TWI814597B - Driving device of display panel - Google Patents

Abstract

A driving device can be switched in different frame rates to drive a display panel for display. The driving device has a gate driver connected to a plurality of gate lines to tum on the gate lines in sequence. When the display panel is switched from a first frame rate to a second frame rate smaller than the first frame rate for display, the display time in the frame period corresponding to the second frame rate is set to be the same as the display time in the frame period corresponding to the first frame rate, the V-blanking period in the frame period corresponding to the second frame rate is set as the V-blanking period in the frame period corresponding to the first frame rate plus an extended V-blanking period, and the extended V-blanking period is divided into a plurality of extended V-blanking fragments that are distributed in the display time of the frame period corresponding to the second frame rate.

Description

Display panel driving device

The present invention relates to a driving device for a display panel, and in particular, to a driving device that can maintain the display brightness of the display panel when switching between a high frame rate and a low frame rate.

In the application of in-cell touch display panels, when the display frame rate of the panel switches from a high frame rate to a low frame rate, in order to reduce the change in visual effects of the panel to The minimum is usually during the frame period, so that the display and touch working time of the panel after switching remains unchanged from the display and touch working time before switching, only by changing the vertical blanking (V- Blanking) period is used to achieve frame period changes, thereby making the charging time of the frame periods corresponding to different frame rates consistent, thereby reducing the impact of frame rate switching on visual effects.

Figure 1 shows a schematic diagram of the frame period when the frame rate of a display panel is switched from 120Hz to 60Hz. As mentioned above, in order to minimize the change in visual effects of the panel, the display and touch screen during the frame period corresponding to the 60Hz frame rate are The working time of the control remains unchanged from the display and touch working time of the frame period of the 120Hz frame rate, but the vertical blanking period corresponding to the frame period of the 60Hz frame rate is increased to match the length of the frame period. However, during this increased vertical blanking period, there is no charging and scanning action on the panel. Taking the 120Hz frame rate as an example, the charging time of the thin film transistor (TFT) element of the panel is about 8.3ms. When the frame rate switches to 60Hz, Then there will be an extra 8.3ms vertical blanking period during the entire frame period. Since the TFT elements of the panel are not charged during the vertical blanking period, an excessively long vertical blanking period will cause leakage problems in the TFT elements of the panel, especially In a high-temperature environment, the leakage problem will be aggravated, which will seriously affect the display quality.

Therefore, there are still many shortcomings in the design of the driving device of the conventional display panel and it is necessary to improve them.

The main purpose of the present invention is to provide a display panel driving device that can solve the problem of leakage in the TFT elements of the panel caused by the increase in the vertical blanking period when the display panel switches from a high frame rate to a low frame rate.

In order to achieve the above object, the present invention proposes a driving device for switching different frame rates to drive a display panel for display. The display panel has a plurality of gate lines, one frame rate corresponds to one frame period, and one frame period has a During the display time and a vertical blanking period, the driving device has a gate driver connected to the plurality of gate lines to sequentially turn on the plurality of gate lines, wherein when the display panel changes from a first frame rate When switching to a second frame rate that is smaller than the first frame rate for display, the display time in the frame period corresponding to the second frame rate is set to be the same as the display time in the frame period corresponding to the first frame rate, The vertical blanking period in the frame period corresponding to the second frame rate is set to the vertical blanking period in the frame period corresponding to the first frame rate plus an extended vertical blanking period, and the extended vertical blanking period is divided into A plurality of extended vertical blanking segments are distributed in the display time of the frame period corresponding to the second frame rate.

The above overview and the detailed description that follows are exemplary in nature and are intended to further The patentable scope of the present invention is further explained, and other objects and advantages of the present invention will be explained in the subsequent descriptions and drawings.

11:Driving device

13:Display panel

111: Gate driver

113: Source driver

115: Timing control unit

GL: gate line

DL: source line

Px: pixel

15:Touch controller

Vsync: vertical synchronization time

DISP,DISP_1,D1SP_2: display time

VB, VB_1, VB_2: vertical blanking period

GT: Gate line opening time period

TP, TP_1, TP_2: touch period

EVB: extended vertical blanking period

S: Extended vertical blanking segment

Figure 1 shows a schematic diagram of the frame period when the frame rate of a display panel is switched from 120 Hz to 60 Hz.

FIG. 2 shows a schematic diagram of driving a display panel using the driving device of the present invention.

FIG. 3 shows a schematic structural diagram of a frame period for driving a display panel to perform display.

FIG. 4 shows a schematic structural diagram of a frame period corresponding to a low frame rate for driving a display panel to switch from a high frame rate to a low frame rate for display.

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the implementation of the present invention and are not intended to limit the present invention.

FIG. 2 shows a schematic diagram of driving a display panel 13 with the driving device 11 of the present invention. The driving device 11 includes a gate driver 111, a source driver 113 and a timing control unit 115. The timing control unit 115 is connected to the gate. The driver 111 and the source driver 113 control the gate driver 111 and the source driver 113 to perform display driving. The display panel 13 has a plurality of gate lines GL, a plurality of source lines DL, and a plurality of pixels Px located respectively at a plurality of At the intersection of the gate lines GL and the plurality of source lines DL, the gate driver 111 is connected to the plurality of gate lines GL, and the source driver 113 is connected to the plurality of gate lines DL. The source line DL is used for displaying on the display panel 13. The timing control unit 115 can control the gate driver 111 to turn on a plurality of gate lines GL in sequence. That is, each gate line GL is connected to a corresponding gate line DL. The line-on period GT is turned on, and the source driver 113 is controlled to write display data into the pixel Px corresponding to the turned-on gate line GL through a plurality of source lines DL.

Optionally, the aforementioned display panel 13 can also be a display panel that provides a touch sensing function. For example, a common electrode of the display panel 13 is cut to serve as a touch sensor (not shown). The touch sensor senses the user's fingers. The touch signal is transmitted to the touch controller 15 for touch detection to realize the touch sensing function. Cutting the common electrode as a touch sensor is known to those skilled in the art, so it will not be described again here. That is to say, in one embodiment, the display panel 13 may be a touch display panel provided with functions such as touch sensing and display.

Driven by the aforementioned driving device 11, the display panel 13 can switch to different frame rates for display, where one frame rate corresponds to one frame period, and one frame period has a display time, a vertical elimination A hidden period and a vertical synchronization time, wherein the display time includes a plurality of gate line turn-on time periods. Therefore, as shown in FIG. 3 , a frame period in which the driving device 11 drives the display panel 13 to display includes the vertical synchronization time Vsync, the display time DISP and the vertical blanking period VB, where the length of the display time DISP is a plurality of gates. The sum of the gate line turn-on periods GT of line GL, and when the display panel 13 provides a touch function, the aforementioned vertical blanking period VB serves as the touch period TP for touch sensing.

Specifically, the aforementioned display panel 13 can switch from a first frame rate to a second frame rate for display, wherein the second frame rate is lower than the first frame rate. For example, but not limited to, the first frame rate can be 120 Hz, The second frame rate may be 60Hz. As shown in Figure 4, according to the previous description, When the display panel 13 displays at a first frame rate, the frame period corresponding to the first frame rate includes the vertical synchronization time Vsync, the display time DISP_1 and the vertical blanking period VB_1, and the vertical blanking period VB_1 is used as the touch period TP_1 .

Please refer to FIG. 4 again. When the display panel 13 switches to the second frame rate for display, the frame period corresponding to the second frame rate includes the vertical synchronization time Vsync, the display time DISP_2 and the vertical blanking period VB_2, wherein, in the In the frame period corresponding to the second frame rate, the display time DISP_2 is set to be the same as the display time DISP_1 in the frame period corresponding to the first frame rate, and the vertical blanking period VB_2 is set to the vertical blanking period in the frame period corresponding to the first frame rate. An extended vertical blanking period EVB is added to the period VB_1, so that the length of the entire frame period can comply with the length of the frame period corresponding to the second frame rate by adding the extended vertical blanking period EVB.

The aforementioned extended vertical blanking period EVB is not a continuous time period, but is divided into a plurality of extended vertical blanking sub-segments S, and the plurality of extended vertical blanking sub-segments S are distributed in the frame period corresponding to the second frame rate. Display time DISP_2.

Please refer to Figure 4 again. The aforementioned display time DISP_2 includes a plurality of gate line turn-on time periods GT. An extended vertical blanking section S of a plurality of extended vertical blanking sections S is interspersed with the turn-on of two consecutive gate lines. In the time period GT, according to this, the plurality of extended vertical blanking segments S can be evenly distributed in the display time DISP_2, or can be irregularly, non-periodic or randomly distributed in the display time DISP_2, thus avoiding Because the TFT elements of the panel are not charged during an excessively long blanking period, the TFT elements of the panel have leakage problems.

In addition, in the frame period corresponding to the second frame rate shown in FIG. 4 , the number of the plurality of extended vertical blanking segments S is less than the number of the plurality of gate line on-time periods GT. One extended vertical blanking segment S The length is greater than one gate line on-time period GT length, the vertical synchronization time Vsync of the frame period is located at the starting position of the frame period, and the frame period has a touch period TP_2, the length of which is equal to the vertical blanking period VB_1 of the frame period corresponding to the first frame rate. This touch period Period TP_2 is located at the end of the frame period. In one embodiment, the lengths of each extended vertical blanking segment S may be equal to each other or unequal, which is not limited here.

From the above description, it can be seen that with the display panel driving device of the present invention, when the display panel switches from a high frame rate to a low frame rate for display, the extended vertical blanking period increased by the frame rate switching will be divided into a plurality of Extended vertical blanking segments, and the plurality of extended vertical blanking segments are distributed in the display time of the frame period corresponding to the low frame rate, thereby avoiding the problem caused by the TFT element of the panel not charging during the too long blanking time. The TFT elements of the panel cause leakage problems, thus effectively ensuring the quality of the display.

The above-mentioned embodiments are only examples for convenience of explanation. The scope of rights claimed by the present invention shall be subject to the scope of the patent application and shall not be limited to the above-mentioned embodiments.

Vsync: vertical synchronization time

DISP_1,DISP_2: display time

VB_1, VB_2: vertical blanking period

GT: Gate line opening time period

TP_1, TP_2: Touch period

EVB: extended vertical blanking period

S: Extended vertical blanking segment

Claims (10)

A driving device used to switch different frame rates to drive a display panel for display. The display panel has a plurality of gate lines, one frame rate corresponds to one frame period, and one frame period has a display time and a vertical blanking period. , the driving device has a gate driver connected to the plurality of gate lines to sequentially turn on the plurality of gate lines, wherein when the display panel switches from a first frame rate to less than the first frame rate When a second frame rate is used for display, the display time in the frame period corresponding to the second frame rate is set to be the same as the display time in the frame period corresponding to the first frame rate, and the frame period corresponding to the second frame rate The vertical blanking period in the period is set to the vertical blanking period in the frame period corresponding to the first frame rate plus an extended vertical blanking period, and the extended vertical blanking period is divided into a plurality of extended vertical blanking segments, The plurality of extended vertical blanking segments are distributed in the display time of the frame period corresponding to the second frame rate. The driving device of claim 1, wherein the display time includes a plurality of gate line turn-on time periods, and one extended vertical blanking subsection of the plurality of extended vertical blanking subsections is interspersed with two consecutive gate line turn-on periods. within the time period. The driving device of claim 2, wherein the plurality of extended vertical blanking segments are evenly distributed in the display time of the frame period corresponding to the second frame rate. The driving device of claim 2, wherein the plurality of extended vertical blanking segments are non-periodically distributed in the display time of the frame period corresponding to the second frame rate. The driving device of claim 2, wherein the number of the plurality of extended vertical blanking segments is less than the number of the plurality of gate line on-time periods. The driving device of claim 2, wherein the length of an extended vertical blanking segment is greater than the length of a gate line on-time period. The driving device as claimed in claim 1, wherein the frame period further has a vertical synchronization time located at the beginning of the frame period. The driving device of claim 1, wherein the display panel has a touch function, and the vertical blanking period of the frame period includes a touch period. The driving device of claim 8, wherein the touch period of the frame period corresponding to the first frame rate is equal to the vertical blanking period of the frame period corresponding to the first frame rate; the frame period corresponding to the second frame rate The touch period in is equal to the vertical blanking period of the frame period corresponding to the first frame rate. The driving device of claim 1, wherein the display panel further has a plurality of source lines, and a plurality of pixels are respectively located at the intersections of the plurality of gate lines and the plurality of source lines; the driving device further There is a source driver connected to the plurality of source lines to write display data into pixels corresponding to the turned-on gate lines through the plurality of source lines.

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