Pre-charging method and circuit, chip and display device

Abstract

The invention discloses a pre-charging method and circuit, a chip and a display device. The pre-charging method comprises the following steps: determining a to-be-started pixel row; generating a first pre-charging voltage according to the to-be-started pixel row, and providing a first pre-charging action for each column line according to the first pre-charging voltage; and a second pre-charging voltage is generated, a second pre-charging action is provided for each column line according to the second pre-charging voltage, the first pre-charging voltage of each pixel row corresponds to the row line load of the pixel row, and the second pre-charging voltage of each pixel row is the same. Through the pre-charging method provided by the invention, the brightness difference of each pixel row caused by the row line load difference can be avoided.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a precharging method, circuit, chip, and display device. Background Art

[0002] With the increasing diversity of application scenarios, richer environments, and continuous improvement of manufacturing processes, special-shaped LED display devices are being used in more and more scenarios and have demonstrated amazing effects in actual use.

[0003] LED display devices typically consist of multiple display modules (light boards), each of which is arranged in an array of LEDs to form an LED display panel. Each LED is connected to a driver circuit via corresponding row and column lines. The driver circuit provides scanning signals to the LEDs via the row lines and driving current via the column lines. When the scanning signal reaches a valid level, the LEDs emit light in response to the driving current.

[0004] The row and column lines are connected in parallel with parasitic capacitance. The charge and discharge problem of parasitic capacitance can be solved by precharging the column lines. Take the five pixel rows R1 to R5 as an example, Figure 1 Figure 2 shows the voltage waveforms of column lines under ideal conditions. Each pixel row corresponds to a row of LEDs. For each pixel row, a precharge voltage is applied to each column line during phase t1, ensuring that each column line maintains the same potential when the pixel row is not turned on. During phase t2, the pixel row is turned on, causing each LED to emit light based on the drive current provided by the corresponding column line.

[0005] Ideally, the same column line should maintain the same pre-charge voltage during the t1 phase before each pixel row turns on. However, in reality, due to various factors such as differences in LED parameters, power supply voltage, and the number of LEDs carried by row and column lines in special-shaped panels, the row line loads vary, resulting in different parasitic capacitances. Due to the different parasitic capacitances of the row lines, if the same column line pre-charge voltage is applied to different pixel rows, the actual potential on the column line will shift during the pre-charge phase and the initial turn-on phase, ultimately leading to inconsistent brightness across the pixel rows. Summary of the Invention

[0006] In view of the above problems, the purpose of this application is to provide a pre-charging method and circuit, chip, and display device that can solve the problem of inconsistent brightness of each pixel row on a display panel.

[0007] According to one aspect of the present application, a precharging method is provided, which includes: determining a pixel row to be turned on; generating a first precharging voltage based on the pixel row to be turned on, and providing a first precharging action to each column line based on the first precharging voltage; and generating a second precharging voltage, and providing a second precharging action to each column line based on the second precharging voltage, wherein the first precharging voltage of each pixel row corresponds to the row line load of the pixel row, and the second precharging voltage of each pixel row is the same.

[0008] Optionally, the step of generating the first pre-charge voltage includes: providing a resistor string, the resistor string having multiple first output nodes for providing each of the first pre-charge voltages; providing a first selection signal according to the pixel row to be turned on; and selecting the first output node corresponding to the pixel row to be turned on according to the first selection signal.

[0009] Optionally, the resistor string has multiple resistors, and the common node of at least some adjacent resistors is the output node of the resistor string. The pre-charging method also includes: obtaining the first output node among the output nodes through a brightness test, and the correspondence between the first output node and the pixel row.

[0010] Optionally, the brightness test of each pixel row includes: before the pixel row is turned on, the output node on the resistor string is selected to provide a test voltage, and the test voltage is used to pre-charge each column line; when the pixel row is turned on, the display brightness of the pixel row is obtained under a set grayscale; and the selected output node is adjusted to adjust the test voltage until the display brightness of the pixel row is consistent with the reference brightness, wherein, for each pixel row, when the display brightness is consistent with the reference brightness, the selected output node is the first output node corresponding to the pixel row.

[0011] Optionally, the resistor string also has a second output node for providing the second pre-charge voltage, and the step of generating the second pre-charge voltage includes: obtaining a first preset time length and a second preset time length for the pixel row to be turned on; after providing the first selection signal of the first preset time length, providing a second selection signal of the second preset time length, and the second selection signal is used to select the second output node.

[0012] Optionally, between each pixel row, the sum of the first preset time length and the second preset time length is the same.

[0013] Optionally, the second pre-charge voltage is the first pre-charge voltage with the largest voltage value.

[0014] According to another aspect of the present application, a pre-charging circuit is provided, wherein the pre-charging circuit includes: a processing unit for determining a pixel row to be turned on; a pre-charging voltage generating unit for generating a first pre-charging voltage and a second pre-charging voltage according to the pixel row to be turned on; and an output unit for providing a first pre-charging action to each column line according to the first pre-charging voltage, and providing a second pre-charging action to each column line according to the second pre-charging voltage, wherein the first pre-charging voltage of each pixel row corresponds to the row line load of the pixel row, and the second pre-charging voltage of each pixel row is the same.

[0015] Optionally, the pre-charge voltage generating unit includes: a resistor string having multiple first output nodes for providing each of the first pre-charge voltages; a selection signal generating module for providing a first selection signal according to the pixel row to be turned on; and a selection module for selecting the first output node corresponding to the pixel row to be turned on according to the first selection signal.

[0016] Optionally, the resistor string also has a second output node for providing the second pre-charge voltage, the selection signal generating module is also used to obtain the first preset time length and the second preset time length corresponding to the pixel row to be turned on, and is used to provide the second selection signal of the second preset time length after providing the first selection signal of the first preset time length to the pixel row to be turned on, and the selection module is also used to select the second output node according to the second selection signal.

[0017] Optionally, between each pixel row, the sum of the first preset time length and the second preset time length is the same.

[0018] According to a third aspect of the present application, a chip is provided, comprising a pre-charging circuit as described in any one of the above items.

[0019] According to a fourth aspect of the present application, a display device is provided, comprising: a display panel comprising a plurality of pixel rows; and a driving circuit for providing a scanning signal and a driving current to each pixel row, the driving circuit also comprising a pre-charging circuit as described in any one of the above items for pre-charging each of the column lines before each of the pixel rows is turned on.

[0020] According to the pre-charging method, circuit, chip, and display device provided in the embodiments of the present application, the pre-charging of each column line is divided into two stages. In the first stage, a first pre-charging voltage related to the row line load of the pixel row to be turned on is provided so that the discharge capacity provided by the first pre-charging voltage corresponds to the parasitic capacitance of the row line. Therefore, the voltage drift of the column line can be avoided, thereby solving the problem of inconsistent brightness of each pixel row, which is conducive to improving the user experience. In the second stage, the same second pre-charging voltage is provided to each pixel row so that the potential of each column line remains consistent when the pixel row is not turned on. When the pixel row is turned on, each column line can synchronously establish a turn-on voltage, which is conducive to further improving the display quality and display stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0022] Figure 1 shows the voltage waveform of the column line under ideal conditions;

[0023] Figure 2 shows a schematic structural diagram of a special-shaped display panel;

[0024] Figure 3 Shown Figure 2 The actual voltage waveform of the special-shaped display panel when it is offline under the traditional pre-charging method is shown;

[0025] Figure 4 A schematic flow chart of the pre-charging method of the present application is shown;

[0026] Figure 5 Shown Figure 2 The actual voltage waveform of the special-shaped display panel when it is offline in the pre-charging method of the present application is shown;

[0027] Figure 6 shows a schematic structural diagram of the pre-charging circuit of the present application;

[0028] Figure 7 Shown Figure 6 A schematic structural diagram of the processing unit;

[0029] Figure 8 Shown Figure 6 A schematic structural diagram of a pre-charge voltage generating unit;

[0030] Figure 9 A schematic structural diagram of the display device of the present application is shown. DETAILED DESCRIPTION

[0031] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, identical elements are represented by identical or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0032] Certain terms are used in this specification and claims to refer to specific components. Those skilled in the art will understand that manufacturers may use different terms to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in their functions.

[0033] It should be understood that in the following description, a "circuit" may include a single or multiple combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by programmable circuits. When an element or circuit is said to be "connected to" another element or an element or circuit is said to be "connected" between two nodes, it can be directly coupled or connected to the other element or there can be intermediate elements. The connection between the elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there are no intermediate elements between the two.

[0034] In addition, it should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0035] It should also be noted that, in the various methods and processes of the present application, the size of the step numbers does not mean the order of execution, nor does it constitute any limitation on the implementation process of the embodiments of the present application.

[0036] For display devices, various factors may contribute to varying row loads. Row load refers to the sum of the equivalent impedance of all load components on a row. The number of load components on a row, their parameters, and structural differences can all contribute to varying row loads. For example, in an LED display device, factors influencing row load include the number of LEDs carried by the row, their electrical parameters, and the length and width of the row.

[0037] The parameters and structure of the load element, as well as the additional capacitance introduced by the load element itself, further lead to differences in parasitic capacitance on the row lines. Therefore, when the row line load varies, the parasitic capacitance of the row line is generally different. During the pixel row switching process, the difference in parasitic capacitance on the row line causes the parasitic capacitance to discharge differently. This results in different brightness levels when each pixel row is turned on when the row line load varies.

[0038] For LED display devices, the difference in the number of LED lamp beads carried by the row line is the main factor causing the difference in row line load. In the following, the difference in the number of LED lamp beads carried by the row line in the special-shaped LED display device is used as an example of the difference in row line load.

[0039] refer to Figure 2 The special-shaped display device 10 includes a driving circuit and a special-shaped display panel. The driving circuit further includes a column driving circuit 11 and a row driving circuit 12.

[0040] The special-shaped display panel includes multiple rows of LEDs. The LED includes an anode and a cathode. When a positive turn-on voltage is applied between the anode and the cathode, the LED lights up. Figure 2 In this example, the common cathode connection of LEDs in the same row is used. That is, the cathodes of the LEDs in the same row are connected to the same row line R, and the anodes are connected to their respective column lines C. For example, row line R1 is connected to 9 LED beads (1-1 to 1-9), row line R2 is connected to 7 LED beads (2-1 to 2-7), row line R3 is connected to 5 LED beads (3-1 to 3-5), row line R4 is connected to 3 LED beads (4-1 to 4-3), and row line R5 is connected to 1 LED (5-1).

[0041] The row driver circuit 12 is connected to each row line R1-R5 and provides scanning signals. The column driver circuit 11 is connected to each column line C1-C9 and provides driving current. During the on-phase of each pixel row, the LED is connected to the active level of the scanning signal via the corresponding row line. The driving current establishes a positive turn-on voltage at the LED anode, thereby illuminating the LED.

[0042] In actual working conditions, parasitic capacitance exists between the row line R and the column line C. The parasitic capacitance Cc of the column line C can be considered to be connected in parallel with the column line C. The parasitic capacitance Cr of the row line R can be considered to be connected in parallel with the row line R. In order to prevent the parasitic capacitance from affecting the display brightness, the display device usually also includes a pre-charge circuit ( Figure 2 ), which is used to provide a pre-charge voltage to each column line during the pre-charge phase of each pixel row to solve the charging and discharging of the parasitic capacitance.

[0043] Figure 3 Shown Figure 2 The actual voltage waveform of the special-shaped display panel under the traditional pre-charging method is shown. Figure 2 and Figure 3 In the traditional pre-charging method, the pre-charging voltage provided to each column line is the same during the pre-charging phase of different pixel rows. However, due to the decreasing number of LEDs on the row lines R1~R5, the parasitic capacitances Cr1~Cr5 on the row lines R1~R5 are different, which will cause the actual voltage on the column line to deviate from the pre-charging voltage during the pre-charging phase of different pixel rows. For example, Figure 3 In the black portion of each t1 phase, the greater the load on the row line, the lower the actual voltage on the column line during the pre-charge phase. This results in different initial column line voltages during the t2 phase when each pixel row is turned on. This causes different voltages between the anode and cathode of the LEDs when different pixel rows are turned on, resulting in different brightness levels for each pixel row.

[0044] To solve this problem, the present application provides a pre-charging method. Figure 4 Schematic flow chart of the pre-charging method of the present application is shown. Figure 4 , the pre-charging method provided in this application includes:

[0045] Step S11, determining the pixel row to be turned on;

[0046] In some embodiments, the pixel row to be turned on may be determined according to a row signal.

[0047] Specifically, the row signal includes multiple pulse signals, and each pixel row on the display panel is sequentially turned on according to the pulse signals. Accordingly, step S11 may include: obtaining the row signal; counting the multiple pulse signals in the row signal to obtain a count value; and determining the pixel row to be turned on based on the count value and the number of pixel rows on the display panel.

[0048] More specifically, in some embodiments, the pixel row to be turned on may be determined based on the remainder of the quotient of the count value and the number of pixel rows. In some other embodiments, in order to reduce computing resources, the count value may be reset each time the count value corresponds to the number of pixel rows of the display panel, so that the currently turned-on pixel row can be directly indicated by the count value, and the pixel row to be turned on can be obtained. For example, there are s pixel rows on the display panel. In the display process of row-by-row drive, the pixel rows from row 1 to row s are turned on in sequence according to the pulse signal in the row signal. If a pulse signal is detected in the row signal, the count value is increased by 1. Then, when the first pulse signal in the row signal is detected, the count value is 1, indicating that the first row of pixels is currently turned on and the second row of pixels to be turned on; when the second pulse signal in the row signal is detected, the count value is 2, indicating that the second row of pixels is currently turned on and the third row of pixels to be turned on... When the sth pulse signal in the row signal is detected, the count value is s, indicating that the sth row of pixels is currently turned on and the first row of pixels to be turned on; when the s+1th pulse signal in the row signal is detected, the count value is reset to 1, indicating that the first row of pixels is currently turned on and the second row of pixels to be turned on, and so on.

[0049] In step S12 , a first pre-charging voltage is generated according to the pixel row to be turned on, and a first pre-charging operation is provided to each column line according to the first pre-charging voltage.

[0050] The first precharge voltage provided in step S12 corresponds to the row line load of the pixel row to be turned on. Specifically, the first precharge voltage and the row line load of the pixel row to be turned on, that is, the sum of the equivalent impedances of all load elements on the row line, are positively correlated.

[0051] The step of generating a first pre-charge voltage may include: providing a resistor string having multiple first output nodes for providing a first pre-charge voltage for each pixel row; providing a first selection signal according to the pixel row to be turned on and selecting the first output node corresponding to the pixel row to be turned on according to the first selection signal.

[0052] The resistor string has multiple resistors, and the common nodes of at least some adjacent resistors serve as output nodes of the resistor string. In order to make the pre-designed resistor string universal, the number of output nodes on the resistor string can be greater than the number of rows. Accordingly, before step S12, the pre-charging method provided by the present application further includes: obtaining a first output node among the output nodes on the resistor string by testing the brightness of each pixel row, and the corresponding relationship between the first output node and the pixel row.

[0053] Furthermore, the brightness test step includes: for each pixel row, before the pixel row is turned on, switching on an output node on the resistor string to provide an initial test voltage and precharging each column line; when the pixel row is turned on, obtaining the display brightness of the pixel row at a set grayscale. Subsequently, adjusting the selected output node based on the comparison result of the display brightness of the pixel row at the set grayscale with a reference brightness, thereby adjusting the test voltage until the display brightness is the same as the reference brightness. In this case, the selected output node is the first output node corresponding to the pixel row.

[0054] It should be noted that the output node that is first strobed can be any output node in the resistor string. In some other embodiments, an output node can be selected based on the approximate range of the first pre-charge voltage as the output node that is first strobed when performing brightness testing on each pixel row, which is more conducive to saving testing time.

[0055] The brightness test described above can be performed during the production phase of the display device. In some embodiments, after obtaining the first output node in the resistor string and the correspondence between the first output node and each pixel row, the correspondence is stored so that the first selection signal corresponding to the pixel row to be turned on can be generated based on the correspondence during the pre-charge phase. In other embodiments, the first selection signal corresponding to each pixel row can be directly stored based on the correspondence so that the first selection signal corresponding to the pixel row to be turned on can be directly provided during the pre-charge phase.

[0056] Furthermore, during the brightness test, the row line precharge process consists of only one phase, and the initial values ​​of the test voltages and the effective levels of the scan signals supplied to each column line are identical. This means that changes in display brightness during the brightness test are only related to the test voltage during the precharge phase.

[0057] In some embodiments, if the initial test voltage for each pixel row during the brightness test is the same, that is, the output node that is first enabled during the brightness test for different pixel rows is the same, then the reference brightness during the brightness test can be the minimum or mode brightness displayed by each pixel row at a set grayscale when pre-charged according to the initial test voltage. For example, in a display panel, the row line loads of most pixel rows are typically the same within a set acceptable deviation range, and the brightness of these pixel rows is therefore considered to be the same. The display brightness corresponding to the pixel rows with the same row line load and a larger proportion (i.e., the mode of the display brightness) can be used as the reference brightness. In particular, for special-shaped display panels, which include a larger conventional area and a smaller special-shaped area, the row line loads of each pixel row in the conventional area are generally considered to be the same, but different from the row line loads of the pixel rows in the special-shaped area. In this case, the mode of the display brightness can be used as the reference brightness. In other words, the display brightness of each pixel row in the conventional area can be used as the reference brightness, so further test voltage adjustment is only required for the smaller special-shaped area, which can improve testing efficiency. For another example, the minimum value of the above-mentioned display brightness can be used as the reference brightness. Under the same conditions, the pixel row with the smallest display brightness has the largest row line load, and its corresponding pre-charge voltage is also the largest, so the initial test voltage is the maximum value of the pre-charge voltage. In the subsequent adjustment process, the test voltage can be lowered according to the changes in the above-mentioned display brightness, and the pre-charge voltage of each pixel row can be obtained. By comparing one by one with the minimum value of the display brightness, the pre-charge voltage of each pixel row can be made more accurate. In actual working conditions, the reference value of the above-mentioned display brightness can be selected in combination with factors such as display effect requirements and time cost.

[0058] Step S13 , generating a second pre-charging voltage, and providing a second pre-charging operation to each column line according to the second pre-charging voltage, wherein the second pre-charging voltage corresponding to each pixel row is the same.

[0059] After the first pre-charging action, the second pre-charging action is performed to improve the voltage consistency of each column line, so that when the pixel row is turned on, each column line can synchronously establish the LED turn-on voltage, which is beneficial to further improve the display quality and display stability.

[0060] It should be noted that since the row line loads of each pixel row are different, the second pre-charge voltage can be greater than, equal to, or less than the first pre-charge voltage. However, it should be understood that both the first pre-charge voltage and the second pre-charge voltage should be less than the LED turn-on voltage, that is, the column line voltage when the pixel row is turned on.

[0061] In some embodiments, the second pre-charge voltage may also be provided by the resistor string provided in step S12. That is, the resistor string provided in step S12 further has a second output node for providing the second pre-charge voltage. Accordingly, after setting the voltage value of the second pre-charge voltage, the second output node in the resistor string and the corresponding second selection signal may be obtained. The second output node and / or the second selection signal may be stored together with the above-mentioned corresponding relationship.

[0062] In a preferred embodiment, in order to simplify the circuit, the maximum value of the first pre-charge voltage can be selected as the second pre-charge voltage. In other words, the first output node (hereinafter referred to as the maximum node) corresponding to the maximum voltage value of the first pre-charge voltage is also the second output node. Accordingly, the first selection signal for selecting the maximum node is also the second selection signal. In some other embodiments, the second pre-charge voltage can also be selected according to actual needs, and this application does not impose too many restrictions.

[0063] In the embodiments of the present application, the durations of the first and second pre-charging operations may be different between pixel rows, but the sum of the durations of the first and second pre-charging operations, i.e., the total pre-charging duration, is the same. For example, if the total pre-charging duration for each pixel row is 10 μs, the first pre-charging operation for the first pixel row may be 7 μs, and the second pre-charging operation may be 3 μs; and the first and second pre-charging operations for the second pixel row may both be 5 μs.

[0064] Furthermore, in an embodiment of the present application, the step of generating the second pre-charge voltage may further include: obtaining a first preset duration and a second preset duration for the pixel row to be turned on; and providing a second selection signal of a second preset duration after providing a first selection signal of the first preset duration. The first preset duration is the duration of the first pre-charge action corresponding to the pixel row to be turned on, and the second preset duration is the duration of the second pre-charge action corresponding to the pixel row to be turned on.

[0065] Specifically, in some embodiments, since the resistor string is pre-designed, in the above-mentioned brightness test, there may not be an output node that makes the display brightness completely consistent with the reference brightness. Then for the pixel row currently undergoing the brightness test, the output node whose display brightness is closest to the reference brightness among the output nodes can be used as the first output node corresponding to the pixel row. Thereafter, the display brightness is made completely consistent with the reference brightness by adjusting the duration of the first pre-charging action. At this time, the duration of the first pre-charging action is the first preset duration of the current pixel row. Since the total duration of the pre-charging is certain, after the first preset duration is determined, the second preset duration is also determined at any time. Similarly, the first preset duration and the second preset duration obtained from each pixel row test can also be stored in a memory, and the first preset duration and the second preset duration are read in the pre-charging stage, and compared with the actual duration of providing the first selection signal and the second selection signal to obtain the best display effect. It should be pointed out that in the case where there is an output node that makes the display brightness completely consistent with the reference brightness, after determining the corresponding relationship of the response, the first preset time length and the second preset time length can be set with reference to the actual working conditions. For example, the first preset time length and the second preset time length can be equal, or the first preset time length can be half of the second preset time length. This application does not impose too many restrictions.

[0066] Figure 5 Shown Figure 2 The actual voltage waveform of the special-shaped display panel under the pre-charging method of this application is shown. Figure 5 For each row of pixels, in the T1 stage, pre-charging is provided to the column line according to the pre-charging method provided in this application; in the T2 stage, the pixel row is turned on.

[0067] Furthermore, for each row of pixels, the pre-charge phase T1 is further divided into a first phase t11 and a second phase t12. The load corresponding to the row lines R1~R5 decreases in sequence, and the first pre-charge voltages V11, V12, V13, V14 and V15 of each pixel row also decrease in sequence. And as an example, the maximum value V11 among the first pre-charge voltages is used as the second pre-charge voltage V2. After experiencing the first phase t11, the residual charge of the parasitic capacitance on the row line is discharged. Therefore, in the second phase t12, providing the second pre-charge voltage V2 to each row line will not affect the subsequent display. And since the second pre-charge voltage V2 is also the maximum first pre-charge voltage V11, the potential of the row lines R2~R4 can be further raised, which is more conducive to shortening the turn-on time of subsequent pixel rows.

[0068] According to the pre-charging method provided in the embodiment of the present application, the pre-charging of each column line is divided into two stages. In the first stage, a first pre-charging voltage related to the row line load of the pixel row to be turned on is provided so that the discharge capacity provided by the first pre-charging voltage corresponds to the parasitic capacitance of the row line. Therefore, the voltage drift of the column line can be avoided, thereby solving the problem of inconsistent brightness of each pixel row, which is conducive to improving the user experience. In the second stage, the same second pre-charging voltage is provided to each pixel row so that the potential of each column line remains consistent when the pixel row is not turned on. When the pixel row is turned on, each column line can synchronously establish a turn-on voltage, which is conducive to further improving display quality and display stability.

[0069] The present application also provides a pre-charging circuit, which can be used to implement the pre-charging method provided above. Figure 6 The schematic structure diagram of the pre-charging circuit of the present application is shown in FIG. Figure 6 The pre-charge circuit of this application is applied to Figure 2 The illustrated special-shaped display device is used as an example, and the connection conditions of the column lines C1 , C3 and C5 are shown as examples.

[0070] Combine Figure 2 and Figure 6 The row driving circuit 12 is used to provide a valid scanning signal to the pixel row via the row line to turn on the pixels in the pixel row; the column driving circuit 11 is used to provide a driving current to the turned-on pixels via the corresponding column line to make the pixels emit light.

[0071] Specifically, the row driver circuit 12 includes multiple row transistors RS. Each row transistor RS is connected to a corresponding row line. When the row transistor RS is turned on, the corresponding row line receives a valid scan signal. The column driver circuit 11 includes multiple current sources I. Each current source I is connected to a corresponding column line via a corresponding column transistor CS.

[0072] exist Figure 6 In the example shown, the anodes of each column of LEDs are connected via a column line C. When the column transistor CS is on, the current source I provides a constant current output, thereby establishing a forward voltage on the column line C, that is, the anodes of each LED connected to that column line. The cathodes of each row of LEDs are connected via a row line R. When the row transistor RS is on, a current path is provided for the LEDs on the corresponding row line. When both the column transistor CS and the row transistor RS are on, the LEDs on the corresponding row and column lines are illuminated.

[0073] The pre-charge circuit includes a processing unit 121 , a pre-charge voltage generating unit 122 , and an output unit corresponding to each column line C.

[0074] The processing unit 121 is used to determine the pixel rows to be turned on. In some embodiments, the processing unit 121 can obtain the pixel rows to be turned on based on the row signal. The row signal includes multiple pulse signals, and the pixel rows on the display panel are turned on in sequence based on the pulse signals. Figure 7 Schematic diagram of the processing unit 121 is shown. Figure 7 , the processing unit 121 includes: a counter 121a, a comparator 121b and an output module 121c. The counter 121a is used to count the pulse signals in the row signal and obtain a count value Cn. The comparator 121b is used to compare the count value Cn with the number of pixel rows of the display panel, and provide a reset signal to reset the count value Cn when the count value Cn corresponds to the number of pixel rows of the display panel. The output module 121c is used to provide a determined pixel row to be turned on according to the count value Cn, specifically, it can be to provide the row number of the pixel row to be turned on. For example, there are a total of s pixel rows on the display panel. In the display process of row-by-row drive, the pixel rows from the 1st row to the sth row are turned on in sequence according to the corresponding pulse signals in the row signal. If a pulse signal is detected in the row signal, the count value Cn is increased by 1. Then, when the first pulse signal in the row signal is detected, the count value is 1, indicating that the first row of pixels is currently turned on and the second row of pixels to be turned on; when the second pulse signal in the row signal is detected, the count value is 2, indicating that the second row of pixels is currently turned on and the third row of pixels to be turned on... When the sth pulse signal in the row signal is detected, the count value is s, indicating that the sth row of pixels is currently turned on and the first row of pixels to be turned on; when the s+1th pulse signal in the row signal is detected, the count value is reset to 1, indicating that the first row of pixels is currently turned on and the second row of pixels to be turned on, and so on.

[0075] The precharge voltage generating unit 122 is used to generate a first precharge voltage and a second precharge voltage. The first precharge voltage of each pixel row corresponds to, for example, a row line load and is positively correlated. The second precharge voltage of each pixel row is the same.

[0076] Figure 8 1 shows a schematic structural diagram of the pre-charge voltage generating unit 122. Figure 8 The pre-charge voltage generating unit 122 includes a resistor string 122a, a selection module 122b and a selection signal generating module 122c.

[0077] The resistor string 122a includes a plurality of first output nodes for providing a first precharge voltage VR1 for each pixel row. Figure 6The resistor string 122a includes five row lines R1-R5 with different loads. The resistor string 122a may include resistors R1-R6. A first output node is defined between any two connected resistors. The resistance values ​​of each resistor can be calculated using the method described in step S12. In some embodiments, the resistor string 122a further includes a second output node for providing a second pre-charge voltage VR2.

[0078] It should be noted that although Figure 8 The example resistor string 122a includes six resistors R1 through R6, with the common node between any two adjacent resistors serving as the first output node corresponding to different rows. However, it should be understood that in actual operation, the resistor string 122a may include more resistors, with the common nodes between at least some of the adjacent resistors serving as the output nodes of the resistor string, and the first output node and / or the second output node serving as only a portion of these output nodes. In other words, the number of output nodes in the resistor string may be greater than the number of first output nodes and / or second output nodes.

[0079] The selection signal generation module 122c is configured to provide a first selection signal based on the pixel row to be enabled. This first selection signal is used to close the corresponding switch element K in the selection module 122b to enable the first output node corresponding to the pixel row to be enabled in the resistor string 122a. Furthermore, the selection signal generation module 122c is configured to provide a second selection signal to close the corresponding switch element in the selection module 122b to enable the second output node in the resistor string 122a.

[0080] The correspondence between each first output node in the resistor string and between the first output node and the pixel row can be obtained by referring to the brightness test described above. In some embodiments, this correspondence can be stored in the selection signal generation module 122c, so that the selection signal generation module 122c provides the first selection signal corresponding to the pixel row to be turned on based on this correspondence. In other embodiments, the first selection signal corresponding to each pixel row can be directly stored in the selection signal generation module 122c. After obtaining the pixel row to be turned on, the display device can directly read the selection signal generation module 122c to provide the corresponding first selection signal.

[0081] In addition, the selection signal generating module 122 c may also store the second selection signal or the corresponding relationship with the second output node to provide the second selection signal in the pre-charging stage.

[0082] In a preferred embodiment, to simplify the circuit, the maximum value among the first pre-charge voltages can be selected as the second pre-charge voltage. In other words, the first output node (hereinafter referred to as the maximum node) corresponding to the maximum voltage value among the first pre-charge voltages is also the second output node. Accordingly, the first selection signal that selects the maximum node is also the second selection signal.

[0083] Furthermore, the selection signal generating module 122c may be a module that provides a second selection signal of a second preset duration after providing a first selection signal of a first preset duration to the pixel row to be turned on. That is to say, after providing a first pre-charging action of a first preset duration to the pixel row to be turned on, a second pre-charging action of a second preset duration is provided to the pixel row to be turned on. It should be noted that the first preset duration and the second preset duration corresponding to each pixel row may be the same or / different, but the sum of the first preset duration and the second preset duration corresponding to each pixel row is the same. That is to say, the total duration of pre-charging of each pixel row is the same. The first preset duration and the second preset duration of each pixel row can be specifically obtained with reference to the brightness test method described above.

[0084] Accordingly, the pre-charge voltage generating unit 122 may further include a timing module 122d and a comparison module 122e. The timing module 122d is configured to start timing when the selection signal generating module 122c generates the first selection signal and the second selection signal, and the comparison module 122e is configured to compare the timing duration with the first preset duration or the second preset duration, thereby achieving duration control of the first pre-charge action and the second pre-charge action.

[0085] The output unit corresponding to each column line C includes an operational amplifier OP and a precharge switch CK. The inverting input and output of the operational amplifier are connected to form a voltage follower. The non-inverting input of the operational amplifier is connected to the precharge voltage generation unit to receive the first precharge voltage or the second precharge voltage. Before the corresponding column transistor CS turns on, the precharge switch CK turns on, and the operational amplifier OP clamps the voltage on the column line to the corresponding first precharge voltage or second precharge voltage, thereby providing the first precharge action or the second precharge action.

[0086] Furthermore, the present application also provides a chip, which may include the above pre-charging circuit and be used to implement the pre-charging method provided in the present application. Therefore, the chip also has any of the above-mentioned beneficial effects.

[0087] Furthermore, the present application also provides a display device. Figure 9 Schematic diagram of the structure of the display device of the present application is shown. Figure 9 , the display device 1 includes a driving circuit 100 and a display panel 200 .

[0088] The display panel 200 includes multiple pixel rows, each pixel row includes multiple pixel units. It should be understood that the display panel 200 can be composed of multiple display modules. Figure 9 , four display modules I to IV are shown as examples, wherein display modules I and IV are special-shaped modules, and display modules II and III are conventional rectangular modules.

[0089] The driver circuit 100 is used to provide scanning signals and drive currents for each pixel row. Specifically, the driver circuit 100 may include a driver chip 110 corresponding to each display module. More specifically, each driver chip includes corresponding row driver circuits and column driver circuits. Each driver chip also includes the above-mentioned pre-charge circuit, which is used to provide a first pre-charge voltage and a second pre-charge voltage based on the row line load before each pixel row is turned on, thereby pre-charging the column line.

[0090] In some embodiments, the first pre-charge voltage for each pixel row in each display module can be obtained through a preliminary brightness test. The second pre-charge voltage for each pixel row in each display module is the same. Furthermore, as in the above example, the first pre-charge voltage for each pixel row in conventional display modules II and III can be the same as the second pre-charge voltage. Therefore, the pre-charge method provided by this application can be implemented by simply storing the above correspondence in the corresponding drive circuits of special-shaped display modules I and IV, which is more conducive to cost savings.

[0091] According to the pre-charge circuit, chip, and display device provided in the embodiments of the present application, the pre-charging of each column line is divided into two stages. In the first stage, a first pre-charge voltage related to the row line load of the pixel row to be turned on is provided so that the discharge capacity provided by the first pre-charge voltage corresponds to the parasitic capacitance of the row line. Therefore, the voltage drift of the column line can be avoided, thereby solving the problem of inconsistent brightness of each pixel row, which is conducive to improving the user experience. In the second stage, the same second pre-charge voltage is provided to each pixel row so that the potential of each column line remains consistent when the pixel row is not turned on. When the pixel row is turned on, each column line can synchronously establish a turn-on voltage, which is conducive to further improving display quality and display stability.

[0092] It should be noted that although the examples above primarily focus on irregular display panels, where the number of LEDs loaded on rows varies, it should be understood that the pre-charging method, circuit, chip, and display device provided herein can also be used in situations where row loads vary due to other factors, such as differences in lamp bead parameters. Furthermore, the pre-charging method, circuit, chip, and display device provided herein can also be used in LED display panels with a common anode connection.

[0093] The embodiments of the present application are as described above, and these embodiments do not describe all details in detail, nor do they limit the present application to specific embodiments. Obviously, based on the above description, many modifications and variations can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The scope of protection of the present application shall be based on the scope defined by the claims of the present application.

Claims

1. A pre-charging method, wherein: include: Determine the pixel row to be turned on; generating a first pre-charge voltage according to the pixel row to be turned on, and providing a first pre-charge action to each column line according to the first pre-charge voltage; as well as generating a second precharge voltage, and providing a second precharge action to each of the column lines according to the second precharge voltage, The first pre-charge voltage of each pixel row corresponds to the row line load of the pixel row, and the second pre-charge voltage of each pixel row is the same.

2. The pre-charging method according to claim 1, wherein The step of generating the first pre-charge voltage includes: Providing a resistor string, the resistor string having a plurality of first output nodes for providing each of the first pre-charge voltages; Providing a first selection signal according to the pixel row to be turned on; and The first output node corresponding to the pixel row to be turned on is selected according to the first selection signal.

3. The pre-charging method according to claim 2, wherein: The resistor string has a plurality of resistors, and the common node of at least some adjacent resistors is the output node of the resistor string. The pre-charging method further includes: obtaining the first output node among the output nodes and a corresponding relationship between the first output node and the pixel row through a brightness test.

4. The pre-charging method according to claim 3, wherein: The brightness test for each row of pixels includes: Before the pixel row is turned on, the output node on the resistor string is turned on to provide a test voltage, wherein the test voltage is used to precharge each of the column lines; When the pixel row is turned on, obtaining the display brightness of the pixel row at a set grayscale; and Regulating the selected output node to adjust the test voltage until the display brightness of the pixel row is consistent with the reference brightness, For each pixel row, when the display brightness is consistent with the reference brightness, the output node that is selected is the first output node corresponding to the pixel row.

5. The pre-charging method according to claim 3, wherein: The resistor string further has a second output node for providing the second pre-charge voltage. The step of generating the second pre-charge voltage includes: Obtaining a first preset duration and a second preset duration of the pixel row to be turned on; After the first selection signal of the first preset duration is provided, a second selection signal of the second preset duration is provided, where the second selection signal is used to select the second output node.

6. The pre-charging method according to claim 5, wherein: Between each of the pixel rows, the sum of the first preset time length and the second preset time length is the same.

7. The pre-charging method according to claim 1, wherein: The second pre-charge voltage is the first pre-charge voltage having the largest voltage value.

8. A pre-charging circuit, wherein: The pre-charging circuit comprises: A processing unit, configured to determine a pixel row to be turned on; a pre-charge voltage generating unit, configured to generate a first pre-charge voltage and a second pre-charge voltage according to the pixel row to be turned on; and an output unit, configured to provide a first pre-charging action to each column line according to the first pre-charging voltage, and to provide a second pre-charging action to each column line according to the second pre-charging voltage, The first pre-charge voltage of each pixel row corresponds to the row line load of the pixel row, and the second pre-charge voltage of each pixel row is the same.

9. The precharge circuit according to claim 8, wherein: The pre-charge voltage generating unit includes: a resistor string having a plurality of first output nodes for providing each of the first pre-charge voltages; A selection signal generating module, configured to provide a first selection signal according to the pixel row to be turned on; and A selection module is configured to select the first output node corresponding to the to-be-enabled pixel row according to the first selection signal.

10. The precharge circuit according to claim 9, wherein: The resistor string further has a second output node for providing the second pre-charge voltage. The selection signal generating module is further configured to obtain a first preset duration and a second preset duration corresponding to the pixel row to be turned on, and to provide a second selection signal of the second preset duration after providing the first selection signal of the first preset duration to the pixel row to be turned on. The selection module is further configured to select the second output node according to the second selection signal.

11. The precharge circuit according to claim 10, wherein: Between each of the pixel rows, the sum of the first preset time length and the second preset time length is the same.

12. A chip, wherein: Comprising a pre-charging circuit as described in any one of claims 8-11.

13. A display device, wherein: include: a display panel comprising a plurality of pixel rows; as well as A driving circuit for providing a scanning signal and a driving current to each pixel row, wherein the driving circuit further comprises a pre-charging circuit as described in any one of claims 8 to 11 for pre-charging each column line before each pixel row is turned on.

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