Brightness compensation method, LED driver and backlight unit

Abstract

The invention discloses a brightness compensation method, an LED driver and a backlight unit, aiming at each Mini LED electrically connected with the LED driver, after the actual output current output to the Mini LED by the LED driver is obtained, the compensation current is determined based on the actual output current and the ideal output current, then the ideal output current is adjusted based on the compensation current, and finally the brightness of the Mini LED is compensated based on the adjusted current. And the brightness of the Mini LED is controlled. After the ideal current is adjusted based on the compensation current, the brightness of the Mini LED is controlled, so that the consistency of the current input to the Mini LED is improved, the shooting space occupied when the brightness of the backlight unit is homogenized is reduced, and the homogenization processing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a brightness compensation method, an LED driver and a backlight unit. Background Art

[0002] In an AM (Active Matrix) Mini LED BLU (Back Light Unit), current and PWM (Pulse Width Modulation) signals are usually used to light up LEDs. However, when the LED driver chip provides current and PWM signals to different LEDs, even if the current and PWM signals are the same, the brightness of different LEDs will be different.

[0003] Differences in LED brightness will cause Mura (uneven brightness) on the display. In related technologies, De-Mura (brightness uniformity) technology is usually used to solve the Mura phenomenon of the display. However, as the size of the display increases, the distance for De-Mura shooting of the display will become larger, thereby occupying a larger shooting space. Summary of the invention

[0004] The present invention provides a brightness compensation method, an LED driver and a backlight unit, which are used to solve the problem of large occupied shooting space when uniformizing the brightness unevenness of a display in the prior art.

[0005] In a first aspect, the present application provides a brightness compensation method applied to a backlight unit, the backlight unit comprising an LED driver and a plurality of Mini LEDs electrically connected to the LED driver, the method comprising:

[0006] For each Mini LED electrically connected to the LED driver, obtaining an actual output current output by the LED driver to the Mini LED;

[0007] Determining a compensation current based on the actual output current and the ideal output current;

[0008] Based on the compensation current, the ideal output current is adjusted, and based on the adjusted current, the brightness of the MiniLED is controlled.

[0009] In a possible implementation, determining the compensation current based on the actual output current and the ideal output current includes:

[0010] The current difference between the ideal output current and the actual output current is used as the compensation current.

[0011] In a possible implementation, adjusting the ideal output current based on the compensation current includes:

[0012] The current sum of the compensation current and the ideal output current is used as the adjusted current.

[0013] In a possible implementation, adjusting the ideal output current based on the compensation current includes:

[0014] Based on the compensation current, the ideal output current is adjusted by adjusting the amplitude or duty cycle of the current PWM signal.

[0015] In a possible implementation, adjusting the ideal output current by adjusting the amplitude or duty cycle of the current PWM signal based on the compensation current includes:

[0016] When it is determined that the compensation current is less than 0, reducing the amplitude of the current PWM signal;

[0017] When it is determined that the compensation current is greater than 0, the duty cycle of the current PWM signal is increased.

[0018] In a possible implementation manner, reducing the amplitude of the current PWM signal includes:

[0019] Based on a first preset ratio, reducing the amplitude of the current PWM signal;

[0020] The step of increasing the duty cycle of the current PWM signal comprises:

[0021] Based on the second preset ratio, the duty cycle of the current PWM signal is increased.

[0022] In a second aspect, the present application further provides an LED driver, which is applied to a backlight unit, wherein the backlight unit comprises an LED driver and a plurality of Mini LEDs electrically connected to the LED driver, wherein the LED driver comprises: a feedback module and an output module;

[0023] For each Mini LED electrically connected to the LED driver:

[0024] The feedback module is used to obtain an actual output current outputted to the Mini LED by the output module; and output a compensation current to the output module based on the actual output current and the ideal output current;

[0025] The output module is used to adjust the ideal output current based on the compensation current, and control the brightness of the Mini LED based on the adjusted current.

[0026] In a possible implementation, the feedback module is specifically used to:

[0027] The current difference between the ideal output current and the actual output current is used as the compensation current.

[0028] In a possible implementation, the output module is specifically used to:

[0029] The current sum of the compensation current and the ideal output current is used as the adjusted current.

[0030] In a possible implementation, the output module is specifically used to:

[0031] Based on the compensation current, the ideal output current is adjusted by adjusting the amplitude or duty cycle of the current PWM signal.

[0032] In a possible implementation, the output module is specifically used to:

[0033] When it is determined that the compensation current is less than 0, reducing the amplitude of the current PWM signal;

[0034] When it is determined that the compensation current is greater than 0, the duty cycle of the current PWM signal is increased.

[0035] In a possible implementation, the output module is specifically:

[0036] Based on a first preset ratio, reducing the amplitude of the current PWM signal;

[0037] Based on the second preset ratio, the duty cycle of the current PWM signal is increased.

[0038] In a third aspect, the present application further provides a backlight unit comprising a plurality of backlight partitions, each backlight partition comprising an LED driver as described in any one of the second aspects, and a plurality of Mini LEDs electrically connected to the LED driver.

[0039] The beneficial effects of the present invention are as follows:

[0040] The embodiment of the present invention provides a brightness compensation method, an LED driver, and a backlight unit. For each Mini LED electrically connected to the LED driver, the actual output current output by the LED driver to the Mini LED is first obtained, and then the compensation current is determined based on the actual output current and the ideal output current, and then the ideal output current is adjusted based on the compensation current, and the brightness of the Mini LED is controlled based on the adjusted current. Since the compensation current is determined based on the ideal output current and the actual output current collected, the brightness of the Mini LED is controlled after the ideal output current is adjusted based on the compensation current, so that the consistency of the current input to the cathode of the Mini LED can be improved, and then when the brightness of the backlight unit is uniformly processed, the occupied shooting space is reduced, and the efficiency of the uniformization process is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 A schematic diagram of the structure of a regional dimming system provided in an embodiment of the present application;

[0043] Figure 2 A schematic diagram of controlling Mini LED provided in an embodiment of the present application;

[0044] Figure 3 A schematic diagram of an LED driver controlling multiple Mini LEDs provided in an embodiment of the present application;

[0045] Figure 4 A schematic diagram of a flow chart of a brightness compensation method provided in an embodiment of the present application;

[0046] Figure 5 A schematic diagram of the structure of an LED driver provided in an embodiment of the present application;

[0047] Figure 6 A schematic diagram of a voltage waveform of a Mini LED being lit provided in an embodiment of the present application;

[0048] Figure 7 A schematic diagram of a voltage waveform of another Mini LED being lit provided in an embodiment of the present application;

[0049] Figure 8 A schematic diagram of a voltage waveform of another Mini LED being lit provided in an embodiment of the present application;

[0050] Fig. 9 A schematic diagram of a voltage waveform of another Mini LED being lit provided in an embodiment of the present application;

[0051] Fig.10 A schematic diagram of a program product of a brightness compensation method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] The purpose, features and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0054] like Figure 1 As shown, it is a schematic diagram of the structure of the regional dimming system provided by an embodiment of the present invention. The regional dimming system includes a timing controller 11, a dimming controller 12 and a backlight unit (BLU) 13, wherein the backlight unit 13 includes a backlight matrix composed of a plurality of MiniLEDs (L11, ..., L(2n)m) and a plurality of LED drivers (LED Driver 11, ..., LED Drivernm). Exemplarily, the Mini LEDs (L11, ..., L(2n)m) can be direct-type AM (English: Active Matrix, Chinese: Active Matrix) Mini LEDs. Specifically, the number of Mini LEDs constituting the backlight matrix can be determined according to the size of the liquid crystal panel (English: Liquid Crystal Panel, abbreviated: LCP) 14, and the number of LED drivers can be determined according to the number of Mini LEDs. For example, one LED driver can control two Mini LEDs, and one LED driver can also control four MiniLEDs. Figure 1 In the example, one LED driver controls two Mini LEDs.

[0055] In a specific implementation, the timing controller 11 is respectively connected to the dimming controller 12 and the liquid crystal panel 14, and is used to transmit local dimming data to the dimming controller 12, and transmit the display image signal to the liquid crystal panel 14, so that the liquid crystal panel 14 displays an image according to the display image signal; the dimming controller 12 is also electrically connected to the LED driver (LEDDriver 11, ..., LED Driver nm) in the backlight unit 13, and is used to control the LED driver (LED Driver 11, ..., LEDDriver nm), and the LED driver (LED Driver 11, ..., LED Driver nm) is used to control the brightness of the Mini LED electrically connected thereto according to the received local dimming data, thereby realizing the adjustment of the brightness of the backlight unit 13.

[0056] The backlight unit in the embodiment of the present application may be an AM Mini LED BLU, that is, the backlight unit 13 includes array-distributed Mini LEDs and array-distributed LED Drivers. One backlight unit 13 includes multiple LED Drivers, and each LED Driver is electrically connected to multiple Mini LEDs.

[0057] like Figure 2 As shown, it is a schematic diagram of controlling Mini LED provided by an embodiment of the present application, from Figure 2 It can be seen that the LED driver controls the Mini LED according to the output current and PWM signal to light up the Mini LED.

[0058] If the LED Driver controls only one Mini LED, there is no brightness difference. However, if one LED Driver controls multiple Mini LEDs, e.g. Figure 3 As shown in the figure, one LED Driver controls 9 Mini LEDs. Due to the deviation of the actual output current of the LED Driver, the brightness of the Mini LEDs will be different, resulting in uneven brightness of the backlight unit. When the brightness of the Mini LED is low, the Mini LED may go out.

[0059] The embodiments of the present invention provide a brightness compensation method, an LED driver and a backlight unit, so that when the brightness of the backlight unit is uniformly processed, shooting space does not need to be occupied, thereby improving the efficiency of the uniform processing.

[0060] like Figure 4FIG. 1 is a flow chart of a brightness compensation method provided in an embodiment of the present application. The brightness compensation method is applied to a backlight unit. The backlight unit includes an LED driver and a plurality of Mini LEDs electrically connected to the LED driver. The method includes the following steps:

[0061] S401, for each Mini LED electrically connected to the LED driver, obtaining an actual output current output by the LED driver to the Mini LED;

[0062] S402, determining a compensation current based on the actual output current and the ideal output current;

[0063] S403: adjusting the ideal output current based on the compensation current, and controlling the brightness of the Mini LED based on the adjusted current.

[0064] The brightness compensation method provided in the embodiment of the present application first obtains the actual output current output by the LED driver to the Mini LED for each Mini LED electrically connected to the LED driver, then determines the compensation current based on the actual output current and the ideal output current, then adjusts the ideal output current based on the compensation current, and controls the brightness of the Mini LED based on the adjusted current. Since the compensation current is determined based on the ideal output current and the actual output current collected, and then the ideal output current is adjusted based on the compensation current, and finally the brightness of the Mini LED is controlled based on the adjusted current, the consistency of the current input to the Mini LED can be improved, and then when the brightness of the backlight unit is uniformly processed, there is no need to occupy the shooting space, thereby improving the efficiency of the uniformization process.

[0065] like Figure 5 , which is a schematic diagram of the structure of an LED driver provided in an embodiment of the present application, wherein the LED driver 51 includes a feedback module 501 and an output module 502;

[0066] The output module 502 sends current and PWM signals to the Mini LED. The feedback module 501 collects the current output by the output module 502, that is, the actual output current, which can also be called feedback current. The feedback module 501 determines the compensation current based on the actual output current and the ideal output current, and then outputs the compensation current to the output module 502. The output module 502 adjusts the ideal output current based on the received compensation current, and then controls the brightness of the Mini LED based on the adjusted current.

[0067] In a specific implementation, the ideal output current includes an initial current, or a current after the last adjustment, where the initial current is a current corresponding to the local dimming data. The initial current may be obtained by the LED driver based on the local dimming data received from the dimming controller, or may be directly sent to the LED driver by the dimming controller. The embodiments of the present application do not limit this.

[0068] It should be noted that, in a specific implementation, a switching unit is also included between the LED driver and the Mini LED. The switching unit may include a power switch tube, such as an NMOS tube, or a PMOS tube. The PWM signal output by the output module 502 controls the on and off of the power switch. When the power switch tube is an NMOS tube, during the high level period of the PWM signal, the NMOS tube is turned on, and the output module 502 provides the output current to the Mini LED, and the Mini LED is lit; when the power switch tube is a PMOS tube, during the low level period of the PWM signal, the PMOS tube is turned on, and the output module 502 provides the output current to the Mini LED, and the Mini LED is lit.

[0069] The greater the current output by the output module 502, the higher the brightness of the Mini LED, and the smaller the current output by the output module 502, the lower the brightness of the Mini LED; the greater the duty cycle of the PWM signal output by the output module 502, the higher the brightness of the Mini LED, and the smaller the duty cycle of the PWM signal output by the output module 502, the lower the brightness of the Mini LED.

[0070] In one embodiment, after obtaining the actual output current, the feedback module 501 determines the compensation current based on the actual output current and the ideal output current. Specifically, the feedback module 501 uses the current difference between the ideal output current and the actual output current as the compensation current.

[0071] For example, if the ideal output current is 3 mA and the actual output current collected by the feedback module 501 is 2 mA, the compensation current is 1 mA. For another example, if the ideal output current is 3 mA and the actual output current collected by the feedback module 501 is 4 mA, the compensation current is -1 mA.

[0072] After the feedback module 501 determines the compensation current, it outputs the compensation current to the output module 502. After receiving the compensation current, the output module 502 adjusts the ideal output current based on the compensation current, and then controls the brightness of the Mini LED based on the adjusted current.

[0073] In a specific implementation, the output module 502 adjusts the ideal output current based on the compensation current. The ideal output current can be adjusted directly, or the ideal output current can be adjusted by adjusting the duty cycle or amplitude of the PWM signal. Specifically, the output duration of the ideal output current can be adjusted by adjusting the duty cycle of the PWM signal, and the size of the ideal output current can be adjusted by adjusting the amplitude of the PWM signal.

[0074] That is to say, the ideal output current can be adjusted based on the compensation current. The size of the ideal output current can be adjusted directly based on the compensation current, or the size of the ideal output current can be adjusted by adjusting the amplitude of the current PWM signal based on the compensation current. The output duration of the ideal output current can also be adjusted by adjusting the duty cycle of the PWM signal based on the compensation current. The following is a detailed explanation of how to adjust the ideal output current based on the compensation current.

[0075] It should be noted that in the embodiment of the present application, the output module 502 can only adjust the size of the ideal output current based on the compensation current, or only adjust the current PWM signal based on the compensation current, or both adjust the size of the ideal output current and the current PWM signal based on the compensation current.

[0076] In one embodiment, the output module 502 adjusts the ideal output current based on the compensation current. Specifically, the output module 502 calculates the current sum of the compensation current and the ideal output current, and uses the calculated current sum as the adjusted current.

[0077] For example, if the ideal output current is 3mA and the compensation current is 1mA, then the adjusted current obtained by adjusting the ideal output current based on the compensation current is 4mA. For another example, if the ideal output current is 3mA and the compensation current is -1mA, then the ideal output current is adjusted based on the compensation current, and the adjusted current obtained is 2mA.

[0078] In the embodiment of the present application, the initial current is the current corresponding to the local dimming data. In the same Mini LED normal lighting interval, the ideal output current can be adjusted once based on the compensation current, or multiple times based on the compensation current. If the ideal output current is adjusted multiple times, when the ideal output current is not adjusted, the ideal output current is the initial current. After the ideal output current is adjusted based on the compensation current, if the feedback module 501 determines that the compensation current is not 0, the next adjustment is performed. In the next adjustment, the adjusted ideal output current is the current after the last adjustment.

[0079] When the LED driver outputs current to the Mini LED, there may be current deviation. The current deviation can be compensated by the compensation current, thereby improving the consistency of the brightness of the Mini LED.

[0080] In another embodiment, based on the compensation current, by adjusting the PWM signal, when adjusting the ideal output current, the duty cycle of the PWM signal is adjusted according to different situations, or the amplitude of the PWM signal is adjusted, which is described in detail below.

[0081] After receiving the compensation current, the output module 502 adjusts the amplitude of the PWM signal to a smaller value if it determines that the compensation current is less than 0, and increases the duty cycle of the PWM signal if it determines that the compensation current is greater than 0.

[0082] In the embodiment of the present application, the compensation current is less than 0, that is, the ideal output current is less than the actual output current. At this time, the brightness of the MiniLED is higher than the normal brightness. At this time, the amplitude of the PWM signal is reduced to make the power switch tube in an incompletely turned-on state, that is, the current output to the Mini LED through the power switch tube becomes smaller, thereby reducing the brightness of the Mini LED.

[0083] For example, when the power switch tube is a PMOS tube, it is turned on during the low level period of the PWM signal, such as Figure 6 As shown in the figure, it is a waveform diagram of the Mini LED being lit. During the low level period of the PWM signal, the power switch tube is fully turned on, and the current output by the output module is input to the Mini LED through the power switch tube, and the Mini LED is lit. Therefore, during the low level period of the PWM signal, that is, the normal lighting interval of the Mini LED, Figure 6 In the example, the on-state voltage of the power switch is Vds, that is, the low-level voltage of the PWM signal is Vds, and the high-level voltage is V. When the PWM signal is at a low level, the power switch is fully turned on, and when the PWM signal is at a high level, the power switch is turned off.

[0084] like Figure 7 As shown in FIG. 1 , another waveform diagram of the Mini LED being lit is shown. In the waveform diagram, the high-level voltage of the PWM signal is V1, and the low-level voltage is V2. V2 is less than V1, and V2 is greater than Vds. Since V2 is less than V1, and V2 is greater than Vds, when the voltage of the PWM signal is V2, the power switch tube is in an incompletely turned-on state. In this interval, the current input to the Mini LED through the power switch tube is less than the current input to the Mini LED through the power switch tube when the power switch tube is in a fully turned-on state. That is, Figure 7 In the low level interval of the PWM signal, that is, in the normal lighting interval of the Mini LED, the brightness of the Mini LED is lower than Figure 6 The brightness of the Mini LED in the normal lighting range of the Mini LED.

[0085] like Figure 8 As shown, it is another voltage waveform diagram of Mini LED being lit. Figure 8 The data collected by the oscilloscope Figure 6 The voltage change waveform of the PWM signal in the figure. The oscilloscope collects the actual voltage change waveform. Figure 6 It is the waveform diagram of voltage change under ideal conditions. Figure 6 The voltage change and Figure 8 The voltage change in the circuit does not affect the control of the power switch tube;

[0086] like Fig. 9 As shown, it is another voltage waveform diagram of Mini LED being lit. Fig. 9 The data collected by the oscilloscope Figure 7 The voltage change waveform of the PWM signal in the oscilloscope is the waveform of the actual voltage change. Figure 7 This is the voltage change waveform under ideal conditions. Figure 7 The voltage change and Fig. 9 The voltage change in the circuit does not affect the control of the power switch tube.

[0087] Based on the above Figure 6 to Figure 9 Analysis of the voltage change waveform in Figure 6 The amplitude of the PWM signal corresponding to the voltage change waveform in the figure is Vds to V1. The PWM signal of this amplitude can control the power switch tube to be fully turned on. Figure 7 The amplitude of the PWM signal corresponding to the voltage change waveform in the figure is V2 to V1. The PWM signal of this amplitude can control the power switch tube to be in a non-complete conduction interval. Figure 7 The amplitude of the PWM signal in Figure 6 The amplitude of the PWM signal in Figure 7 Under the control of the corresponding PWM signal, the current output to the Mini LED through the power switch tube is less than Figure 6 Under the control of the corresponding PWM signal, the current is output to the Mini LED through the power switch tube.

[0088] Therefore, when the compensation current is less than 0, that is, the brightness of the Mini LED is higher than the normal brightness, the amplitude of the PWM signal is reduced to reduce the brightness of the Mini LED.

[0089] In a specific implementation, the amplitude of the PWM signal may be reduced by reducing the amplitude of the PWM signal based on a first preset ratio, wherein the first preset ratio is preset.

[0090] For example, the first preset ratio is 2%, the feedback module 501 determines that the compensation current is -1 mA, and the amplitude of the current PWM signal is V1-Vds, then the amplitude of the current PWM signal V1-Vds is reduced by 2%.

[0091] In a normal lighting interval of a Mini LED, after the amplitude of the PWM signal is adjusted, if the next determined compensation current is still less than 0, the amplitude of the current PWM signal continues to be reduced based on the first preset ratio.

[0092] For example, the amplitude of the current PWM signal is (V1-Vds)×2%. If it is determined that the compensation current is less than 0, the amplitude of the current PWM signal is reduced by a first preset ratio of 2% by (V1-Vds)×2%.

[0093] In another embodiment, the compensation current is greater than 0, that is, the ideal output current is greater than the actual output current. At this time, the brightness of the Mini LED is lower than the normal brightness. At this time, the duty cycle of the PWM signal is increased to improve the brightness of the Mini LED.

[0094] The duty cycle of the PWM signal here is the proportion of the level that can turn on the power switch tube. When the power switch tube is an NMOS tube, the duty cycle of the PWM signal is the proportion of the high level. When the power switch tube is a PMOS tube, the duty cycle of the PWM signal is the proportion of the low level.

[0095] In a specific implementation, the duty cycle of the current PWM signal may be increased by increasing the duty cycle of the current PWM signal based on a second preset ratio, wherein the second preset ratio is preset.

[0096] The first preset ratio may be equal to or different from the second preset ratio.

[0097] For example, the second preset ratio is 2%, the output module 502 determines that the compensation current is 1 mA, and the duty cycle of the current PWM signal is 70%, then the duty cycle of the current PWM signal is increased by 2%.

[0098] In a normal lighting interval of a Mini LED, after the duty cycle of the PWM signal is adjusted, if it is determined next time that the compensation current is still greater than 0, the duty cycle of the current PWM signal continues to be adjusted based on the second preset ratio.

[0099] For example, the current duty cycle of the PWM signal is 70%×98%. At this time, it is determined that the compensation current is greater than 0, so the current duty cycle of the PWM signal is increased by a second preset ratio of 2% to 70%×98%.

[0100] In another embodiment, in a normal lighting interval of a Mini LED, if the amplitude of the PWM signal is reduced, and the compensation current is determined to be greater than 0 next time, the duty cycle of the current PWM signal is increased; in a normal lighting interval of a Mini LED, if the duty cycle of the PWM signal is increased, and the compensation current is determined to be less than 0 next time, the amplitude of the current PWM signal is reduced.

[0101] In the embodiment of the present application, the PWM signal can be adjusted once or multiple times in a normal lighting interval of a Mini LED. If the current PWM signal is adjusted multiple times, when the current PWM signal is not adjusted, the current PWM signal is the initial PWM signal. After the PWM signal is adjusted based on the compensation current, if the feedback module 501 determines that the compensation current is not 0, the next adjustment is performed. In the next adjustment, the adjusted current PWM signal is the PWM signal after the last adjustment.

[0102] The brightness compensation method provided in the embodiment of the present application adjusts the ideal output current based on the compensation current. Specifically, the ideal output current is adjusted by adjusting the ideal output current itself and / or by adjusting the PWM signal. When adjusting the PWM signal, the amplitude of the PWM signal can be adjusted, and the duty cycle of the PWM signal can also be adjusted. Based on the adjusted current, the brightness of the Mini LED is controlled to solve the problem of uniformity of the brightness of each Mini LED in the backlight unit. The Demura technology provided by the related technology to solve the uniformity problem of the backlight unit can reduce the space occupied by shooting and improve the efficiency of brightness uniformity processing.

[0103] In addition, by adopting the brightness compensation method provided in the embodiment of the present application, the backlight unit can more stably display low brightness, thereby improving the Mura phenomenon of the backlight unit, that is, improving the adverse phenomenon of the backlight unit caused by current deviation.

[0104] Based on the same inventive concept, an embodiment of the present application further provides an LED driver. The principle of the LED driver in solving the technical problem is similar to the principle of any of the above-mentioned brightness compensation methods in solving the technical problem. The implementation of the LED driver can refer to the implementation of the brightness compensation method, and the repeated parts will not be repeated.

[0105] like Figure 5 As shown, an LED driver provided by an embodiment of the present application is applied to a backlight unit. The backlight unit includes an LED driver and a plurality of Mini LEDs electrically connected to the LED driver. The LED driver includes: a feedback module 501 and an output module 502;

[0106] For each Mini LED electrically connected to the LED driver:

[0107] The feedback module 501 is used to obtain the actual output current output by the output module to the Mini LED; and output a compensation current to the output module based on the actual output current and the ideal output current;

[0108] The output module 502 is used to adjust the ideal output current based on the compensation current, and control the brightness of the Mini LED based on the adjusted current.

[0109] In one embodiment, the feedback module 501 is specifically used for:

[0110] The current difference between the ideal output current and the actual output current is used as the compensation current.

[0111] In one embodiment, the output module 502 is specifically used for:

[0112] The current sum of the compensation current and the ideal output current is used as the adjusted current.

[0113] In one embodiment, the output module 502 is specifically used for:

[0114] Based on the compensation current, the ideal output current is adjusted by adjusting the amplitude or duty cycle of the current PWM signal.

[0115] In one embodiment, the output module 502 is specifically used for:

[0116] When it is determined that the compensation current is less than 0, reducing the amplitude of the current PWM signal;

[0117] When it is determined that the compensation current is greater than 0, the duty cycle of the current PWM signal is increased.

[0118] In one embodiment, the output module 502 is specifically used for:

[0119] Based on a first preset ratio, reducing the amplitude of the current PWM signal;

[0120] Based on the second preset ratio, the duty cycle of the current PWM signal is increased.

[0121] Based on the same concept, an embodiment of the present invention further provides a backlight unit, which includes a plurality of backlight partitions, each of which includes any one of the above-mentioned LED drivers and a plurality of Mini LEDs electrically connected to the LED driver.

[0122] The principle of the backlight unit to solve the problem is similar to the principle of the aforementioned LED driver to solve the technical problem, so the implementation of the backlight unit can refer to the implementation of the aforementioned dimmer, and the repeated parts will not be repeated.

[0123] The embodiment of the present application provides a brightness compensation method, an LED driver and a backlight unit, the method comprising: for each Mini LED electrically connected to the LED driver, obtaining the actual output current output by the LED driver to the Mini LED, determining the compensation current based on the actual output current and the ideal output current, adjusting the ideal output current based on the compensation current, and finally controlling the brightness of the Mini LED based on the adjusted current. Specifically, the current difference between the ideal output current and the actual output current is used as the compensation current, when the ideal output current is adjusted based on the compensation current, the current sum of the compensation current and the ideal output current can be used as the adjusted current, and the current PWM signal can also be adjusted based on the compensation current. When the compensation current is less than 0, the amplitude of the current PWM signal is reduced based on a first preset ratio to reduce the current output to the Mini LED, thereby reducing the brightness of the Mini LED. When the compensation current is greater than 0, the duty cycle of the current PWM signal is increased based on a second preset ratio to increase the output duration of the current output to the Mini LED, thereby improving the brightness of the Mini LED.

[0124] By adopting the above brightness compensation method, the consistency of the current input to the cathode of the Mini LED can be improved, thereby reducing the occupied space and improving the efficiency of the uniformization process when the brightness of the backlight unit is uniformized.

[0125] In some possible embodiments, various aspects of the present invention may also be implemented in the form of a program product, which includes a program code. When the program product runs on an LED driver, the program code is used to enable the LED driver to perform the steps described in the above “Exemplary Method” section of this specification, for example, for each MiniLED electrically connected to the LED driver, obtaining the actual output current output by the LED driver to the Mini LED; determining a compensation current based on the actual output current and the ideal output current; adjusting the ideal output current based on the compensation current, and controlling the brightness of the Mini LED based on the adjusted current.

[0126] The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0127] like Fig.10 As shown, a program product 120 for a brightness compensation method according to an embodiment of the present invention is described, which can be in a portable compact disk read-only memory (CD-ROM) and includes program code, and can be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto, and in this document, a readable storage medium can be any tangible medium containing or storing a program, which can be used by or in combination with an instruction execution system, an apparatus or a device.

[0128] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, wherein readable program code is carried. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the foregoing. A readable signal medium may also be any readable medium other than a readable storage medium, which may transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0129] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0130] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0131] It should be noted that although several modules or submodules of the system are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more modules described above can be embodied in one module. Conversely, the features and functions of one module described above can be further divided into multiple modules to be embodied.

[0132] In addition, although the operations of the modules of the system of the present invention are described in a specific order in the drawings, this does not require or imply that the operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired results. Additionally or alternatively, some operations may be omitted, multiple operations may be combined into one operation, and / or one operation may be decomposed into multiple operations.

[0133] The present application is described above with reference to the block diagrams and / or flow charts showing the methods, devices (systems) and / or computer program products according to the embodiments of the present application. It should be understood that a block of the block diagram and / or flow chart diagram and a combination of blocks of the block diagram and / or flow chart diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer and / or other programmable data processing device to produce a machine, so that the instructions executed by the computer processor and / or other programmable data processing device create a method for implementing the functions / actions specified in the block diagram and / or flow chart block.

[0134] Accordingly, the present application may also be implemented with hardware and / or software (including firmware, resident software, microcode, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable storage medium, which has a computer-usable or computer-readable program code implemented in the medium, for use by an instruction execution system or in conjunction with an instruction execution system. In the context of the present application, a computer-usable or computer-readable medium may be any medium that may contain, store, communicate, transmit, or convey a program for use by an instruction execution system, device, or apparatus, or in conjunction with an instruction execution system, device, or apparatus.

[0135] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A brightness compensation method, characterized in that: Applied to a backlight unit, the backlight unit includes an LED driver and a plurality of Mini LEDs electrically connected to the LED driver, the method includes: For each Mini LED electrically connected to the LED driver, obtaining an actual output current output by the LED driver to the Mini LED; Determining a compensation current based on the actual output current and the ideal output current; Based on the compensation current, the ideal output current is adjusted, and based on the adjusted current, the brightness of the Mini LED is controlled.

2. The method according to claim 1, characterized in that The determining of the compensation current based on the actual output current and the ideal output current includes: The current difference between the ideal output current and the actual output current is used as the compensation current.

3. The method according to claim 1, characterized in that The adjusting the ideal output current based on the compensation current includes: The current sum of the compensation current and the ideal output current is used as the adjusted current.

4. The method according to claim 1, characterized in that The adjusting the ideal output current based on the compensation current includes: Based on the compensation current, the ideal output current is adjusted by adjusting the amplitude or duty cycle of the current PWM signal.

5. The method according to claim 4, characterized in that Based on the compensation current, adjusting the ideal output current by adjusting the amplitude or duty cycle of the current PWM signal includes: When it is determined that the compensation current is less than 0, reducing the amplitude of the current PWM signal; When it is determined that the compensation current is greater than 0, the duty cycle of the current PWM signal is increased.

6. The method according to claim 5, characterized in that The step of reducing the amplitude of the current PWM signal comprises: Based on a first preset ratio, reducing the amplitude of the current PWM signal; The step of increasing the duty cycle of the current PWM signal comprises: Based on the second preset ratio, the duty cycle of the current PWM signal is increased.

7. An LED driver, characterized in that: Applied to a backlight unit, the backlight unit comprises an LED driver and a plurality of Mini LEDs electrically connected to the LED driver, the LED driver comprises: a feedback module and an output module; For each Mini LED electrically connected to the LED driver: The feedback module is used to obtain an actual output current outputted to the Mini LED by the output module; and output a compensation current to the output module based on the actual output current and the ideal output current; The output module is used to adjust the ideal output current based on the compensation current, and control the brightness of the Mini LED based on the adjusted current.

8. The LED driver according to claim 7, characterized in that: The feedback module is specifically used for: The current difference between the ideal output current and the actual output current is used as the compensation current.

9. The LED driver according to claim 7, characterized in that: The output module is specifically used for: The current sum of the compensation current and the ideal output current is used as the adjusted current.

10. The LED driver according to claim 9, characterized in that: The output module is specifically used for: Based on the compensation current, the ideal output current is adjusted by adjusting the amplitude or duty cycle of the current PWM signal.

11. The LED driver according to claim 10, characterized in that: The output module is specifically used for: When it is determined that the compensation current is less than 0, reducing the amplitude of the current PWM signal; When it is determined that the compensation current is greater than 0, the duty cycle of the current PWM signal is increased.

12. The LED driver according to claim 10, characterized in that: The output module is specifically: Based on a first preset ratio, reducing the amplitude of the current PWM signal; Based on the second preset ratio, the duty cycle of the current PWM signal is increased.

13. A backlight unit, characterized in that: It comprises the LED driver as claimed in any one of claims 7 to 12, and a plurality of Mini LEDs electrically connected to the LED driver.

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