Display module and driving method thereof

Abstract

The application provides a display module and a driving method thereof. For a GOA circuit including two groups of pull-down maintaining modules and outputting scanning driving signals by alternately pulling down, a time switch node of alternately working of the two groups of pull-down maintaining modules is set by a timing controller according to a length of a field blanking period input by a front-end system chip, so that the time switch node is located in the field blanking period, and thus the scanning driving signals can be kept stable at the switching moment of the alternately working of the two groups of pull-down maintaining modules, and a horizontal defect of a display panel is avoided.

Description

TECHNICAL FIELD

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

[0002] At present, the GOA circuit is composed of a plurality of cascaded GOA units, each GOA unit is usually composed of a pull-up control unit, a pull-up unit, a pull-down unit and a pull-down maintenance unit, as shown in FIG. 1, in order to prevent the pull-down transistor in the pull-down maintenance unit for maintaining the low potential of the scan driving signal G(N) from being in high potential for a long time, which is easy to cause electrical drift, resulting in unstable scan driving signal G(N), the pull-down maintenance unit can be composed of two groups of symmetrical pull-down maintenance sub-units, i.e. a first pull-down maintenance sub-unit and a second pull-down maintenance sub-unit, the two groups of symmetrical pull-down maintenance sub-units are controlled by the first low-frequency control signal LC1 and the second low-frequency control signal LC2 in anti-phase to work alternately, so that the pull-down transistors in the two pull-down maintenance sub-units only work for half of the time, thereby reducing the threshold voltage drift of the pull-down transistors in the pull-down maintenance unit, making the scan driving signal G(N) more stable. Figure 1 In combination

[0003] and Figure 1 As shown in FIG. 2, each frame of picture includes a display period (Vd) and a field blanking period (Vb), the first low-frequency control signal LC1 and the second low-frequency control signal LC2 are switched once at a fixed time, and the high and low levels of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 are switched once every N frames, for example, N=200. It should be noted that if the first low-frequency control signal LC1 and the second low-frequency control signal LC2 are switched within the display period (Vd) of a certain frame, as shown in FIG. 3, it will cause the scan driving signal G(N) to be unstable, so that the display panel presents the phenomenon of horizontal defects, including flickering, bright lines and dark lines and other problems, therefore, it is best to make the first low-frequency control signal LC1 and the second low-frequency control signal LC2 switch within the field blanking period (Vb) of a certain frame, to prevent the scan driving signal G(N) from being unstable and make the display panel present the phenomenon of horizontal defects. However, at present, the switching time of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 is fixed, while the length of the field blanking period (Vb) is variable, therefore, it cannot be guaranteed that the first low-frequency control signal LC1 and the second low-frequency control signal LC2 will switch within the field blanking period (Vb) of a certain frame, thus it cannot be guaranteed that the scan driving signal G(N) will remain stable during the pull-down process, so as to avoid the display panel from presenting the phenomenon of horizontal defects. Figure 2 SUMMARY Figure 2 BACKGROUND

[0004] ​To solve the above problems, the display module and the driving method thereof are provided.

[0005] In a first aspect, the display module is provided, comprising a front-end system chip, a timing controller and a GOA circuit connected in sequence, wherein,

[0006] The front-end system chip is configured to input frame parameters to the timing controller, the frame parameters comprising a length of a field blanking period;

[0007] The GOA circuit is configured to output a scan driving signal, and comprises two groups of pull-down maintaining modules, the two groups of pull-down maintaining modules being configured to alternately pull down the scan driving signal;

[0008] The timing controller is configured to set a time switching node at which the two groups of pull-down maintaining modules alternately work according to the length of the field blanking period, so that the time switching node is located within the field blanking period, and set time points at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the time switching node.

[0009] In some embodiments, the length of the time switching node from the beginning of the field blanking period and the length of the time switching node from the end of the field blanking period are both not less than a preset threshold.

[0010] In some embodiments, the timing controller comprises a receiving module, a counting module and a setting module connected in sequence, wherein,

[0011] The receiving module is configured to receive frame parameters sent by the front-end system chip, the frame parameters comprising a length of a field blanking period;

[0012] The counting module is configured to obtain the length of the field blanking period from the frame parameters;

[0013] The setting module is configured to determine a time switching node at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the length of the field blanking period, so that the time switching node is located within the field blanking period.

[0014] In some embodiments, the timing controller further comprises a GOA setting module, an input end of the GOA setting module being connected to the setting module, and an output end of the GOA setting module being connected to the GOA circuit; the GOA setting module is configured to set time points at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the time switching node.

[0015] In some embodiments, the display module further comprises a flash memory connected to the GOA setting module, and the flash memory is configured to store parameters of the GOA circuit except the time switching node.

[0016] In some embodiments, the display module further comprises a source driver, and the timing controller further comprises a source driving module connected to the source driver, and the source driving module is configured to control the source driver to output a data signal.

[0017] In some embodiments, the display module further comprises a power management module, and the power management module is configured to provide power supply for the GOA circuit and the source driver.

[0018] In some embodiments, the display module further comprises a display panel, and the GOA circuit and the source driver are located in a non-display area of the display panel, and the GOA circuit and the source driver are configured to drive pixel units of the display panel to display a picture.

[0019] In the second aspect, the embodiments of the present application further provide a driving method of a display module, configured to drive the display module as described above, and the driving method comprises the following steps of:

[0020] inputting frame parameters into the timing controller through a front-end system chip, and the frame parameters comprise a time length of a field blanking period;

[0021] outputting a scan driving signal through the GOA circuit, and the GOA circuit comprises two groups of pull-down maintaining modules, and the two groups of pull-down maintaining modules are configured to alternately pull down the scan driving signal;

[0022] setting, by the timing controller, a time switching point at which the two groups of pull-down maintaining modules alternately work according to the time length of the field blanking period, so that the time switching node is located in the field blanking period, and setting time points at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the time switching node.

[0023] In some embodiments of the driving method of the display module, the time switching node is located in the field blanking period, and specifically comprises the following steps of:

[0024] making, by the timing controller, the time length from the time switching node to the beginning of the field blanking period and the time length from the time switching node to the end of the field blanking period both not less than a preset threshold.

[0025] The embodiment of the present application provides a display module and a driving method thereof. For a GOA circuit including two groups of pull-down maintaining modules and outputting scanning driving signals by alternately pulling down the two groups of pull-down maintaining modules, a time switch node of alternately working of the two groups of pull-down maintaining modules is set by a timing controller according to a length of a field blanking period input by a front-end system chip, so that the time switch node is located in the field blanking period, and thus the scanning driving signals can be kept stable at the switching moment of the alternately working of the two groups of pull-down maintaining modules, and the phenomenon of horizontal defects of a display panel is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0026] The technical scheme and other beneficial effects of the present application will be apparent through the following detailed description of the specific embodiments of the present application in combination with the accompanying drawings.

[0027] Figure 1 A structural schematic diagram of a GOA circuit including two groups of pull-down maintaining sub-units in the prior art;

[0028] Figure 2 A timing schematic diagram of switching of two groups of pull-down maintaining sub-units in the GOA circuit in the prior art;

[0029] Figure 3 A structural schematic diagram of a driving device of a display panel in the prior art;

[0030] Figure 4 A structural schematic diagram of a display module provided by the embodiment of the present application;

[0031] Figure 5 A timing schematic diagram of switching of two groups of pull-down maintaining modules in a GOA circuit of the display module provided by the embodiment of the present application;

[0032] Figure 6 A structural schematic diagram of a timing controller of the display module provided by the embodiment of the present application;

[0033] Figure 7 Another structural schematic diagram of the display module provided by the embodiment of the present application;

[0034] Figure 8 A flow schematic diagram of a driving method of the display module provided by the embodiment of the present application. DETAILED DESCRIPTION

[0035] As Figure 3 and Figure 4As shown, at present, in the driving device of the display panel, the switching time point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 and the related setting information of the GOA circuit are pre-stored in the flash of the control board. When the display device is powered on, the timing controller TCON obtains the switching time point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 from the flash and transmits it to the GOA circuit, and then to the display panel Cell.

[0036] The length of the display period Vd and the length of the field blanking period Vb of each frame are set by the front-end system chip SOC, as shown in Table 1. Taking a 4K2K@120Hz display panel as an example, the total length of each frame Vt = the length of the display period Vd + the length of the field blanking period Vb. If the length of time required for the GOA circuit to scan each row of pixels is t, the minimum value of the total length of each frame Vt is 2200t, the typical value (median value) is 2250t, and the maximum value is 2350t. If the length of the display period Vd of each frame is 2160t, the minimum value of the length of the field blanking period Vb of each frame is 40t, the typical value (median value) is 90t, and the maximum value is 190t. That is, the length of the field blanking period Vb ranges from 40t to 190t.

[0037] Table 1

[0038]

[0039] That is, in the prior art, the time switching point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 transmitted by the timing controller TCON to the GOA circuit is pre-set in the flash, and the field blanking period Vb is transmitted by the front-end system chip SOC to the timing controller TCON. That is, the time switching point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 is fixed, while the field blanking period Vb may change according to the change of the frame frequency of the transmitted image signal by the front-end system chip SOC. Therefore, the field blanking period Vb is irrelevant to the time switching point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2, which makes the time switching point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 not within the field blanking period Vb even if the time switching point of the first low-frequency control signal LC1 and the second low-frequency control signal LC2 is set within the field blanking period Vb in advance, as shown in Figure 1 Therefore, when the first low-frequency signal LC1 and the second low-frequency signal LC2 are switched, it is easy to cause the scanning driving signal G(N) to be unstable, and the display panel to have a horizontal defect.

[0040] Therefore, in combination with Figure 4 and Figure 5As shown, the embodiment of the present application provides a display module, which comprises a front-end system chip (SOC) 1, a timing controller (TCON) 2 and a GOA circuit 3 connected in sequence, wherein,

[0041] The front-end system chip 1 is configured to input frame parameters to the timing controller 2, and the frame parameters comprise a length Vb of a field blanking period;

[0042] The GOA circuit 3 is configured to output a scan driving signal G(N), and the GOA circuit comprises two groups of pull-down maintaining modules, and the two groups of pull-down maintaining modules are configured to alternately pull down the scan driving signal G(N);

[0043] The timing controller 2 is configured to set a time switching node A at which the two groups of pull-down maintaining modules (controlled by a first low-frequency control signal LC1 and a second low-frequency control signal LC2 respectively) alternately work according to the length Vb of the field blanking period, so that the time switching node A is located within the field blanking period, and set a time point at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the time switching node A.

[0044] Specifically, the front-end system chip 1, the timing controller 2 and the GOA circuit 3 are connected in sequence, the front-end system chip 1 inputs frame parameters to the timing controller 2, the frame parameters generally comprise a total length Vt of each frame, a length Vd of a display period of each frame and a length Vb of a field blanking period of each frame, the timing controller 2 determines a time switching node at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the field blanking period, so that the time switching node A is located within the field blanking period, i.e., a length Vb1 from the beginning of the field blanking period to the time switching node A is less than the length Vb of the field blanking period, thereby ensuring that the two groups of pull-down maintaining modules alternately work within the field blanking period of each frame but not within the display period of each frame, so that the two groups of pull-down maintaining modules do not switch when the scan driving signal G(N) is output, and only switch when the scan driving signal G(N) is not output, thereby ensuring that the scan driving signal G(N) is stable when the two groups of pull-down maintaining modules alternately work in the GOA circuit, and avoiding the phenomenon of horizontal defects of the display panel. Wherein, Figure 5 Vb2 in the formula is a length from the end of the field blanking period to the time switching node A.

[0045] The display module provided by the embodiment of the present application is used for the GOA circuit 3 including two groups of pull-down maintaining modules and outputting the scanning driving signal G(N) by alternately pulling down the two groups of pull-down maintaining modules, and the time switching node A of the alternately working of the two groups of pull-down maintaining modules is set by the timing controller 2 according to the length Vb of the field blanking period input by the front-end system chip 1, so that the time switching node A is located in the field blanking period, and the scanning driving signal G(N) can be kept stable at the switching moment of the alternately working of the two groups of pull-down maintaining modules, and the horizontal bad phenomenon of the display panel is avoided.

[0046] Based on the above embodiment, please continue to refer to Figure 5 , the length Vb1 of the time switching node A from the start of the field blanking period and the length Vb2 of the time switching node from the end of the field blanking period are not less than a preset threshold, that is, the time switching node A is located at a certain distance from the start and the end of the field blanking period, so that a certain buffer interval is left for the alternately working of the two groups of pull-down maintaining modules, that is, a certain action time is left for the alternately working of the two groups of pull-down maintaining modules, so that the switching of the two groups of pull-down maintaining modules in the field blanking period is ensured, thereby preventing the two groups of pull-down maintaining modules from entering the display period before the switching is completed, so that the scanning driving signal G(N) cannot be kept stable. Preferably, the time switching node A can be located at the middle of the field blanking period, that is, the length Vb1 of the time switching node A from the start of the field blanking period is equal to the length Vb2 of the time switching node A from the end of the field blanking period, so that the distance of the time switching node A from the start and the end of the field blanking period is not less than the preset threshold. It should be noted that the preset threshold is generally not less than 10t, and t is the time length required for the GOA circuit to scan each row of pixels.

[0047] Based on the above embodiment, as shown in Figure 6 , the timing controller 2 includes a receiving module 21, a counting module 22 and a setting module 23 connected in sequence, wherein,

[0048] The receiving module 21 is used for receiving the frame parameters sent by the front-end system chip 1, and the frame parameters include the length of the field blanking period;

[0049] The counting module 22 is used for obtaining the length of the field blanking period from the frame parameters;

[0050] The setting module 23 is used for determining the time switching node A of the alternately working of the two groups of pull-down maintaining modules in the GOA circuit according to the length Vb of the field blanking period, so that the time switching node A is in the field blanking period.

[0051] Specifically, the timing controller 2 uses the receiving module 21 to receive the frame parameters sent by the front-end system chip 1, including the duration Vb of the field blanking period. Then, the counting module 22 uses the counting module 22 to obtain the duration Vb of the field blanking period from the frame parameters. Then, the setting module 23 uses the setting module 23 to determine the time switching node A of the two sets of pull-down sustaining modules in the GOA circuit to work alternately according to the duration Vb of the field blanking period, so that the time switching node A is located within the field blanking period.

[0052] Furthermore, such as Figure 6 As shown, the timing controller 2 also includes a GOA setting module 24. The input terminal of the GOA setting module 24 is connected to the setting module 23, and the output terminal of the GOA setting module 24 is connected to the GOA circuit 3 (not shown in the figure). The GOA setting module 24 is used to set the time point for the alternating operation between the two sets of pull-down sustaining modules in the GOA circuit according to the time switching node A.

[0053] Furthermore, such as Figure 6 As shown, the display module also includes a flash memory 4 connected to the GOA setting module. The flash memory 4 is used to store relevant parameters of the GOA circuit other than the time switching node A. That is, compared with the prior art, the flash memory 4 no longer needs to store the relevant parameters of the time switching node A of the two sets of pull-down sustaining modules in the GOA circuit. The timing controller 2 directly determines the position of the time switching node A based on the duration Vb of the field blanking period input by the front-end system chip 1, thereby saving the storage space of the flash memory 4 and reducing the time for the timing controller 2 to import data from the flash memory 4.

[0054] Based on the above embodiments, such as Figure 7 As shown, the display module also includes a source driver 5, and the timing controller 2 also includes a source driver module (not shown in the figure) connected to the source driver 5. The source driver module is used to control the source driver 5 to output data signals.

[0055] For further information, please refer to [link / reference]. Figure 7 The display module also includes a power management module (DC / DC) 6, which provides DC power to the GOA circuit 3 and the source driver.

[0056] For further information, please refer to [link / reference]. Figure 7 The display module also includes a display panel (Cell) 7; the GOA circuit 3 and the source driver 5 are located in the non-display area of ​​the display panel 7, and the GOA circuit 3 and the source driver 5 are used to drive the pixel units of the display panel 7 to display the image.

[0057] Based on the above embodiments, combined with Figure 4 、 Figure 5 and Figure 8 , the present embodiment also provides a driving method of a display module, which is used for driving the display module as described above, and the driving method comprises the following steps:

[0058] S1, inputting a frame parameter to a timing controller 2 through a front-end system chip 1, wherein the frame parameter comprises a time length of a field blanking period;

[0059] S2, outputting a scan driving signal G(N) through a GOA circuit 3, wherein the GOA circuit comprises two groups of pull-down maintaining modules, and the two groups of pull-down maintaining modules alternately pull down the scan driving signal;

[0060] S3, determining a time switching point A at which the two groups of pull-down maintaining modules alternately work according to the time length of the field blanking period through the timing controller 2, so that the time switching point A is located within the field blanking period, and setting time points at which the two groups of pull-down maintaining modules alternately work in the GOA circuit according to the time switching point A.

[0061] The driving method of the display module provided by the present embodiment is used for the GOA circuit 3 comprising two groups of pull-down maintaining modules and alternately pulling down the output scan driving signal G(N) through the two groups of pull-down maintaining modules, and the time switching point A at which the two groups of pull-down maintaining modules alternately work is set according to the time length Vb of the field blanking period input by the front-end system chip 1 through the timing controller 2, so that the time switching point A is located within the field blanking period, thereby making the scan driving signal G(N) stable at the switching moment at which the two groups of pull-down maintaining modules alternately work, and avoiding the phenomenon of horizontal defects of the display panel.

[0062] Further, in the driving method of the display module, the time switching point A is located within the field blanking period, specifically including: making the time length Vb1 from the beginning of the field blanking period and the time length Vb2 from the end of the field blanking period of the time switching point A both not less than a preset threshold through the timing controller 2.

[0063] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0064] The above description of the embodiments is only used to help understand the technical solutions and core ideas of the present application; those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display module, characterized in that, This includes a front-end system chip, a timing controller, and a GOA circuit connected in sequence, wherein, The front-end system chip is used to input frame parameters to the timing controller, and the frame parameters include the duration of the field blanking period; The GOA circuit is used to output a scan drive signal. The GOA circuit includes two sets of pull-down sustaining modules, which are used to alternately pull down the scan drive signal. The timing controller is used to set the time switching nodes for the two sets of pull-down sustaining modules to work alternately according to the duration of the field blanking period, so that the time switching nodes are located within the field blanking period, and to set the time points for the two sets of pull-down sustaining modules to work alternately in the GOA circuit according to the time switching nodes. The timing controller includes a receiving module, a counting module, and a setting module connected in sequence. The receiving module receives the frame parameters sent by the front-end system chip. The counting module obtains the duration of the field blanking period from the frame parameters. The setting module determines the time switching node for the alternating operation of the two sets of pull-down sustaining modules in the GOA circuit based on the duration of the field blanking period, so that the time switching node is located within the field blanking period. The time between the time switching node and the beginning of the field blanking period, and the time between the time switching node and the end of the field blanking period, are both not less than a preset threshold. The preset threshold is not less than 10t, where t is the time required for the GOA circuit to scan each row of pixels.

2. The display module as described in claim 1, characterized in that, The timing controller further includes a GOA setting module, the input of which is connected to the setting module, and the output of which is connected to the GOA circuit. The GOA setting module is used to set the time points at which the two sets of pull-down sustaining modules in the GOA circuit work alternately according to the time switching node.

3. The display module as described in claim 2, characterized in that, It also includes a flash memory connected to the GOA setting module, the flash memory being used to store relevant parameters of the GOA circuit other than the time switching node.

4. The display module as described in claim 1, characterized in that, It also includes a source driver, and the timing controller further includes a source driver module connected to the source driver, the source driver module being used to control the source driver to output data signals.

5. The display module as described in claim 4, characterized in that, It also includes a power management module, which provides power to the GOA circuit and the source driver.

6. The display module as described in claim 4, characterized in that, It also includes a display panel; the GOA circuit and the source driver are located in the non-display area of ​​the display panel, and the GOA circuit and the source driver are used to drive the pixel units of the display panel to display the image.

7. A driving method for a display module, used to drive the display module as described in any one of claims 1-6, characterized in that, The driving method includes: The frame parameters, including the duration of the field blanking period, are input to the timing controller through the front-end system chip. The scan drive signal is output through the GOA circuit, wherein the GOA circuit includes two sets of pull-down sustaining modules, and the two sets of pull-down sustaining modules alternately pull down the scan drive signal; The timing controller sets the time switching points for the two sets of pull-down sustaining modules to work alternately according to the duration of the field blanking period, so that the time switching node is located within the field blanking period, and sets the time points for the two sets of pull-down sustaining modules to work alternately in the GOA circuit according to the time switching node. The timing controller includes a receiving module, a counting module, and a setting module connected in sequence. The step of setting the time switching points for the two sets of pull-down sustaining modules to work alternately based on the duration of the field blanking period, so that the time switching node is located within the field blanking period, includes: receiving the frame parameters sent by the front-end system chip through the receiving module; obtaining the duration of the field blanking period from the frame parameters through the counting module; and determining the time switching nodes for the two sets of pull-down sustaining modules to work alternately in the GOA circuit through the setting module based on the duration of the field blanking period, so that the time switching node is located within the field blanking period. The step of ensuring the time switching node is located within the field blanking period includes: ensuring that the time between the time switching node and the beginning of the field blanking period, and the time between the time switching node and the end of the field blanking period, are both not less than a preset threshold; the preset threshold is not less than 10t, where t is the time required for the GOA circuit to scan each row of pixels.

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