An LED display driving chip and an LED display

Abstract

This application relates to an LED display driving chip and an LED display. The driving chip is configured such that: when the gray value R of the gray-scale data is less than or equal to Q, the gray-scale data is assigned to one of M display groups; when the gray value R of the gray-scale data is greater than Q, the gray value of one of the M display groups is P, where P ≥ Q, and the sum of the gray values of the remaining M - 1 display groups is R - P; among the display groups with non-zero gray values in the remaining M - 1 display groups, the number of display groups with gray values less than L is no more than 1, where L ≥ 1, Q > L, and Q is the centralized display threshold. This application can make the low-gray display effect smoother and improve the display effect.

Description

Technical Field

[0001] The present application relates to the field of LED displays, and particularly to an LED display panel driving chip and an LED display screen. Background Art

[0002] The common structure of the existing LED display panel is as Figure 1 shown. The LED row driving usually adopts a switching power tube, and the column driving usually adopts a constant current source driving. The constant current source driving chip usually includes a plurality of constant current output channels, and the constant current output channels (OUT terminals) are connected to the Figure 1 column lines in

[0003] (the first column / the second column...). The principle is as follows:

[0004] First, the power tube of the first row is turned on, and the power tubes of other rows are turned off. The row lines of other rows are high impedance;

[0005] The column driving outputs a constant current source corresponding to the display data of the first row by column to light up the LED display lamp beads of the first row and display the display image of the first row;

[0006] In this way, the rows are changed in turn until the images of all rows and all columns are displayed. Figure 2 shown:

[0007] The image of one frame is divided into M display groups. At this time, the display refresh rate = frame rate * M, and the refresh rate is increased by M times;

[0008] Each display group contains a complete display from the first row to the p-th row; and for the display time of each row, there can be one or more display areas.

[0009] In the existing LED driving chips, when the gray value is low, the number of groups is large, and the gray value of each display group is low. This will cause multiple non-ideal switching processes as the gray value increases in low gray, for example, the PWM is not an ideal square wave. At this time, the actual display time will be affected, thus affecting the low gray display effect.

[0010] The above problems become problems that need to be solved urgently. Summary of the Invention

[0011] The purpose of the present application is to overcome the deficiencies of the prior art and provide an LED display panel driving chip and an LED display screen, which can make the low gray display effect smoother and improve the LED display effect.

[0012] The purpose of the present application is achieved by the following technical solutions:

[0013] The first aspect of the present application provides an LED display driving chip, and the driving chip is configured to:

[0014] When the gray value R of the gray data ≤ Q, the gray data is allocated to one of the M display groups;

[0015] When the gray value R of the gray data > Q, the gray value of one of the M display groups is configured to be P, P ≥ Q, and the sum of the gray values of the remaining M - 1 display groups is R - P;

[0016] Wherein, among the display groups with non - zero gray values in the remaining M - 1 display groups, the number of display groups with gray values less than L is no more than 1, L ≥ 1, Q > L, and Q is the centralized display threshold.

[0017] By centrally displaying the first Q gray levels of the low - gray part in a certain display group within a frame in the present application, and then evenly distributing the remaining unallocated gray values, the problem of uneven display when displaying low - gray levels in the prior art can be eliminated, and the display effect can be optimized.

[0018] Optionally, if R - P < (M - 1)*L, the gray value R - P is allocated to group A among the remaining M - 1 display groups with each group having a gray value of L, and the remaining gray value less than L is allocated to the remaining M - 1 display groups, where A is the integer part of (R - P) / L; when R - P ≥ (M - 1)*L, the gray value of each of the M - 1 display groups is at least L.

[0019] Optionally, when Q < R ≤ M*Q, the LED display driving chip is configured to:

[0020] When C ≥ L, the gray value of one of the M display groups is configured to be Q + x, x ≥ 0, and the gray value of the i - th display group among the remaining M - 1 display groups is configured to be C + x i , x i ≥ 0, i ∈ {1,..., M - 1}, where

[0021] When C < L, the gray value of one of the M display groups is configured to be Q + y, y ≥ 0, and the gray value of the j - th display group among the M - 1 - A display groups is configured to be z j , z j ≥ 0, j ∈ {1,..., M - 1 - A}, when A > 0, the gray value of the k - th display group among the A display groups of the M display groups is configured to be L + y k , y k ≥ 0, k ∈ {1,..., A}, where When A = 0,

[0022] where A and B are respectively the integer part and the remainder part of (R - Q) / L, and C and D are respectively the integer part and the remainder part of (R - Q) / (M - 1).

[0023] Optionally, when R > M * Q, the LED display driving chip is configured to: allocate the grayscale data to the M display groups. At this time, the grayscale values of all M display groups are not 0.

[0024] Optionally, when C < L and A > 0,

[0025] Optionally, when C < L,

[0026] Optionally, when C < L, y = B.

[0027] Optionally, when C ≥ L,

[0028] Optionally, x i ∈ {0, 1}, i ∈ {1,..., M - 1}.

[0029] Optionally, when R > M * Q, the LED display driving chip is configured to:

[0030] the grayscale value of the h-th display group in the M display groups is E + f h , h ∈ {1,..., M}, where,

[0031] where E and F are respectively the integer part and the remainder part of R / M.

[0032] Optionally, f h ∈ {0, 1}, h ∈ {1,..., M}.

[0033] The second aspect of the present application provides an LED display, which includes a display panel and an LED display driving chip as described in the first aspect.

[0034] The beneficial effects of the present application are:

[0035] Compared with the prior art, by cleverly configuring the driving method of the LED display driving chip, the present application centrally displays the low-gray data, which can eliminate the uneven display phenomenon generated when displaying the low-gray data and significantly improve the display effect. Description of the Drawings

[0036] Figure 1is the common structure of the LED display unit board provided by the prior art;

[0037] Figure 2 is a schematic diagram of the display of a frame of image provided by the prior art;

[0038] Figure 3 is the gray-scale allocation schematic provided by an embodiment of the present application Figure 1 ;

[0039] Figure 4 is the gray-scale allocation schematic provided by another embodiment of the present application Figure 2 ;

[0040] Figure 5 is the gray-scale allocation schematic provided by another embodiment of the present application Figure 3 ;

[0041] Figure 6 is the gray-scale allocation schematic provided by another embodiment of the present application Figure 4 ;

[0042] Figure 7 is the gray-scale allocation schematic provided by another embodiment of the present application Figure 5 . Detailed implementation manners

[0043] The technical solution of the present application will be further described in detail below in conjunction with specific embodiments, but the protection scope of the present application is not limited to the following.

[0044] For the convenience of subsequent description, relevant symbols of the present application are briefly described below. In the present application, the number of display data bits is N-bit, and the number of display groups is M (a frame of image is divided into M sub-frames, that is, M display groups, M is an integer, generally M is greater than or equal to 2, preferably, M is greater than or equal to 3, specifically, please refer to Figure 2 ). The centralized display gray-scale threshold is Q; the gray-scale value R of the gray-scale data (display data) refers to the total gray-scale value of the lamp beads in a frame of image, and the gray-scale values of each display group refer to the shares of the gray-scale value R allocated to each display group. The sum of the gray-scale values of all M display groups is equal to the total gray-scale value R (greater than or equal to 0). A non-zero gray-scale value indicates that the lamp bead is lit, and the magnitude of the gray-scale value represents the length of the lighting time of the lamp bead. The LED display driving chip can drive the LED display (display panel) to display according to the gray-scale value of each display group, that is, drive the LED display to sequentially display the images of each sub-frame of a frame of image according to the gray-scale value of each sub-frame. In addition, the present application Figures 3 - 7Among them, the vertical axis represents the total grayscale value of the grayscale data. In each display group, the dark part (width or number of dark frames) represents the grayscale value of that display group. The sum of the widths or the number of dark frames in the dark parts of multiple display groups represents the total grayscale value of the grayscale data. The dark part indicates that the LED is lit, and the width of the dark part (i.e., the grayscale value) represents the lighting time of the LED.

[0045] An embodiment of the present application provides an LED display driving chip, which is configured as follows:

[0046] When the grayscale value R of the grayscale data ≤ Q, the grayscale data is allocated to one of the M display groups;

[0047] When the grayscale value R of the grayscale data > Q, the grayscale value of one of the M display groups is configured as P, P ≥ Q, and the sum of the grayscale values of the remaining M - 1 display groups is R - P;

[0048] Among them, among the display groups with non - zero grayscale values in the remaining M - 1 display groups, the number of display groups with grayscale values less than L is no more than 1, L ≥ 1, Q > L, and Q is the centralized display threshold.

[0049] In order to obtain a smooth display effect in low grayscales, in the present application, the centralized display threshold Q is set. According to the relationship between the grayscale value R of the grayscale data and the centralized display threshold Q, it is determined how to allocate the total grayscale value R among the M sub - frames (M display groups) of a frame of image. The LED driving chip then drives the display according to the grayscale values of each display group. That is, the present application actually determines the way for the LED display driving chip to drive the LED display for display.

[0050] Specifically, in the present application, low - grayscale data (grayscale value R less than or equal to the centralized display threshold Q) is concentrated in one display group (it can be fixedly selected from a certain group among the M groups. For example, as long as R is less than or equal to Q, it is all allocated to the first group; or it can be arbitrarily selected from the M groups. Taking Q = 8 as an example, when R = 4, select the first group, and when R = 5, select the third group) for display.

[0051] When the grayscale value R of the grayscale data is greater than the centralized display threshold Q, the grayscale value of at least one of the M display groups is at least the centralized display threshold Q. For example, first configure the grayscale value of one display group as Q, and then distribute the remaining unallocated grayscale value (with a size of R - Q) as additional grayscale values in one or more of the M display groups of a frame of image (including the display group whose grayscale value was previously configured as Q) in a relatively uniform manner.

[0052] In this application, the centralized display gray-scale threshold Q is a fixed value or adjustable. That is, it can be set to a fixed value according to needs, or its value can be adjusted appropriately according to the display requirements.

[0053] It should be noted that in this application, one group can be fixedly selected from the M groups as the centralized display group. For example, the 4th group. When the gray-scale value of the gray-scale data is less than or equal to the centralized display threshold, the gray-scale data is centrally allocated to this group. When the gray-scale value of the gray-scale data is greater than the centralized display threshold, the gray-scale value of this group is configured as P (P≥Q), and the remaining unallocated gray-scale value (with a size of R - P) is then allocated to one or more of the remaining M - 1 display groups. Of course, it can also be not fixed. When the gray-scale value of the gray-scale data is less than or equal to the centralized display threshold, any one of the M display groups is selected for centralized display; when the gray-scale value of the gray-scale data is greater than the centralized display threshold, the gray-scale value in one of the M display groups is first configured as Q (ensuring that at least one display group is allocated at least Q gray-scale values), and the remaining gray-scale value (with a size of R - Q) is allocated among all M display groups (including the display group whose gray-scale value was previously configured as Q).

[0054] Taking Q = 4 and L = 1 as an example, as Figure 3 shown, when the gray-scale value R of the gray-scale data is less than or equal to 4, at this time, all the gray-scale values are uniformly allocated to the 1st group for centralized display; when the gray-scale value of the gray-scale data is greater than 4, for example, when the gray-scale value is 5, the gray-scale value of the 1st display group is configured as 4, and the remaining gray-scale value (with a size of 1) is then allocated to the remaining 3 groups (the 3rd group in the figure). When the gray-scale value is between 5 and 16, only consider allocating the remaining gray-scale value (from 1 to 12) among the 2nd to 4th display groups. If the gray-scale value of the gray-scale data is relatively large (for example, exceeding 16), the gray-scale value of each display group can be configured to be at least Q, then consider allocating the remaining gray-scale value (with a size of R - Q) among all M display groups. Of course, the remaining gray-scale value (with a size of R - Q) can also be directly allocated to the selected display groups among all M display groups at the beginning, rather than only among the remaining M - 1 display groups.

[0055] It should be noted that when allocating gray-scale values, it should be considered to be as uniform as possible. Assuming that data is allocated to the 1st group, try not to allocate data to the display groups adjacent to the 1st group. Please refer to Figure 3, when the gray value of the gray data is 5, the remaining gray values (with a size of 1) are assigned to the 3rd display group. When the gray value of the gray data is 6, the remaining gray values (with a size of 2) are assigned to the 3rd and 4th groups. When the gray value of the gray data is 7, each of the other three groups is additionally assigned gray values with a size of 1. This can achieve relatively uniform distribution, and the gray data will not be completely concentrated in one or several groups, but is relatively uniform among all display groups.

[0056] In this application, a threshold L greater than or equal to 1 is set. For the M - 1 display groups other than the display group with the gray value P among the M display groups, the number of display groups with the assigned gray value less than L among these M - 1 display groups is no more than 1. That is, please refer to Figures 4 - 6 , L = 3. Assuming the gray value is 5, it can be divided into 4 + 1, 5 + 0. Assuming the gray value is 6, it can be divided into 4 + 2, 5 + 1, 6 + 0, and the situation of 4 + 1 + 1 will not occur.

[0057] In this application, L is not equal to Q. In particular, L can be selected to be less than Q. Optionally, L is greater than 1. Preferably, L is an integer. It should be noted that in this application, Q can be selected as an integer.

[0058] In some embodiments, the gray data is graded according to the gray value size, and the gray value is assigned according to the divided gray levels, so as to determine how to perform the display.

[0059] Optionally, the gray value can be divided into three levels. For example, two thresholds are set for the gray data. That is, the aforementioned centralized display threshold Q and the first gray threshold S, where S is greater than Q. The gray value size of each display group is determined according to which level the gray value of the gray data belongs to.

[0060] When R ≤ Q, the gray data is assigned to one of the M display groups;

[0061] When Q < R ≤ S, the gray data is assigned to one or more of the M display groups, and the gray values of one or more of the M display groups are not 0, and the gray value of one of the display groups is greater than or equal to Q;

[0062] When R > S, the gray data is assigned to the M display groups. That is, the gray value of each display group is not 0, and preferably the gray value sizes of each display group are close to ensure uniformity.

[0063] For the gray data of each level, different display driving methods or gray value assignment methods are adopted, and the gray values can be relatively evenly assigned to the M display groups of a complete frame, achieving a win - win situation of high refresh rate and smooth display, and obtaining a better display effect.

[0064] In one embodiment, if RP<(M-1)*L, the grayscale value RP is distributed to A groups of the remaining M-1 display groups according to the grayscale value of each group being L, and the remaining grayscale values less than L are distributed to the remaining M-1 display groups, where A is the integer part of (RP) / L;

[0065] When RP≥(M-1)*L, the grayscale value of each display group in the remaining M-1 display groups is at least L.

[0066] That is, when the grayscale value R>Q of the grayscale data, the size of RP and (M-1)*L is judged to confirm how to allocate the grayscale value of size RP. The grayscale value of a display group is configured to be at least Q (assuming it is P), and the number of display groups with grayscale values of at least L in the remaining M-1 display groups is as large as possible. The above A is the maximum value that the number of display groups with grayscale values of at least L in the remaining M-1 display groups can reach. For example, assuming that the grayscale value of a display group is configured to be P, the remaining grayscale value RP can be allocated in the following manner, and the grayscale values of A display groups in the M-1 display groups are preferentially configured to be L, until the remaining grayscale values are less than L, at which time the remaining grayscale values are redistributed as additional grayscale values to one or more display groups in the aforementioned M-1 display groups. For example, if M=4, R=17, P=Q=8, and L=4, then the grayscale value of one display group is P=8. The remaining grayscale value of 9 is allocated as follows: first, two display groups are selected from the other three display groups, and the grayscale value is assigned to 4 respectively. The remaining unassigned grayscale value (size 1) is allocated to these three display groups. In other words, the grayscale values of these four display groups may be 8, 4, 4, 1, or 8, 5, 4, 0.

[0067] Optionally, S=M*Q, that is, S is equal to the product of the number M of display groups and the centralized display threshold Q.

[0068] Optionally, when the gray value R is in the middle position, that is, Q <R≤M*Q时,此时S=M*Q,LED显示屏驱动芯片可被配置为:

[0069] When C≥L, the grayscale value of one display group in the M display groups is configured as Q+x, x≥0, and the grayscale value of the i-th display group in the remaining M-1 display groups is configured as C+x i , x i ≥0, i∈{1,…,M-1}, where,

[0070] When C < L, the gray value of one display group among the M display groups is configured as Q + y, y ≥ 0, and the gray value of the j-th display group among the M - 1 - A display groups is configured as z j , z j ≥ 0, j ∈ {1, …, M - 1 - A}. When A > 0, the gray value of the k-th display group among the A display groups in the M display groups is configured as L + y k , y k ≥ 0, k ∈ {1, …, A}, where When A = 0,

[0071] where A and B are respectively the integer part (i.e., the quotient) and the remainder part of (R - Q) / L, and C and D are respectively the integer part (i.e., the quotient) and the remainder part of (R - Q) / (M - 1).

[0072] It should be noted that in this application, x, x i , y, y k , z j are all numbers greater than or equal to 0. And in this application, A is an integer greater than or equal to 0. When A = 0, the remainder B can be distributed to the centralized display group and / or the other M - 1 display groups (i.e., all M display groups). That is, the gray value of one display group among the M display groups is Q + B, and the gray values of the other M - 1 display groups are 0, or the gray value of one display group is Q, the gray value of one display group is B, and the gray values of the other M - 2 display groups are 0, or the gray value of one display group is Q + y, the gray value of one display group is B - y, and the gray values of the other M - 2 display groups are 0.

[0073] Optionally, when R > M * Q, the LED display driving chip is configured to: distribute the gray data to the M display groups. At this time, the total gray value is relatively large. For the sake of uniformity, the gray data is preferably evenly distributed to all the display groups. It can be understood that at this time, the gray values of all the display groups are greater than 0.

[0074] When the total gray value R of the gray data satisfies Q < R ≤ M * Q, calculate the quotient A and the remainder B of (R - Q) / L and the quotient C and the remainder D of (R - Q) / (M - 1). Judge the magnitude relationship between C and L:

[0075] (1) If C ≥ L, it indicates that when the gray value of one display group among the M display groups is configured as Q, for the remaining M - 1 display groups, the gray value of each display group can be at least C. To ensure relative uniformity, the gray value of each of these M - 1 display groups can be directly configured to be at least C. The remaining unallocated gray value (with a size of D) is redistributed as additional gray value to one or more of these M display groups. That is, among these M - 1 display groups, the gray value of the i-th display group is C + x i , and the gray value of the remaining 1 display group is Q + x.

[0076] The gray value with a size of the remainder D can be redistributed as additional gray value to one or more of all M display groups. The additional gray values (such as x, x i ) in each of these M display groups can be any value greater than or equal to 0 and less than or equal to D, and the sum of the additional gray values of these M display groups is D.

[0077] For example, it can be x = D. That is, the gray value of 1 display group is configured as Q + D, and the gray value of each of the remaining M - 1 display groups is C.

[0078] Of course, it can also be that, that is, the gray value of 1 display group is configured as Q, and the gray value with a size of the remainder D is redistributed as additional gray value to the remaining M - ۱ display groups. The additional gray values in each of these M - 1 display groups can be any value greater than or equal to 0 and less than or equal to D, and the sum of the additional gray values of these M - 1 display groups is D.

[0079] Preferably, x i ∈ {0, 1}, i ∈ {1,..., M - 1}. That is, among the remaining M - 1 display groups, D display groups are selected, and an additional gray value with a size of 1 is assigned to each display group. The gray value of each of these D display groups is C + 1. It should be noted that, according to needs, the gray values in this application can be represented only by integers, that is, R is an integer.

[0080] Of course, it can also be to select one or more display groups among all M display groups for distribution. For example, D display groups are selected among these M display groups, and the additional gray value of each of these D display groups is 1.

[0081] (2) If C < L, it indicates that when the gray value of one of the M display groups is configured as Q, the gray values of not every one of the remaining M - 1 display groups can reach L. At this time, some of the M - 1 groups can be selected (A display groups, where A is an integer greater than or equal to 0 and less than or equal to M - 1), and the gray value of each selected display group is configured to be at least L. The remaining unallocated gray value (with a size of B) is then distributed among these M display groups as additional gray values.

[0082] It can be that when C < L and A > 0 (A is an integer), Since y ≥ 0, z j ≥ 0, j ∈ {1,..., M - 1 - A}, then necessarily y = 0, z j = 0. That is, the gray value with a size of the remainder B is distributed to one or more of the aforementioned A display groups. Preferably, one of the A display groups can be selected, and its gray value is directly configured as L + B, that is, y k ∈ {0, B}. At this time, for the gray data with a gray value size of R, the distribution method among the M display groups is: the gray value in one display group is Q, the gray value in one display group is L + B, the gray values in A - 1 display groups are L, and the gray values in the remaining display groups are 0.

[0083] It should be noted that the size of L + B is preferably not more than the maximum display gray threshold of each display group, otherwise it will cause overflow. In this application, M is preferably an integer greater than or equal to 3.

[0084] See Figure 5 , at this time L = 3, Q = 4, when R = 8, C = 1, D = 1, A = 1, B = 1, C is less than L. At this time, since the gray value of the first display group is configured as 4, then one of the groups 2 - 4 is selected (here it is the third group), and the remaining unallocated gray value (with a size of 4) is configured to the third display group, that is, the gray value of the third display group is L + B = 3 + 1. Therefore, when R = 8, the total gray value of the first display group is 4, the total gray value of the third display group is 4, and the gray values of other display groups are 0.

[0085] It can also be that when C < L, M - 1 - A must be an integer greater than 0 and less than or equal to M - 1. At this time, y = 0, when A is not equal to 0, y k = 0, k ∈ {1,..., A}, indicating that one display group is allocated a gray value of Q, and the gray values of A display groups are L (that is, y k= 0, k ∈ {1, …, A}), one display group has a gray value of B, and the other M - A - 2 display groups (if any) have a gray value of 0; when A is 0, it means that one display group is assigned a gray value of Q, and one display group is assigned a gray value of B. The other M - 2 display groups have a gray value of 0.

[0086] See Figure 4 , at this time L = 3, Q = 4, when R = 6, C = 0, D = 2, A = 0, B = 2, C is less than L. At this time, the gray value of the first display group is configured as 4, and one group is selected from the second to fourth groups (here it is the third group), and its gray value is configured as B, that is, 2.

[0087] For another example, when R = 9, C = 1, D = 2, A = 1, B = 2. At this time, the gray value of the first display group is 4, the gray value of the third display group is configured as L (with a size of 3), and the gray value of the second display group is B (with a size of 2).

[0088] It can also be that when C < L, y = B, (that is, z j = 0, j ∈ {1, …, M - 1 - A}), when A is not 0, y k = 0, k ∈ {1, …, A}, that is, the gray value in one display group is Q + B, and the gray value of each of the A display groups is L, and the gray value of the other M - 1 - A display groups (if any) is 0; when A = 0, that is, the gray value in one display group is Q + B, and the gray value of the other M - 1 display groups is 0. It should be noted that the size of Q + B should preferably not exceed the maximum display gray threshold of each display group; otherwise, overflow will occur.

[0089] Of course, it can also be that At this time, z j = 0, j ∈ {1, …, M - 1 - A}. If M - 1 - A is equal to 0, then A = M - 1.

[0090] It can also be that only one of z1, z2, ……, z M-1-A is not 0, for example, it is v, and the remaining gray value of size B - v is distributed to other display groups. At this time

[0091] See Figure 6 , when R = 9, C = 1, D = 2, A = 1, B = 2. At this time, the gray value of one display group (Group1) is 4 + 2, the gray value of one display group (Group3) is 3, and the gray value of the other display groups (Group2 and Group4) is 0.

[0092] In some embodiments, when R > M * Q, the LED display driving chip is configured to:

[0093] The gray value of the h-th display group among the M display groups is E + f h , h ∈ {1,..., M}, where

[0094] where E and F are the integer part and the remainder part of R / M (i.e., the quotient and the remainder), respectively.

[0095] When R > M * Q, it indicates that the gray value of the gray data is relatively large. The gray value of each of the M display groups can be configured to be at least Q. Calculate R / M to obtain the quotient E and the remainder F, then the gray value of each display group can be at least E. When the initially assigned gray value of each display group reaches E, the remaining unassigned gray value (with a size of F) is relatively evenly distributed among the M display groups.

[0096] Optionally, f h ∈ {0, 1}, h ∈ {1,..., M}. By selecting F display groups from the M display groups, the gray value of each selected display group is incremented by 1 based on the initially assigned gray value E to obtain the final gray value. This way can make the gray value distribution in each display group relatively uniform and avoid the problem of uneven display.

[0097] Of course, f h does not necessarily take 0 or 1. In fact, it can be arbitrarily assigned. For example, when F = 3, two display groups are selected, one is assigned 2 and the other is assigned 1, as long as these display groups can accommodate the assigned gray value.

[0098] It should be noted that if the gray data in this application is represented by integers (i.e., R only takes integer values), at this time, preferably, Q, L, x, x i , y, y k , z j , f h and so on all take integer values.

[0099] In this application, when selecting some groups from multiple groups to assign gray values, the selection can be made in the following way.

[0100] Adopt an interval method, which means preferentially selecting non - adjacent display groups to assign gray values until only adjacent display groups are left and then selecting the remaining display groups.

[0101] For example, referring to Figure 3 , the gray value is 5, Q = 4, the gray value of the first group is 4, and the remaining unassigned gray value (with a size of 1) is preferentially assigned to the third group or the fourth group. Similarly, referring to Figure 4, when L is not equal to 1 (for example, equal to 3), when the gray value is between 5 and 7, the gray value of the first group is 4, and the remaining gray values (with a size of 1 or 2 or 3) are preferentially assigned to the third group; if the gray value is between 8 and 10, the gray value of the first group is 4, and the non-adjacent gray value of the third group is 3. The remaining second group and fourth group are adjacent to the previously selected first group and third group respectively. At this time, the remaining gray values (with a size of 1 or 2 or 3) are only then assigned to the second group or the fourth group.

[0102] In addition, it should be noted that the gray value of each display group in this application should not exceed the pre-set maximum gray threshold. Generally, the maximum gray threshold is set relatively large, and the gray data is limited. Allocating according to the method of this application will not cause the gray value allocated to each display group to overflow.

[0103] The following takes Figure 7 to illustrate some embodiments of this application.

[0104] Taking L = 4 as an example, please refer to Figure 7 , the display data is 6-bit, the number of display groups is 4 groups, and the centralized display gray level Q is 8 levels. When the gray level is less than or equal to 8 levels, it is concentrated in the fourth group for display; when the gray level is 9 / 10 / 11 / 12 levels, 8 levels of gray are concentrated in the fourth group for display, and the remaining 1 / 2 / 3 / 4 levels of gray are allocated to the second group for display; when the gray level is 13 / 14 / 15 / 16 levels, 8 levels of gray are concentrated in the fourth group for display, 4 levels of gray are concentrated in the second group for display, and the remaining 1 / 2 / 3 / 4 levels of gray are allocated to the first group for display; when the gray level is 17 / 18 / 19 / 20 levels, 8 levels of gray are concentrated in the fourth group for display, 4 levels of gray are concentrated in the second group for display, 4 levels of gray are concentrated in the first group for display, and the remaining 1 / 2 / 3 / 4 are allocated to the third group for display; and so on until the gray level 32, and the other 3 groups are all allocated with the centralized display set gray level 8.

[0105] In a second aspect, this application provides an LED display screen, which includes a display panel and the aforementioned LED display screen driving chip.

[0106] The above are only the preferred embodiments of this application. It should be understood that this application is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and alterations made by those skilled in the art that do not depart from the spirit and scope of this application shall fall within the protection scope of the appended claims of this application.

Claims

1. An LED display driving chip, characterized in that, The driving chip is configured to: When the gray value R of the gray data is less than or equal to Q, the gray data is assigned to one of the M display groups; When the gray value R of the gray data is greater than Q, the gray value of one of the M display groups is configured to be P, P ≥ Q, and the sum of the gray values of the remaining M - 1 display groups is R - P; if R - P < (M - 1)*L, the gray values of A display groups among the remaining M - 1 display groups are not less than L, where A is the integer part of (R - P) / L; when R - P ≥ (M - 1)*L, the gray value of each of the remaining M - 1 display groups is at least L; Wherein, among the display groups with non - zero gray values in the remaining M - 1 display groups, the number of display groups with gray values less than L is not greater than 1, L ≥ 1, Q > L, and Q is the centralized display threshold.

2. The LED display driving chip according to claim 1, wherein When Q < R ≤ M*Q, the LED display driving chip is further configured to: When C≥L, the gray value of one of the M display groups is configured as Q + x, where x≥0, and the gray value of the i-th display group among the remaining M - 1 display groups is configured as C + x i , x i ≥0, i ∈ {1, …, M - 1}, where When C < L, the gray value of one of the M display groups is configured as Q + y, where y ≥ 0, and the gray value of the j-th display group among the M - 1 - A display groups is configured as z j , z j ≥ 0, j ∈ {1,..., M - 1 - A}, and when A > 0, the gray value of the k-th display group among the A display groups of the M display groups is configured as L + y k , y k ≥ 0, k ∈ {1,..., A}, When A = 0, Wherein, A and B are respectively the integer part and the remainder part of (R - Q) / L, and C and D are respectively the integer part and the remainder part of (R - Q) / (M - 1).

3. An LED display driving chip according to claim 2, characterized in that, When C < L and A > 0, 4. The LED display driving chip according to claim 2, wherein When C < L, z j ∈ {0, B}.

5. An LED display driving chip according to claim 2, wherein, When C < L, y = B.

6. An LED display driving chip according to claim 2, characterized in that, When C ≥ L, x = 0.

7. An LED display driving chip according to claim 6, characterized in that, x i ∈ {0, 1}, i ∈ {1, …, M - 1}.

8. An LED display driving chip according to any one of claims 2-7, characterized in that, When R > M*Q, the LED display driving chip is configured to: The gray value of the h-th display group among the M display groups is E + f h , h ∈ {1, …, M}, where where E and F are the integer part and the remainder part of R / M, respectively.

9. An LED display driving chip according to claim 8, wherein, f h ∈ {0, 1}, h ∈ {1, …, M}.

10. An LED display screen, characterized in that, Comprising a display panel and an LED display driving chip according to any one of claims 1 - 9.

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