Display device and its brightness correction method

Abstract

The application discloses a display device and a brightness correction method thereof, and relates to the technical field of display. The brightness correction method of the display device comprises the following steps: a preset current is applied to lamp beads on a mini LED lamp panel and lasts for a preset time; an ideal gray scale corresponding to an actual current value and an actual gray scale within the preset time are recorded to obtain a curve model; a gray scale difference between the actual gray scale and the ideal gray scale is calculated through the curve model; all gray scale differences are counted, and an average value between all gray scale differences is recorded to obtain fluctuation difference data; the size of the preset current is changed, and the above steps are repeated to obtain corresponding fluctuation difference data under different preset currents, and a mapping relationship is formed; and the mapping relationship is written into a memory of the display panel, so that the display device compensates display data in the display panel according to the mapping relationship. Through the above method, the brightness uniformity of a display product when displaying a low gray scale picture can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a display device and a brightness correction method thereof. BACKGROUND

[0002] With the development of display technology, various display effects and technologies are emerging in an endless stream. In the past few years, mini LED technology has rapidly emerged with its strong advantages, and has been widely used in the direct display and backlight markets due to its higher resolution, contrast ratio, color gamut range and other characteristics.

[0003] However, due to the characteristics of mini LED, the LED lamp bead spacing of direct display products is very small, which leads to uneven brightness in low gray scale picture blocks, greatly affecting the display effect. SUMMARY

[0004] The purpose of the present application is to provide a display device and a brightness correction method thereof to improve the brightness uniformity of display products when displaying low gray scale pictures.

[0005] The present application discloses a brightness correction method of a display device, the display device comprising a display panel and a mini LED lamp plate, the brightness correction method of the display device comprising the steps of:

[0006] applying a preset current to the lamp beads on the mini LED lamp plate and maintaining for a preset time;

[0007] recording the actual current value received by the mini LED lamp plate within the preset time, and the ideal gray scale generated based on the actual current value;

[0008] recording the brightness emitted by the lamp beads on the mini LED lamp plate within the preset time to obtain the actual gray scale generated by the actual current value;

[0009] forming a curve between the actual current value and the actual gray scale within the preset time, and a curve between the actual current value and the ideal gray scale, and combining the two curves to obtain a curve model;

[0010] calculating the gray scale difference between the actual gray scale and the ideal gray scale at different times under the preset current through the curve model;

[0011] statistically all the gray scale difference values and recording the average value between all the gray scale difference values to obtain fluctuation difference value data;

[0012] changing the size of the preset current, repeating the above steps to obtain fluctuation difference value data, obtaining corresponding fluctuation difference value data under different preset currents, and forming a mapping relationship; and

[0013] write the mapping relationship into a memory of the display panel, so that the display device compensates display data in the display panel according to the mapping relationship.

[0014] Optionally, in the step of changing the magnitude of the preset current and repeating the steps of obtaining fluctuation difference data, corresponding fluctuation difference data under different preset currents in each stage is obtained, and at least two mapping relationships are formed.

[0015] determining an adjustment range of the preset current;

[0016] dividing the adjustment range of the preset current into at least two stages according to the magnitude of the preset current; and

[0017] changing the magnitude of the preset current in each stage in turn, and repeating the steps of obtaining fluctuation difference data, so that corresponding fluctuation difference data under different preset currents in each stage is obtained, and at least two mapping relationships are formed.

[0018] In the step of writing the mapping relationship into a memory of the display panel, so that the display device compensates display data in the display panel according to the mapping relationship, at least two mapping relationships are written into the memory of the display panel to form a mapping group, so that the display panel compensates display data in the display panel according to the mapping group.

[0019] Optionally, the adjustment range of the preset current is divided into a first stage, a second stage and a third stage, and corresponding first mapping relationship, second mapping relationship and third mapping relationship are obtained, and the mapping group is composed of the first mapping relationship, the second mapping relationship and the third mapping relationship; wherein the preset current in the third stage is greater than the preset current in the second stage, and the preset current in the second stage is greater than the preset current in the first stage.

[0020] Optionally, in the first stage, the second stage and the third stage, the magnitude of the preset current is changed in turn according to the order from small to large, and the difference between adjacent preset currents in each stage is the same.

[0021] Optionally, in the first stage, the difference between adjacent preset currents is a first difference; in the second stage, the difference between adjacent preset currents is a second difference; in the third stage, the difference between adjacent preset currents is a third difference; wherein the first difference is less than the second difference, and the second difference is less than the third difference.

[0022] Optionally, the first difference value is 0.1-0.2 mA, the second difference value is 0.3-0.4 mA, and the third difference value is 0.5-0.6 mA.

[0023] Optionally, in the step of writing the mapping relationship into the memory of the display panel and enabling the display device to compensate the display data in the display panel according to the mapping relationship, the step comprises the following steps:

[0024] writing the first mapping relationship, the second mapping relationship and the third mapping relationship into the memory of the display panel;

[0025] reading the current applied to the lamp beads on the mini LED lamp panel when the display panel is displaying;

[0026] determining the corresponding stage of the current in the mapping group;

[0027] determining the corresponding fluctuation difference value data according to the mapping relationship corresponding to the current; and

[0028] feeding back the fluctuation difference value data to the timing control of the display panel to compensate the display data of the display panel.

[0029] Optionally, after the step of feeding back the fluctuation difference value data to the timing control of the display panel to compensate the display data of the display panel, the method further comprises the following steps:

[0030] detecting the light output brightness of the current display picture;

[0031] increasing the current for driving the lamp beads on the mini LED lamp panel;

[0032] decreasing the PWM duty cycle until the light output brightness of the display picture returns to normal;

[0033] repeating the above steps multiple times, and increasing the current for driving the lamp beads on the mini LED lamp panel in sequence to obtain a dimming curve of the corresponding PWM duty cycle under different currents; and

[0034] when the display panel is displaying, increasing the current for driving the lamp beads on the mini LED lamp panel according to the dimming curve, and decreasing the PWM duty cycle according to the dimming curve.

[0035] Optionally, the first stage is divided into a first sub-stage, a second sub-stage and a third sub-stage, each of the sub-stages corresponds to a preset current adjustment range, the preset current in the third sub-stage is greater than the preset current in the second sub-stage, and the preset current in the second sub-stage is greater than the preset current in the first sub-stage.

[0036] When the display panel is displaying, when it is detected that the current of the lamp beads on the mini LED lamp plate is in the first sub-stage, the current driving the lamp beads on the mini LED lamp plate is increased by a first preset proportion; when it is detected that the current of the lamp beads on the mini LED lamp plate is in the second sub-stage, the current driving the lamp beads on the mini LED lamp plate is increased by a second preset proportion; when it is detected that the current of the lamp beads on the mini LED lamp plate is in the third sub-stage, the current driving the lamp beads on the mini LED lamp plate is increased by a third preset proportion.

[0037] The first preset proportion is greater than the second preset proportion, and the second preset proportion is greater than the third preset proportion.

[0038] The application further discloses a display device adopting the brightness correction method of the display device.

[0039] Compared with the technical solution of solving the problem of low gray scale block brightness non-uniformity in the Mini LED product by replacing a chip with higher current precision, the application measures the curve model between the preset current, the actual current value, the actual gray scale and the ideal gray scale through a large number of experiments in advance, calculates the fluctuation difference data corresponding to the preset current through the curve model, and then obtains the mapping relationship, and compensates the display data in the display panel according to the mapping relationship; so that when the lamp beads on the mini LED lamp plate receive a driving current, the display panel can receive the corresponding gray scale compensation, the original display brightness is improved to the ideal gray scale brightness, and the problem of low gray scale block brightness non-uniformity is avoided, thereby improving the display effect; and since the application only adds the mapping relationship in the memory of the display panel and adjusts the driving mode, the chip hardware is not changed, so that the cost is not increased. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings included are intended to provide a further understanding of the embodiments of the application, and constitute a part of the specification, serve to explain the principles of the application, and together with the text description, explain the principles of the application. Obviously, the accompanying drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0041] Figure 1 is a flowchart of a brightness correction method of a display device provided by an embodiment of the application;

[0042] Figure 2 is a display device provided by an embodiment of the application; Figure 1A specific flowchart of the step S7 in the method is shown in the following table:

[0043] Figure 3 A specific flowchart of the step S8 in the method is shown in the following table. Figure 1 A specific flowchart of the step S8 in the method is shown in the following table.

[0044] Figure 4 A specific flowchart of the step S8 in the method is shown in the following table. DETAILED DESCRIPTION

[0045] It needs to be understood that the terms used herein, the specific structures and functional details disclosed, are only for the purpose of describing specific embodiments, and are representative, but the present application can be embodied in many alternative forms, and should not be interpreted as being limited to the embodiments set forth herein.

[0046] In addition, unless otherwise explicitly specified and limited, "connected", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0047] The display device provided by the embodiment of the present application comprises a display panel, a backlight module and a driving circuit, and the backlight module comprises a mini LED lamp panel.

[0048] As shown in the following table, the display device provided by the embodiment of the present application further comprises a brightness correction method, which specifically comprises the following steps: Figure 1

[0049] S1: A preset current is applied to the lamp beads on the mini LED lamp panel for a preset time;

[0050] S2: Record the actual current value received by the mini LED lamp panel within the preset time, and the ideal gray scale generated based on the actual current value;

[0051] S3: Record the brightness emitted by the lamp beads on the mini LED lamp panel within the preset time, to obtain the actual gray scale generated by the actual current value;

[0052] S4: Form a curve between the actual current value and the actual gray scale within the preset time, and a curve between the actual current value and the ideal gray scale, and integrate the two curves to obtain a curve model;

[0053] ​S5: calculating, through the curve model, a gray scale difference value between the actual gray scale and the ideal gray scale at different time instants under the preset current;

[0054] S6: counting all the gray scale difference values and recording an average value between all the gray scale difference values to obtain fluctuation difference data;

[0055] S7: changing the size of the preset current, repeating the above steps of obtaining the fluctuation difference data, and obtaining corresponding fluctuation difference data under different preset currents to form a mapping relationship;

[0056] S8: writing the mapping relationship into a memory of the display panel, so that the display device compensates display data in the display panel according to the mapping relationship.

[0057] Because in the mini LED lamp panel, firstly, the spacing between the lamp beads is very small, and the lamp beads with small spacing are very sensitive to current, and slight changes in current will cause changes in brightness. In the display process of the mini LED product, the current fluctuation of different display blocks causes the brightness of the display picture in these areas to be different, and the effect presented is that the partition brightness is uneven. Secondly, the mini LED direct display product is composed of a lamp box, a lamp panel and lamp beads. Different lamp beads are placed on different lamp panels, and multiple lamp panels are placed in a lamp box. Therefore, under this structure, the control signals between different lamp panels cannot be completely synchronized, and there is always a delay and attenuation in signal transmission. Therefore, the display brightness of the lamp beads between different lamp panels also differs, causing the brightness of different lamp panels to be inconsistent at low gray scales. Based on the above two reasons, when using the mini LED display product, the problem of uneven brightness of low gray scale picture blocks is prone to occur.

[0058] Based on this, the embodiments of the present application measure the curve model between the preset current, the actual current value, the actual gray scale and the ideal gray scale through a large number of experiments in advance, calculate the fluctuation difference data corresponding to the preset current through the curve model, and then obtain the mapping relationship. According to the mapping relationship, the display data in the display panel is compensated. When the lamp beads on the mini LED lamp panel receive a driving current, the display panel can receive the corresponding gray scale compensation, the original display brightness is improved to the ideal gray scale brightness, the problem of uneven brightness of low gray scale blocks is avoided, and the display effect is improved. Moreover, compared with the technical solution of solving the problem of uneven brightness of low gray scale picture blocks in the mini LED product by replacing the chip with higher current precision, since the present application only adds the mapping relationship in the memory of the display panel and adjusts the driving mode, the chip hardware is not changed, so that the cost is not increased.

[0059] In the embodiment of the present application, there can be only one mini LED lamp panel in the display device, at which time only the mapping relationship between the driving current and the brightness change of the lamp beads on the lamp panel needs to be detected. The display device can also have multiple mini LED lamp panels, using a spliced lamp panel technology, at which time all the lamp beads on the lamp panels can be powered on and detected at the same time, all the lamp panels are detected as a whole to obtain a mapping relationship; or each lamp panel is detected separately to obtain the mapping relationship between the driving current and the brightness change of the lamp beads on each lamp panel, and then all the mapping relationships are written into the memory of the display device. When a display area corresponding to a certain lamp panel needs to display a low gray scale picture, the corresponding mapping relationship is read to make the display device compensate the display data of the corresponding area in the display panel according to the mapping relationship, improve the brightness of the area, and further avoid the problem of uneven brightness in the area, so that the display area corresponding to each mini LED lamp panel can be compensated in brightness when displaying a low gray scale picture, and the display effect is better.

[0060] Specifically, in the S1 step, the preset current refers to any current size in the interval of the lowest current and the highest current received by the lamp beads in the process of normal display of the display panel; the preset time is selected according to the actual situation, the longer the preset time, the higher the detection accuracy, which can be selected to be more than 10s, which is not limited here.

[0061] In the S2 step, the actual current value is read in real time by connecting a high-precision current measuring instrument between the current source and the lamp beads; and the ideal gray scale corresponding to the actual current value is obtained according to the formula or directly according to the algorithm controller.

[0062] In the S3 step, the display picture or the lamp beads are photographed by the CCD camera, and the picture brightness data is read to obtain the actual gray scale.

[0063] In the S4 step, a rectangular coordinate system is established, the current value is taken as one coordinate, and the gray scale value is taken as the other coordinate. The curve between the actual current value and the actual gray scale, and the curve between the actual current value and the ideal gray scale are all displayed in the rectangular coordinate system to obtain a curve model. In the curve model, one actual current value corresponds to one actual gray scale and one ideal gray scale, so that the gray scale or brightness fluctuation of the lamp beads when different actual current values are used can be obtained.

[0064] In step S5, the brightness fluctuation of the lamp bead is obtained under a preset current as time goes on. In step S6, the gray scale difference between the actual gray scale and the ideal gray scale at each time point in the preset time under the preset current is calculated, and a plurality of gray scale differences are obtained by selecting a plurality of time points in the preset time. The fluctuation difference data is obtained by calculating the average of the plurality of gray scale differences.

[0065] As shown in Figure 2 , in step S7, the method comprises the following steps:

[0066] S71: determining the adjustment range of the preset current;

[0067] S72: dividing the adjustment range of the preset current into at least two stages according to the size of the preset current;

[0068] S73: changing the size of the preset current in each stage in turn, repeating the above steps of obtaining the fluctuation difference data, obtaining the corresponding fluctuation difference data under different preset currents in each stage, and forming at least two mapping relationships.

[0069] In step S8, the at least two mapping relationships are written into the memory of the display panel to form a mapping group, so that the display panel compensates the display data in the display panel according to the mapping group.

[0070] Specifically, in step S71, the adjustment range of the preset current is the range between the maximum current and the minimum current that the lamp bead can receive during normal display.

[0071] In the embodiment, the adjustment range of the preset current is divided into stages, and each stage contains a small adjustment range of the preset current. Since the lower the gray scale value is, the more obvious the brightness change of the lamp bead caused by the fluctuation of the current is, the fluctuation difference data obtained when the preset current is large and small is quite different. If all the fluctuation difference data is put into the same mapping relationship, the number of tests when the preset current is changed will not be enough, which will make the obtained mapping relationship not accurate enough. Therefore, in the embodiment, the small current range and the large current range are tested separately to obtain different mapping relationships. Since the detection results in different stages are similar and the mapping relationship fluctuates little, the mapping result is accurate without a large number of experimental tests.

[0072] The mapping relationship can exist in the form of a table or in the form of a curve, which is not limited here.

[0073] Further, the adjustment range of the preset current is divided into a first stage, a second stage and a third stage, to obtain a first mapping relationship, a second mapping relationship and a third mapping relationship respectively, and the mapping set is composed of the first mapping relationship, the second mapping relationship and the third mapping relationship; wherein the preset current in the third stage is greater than the preset current in the second stage, and the preset current in the second stage is greater than the preset current in the first stage.

[0074] It should be noted that the number of stages in which the adjustment range of the preset current is divided is not limited in the embodiments of the present application, and can be two stages, three stages or more, and the embodiments of the present application are only exemplified and described in detail with three stages.

[0075] After the adjustment range of the preset current is divided into three stages, the first stage (small current stage), the second stage (medium current stage) and the third stage (large current stage) are formed according to the current size, which can basically meet most use cases and ensure the accuracy of the final compensation.

[0076] Moreover, in the first stage, the second stage and the third stage, the size of the preset current is sequentially changed in order from small to large, and the difference between adjacent preset currents in each stage is the same. During the test, the current can be gradually increased from the minimum current, and the current difference in each stage is equal, so that the adjustment test is facilitated. Moreover, since the preset currents in different stages are uniformly distributed, the mapping relationship stores the fluctuation difference data corresponding to the preset currents in each small range, so that the compensation effect is more accurate.

[0077] In the first stage, the difference between adjacent preset currents is the first difference; in the second stage, the difference between adjacent preset currents is the second difference; in the third stage, the difference between adjacent preset currents is the third difference; wherein the first difference is less than the second difference, and the second difference is less than the third difference.

[0078] Since the lower the gray scale value, the more obvious the brightness change of the lamp bead caused by current fluctuation, the higher the compensation accuracy required, the embodiments of the present application reduce the current difference in the small preset current adjustment range, increase the number of tests in the small preset current adjustment range, and ensure high light emitting accuracy when the lamp bead current is low.

[0079] The inventor has found through implementation that when the first difference is 0.1-0.2 mA, the second difference is 0.3-0.4 mA, and the third difference is 0.5-0.6 mA, both the accuracy requirement and the early test efficiency can be ensured.

[0080] As Figure 3 shown, in the S8 step, specifically includes steps of:

[0081] S81: write the first mapping relationship, the second mapping relationship and the third mapping relationship into the memory of the display panel;

[0082] S82: read the current applied to the lamp beads on the mini LED lamp panel when the display panel displays;

[0083] S83: determine the corresponding stage of the current in the mapping group;

[0084] S84: determine the corresponding fluctuation difference value data according to the mapping relationship corresponding to the current;

[0085] S85: feedback the fluctuation difference value data to the timing control of the display panel, and compensate the display data of the display panel.

[0086] As a specific example, the adjustment range of the preset current is 0.2mA-10mA, the preset current range in the first stage is 0.2mA-3mA, the preset current range in the second stage is 3.3mA-5.1mA, and the preset current range in the third stage is 5.5mA-10mA. In the first stage, the applied current (preset current) changes by 0.2mA, 0.4mA, 0.6mA…3mA, and this experiment is defined as verification of the first stage T1 (Test1); in the second stage, the applied current (preset current) changes by 3.3mA, 3.6mA, 3.9mA…5.1mA, and is defined as verification of the second stage T2 (Test2); in the third stage, the applied current (preset current) changes by 5.5mA, 6mA, 6.5mA…10mA, and is defined as verification of the third stage T3 (Test3).

[0087] When a preset current of 0.6mA is used to drive the lamp beads, in this process, the high-precision current measuring instrument is connected in series between the current source and the lamp beads to read the current data in real time to observe the current fluctuation value, then the CCD camera is used to take a picture of the picture and read the picture brightness data (actual gray scale); at different times, the data of the current measuring instrument and the CCD camera are recorded at the same time, and the corresponding curves of the current (actual current value) and the gray scale data (actual gray scale) at each time under 0.6mA are obtained; by sequentially changing the preset current size, the corresponding curves of the current and the gray scale data at each time under different currents and the difference between the gray scale data under the corresponding current and the ideal gray scale can be obtained.

[0088] And, the interval value of the applied current gradually increases from T1 to T3, which means that the accuracy of the applied current gradually decreases; the current values of different stages correspond to different current fluctuation data, and the current fluctuation values of compensation can be determined by the different applied currents in the display process.

[0089] As a specific embodiment, the mapping relationship of each stage forms a plurality of specific current corresponding to a plurality of fluctuation difference data by using the above scheme.

[0090] As another specific embodiment, the mapping relationship of each stage forms a current range corresponding to a fluctuation difference data, specifically, the above experiment process is further subjected to data collection for hundreds of times, and a plurality of difference data can be obtained, and the difference data is averaged to obtain the fluctuation difference data D1 in the current change process of T1 stage; the data collection is performed on T2 and T3 to obtain the fluctuation difference data D2 and D3.

[0091] Finally, the data is written into the Flash (memory), and in the process of picture display, the PID fuzzy algorithm controller reads the gray scale data (i.e. the current applied to the LED lamp bead) to be displayed in the data processor, and the corresponding current value belongs to which stage of T1, T2 and T3, and then in the process of display, the corresponding fluctuation difference data is added to the data line output, so as to compensate the fluctuation of the current, and realize the brightness uniformity of different blocks.

[0092] As shown in Figure 4 , as a further design of the embodiment of the present application, after the step S85, the method further includes the steps of:

[0093] S91: detecting the light output brightness of the current display picture;

[0094] S92: increasing the current driving the lamp beads on the mini LED lamp panel;

[0095] S93: reducing the PWM duty cycle until the light output brightness of the display picture returns to normal;

[0096] S94: repeatedly performing the above steps multiple times, and sequentially increasing the current driving the lamp beads on the mini LED lamp panel to obtain the dimming curve of the PWM duty cycle corresponding to different currents;

[0097] S95: when the display panel is displaying, the current driving the lamp beads on the mini LED lamp panel is increased according to the dimming curve, and the PWM duty cycle is reduced according to the dimming curve.

[0098] The steps of S91-S94 for making the dimming curve corresponding to the PWM duty ratio under different currents are independent of the steps of S1-S7 for obtaining the mapping relationship, and there is no sequence relationship.

[0099] In the step S95, the lamp bead can be provided with additional current from other wiring through the backup power supply in the display device, that is, an additional current is added on the basis of the normal driving current of the lamp bead, so as to avoid the change of the mapping relationship caused by directly increasing the driving current of the lamp bead.

[0100] Compared with the gear of adjusting the PWM duty ratio, the gear of adjusting the current is higher, and the minimum adjustment unit of the current is greater than the adjustment unit of the PWM duty ratio, so that the adjustment precision of the brightness can be increased by adjusting the PWM duty ratio.

[0101] Further, the first stage is divided into a first sub-stage, a second sub-stage and a third sub-stage, each of the sub-stages corresponds to a preset current adjustment range, and the preset current in the third sub-stage is greater than the preset current in the second sub-stage, and the preset current in the second sub-stage is greater than the preset current in the first sub-stage.

[0102] When the display panel is displaying, when it is detected that the current of the lamp bead on the mini LED lamp plate is in the first sub-stage, the current driving the lamp bead on the mini LED lamp plate is increased by a first preset ratio; when it is detected that the current of the lamp bead on the mini LED lamp plate is in the second sub-stage, the current driving the lamp bead on the mini LED lamp plate is increased by a second preset ratio; when it is detected that the current of the lamp bead on the mini LED lamp plate is in the third sub-stage, the current driving the lamp bead on the mini LED lamp plate is increased by a third preset ratio. Wherein, the first preset ratio is greater than the second preset ratio, and the second preset ratio is greater than the third preset ratio.

[0103] In the embodiments of the present application, for the case that the LED lamp bead current has a high control precision requirement, in order to solve the control precision problem, the first stage is split, for example, 0.2mA to 1mA is defined as the first sub-stage (T1-1), 1mA to 2mA is defined as the second sub-stage (T1-2), and 2mA to 3mA is defined as the third sub-stage (T1-3); in the case of displaying low gray scale (or applying low current to the lamp bead), the current of T1-1 stage is provided by 3 times, for example, the actual 0.6mA is provided instead of 0.2mA, the current of T1-2 stage is provided by 2 times, for example, the actual 2mA is provided instead of 1mA, and the current of T1-3 stage is provided by 0.5mA, for example, the actual 3.5mA is provided instead of 3mA.

[0104] At the same time, the current of the second stage (T2) can also be provided according to the current of the T1-3 stage, and the current of the third stage (T3) is provided according to the actual value.

[0105] In this case, the actual current of the T1 and T2 stages is larger than the ideal current, and then the PWM duty cycle is reduced until the actual brightness of the picture is consistent with the ideal brightness; for example, it is intended to achieve 60 nit brightness, and the current should be 5 mA, and actually 5.5 mA is given, and the brightness under 5.5 mA is already greater than 60 nit, at this time, the PWM duty cycle is reduced. In this process, the optical brightness measuring instrument continuously detects the actual brightness until the actual brightness reaches 60 nit, at this time, the PWM duty cycle corresponding to the current of 5.5 mA under 60 nit is formed; according to the above scheme, a plurality of experiments are carried out to obtain the dimming curve corresponding to the PWM duty cycle under different currents, and during picture display, the data processor adjusts the PWM actual output according to the PWM duty cycle corresponding to the dimming curve according to the actual output current, and then adjusts the display brightness of the LED lamp bead under the low gray scale, and finally realizes the effect of uniform brightness of each block.

[0106] It should be noted that the limitations of each step involved in the present scheme do not limit the order of the steps without affecting the implementation of the specific scheme. The steps written in the front can be executed first, or executed later, or even executed simultaneously. Different embodiments of the scheme can be combined and applied without conflict, as long as the scheme can be implemented, it should be considered to belong to the protection scope of the present application.

[0107] The above content is a further detailed description of the present application in combination with specific optional embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered to belong to the protection scope of the present application.

Claims

1. A brightness correction method of a display apparatus including a display panel and a mini LED light panel, the method comprising: The brightness correction method of the display device comprises the steps of: applying a preset current to the lamp beads on the mini LED lamp panel and maintaining for a preset time; recording the actual current value received by the mini LED lamp panel within the preset time, and the ideal gray scale generated based on the actual current value; recording the brightness emitted by the lamp beads on the mini LED lamp panel within the preset time to obtain the actual gray scale generated by the actual current value; forming a curve between the actual current value and the actual gray scale within the preset time, and a curve between the actual current value and the ideal gray scale, and combining the two curves to obtain a curve model; calculating the gray scale difference between the actual gray scale and the ideal gray scale at different times under the preset current through the curve model; statistically counting all the gray scale difference values and recording the average value between all the gray scale difference values to obtain fluctuation difference data; changing the size of the preset current, repeating the above steps of obtaining fluctuation difference data, and obtaining corresponding fluctuation difference data under different preset currents to form a mapping relationship; and writing the mapping relationship into the memory of the display panel so that the display device compensates the display data in the display panel according to the mapping relationship; In the step of changing the size of the preset current, repeating the above steps of obtaining fluctuation difference data, and obtaining corresponding fluctuation difference data under different preset currents to form a mapping relationship, the step comprises the steps of: determining the adjustment range of the preset current; dividing the adjustment range of the preset current into at least two stages according to the size of the preset current; and changing the size of the preset current in each stage in turn, repeating the above steps of obtaining fluctuation difference data, and obtaining corresponding fluctuation difference data under different preset currents in each stage to form at least two mapping relationships; In the step of writing the mapping relationship into the memory of the display panel so that the display device compensates the display data in the display panel according to the mapping relationship, at least two mapping relationships are written into the memory of the display panel to form a mapping group, so that the display panel compensates the display data in the display panel according to the mapping group; each stage contains a small adjustment range of the preset current; The display device has a plurality of mini LED lamp panels, when a display area corresponding to a certain mini LED lamp panel needs to display a low gray scale picture, the corresponding mapping relationship is read to make the display device compensate the display data in the corresponding area of the display panel according to the mapping relationship.

2. The brightness correction method of a display device according to claim 1, wherein The adjustment range of the preset current is divided into first, second and third stages to obtain corresponding first, second and third mapping relationships respectively, and the mapping group is composed of the first, second and third mapping relationships; The preset currents in the third stage are all greater than the preset currents in the second stage, and the preset currents in the second stage are all greater than the preset currents in the first stage.

3. The brightness correction method of a display device according to claim 2, wherein In the first stage, the second stage and the third stage, the preset currents are sequentially changed in order from small to large, and the difference between adjacent preset currents in each stage is the same.

4. The brightness correction method of a display device according to claim 3, wherein In the first stage, the difference between adjacent preset currents is a first difference; in the second stage, the difference between adjacent preset currents is a second difference; In the third stage, the difference between adjacent preset currents is a third difference; The first difference is less than the second difference, and the second difference is less than the third difference.

5. The brightness correction method of a display device according to claim 4, wherein The first difference is 0.1-0.2mA, the second difference is 0.3-0.4mA, and the third difference is 0.5-0.6mA.

6. The brightness correction method of a display device according to claim 2, wherein In the step of writing the mapping relationship into the memory of the display panel, the display device compensates the display data in the display panel according to the mapping relationship. Write the first mapping relationship, the second mapping relationship and the third mapping relationship into the memory of the display panel; When the display panel displays, read the current applied to the lamp beads on the mini LED lamp panel; Determine the corresponding stage of the current in the mapping group; Determine the corresponding fluctuation difference data according to the corresponding mapping relationship of the current; And Feed back the fluctuation difference data to the timing control of the display panel to compensate the display data of the display panel.

7. The brightness correction method of a display device according to claim 6, wherein After the step of feeding back the fluctuation difference data to the timing control of the display panel to compensate the display data of the display panel, the method further comprises the steps of: Detecting the light output brightness of the current display picture; Increasing the current driving the lamp beads on the mini LED lamp panel; Decreasing the PWM duty cycle until the light output brightness of the display picture returns to normal; Repeat the above steps multiple times, and sequentially increase the current driving the lamp beads on the mini LED lamp panel to obtain the dimming curve of the corresponding PWM duty cycle under different currents; And When the display panel displays, increase the current driving the lamp beads on the mini LED lamp panel according to the dimming curve, and decrease the PWM duty cycle according to the dimming curve.

8. The brightness correction method of a display device according to claim 7, wherein The first stage is divided into a first sub-stage, a second sub-stage and a third sub-stage, each of the sub-stages corresponds to a preset current adjustment range, and the preset currents in the third sub-stage are all greater than the preset currents in the second sub-stage, and the preset currents in the second sub-stage are all greater than the preset currents in the first sub-stage. When the display panel is displaying, when it is detected that the current of the lamp beads on the mini LED lamp plate is in a first sub-stage, the current driving the lamp beads on the mini LED lamp plate is increased by a first preset proportion; when it is detected that the current of the lamp beads on the mini LED lamp plate is in a second sub-stage, the current driving the lamp beads on the mini LED lamp plate is increased by a second preset proportion; when it is detected that the current of the lamp beads on the mini LED lamp plate is in a third sub-stage, the current driving the lamp beads on the mini LED lamp plate is increased by a third preset proportion; Wherein, the first preset proportion is greater than the second preset proportion, and the second preset proportion is greater than the third preset proportion.

9. A display device, characterized by A brightness correction method of a display device as claimed in any one of claims 1-8.

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