Display module, and backlight module and control method, calibration method and calibration system therefor

Abstract

A display module, and a backlight module and a control method, calibration method and calibration system therefor, which relate to the technical field of display. The backlight module comprises a substrate and a backlight unit, wherein the backlight unit comprises a driving chip and a plurality of light-emitting components controlled by the driving chip; the plurality of light-emitting components comprise a first light-emitting component and a second light-emitting component, and the driving distance to the first light-emitting component is longer than the driving distance to the second light-emitting component; the driving strength for one light-emitting component being smaller than that for the other light-emitting component is defined as the duty ratio of a control signal of the driving chip for controlling one light-emitting component being smaller than the duty ratio of a control signal for controlling the other light-emitting component, and / or, the current of the driving chip for controlling one light-emitting component being smaller than the current for controlling the other light-emitting component; and at a first working moment of the backlight module, the driving strength for the first light-emitting component is smaller than the driving strength for the second light-emitting component.

Description

Display module, backlight module, control method, debugging method, and debugging system thereof

[0001] Cross-references

[0002] This disclosure claims priority to Chinese patent application number 202410139714.4 filed on January 31, 2024, entitled “Display module, backlight module, control method, debugging method, and debugging system thereof,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular to a display module, a backlight module, a control method for the backlight module, a debugging method for the backlight module, and a debugging system for the backlight module. Background Art

[0004] Display panels are an indispensable part of electronic devices such as televisions and mobile phones, with liquid crystal display panels being the most widely used. The backlights of existing liquid crystal display panels are prone to uneven brightness, especially when displaying solid-color images.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0006] The present disclosure provides a display module, a backlight module, a control method of the backlight module, a debugging method of the backlight module, and a debugging system of the backlight module, which can improve the uniformity of the backlight.

[0007] According to one aspect of the present disclosure, a backlight module is provided, comprising a substrate and a plurality of backlight units disposed on the substrate, wherein one of the backlight units comprises a driver chip and a plurality of light-emitting elements controlled by the driver chip, wherein a distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements; in one of the backlight units, the plurality of light-emitting elements comprises a first light-emitting element and a second light-emitting element, wherein the driving distance of the first light-emitting element is a first distance, and the driving distance of the second light-emitting element is a second distance, wherein the first distance is greater than the second distance;

[0008] In the backlight unit, the driving strength of one light-emitting element being smaller than the driving strength of another light-emitting element is defined as follows: a duty cycle of a control signal used by the driver chip to control the one light-emitting element is smaller than a duty cycle of a control signal used to control the other light-emitting element; and / or a current used by the driver chip to control the one light-emitting element is smaller than a current used to control the other light-emitting element.

[0009] At a first operating moment of the backlight module, the driving intensity of the first light-emitting element is smaller than the driving intensity of the second light-emitting element.

[0010] In an exemplary embodiment of the present disclosure, at the first operating moment, in the backlight unit, the driving intensity of the light-emitting element is negatively correlated with the driving distance thereof.

[0011] In an exemplary embodiment of the present disclosure, at a first working moment, in a backlight unit, the duty cycle of the control signal of the light-emitting element controlled by the driver chip is negatively correlated with the driving distance of the light-emitting element; and / or, the current of the light-emitting element controlled by the driver chip is negatively correlated with the driving distance of the light-emitting element.

[0012] In an exemplary embodiment of the present disclosure, at the first working moment, in the backlight unit, the driving intensity of the light-emitting element satisfies the following relationship:

[0013] Dr=Dt+K×Dt;

[0014] Dr is the driving strength of the light-emitting element; Dt is the driving strength of the light-emitting element determined by the driver chip based on the received signal; and K is the compensation coefficient of the driving strength of the light-emitting element.

[0015] In an exemplary embodiment of the present disclosure, at a first operating moment, in a backlight unit, the driving intensity of the light-emitting element satisfies the following relationship:

[0016] Dr = Dt - K × Dt;

[0017] Dr is the driving strength of the light-emitting element; Dt is the driving strength of the light-emitting element determined by the driver chip based on the received signal; and K is the compensation coefficient of the driving strength of the light-emitting element.

[0018] In an exemplary embodiment of the present disclosure, the backlight module further includes a temperature sensing circuit for detecting the temperature of the driving chip;

[0019] At the first working moment, in the backlight unit, K=-iX+jT; 0<i, 0<j;

[0020] X is the driving distance; T is the temperature of the driving chip at the first working moment.

[0021] In an exemplary embodiment of the present disclosure, at the second working moment of the backlight module, the driving intensity of the first light-emitting element is the same as the driving intensity of the second light-emitting element, and the difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range.

[0022] In an exemplary embodiment of the present disclosure, a difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range.

[0023] According to one aspect of the present disclosure, a display module is provided, comprising a display panel and any one of the backlight modules described above.

[0024] According to one aspect of the present disclosure, a method for controlling a backlight module is provided. The backlight module includes a substrate and a plurality of backlight units disposed on the substrate. One of the backlight units includes a driver chip and a plurality of light-emitting elements controlled by the driver chip. The distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements. In one of the backlight units, the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element. The driving distance of the first light-emitting element is a first distance, and the driving distance of the second light-emitting element is a second distance. The first distance is greater than the second distance.

[0025] In the backlight unit, the driving strength of one light-emitting element being smaller than the driving strength of another light-emitting element is defined as follows: a duty cycle of a control signal used by the driver chip to control the one light-emitting element is smaller than a duty cycle of a control signal used to control the other light-emitting element; and / or a current used by the driver chip to control the one light-emitting element is smaller than a current used to control the other light-emitting element.

[0026] Control methods include:

[0027] At the first working moment, the driving intensity of the first light-emitting element is controlled to be smaller than the driving intensity of the second light-emitting element.

[0028] In an exemplary embodiment of the present disclosure, the backlight module further includes a temperature sensing circuit for detecting the temperature of the driving chip;

[0029] At the first working moment, in the backlight unit, the driving intensity of the light-emitting element satisfies the following relationship:

[0030] Dr=Dt+K×Dt;

[0031] K=-iX+jT;

[0032] 0<i,0<j;0<T;

[0033] Dr is the driving strength of the light-emitting element; Dt is the driving strength of the light-emitting element determined by the driver chip based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element; X is the driving distance; T is the temperature of the driver chip at the first working moment.

[0034] In an exemplary embodiment of the present disclosure, the backlight module further includes a temperature sensing circuit for detecting the temperature of the driving chip;

[0035] At the first working moment, in the backlight unit, the driving intensity of the light-emitting element satisfies the following relationship:

[0036] Dr=Dt-K×Dt;

[0037] K=-iX+jT;

[0038] 0<i,0<j;0<T;

[0039] Dr is the driving strength of the light-emitting element; Dt is the driving strength of the light-emitting element determined by the driver chip based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element; X is the driving distance; T is the temperature of the driver chip at the first working moment.

[0040] In an exemplary embodiment of the present disclosure, a difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range.

[0041] According to one aspect of the present disclosure, a debugging method for a backlight module is provided. The backlight module includes a substrate and a plurality of backlight units disposed on the substrate. One of the backlight units includes a driver chip and a plurality of light-emitting elements controlled by the driver chip. The distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements. In one of the backlight units, the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element. The driving distance of the first light-emitting element is a first distance, and the driving distance of the second light-emitting element is a second distance. The first distance is greater than the second distance.

[0042] Debugging methods include:

[0043] Controlling the driver chip to transmit a control signal to each of the light-emitting elements controlled by it through a test drive signal, and detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; the duty cycle and / or current of the control signal are the same;

[0044] When the driver chip is at at least one temperature, a relationship between the attenuation degree of the actual test brightness and the driving distance is established as a compensation relationship; in one of the backlight units, the attenuation degree of the actual test brightness is negatively correlated with the driving distance;

[0045] The compensation relationship is stored for the driver chip to call.

[0046] In an exemplary embodiment of the present disclosure, the backlight module further includes a temperature sensing circuit for detecting the temperature of the driving chip;

[0047] Detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; comprising:

[0048] Acquiring the temperature output by the temperature sensing circuit as the temperature of the driver chip;

[0049] The backlight module is tested by a brightness testing device to obtain the actual test brightness of each light emitting element.

[0050] In an exemplary embodiment of the present disclosure, establishing a relationship between the attenuation degree of the actual test brightness and the driving distance as a compensation relationship includes:

[0051] determining an attenuation degree of the light emitting element according to the actual test brightness and a deviation from a target test brightness determined based on a duty cycle and / or current of the control signal;

[0052] A compensation function is obtained by fitting according to the driving distance of the light emitting element and the attenuation degree as a compensation relationship.

[0053] According to one aspect of the present disclosure, a debugging system for a backlight module is provided. The backlight module includes a substrate and a plurality of backlight units disposed on the substrate. One of the backlight units includes a driver chip and a plurality of light-emitting elements controlled by the driver chip. The distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements. In one of the backlight units, the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element. The driving distance of the first light-emitting element is a first distance, and the driving distance of the second light-emitting element is a second distance. The first distance is greater than the second distance.

[0054] The debugging system includes:

[0055] a brightness detection device, for detecting the brightness of the light-emitting element;

[0056] The processing circuit is configured to perform the following steps:

[0057] Transmitting a control signal to each light-emitting element controlled by the control driver chip, and detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; the duty cycle and / or current of the control signal are the same;

[0058] When the driver chip is at at least one temperature, a relationship between the attenuation degree of the actual test brightness and the driving distance is established as a compensation relationship; in one of the backlight units, the attenuation degree of the actual test brightness is negatively correlated with the driving distance;

[0059] The compensation relationship is stored for the driver chip to call.

[0060] The present disclosure can control the driving intensity of the light-emitting elements according to the distance between the driver chip and the light-emitting elements it controls, so that the driving intensity of the first light-emitting element farther from the driver chip is less than the driving intensity of the second light-emitting element, and the difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range, thereby achieving the purpose of making the brightness of the light-emitting elements with different driving distances controlled by the same driver chip uniform, that is, achieving uniform brightness of each light-emitting element in the same backlight unit. Specifically, due to the influence of the heat generated by the driver chip, the brightness of the light-emitting elements closer to the driver chip will be lower than the brightness of the light-emitting elements farther from the driver chip. Therefore, the brightness of the light-emitting elements in the same backlight unit can be made uniform by making the duty cycle of the control signal of the light-emitting element farther from the driver chip smaller than the duty cycle of the control signal of the light-emitting element closer to the driver chip; and / or making the current of the light-emitting element farther from the driver chip smaller than the current of the light-emitting element closer to the driver chip; compensating for the reduction in the brightness of the light-emitting elements due to the heat generated by the driver chip. In addition, since the solution disclosed herein can improve the problem of uneven brightness caused by the temperature of the driver chip, it is conducive to the use of a multi-channel driver chip, that is, one driver chip can drive more light-emitting elements.

[0061] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0063] FIG1 is a schematic diagram of an embodiment of a display module disclosed herein.

[0064] FIG2 is a schematic diagram of an embodiment of the backlight module disclosed herein.

[0065] FIG3 is a diagram showing the relationship between the compensation coefficient and the driving distance of the present disclosure.

[0066] FIG. 4 is a schematic diagram of brightness compensation of a backlight module according to an embodiment of the present disclosure.

[0067] FIG. 5 is a schematic diagram of brightness compensation of a backlight module according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0068] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0069] The terms "a", "an", "the" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.; the terms "first", "second", etc. are used only as labels and are not intended to limit the quantity of their objects.

[0070] As shown in FIG1 , an embodiment of the present disclosure provides a display module, which may be a liquid crystal display module having multiple pixels, wherein each pixel may include three or more sub-pixels. The display module may include a display panel, which may include an array substrate TB and an opposing substrate FB disposed oppositely, and a liquid crystal layer LL disposed between the array substrate TB and the opposing substrate FB.

[0071] The display panel PNL also includes pixel electrodes and common electrodes. The pixel electrodes can be provided on the array substrate TB, and the common electrodes can be provided on the array substrate TB or the opposing substrate FB, and a sub-pixel includes a pixel electrode and its corresponding common electrode and a liquid crystal layer LL. The array substrate TB has a driving circuit, and the control circuit CU can be provided on the array substrate TB, and can control the voltage between the pixel electrode and the common electrode through the driving circuit, thereby controlling the degree of deflection of the liquid crystal molecules in the liquid crystal layer LL, and then controlling the transmittance of each sub-pixel to light, thereby adjusting the grayscale of each sub-pixel. At the same time, the opposing substrate FB may include a color filter layer, and the color filter layer includes multiple filter parts. A sub-pixel may also include a filter part. Through the filtering effect of the filter part, a sub-pixel can emit monochromatic light, and the light emission colors of different sub-pixels of the same pixel can be different, so as to achieve color display.

[0072] As shown in Figure 1, the display module may also include a backlight module (BLU), which may be located on a side of the array substrate (TB) away from the opposing substrate (FB). The backlight module (BLU) may emit light toward the array substrate (TB). The backlight module (BLU) may include a substrate and multiple light-emitting elements (LEDs) located on the substrate. The substrate may be a circuit board, on which a driver chip (BIC) and circuitry are located that can drive the light-emitting elements (LEDs). The specific circuitry is not specifically defined herein. The light-emitting elements (LEDs) may be arranged in an array along rows and columns. The spacing between adjacent light-emitting elements (LEDs) in the rows and columns is greater than the dimensions of the driver chip (BIC) in the rows and columns, allowing the driver chip (BIC) to be located within the gaps between the light-emitting elements (LEDs). The same driver chip (BIC) may be connected to multiple light-emitting elements (LEDs), thereby controlling the emission of multiple LEDs. The light-emitting elements (LEDs) may be Mini LEDs (sub-millimeter light-emitting diodes, 100μm-200μm in size), Micro LEDs (micro light-emitting diodes, no larger than 100μm in size), or LEDs (light-emitting diodes, larger than 200μm in size). There are no specific limitations here, as long as they can emit light.

[0073] The row direction and column direction mentioned above are merely two intersecting directions, which may be perpendicular to each other but are not limited to the horizontal and vertical directions. A person skilled in the art will appreciate that the actual directions of the row and column directions may change if the display module is rotated.

[0074] As shown in FIG2 , the light-emitting elements LED and the driver chip BIC can be divided into multiple backlight units BU. A backlight unit BU includes a driver chip BIC and multiple light-emitting elements LED controlled by it. The distance between the driver chip BIC and the light-emitting element LED controlled by it can be defined as the driving distance of the light-emitting element LED. That is, for any light-emitting element LED, the distance between the driver chip BIC that controls the light-emitting element LED and the light-emitting element LED is the driving distance of the light-emitting element LED. The light-emitting element LEDs controlled by the same driver chip BIC are located around the driver chip BIC, and there are no light-emitting element LEDs controlled by other driver chips BIC within the range. In a backlight unit BU, the driving distances of at least two light-emitting element LEDs are different. For example, the multiple light-emitting element LEDs of the same backlight unit BU include a first light-emitting element and a second light-emitting element. The driving distance of the first light-emitting element is a first distance L1, and the driving distance of the second light-emitting element is a second distance L2. The first distance L1 is greater than the second distance L2.

[0075] When displaying an image, the driver chip BIC can receive a backlight driving signal and generate a control signal for controlling the brightness of the light-emitting element LED according to the backlight driving signal. The control signal causes the light-emitting element LED to emit light of a specific brightness.

[0076] The control signal can be a pulse signal, whose duty cycle is controlled to adjust the pulse width, thereby controlling the brightness of the LED (i.e., using PWM (Pulse Width Modulation) dimming). Alternatively, the brightness of the LED can be controlled by controlling the amplitude of the pulse signal, i.e., using PAM (Pulse Amplitude Modulation) dimming. Of course, both pulse width and pulse amplitude can also be adjusted simultaneously. Furthermore, the control signal can be a DC signal, which directly adjusts the current, increasing the power of the LED to control the brightness of the LED (i.e., using DC dimming).

[0077] As shown in Figure 2, the driver chip BIC of the same backlight unit (BU) can send the same control signal to each of the light-emitting diodes (LEDs) it drives. However, the inventors discovered that although the driver chip BIC outputs the same control signal to each of the controlled LEDs, the brightness of the LEDs varies, resulting in uneven brightness. After testing and analysis, the inventors found that the uneven brightness of the LEDs is primarily affected by temperature. As the display module's operating time increases, the temperature of the driver chip BIC increases, which in turn affects the brightness of the LEDs surrounding the driver chip BIC, causing the brightness of the LEDs to decrease, meaning that the actual brightness is less than the target brightness based on the control signal. Furthermore, the closer the LED is to the driver chip BIC, the greater the impact of the temperature of the driver chip BIC, meaning the greater the reduction in actual brightness compared to the target brightness. In other words, the degree of brightness reduction of the LEDs is negatively correlated with their driving distance. Within the same backlight unit (BU), the LEDs with the greatest driving distance are less or not affected by the temperature of the driver chip BIC, and their actual brightness can be equal to the target brightness. However, the LEDs with the smallest driving distance are more affected by the temperature of the driver chip BIC, and their actual brightness is less than the target brightness. SS in FIG2 schematically shows the influence range of the temperature of the driver chip BIC.

[0078] When the temperature of the driver chip BIC reaches a temperature threshold, it begins to affect the brightness of surrounding driver chips BIC. As the temperature increases, at least within a certain temperature range, the driver chip BIC's impact on the actual brightness of the light-emitting element LED increases. According to calculations, this temperature threshold can be 50°C-60°C.

[0079] The above-mentioned actual brightness is the brightness of the light-emitting element LED measured under the control of a control signal, and the target brightness is the theoretical brightness of the light-emitting element LED based on the control signal. When the temperature of the driver chip BIC is low (for example, lower than 50°C) or the driving distance is large and is not affected by the temperature of the driver chip BIC, the actual brightness is the same as the target brightness. However, under the influence of the temperature of the driver chip BIC, the actual brightness is lower than the target brightness.

[0080] Based on the above technical problems, the inventors propose that the control signals output by the same driver chip (BIC) for at least some of the light-emitting elements (LEDs) in the same backlight unit (BU) can be compensated to ensure that the difference in actual brightness between any two LEDs falls within a specified range. This specified range can be 0-10%, i.e., not less than 0 and not greater than 10%. In other words, if at least the difference in actual brightness falls within this specified range, the actual brightness can be considered the same, thereby avoiding the impact of measurement errors and other factors on the results. Compensation of the control signal can be achieved by controlling at least one of the duty cycle of the control signal and the current controlling the light-emitting element (LED). The following is an exemplary explanation:

[0081] In a backlight unit BU, the driving strength of one light-emitting element LED being lower than the driving strength of another light-emitting element LED can be defined as follows: the duty cycle of the control signal used by the driver chip BIC to control the one light-emitting element LED is lower than the duty cycle of the control signal used to control the other light-emitting element LED; and / or the current used by the driver chip BIC to control the one light-emitting element LED is lower than the current used to control the other light-emitting element LED. In other words, for two light-emitting element LEDs, as long as at least one of the duty cycle of the control signal and the current satisfies the above relationship, the driving strength of one light-emitting element LED can be defined as lower than the driving strength of the other light-emitting element LED.

[0082] For control signals using pulse signals, the brightness of the light-emitting element LED can be controlled by adjusting the duty cycle, the pulse amplitude, or both. Adjusting the pulse amplitude is considered current regulation. For control signals using DC signals, the brightness of the light-emitting element LED can be controlled directly by controlling the current.

[0083] For the backlight unit (BLU), during the first operating moment, the driving intensity of the first light-emitting element can be lower than that of the second light-emitting element, and the difference in brightness between the first and second light-emitting elements can be within a specified range. Thus, by setting the target brightness of the first light-emitting element (with a longer driving distance) lower than the target brightness of the second light-emitting element (with a shorter driving distance), the temperature effect of the driver chip (BIC) can be compensated, and the difference in actual brightness between the two elements can be kept within a specified range, achieving uniform brightness.

[0084] The first working moment may be any moment after the temperature of the driver chip BIC reaches the above-mentioned temperature threshold. Of course, the first working moment may also be before the temperature reaches the temperature threshold, that is, the above-mentioned compensation solution may be adopted.

[0085] In a backlight unit (BU), the driving intensity of the light-emitting element (LED) can be negatively correlated with its driving distance, thereby aligning the degree of compensation with the effects of temperature. Furthermore, the duty cycle of the control signal used by the driver chip (BIC) to control the light-emitting element (LED) is negatively correlated with the driving distance of the light-emitting element (LED); and / or the current used by the driver chip (BIC) to control the light-emitting element (LED) is negatively correlated with the driving distance of the light-emitting element (LED).

[0086] For the PWM mode dimming solution, the upper limit of the duty cycle data bit number is limited, and the increase in brightness has an upper limit, which may lead to the risk of data overflow. Therefore, the brightness of the light-emitting element LED with a larger driving distance can be reduced to make it consistent with the brightness of the light-emitting element LED with a smaller driving distance. As shown in FIG4 , in some embodiments of the present disclosure, in a backlight unit BU, the driving intensity of the light-emitting element LED can satisfy the following relationship:

[0087] Dr = Dt - K × Dt;

[0088] Dr is the driving strength of the light-emitting element LED; Dt is the driving strength of the light-emitting element LED determined by the driver chip BIC based on the received backlight driving signal; K is the compensation coefficient of the driving strength of the light-emitting element LED.

[0089] The driving intensity of the light-emitting element LED controlled by the driver chip BIC can be reflected by the duty cycle mentioned above, that is, Dt can be replaced with the duty cycle of the control signal generated based on the backlight driving signal, and Dr is the duty cycle of the new control signal.

[0090] As shown in Figure 3, the compensation coefficient K can satisfy the following relationship:

[0091] K=-iX+jT;0<i,0<j;

[0092] X is the driving distance; T is the temperature of the driver chip BIC at the first operating moment. The temperature of the driver chip can be detected in real time using a temperature sensing circuit. The temperature sensing circuit can be integrated into the driver chip or provided as a detection device external to the driver chip, as long as it can detect the temperature of the driver chip.

[0093] In the case where different light-emitting elements LED emit uneven light based on the same control signal, the brightness of the light-emitting element LED with a shorter driving distance can be increased to make it consistent with the brightness of the light-emitting element LED with a longer driving distance. In this way, the brightness of the light-emitting element LED with the longest driving distance may not be affected by the temperature of the driver chip BIC. As shown in FIG5 , in some embodiments of the present disclosure, in a backlight unit BU, the driving intensity of the light-emitting element LED can satisfy the following relationship:

[0094] Dr=Dt+K×Dt;

[0095] The descriptions of Dr, Dt and K have been given above and will not be repeated here.

[0096] The compensation method of this embodiment is applicable to PAM dimming mode and DC dimming mode, without considering the upper limit of the duty cycle. For PWM dimming mode, if the brightness range is small or the number of data bits of the control signal is large, the driving strength can also meet the above relationship of this embodiment.

[0097] Based on the above compensation scheme, in some embodiments of the present disclosure, if the temperature of the driver chip BIC is insufficient to affect the brightness of the light-emitting element LED, brightness compensation may not be performed. Therefore, at the second operating time of the backlight module, the driving intensity of the first light-emitting element is the same as the driving intensity of the second light-emitting element, that is, the duty cycle or current of the control signal is the same. The light-emitting element LED is directly controlled by the control signal generated based on the backlight drive signal, and the difference in brightness between the first light-emitting element and the second light-emitting element is within a specified range. The second operating time can be any time before the temperature reaches the temperature threshold.

[0098] For a light-emitting element (LED), its driving distance is fixed, while the temperature of the driver chip (BIC) varies. With increasing usage time or power, its temperature may increase. Therefore, each temperature has a corresponding compensation coefficient K, and the compensation coefficients corresponding to different temperatures can be different, so the compensation coefficient K may be different at different times. The compensation coefficient K can be determined through a specialized debugging method and debugging system, which will be explained below.

[0099] The present disclosure provides a control method and debugging method for a backlight module. The backlight module can adopt any of the above-mentioned embodiments. Its specific structure can refer to the embodiments of the backlight module above and will not be repeated here. The control method of the present disclosure may include:

[0100] At the first working moment, the driving intensity of the first light-emitting element is controlled to be smaller than the driving intensity of the second light-emitting element, and the difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range.

[0101] Furthermore, in some embodiments of the present disclosure, at the first working moment, in a backlight unit BU, the driving intensity of the light-emitting element LED satisfies the following relationship:

[0102] Dr=Dt+K×Dt;

[0103] K=-iX+jT;

[0104] 0<i,0<j;0<T;

[0105] Dr is the driving strength of the light-emitting element LED; Dt is the driving strength of the light-emitting element LED determined by the driver chip BIC based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element LED; X is the driving distance; T is the temperature of the driver chip BIC at the first working moment.

[0106] In some embodiments of the present disclosure, at a first working moment, in a backlight unit BU, the driving intensity of the light-emitting element LED satisfies the following relationship:

[0107] Dr=Dt-K×Dt;

[0108] K=-iX+jT;

[0109] 0<i,0<j;0<T;

[0110] Dr is the driving strength of the light-emitting element LED; Dt is the driving strength of the light-emitting element LED determined by the driver chip BIC based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element LED; X is the driving distance; T is the temperature of the driver chip BIC at the first working moment.

[0111] The specific principle of the above control method has been described in detail in the backlight module above, so reference may be made to the implementation of the backlight module and will not be described in detail here.

[0112] The debugging method of the backlight module disclosed herein may include steps S110 to S130, wherein:

[0113] Step S110, controlling the driver chip to transmit control signals to each light-emitting element controlled by it through a test control signal, and detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; the duty cycle and / or current of the control signal are the same.

[0114] During testing, a test control signal is input to the driver chip. Based on the test control signal, the driver chip generates a control signal to control the light-emitting elements. At least one of the duty cycle and current of the control signal for each light-emitting element in the same backlight unit (BU) is identical. This depends on the type of control signal. If PWM dimming is used, the duty cycle is identical; if PAM dimming or DC dimming is used, the current is identical. This ensures that the light-emitting elements in the same backlight unit (BU) emit at the same brightness. One duty cycle or one current corresponds to one target test brightness.

[0115] The temperature of the driver chip can be detected. The temperature of the driver chip can be detected in real time through a temperature sensing circuit. The temperature sensing circuit can be integrated into the driver chip or can be a detection device set outside the driver chip. As long as it can detect the temperature of the driver chip, it can be used. Taking the temperature sensing circuit integrated into the driver chip as an example:

[0116] In some embodiments of the present disclosure, step S110 may include step S1110 and step S1120, wherein:

[0117] Step S1110 : obtaining the temperature output by the temperature sensing circuit as the temperature of the driver chip.

[0118] The temperature sensing circuit can detect the temperature of the driver chip in real time. A driver chip can have multiple temperature sensing circuits to simultaneously detect the temperatures of different areas of the driver chip. The average value, maximum value, etc. of the temperatures detected by each temperature sensing circuit can be used as the temperature of the driver chip.

[0119] Step S1120: Detect the backlight module using a brightness detection device to obtain the actual test brightness of each light-emitting element.

[0120] The brightness detection device may be an imaging colorimeter or other device capable of detecting brightness, which is not particularly limited herein, and can be used to detect the brightness of each light-emitting element of the backlight unit BU to obtain actual test brightness.

[0121] Step S120 , when the driver chip is at at least one temperature, establish a relationship between the attenuation degree of the actual test brightness and the driving distance as a compensation relationship; in a backlight unit BU, the attenuation degree of the actual test brightness is negatively correlated with the driving distance.

[0122] When the temperature of the driver chip reaches the temperature threshold, the brightness of the light-emitting element will decay, making its actual test brightness lower than the target test brightness that should be emitted. As the driving distance increases, the degree of attenuation gradually decreases, that is, the impact of temperature on brightness becomes smaller, that is, the degree of attenuation is negatively correlated with the driving distance.

[0123] In some embodiments of the present disclosure, step S120 may include step S1210 and step S1220, wherein:

[0124] Step S1210: Determine the attenuation degree of the light emitting element according to the actual test brightness and the deviation from the target test brightness determined based on the duty cycle and / or current of the control signal.

[0125] The degree of attenuation can be expressed as the difference between the actual test brightness and the target test brightness, or as the proportion of the difference in the target test brightness, as long as the degree of brightness reduction can be measured.

[0126] Step S1220: A compensation function is obtained by fitting according to the driving distance and attenuation degree of the light emitting element as a compensation relationship.

[0127] In some embodiments of the present disclosure, a compensation function may be used to reflect the relationship between the compensation coefficient, the driving distance, and the temperature of the driver chip, as follows:

[0128] K=-iX+jT;

[0129] 0<i,0<j;

[0130] K is the compensation coefficient; X is the driving distance; and T is the temperature of the driver chip at the first working moment.

[0131] The compensation coefficients vary at different temperatures, and the degree to which light-emitting elements at different driving distances are affected by temperature varies, resulting in different compensation coefficients. In other words, at each temperature, there are multiple compensation coefficients. For example, the compensation coefficients for all light-emitting elements can be expressed as:

[0132] K[n][m] is the compensation coefficient of the light-emitting element in the nth row and the mth column. The compensation coefficient can be set for each light-emitting element. For a light-emitting element that is not affected by temperature, that is, a light-emitting element that does not experience brightness attenuation, the compensation coefficient is 0.

[0133] Step S130: storing the compensation relationship in the driver chip.

[0134] The compensation coefficients mentioned above can be stored in the driver chip or in other storage devices for the driver chip to call.

[0135] At a first moment at a temperature, a compensation coefficient corresponding to the temperature may be called, and the compensation coefficient may be determined individually for each light emitting element according to different driving distances, and compensation may be performed.

[0136] Based on the above debugging method, the present disclosure further provides a debugging system for a backlight module, which may include a brightness detection device and a processing circuit, wherein:

[0137] The brightness detection device can detect the brightness of the light-emitting element;

[0138] The processing circuit is used to execute at least part of the steps of the above debugging method.

[0139] The details and principles of the backlight module and the debugging system have been described in detail above. For details, please refer to the implementation methods of the backlight module and the debugging method above, which will not be described in detail here.

[0140] It should be noted that although the steps of the control method and debugging method of the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all steps must be performed to achieve the desired results. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0141] When determining whether the solution of the present disclosure is adopted and thus falls within the protection scope of the present disclosure, an oscilloscope and a current probe can be used to detect the duty cycle and current of the control signals of each light-emitting element in the same backlight unit BU. If the duty cycle of the control signals of the light-emitting elements is the same or the current is the same, the solution of the present disclosure is not adopted. If at any moment, the duty cycle and current meet the magnitude relationship described in this document, the solution of the present disclosure is adopted and falls within the protection scope of the present disclosure.

[0142] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A backlight module comprising a substrate and a plurality of backlight units disposed on the substrate, wherein one of the backlight units comprises a driver chip and a plurality of light-emitting elements controlled by the driver chip, wherein the distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements; In one of the backlight units, the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element, the driving distance of the first light-emitting element is a first distance, the driving distance of the second light-emitting element is a second distance, and the first distance is greater than the second distance; In the backlight unit, the driving strength of one light-emitting element is smaller than the driving strength of another light-emitting element, which is defined as follows: the duty cycle of the control signal of the driver chip controlling the one light-emitting element is smaller than the duty cycle of the control signal controlling the other light-emitting element; And / or, the current controlled by the driver chip for one of the light-emitting elements is smaller than the current controlled for another light-emitting element; At a first operating moment of the backlight module, the driving intensity of the first light-emitting element is smaller than the driving intensity of the second light-emitting element.

2. The backlight module according to claim 1, wherein: At the first working moment, in a backlight unit, the driving intensity of the light-emitting element is negatively correlated with the driving distance thereof.

3. The backlight module according to claim 2, wherein: At a first working moment, in one of the backlight units, the duty cycle of the control signal of the driving chip controlling the light-emitting element is negatively correlated with the driving distance of the light-emitting element; And / or, the current of the light-emitting element controlled by the driving chip is negatively correlated with the driving distance of the light-emitting element.

4. The backlight module according to claim 2, wherein: At the first working moment, in the backlight unit, the driving intensity of the light emitting element satisfies the following relationship: Dr=Dt+K×Dt; Dr is the driving intensity of the light emitting element; Dt is the driving strength of the light-emitting element determined by the driving chip based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element.

5. The backlight module according to claim 2, wherein: At a first working moment, in a backlight unit, the driving intensity of the light emitting element satisfies the following relationship: Dr=Dt-K×Dt; Dr is the driving intensity of the light emitting element; Dt is the driving strength of the light-emitting element determined by the driving chip based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element.

6. The backlight module according to claim 4 or 5, wherein: The backlight module further includes a temperature sensing circuit for detecting the temperature of the driver chip; At the first working moment, in one of the backlight units, K=-iX+jT; 0<i,0<j; X is the driving distance; T is the temperature of the driving chip at the first working moment.

7. The backlight module according to claim 1, wherein: At a second operating moment of the backlight module, the driving intensity of the first light-emitting element is the same as the driving intensity of the second light-emitting element.

8. The backlight module according to any one of claims 1 to 7, wherein: A difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range.

9. A display module comprising a display panel and the backlight module according to any one of claims 1 to 8.

10. A method for controlling a backlight module, the backlight module comprising a substrate and a plurality of backlight units disposed on the substrate, wherein one of the backlight units comprises a driver chip and a plurality of light-emitting elements controlled by the driver chip, wherein the distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements; In one of the backlight units, the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element, a driving distance of the first light-emitting element is a first distance, a driving distance of the second light-emitting element is a second distance, and the first distance is greater than the second distance; In the backlight unit, the driving strength of one light-emitting element is smaller than the driving strength of another light-emitting element, which is defined as follows: the duty cycle of the control signal of the driver chip controlling the one light-emitting element is smaller than the duty cycle of the control signal controlling the other light-emitting element; And / or, the current controlled by the driver chip for one of the light-emitting elements is smaller than the current controlled for another light-emitting element; Control methods include: At a first working moment, the driving intensity of the first light-emitting element is controlled to be smaller than the driving intensity of the second light-emitting element.

11. The control method according to claim 10, wherein: The backlight module further includes a temperature sensing circuit for detecting the temperature of the driver chip; at the first working moment, in one of the backlight units, the driving intensity of the light-emitting element satisfies the following relationship: Dr = Dt + K × Dt; K = -iX + jT; 0<i,0<j;0<T; Dr is the driving intensity of the light emitting element; Dt is the driving strength of the light-emitting element determined by the driver chip based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element; X is the driving distance; and T is the temperature of the driver chip at the first working moment.

12. The control method according to claim 10, wherein: The backlight module further includes a temperature sensing circuit for detecting the temperature of the driver chip; at the first working moment, in one of the backlight units, the driving intensity of the light emitting element satisfies the following relationship: Dr = Dt - K × Dt; K = -iX + jT; 0<i,0<j;0<T; Dr is the driving intensity of the light emitting element; Dt is the driving strength of the light-emitting element determined by the driver chip based on the received signal; K is the compensation coefficient of the driving strength of the light-emitting element; X is the driving distance; and T is the temperature of the driver chip at the first working moment.

13. The control method according to claim 10, wherein: A difference between the brightness of the first light-emitting element and the brightness of the second light-emitting element is within a specified range.

14. A method for debugging a backlight module, the backlight module comprising a substrate and a plurality of backlight units disposed on the substrate, wherein one of the backlight units comprises a driver chip and a plurality of light-emitting elements controlled by the driver chip, wherein the distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements; In one of the backlight units, the plurality of light emitting elements include a first light emitting element and a second light emitting element, the driving distance of the first light emitting element is a first distance, the driving distance of the second light emitting element is a second distance, and the first distance is greater than the second distance. Debugging methods include: Controlling the driver chip to transmit a control signal to each of the light-emitting elements controlled by it through a test drive signal, and detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; the duty cycle and / or current of the control signal are the same; When the driver chip is at at least one temperature, a relationship between the attenuation degree of the actual test brightness and the driving distance is established as a compensation relationship; in one of the backlight units, the attenuation degree of the actual test brightness is negatively correlated with the driving distance; The compensation relationship is stored for the driver chip to call.

15. The debugging method according to claim 14, wherein: The backlight module further includes a temperature sensing circuit for detecting the temperature of the driver chip; Detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; comprising: Acquiring the temperature output by the temperature sensing circuit as the temperature of the driver chip; The backlight module is tested by a brightness testing device to obtain the actual test brightness of each light emitting element.

16. The debugging method according to claim 14, wherein: Establishing a relationship between the attenuation degree of the actual test brightness and the driving distance as a compensation relationship; include: determining an attenuation degree of the light emitting element according to the actual test brightness and a deviation from a target test brightness determined based on a duty cycle and / or current of the control signal; A compensation function is obtained by fitting according to the driving distance of the light emitting element and the attenuation degree as a compensation relationship.

17. A debugging system for a backlight module, the backlight module comprising a substrate and a plurality of backlight units disposed on the substrate, wherein one of the backlight units comprises a driver chip and a plurality of light-emitting elements controlled by the driver chip, wherein the distance between the driver chip and the light-emitting elements controlled by the driver chip is a driving distance of the light-emitting elements; In one of the backlight units, the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element, the driving distance of the first light-emitting element is a first distance, the driving distance of the second light-emitting element is a second distance, and the first distance is greater than the second distance; The debugging system includes: a brightness detection device, for detecting the brightness of the light-emitting element; The processing circuit is configured to perform the following steps: Transmitting a control signal to each light-emitting element controlled by the control driver chip, and detecting the temperature of the driver chip and the actual test brightness of the light-emitting element; the duty cycle and / or current of the control signal are the same; When the driver chip is at at least one temperature, a relationship between the attenuation degree of the actual test brightness and the driving distance is established as a compensation relationship; in one of the backlight units, the attenuation degree of the actual test brightness is negatively correlated with the driving distance; The compensation relationship is stored for the driver chip to call.

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