voltage value change of the second initial driving voltage VLED2 is (R1*zI FB12 +R1*yI FB2 / 3); the voltage value change of the third initial driving voltage VLED3 is R1*yI FB2 / 3. The adjusted first initial driving voltage VLED1 and the second initial driving voltage VLED2 may or may not be equal. The adjusted third initial driving voltage VLED3 may be slightly increased, but because the third first driving chip 23 is in a non-operating state and consumes no current, power consumption and heat generation are not affected.

[0089] Wherein, x is the current adjustment step of the first first driver chip 21 in the seventh working mode; z is the current adjustment step of the second first driver chip 22 in the seventh working mode; y is the current adjustment step of the second driver chip 30 in the seventh working mode. As can be seen from the above embodiment, when the current source 201 adjusts one step, the current value of the first feedback signal FB1 or the second feedback signal FB2 changes by 1 microampere. Therefore, xI FB11 represents the current variation fed back by the first first driver chip 21; zI FB12 yI represents the current change amount fed back by the second first driver chip 22; FB2 Indicates the current change fed back by the second driver chip 30.

[0090] In the seventh operating mode, the adjusted voltage values ​​of the first initial driving voltage VLED1 , the second initial driving voltage VLED2 , and the third initial driving voltage VLED3 may all be different.

[0091] Similarly, when the first first driver chip 21, the third first driver chip 23 and the second driver chip 30 have channel outputs, or when the second first driver chip 22, the third first driver chip 23 and the second driver chip 30 have channel outputs, the above-mentioned seventh working mode can be referred to, and they will not be described in detail here.

[0092] In the eighth working mode, when the first first driver chip 21, the second first driver chip 22, the third first driver chip 23 and the second driver chip 30 are all outputting at the same time, that is, when they are all in the non-working state, the voltage value change of the first initial driving voltage VLED1 is (R1*xI FB11 +R1*yI FB2 / 3); the voltage value change of the second initial driving voltage VLED2 is (R1*zI FB12 +R1*yI FB2 / 3); the voltage value change of the third initial driving voltage VLED3 is (R1*uI FB13 +R1*yI FB2 / 3). The adjusted voltage values ​​of the first initial driving voltage VLED1, the second initial driving voltage VLED2, and the third initial driving voltage VLED3 may be equal or unequal.

[0093] Wherein, x is the current adjustment step of the first first driver chip 21 in the eighth working mode; z is the current adjustment step of the second first driver chip 22 in the eighth working mode; u is the current adjustment step of the third first driver chip 23 in the eighth working mode; y is the current adjustment step of the second driver chip 30 in the eighth working mode. As can be seen from the above embodiment, when the current source 201 adjusts one step, the current value of the first feedback signal FB1 or the second feedback signal FB2 changes by 1 microampere. Therefore, xI FB11 represents the current variation fed back by the first first driver chip 21; zI FB12 Indicates the current change fed back by the second first driver chip 22; uI FB13 y represents the current variation fed back by the third first driver chip 23; I FB2 Indicates the current change fed back by the second driver chip 30.

[0094] It should be noted that in the various operating modes described above, when the first driver chip 20 and the second driver chip 30 operate simultaneously, the initial drive voltage VLED output by the same power chip 10 is affected by the feedback from the two driver chips (the first driver chip 20 and the second driver chip 30). To ensure that both the first light-emitting unit 51 and the second light-emitting unit 52 can emit light normally, it is necessary to dynamically adjust the current adjustment steps corresponding to the first driver chip 20 and the second driver chip 30.

[0095] For example, in the sixth operating mode, the feedback result from the first driver chip 21 may require an increase in the voltage value of the first initial driving voltage VLED1, while the feedback result from the second driver chip 30 may require a decrease in the voltage value of the first initial driving voltage VLED1. In this case, m and n need to be adjusted to achieve a balance in the voltage value of the first initial driving voltage VLED1, ensuring the normal operation of both the first driver chip 21 and the second driver chip 30. The same applies to other operating modes, which will not be further elaborated here.

[0096] Correspondingly, this application also provides a display device. For details, please refer to Figure 4 , Figure 4 1 is a schematic diagram of the structure of a display device provided in this application. Display device 1000 includes a display panel 200 and a backlight module 100. Backlight module 100 is used to provide backlight to display panel 200. Backlight module 100 is the backlight module 100 described in any of the above embodiments. For details, please refer to the above content and will not be repeated here.

[0097] In this application, the display device may be a smart phone, a tablet computer, a video player, a personal computer (PC), etc., and this application does not limit this.

[0098] In the display device 1000 provided in the present application, the backlight module 100 includes N power chips, N first driver chips, at least one second driver chip and N voltage regulating modules, where N is an integer greater than or equal to 2. The present application ensures the normal operation of the first driver chips and the normal application of the feedback function by setting N first driver chips and N power chips in a one-to-one correspondence, and connecting the N first driver chips to the output terminals of the N power chips in a one-to-one correspondence, and connecting the first feedback terminals of the N first driver chips to the reference voltage regulating terminals of the N power chips in a one-to-one correspondence. Then, the second driver chip is set to be connected to the output terminals of the M power chips respectively, and the second feedback terminal of the second driver chip is connected to the reference voltage regulating terminals of the M power chips respectively, where M is an integer greater than or equal to 1 and less than or equal to N, thereby ensuring the normal operation of the second driver chip and the normal application of the feedback function; thereby, the number of power chips is reduced, the excessive specifications of the power chips are avoided, and the cost is reduced.

[0099] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A backlight module, characterized in that: include: N power supply chips, each of the power supply chips includes an output terminal and a reference voltage regulating terminal, the output terminal is used to output an initial driving voltage; N is an integer greater than or equal to 2; N first driver chips, each of which is connected to the output terminal in a one-to-one correspondence; each of the first driver chips includes a first feedback terminal, which is connected to the reference voltage regulating terminal in a one-to-one correspondence, and the first feedback terminal is used to output a first feedback signal; at least one second driver chip, the second driver chip being respectively connected to the output terminals of the M power supply chips; the second driver chip comprising a second feedback terminal, the second feedback terminal being respectively connected to the reference voltage regulating terminals of the M power supply chips, the second feedback terminal being configured to output a second feedback signal; M being an integer greater than or equal to 1 and less than or equal to N; and N voltage regulating modules are arranged in a one-to-one correspondence with the power supply chips; each of the voltage regulating modules is connected to the output terminal, the reference voltage regulating terminal and the ground terminal, and at least one of the voltage regulating modules is used to adjust the initial driving voltage according to the first feedback signal and the second feedback signal when the first driver chip is in an operating state and the second driver chip is in an operating state.

2. The backlight module according to claim 1, wherein: The backlight module further includes a plurality of first light emitting units connected to the first driving chip and a plurality of second light emitting units connected to the second driving chip; The second driving chip has a plurality of first control terminals, the anodes of the second light-emitting units are connected to the corresponding output terminals, and the cathodes of the second light-emitting units are connected to the corresponding first control terminals; The second light-emitting units connected to the same second driver chip are divided into M groups, and the M groups of second light-emitting units are connected one-to-one to the output ends of the M power chips; the first driver chip has multiple second control ends, and the second control ends are connected to the corresponding cathodes.

3. The backlight module according to claim 2, wherein: In the M groups of the second light-emitting units, the number of the second light-emitting units in each group is equal.

4. The backlight module according to claim 2, wherein: Each of the first light-emitting units and each of the second light-emitting units includes one or more light-emitting diodes.

5. The backlight module according to claim 1, wherein: The voltage regulating module includes a first resistor and a second resistor; One end of the first resistor is connected to the output end, the other end of the first resistor and one end of the second resistor are both connected to the reference voltage regulating end, and the other end of the second resistor is connected to the ground end.

6. The backlight module according to claim 1, wherein: A first unidirectional diode is provided between the reference voltage regulating terminal and the corresponding first feedback terminal; the anode of the first unidirectional diode is connected to the first feedback terminal, and the cathode of the first unidirectional diode is connected to the reference voltage regulating terminal; A second unidirectional diode is provided between the reference voltage regulating terminal and the corresponding second feedback terminal; the anode of the second unidirectional diode is connected to the second feedback terminal, and the cathode of the second unidirectional diode is connected to the reference voltage regulating terminal.

7. The backlight module according to claim 1, wherein: When at least one of the first driver chips is in an operating state and the second driver chip is in a non-operating state, the voltage regulating module corresponding to the first driver chip in the operating state is configured to adjust the initial driving voltage according to the first feedback signal.

8. The backlight module according to claim 1, wherein: When the N first driver chips are in a non-operating state and the second driver chip is in an operating state, the voltage regulating modules corresponding to the M power chips are configured to adjust the initial driving voltage according to the second feedback signal.

9. The backlight module according to claim 1, wherein: When N of the first driver chips are in working state and the second driver chip is in working state, the voltage regulating module corresponding to the M power supply chips is used to adjust the initial driving voltage according to the first feedback signal and the second feedback signal, and the voltage regulating module corresponding to the other (NM) power supply chips is used to adjust the initial driving voltage according to the first feedback signal.

10. The backlight module according to any one of claims 1 to 9, characterized in that: Each of the first driver chip and each of the second driver chip includes at least one current source. The current source has a current adjustment level. Each time the current source is adjusted by one level, the current value of the first feedback signal or the second feedback signal changes by a preset value.

11. The backlight module according to claim 10, wherein: The current adjustment order range is 0-255, and the preset value is 1 microampere.

12. A display device, characterized in that: The display device includes a display panel and a backlight module according to any one of claims 1 to 11.

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