TW201915684A - Driving Method for Uniforming Brightness of In-cell Touch Display Panel and Driving Circuit Using the Same - Google Patents

Abstract

A driving method for uniforming the brightness of an in-cell touch display panel and a driving circuit using the same are provided in the present invention. The method includes: performing a first operation mode, including: performing a continuous display driving for a frame of a in-cell touch display panel; and performing a touch sensing of a frame after the continuous display driving; performing a second operation mode, including: performing a plurality of discontinuous display driving in a frame period of the in-cell touch display panel; and performing a touch sensing of a partial frame between at least a pair of the neighboring discontinuous display drivings and the next interrupted display driving; and controlling the charging time of a scan-line in the first operation mode substantially equal to the charging time of the scan-line in the second operation mode.

Description

 Brightness uniform driving method of embedded touch display panel and driving circuit using same  

The present invention relates to a touch panel technology, and more particularly to a brightness uniform driving method for an embedded touch display panel and a driving circuit using the same.

In the embedded touch panel (In-Cell Touch Panel) architecture, display drivers and touch scans are often used in shared hardware and Time Division Multiplexing. Display time and touch are displayed. Touch Term works separately in time sharing. When the drive data is displayed, the touch scan stops or only the touch scan data is processed. When the touch scans, the display drive stops. In order to avoid noise generated in the embedded touch panel, reducing the scan signal noise ratio (SNR) value or affecting the surface content value causes a false positive point. There are three common time-sharing multiplex modes. They are shown as 1A, 1B, and 1C, respectively.

FIG. 1A is a schematic diagram of vertical blank touch sensing (V-blanking TP term) for the prior art embedded touch panel. Please refer to FIG. 1A. TP indicates the touch sensing period, and the DSP indicates the display period. In this example, the entire touch sensing operation is arranged between the display frame and the frame, that is, during the vertical synchronization period (V-banking).

FIG. 1B is a schematic diagram showing a horizontal blank touch sensing (H-blanking TP term) of the prior art embedded touch panel. In this example, one or several touch sensing operations are arranged between the display display line and the scan line. That is to say, the work of touch sensing is configured during the horizontal blank period (H-blanking).

FIG. 1C is a schematic diagram showing hybrid touch sensing of the prior art embedded touch panel. In this example, one or several touch sensing operations are arranged between the display scan line and the scan line and displayed. Between the frame and the frame. In other words, it is the combination of the above 1A and 1B.

When the touch sensor is used for the touch sensing, the three touch sensing modes are switched according to different applications. However, during the switching process, the brightness of the screen changes frequently, which affects the display quality.

An object of the present invention is to provide a method for uniformly driving a brightness of an embedded touch display panel and a driving circuit using the same, which can maintain the same brightness of the screen by changing the driving method, thereby improving the display quality of the touch display panel.

In view of the above, the present invention provides a method for uniformly driving a brightness of an embedded touch display panel. The method for uniformly driving the brightness of the embedded touch display panel includes the following steps: performing a first operation mode, where the first operation mode includes : performing a continuous display scan driving for one screen time of an embedded touch display panel; and performing a full frame touch detection after the continuous display scan driving completes one screen; performing a second operation a mode, wherein the second mode of operation comprises: performing a plurality of non-continuous display scan driving for one frame time of an embedded touch display panel; and between at least one pair of adjacent non-continuous display scan drivers And performing part of the touch detection of the frame; and the pixel charging time of the scan line for controlling the first operation mode is substantially equivalent to the pixel charging time of the scan line of the second operation mode, so that the brightness of the picture is uniform.

In view of the above, the present invention provides a driving circuit for an embedded touch display panel for driving an embedded touch display panel. The driving circuit of the embedded touch display panel includes a touch display timing driving circuit. The control display timing driving circuit is coupled to the embedded touch display panel, wherein the touch display timing driving circuit comprises a first operating mode and a second operating mode, wherein the first operating mode comprises: displaying the embedded touch A continuous display scan driving is performed within one screen time of the panel; and after the continuous display scan driving completes one screen, a full frame touch detection is performed. The second mode of operation includes: performing a plurality of non-continuous display scan driving for one picture time of an embedded touch display panel; and performing a part of the frame between at least one pair of adjacent non-continuous display scan drivers In the touch detection, the touch display timing driving circuit controls the pixel charging time of the scan line of the first operation mode to be substantially equivalent to the pixel charging time of the scan line of the second operation mode, so that the brightness of the screen is uniform.

A method for uniformly driving a brightness of an embedded touch display panel according to a preferred embodiment of the present invention, and a driving circuit using the same, wherein a pixel charging time of a scan line of a first operation mode and a scan line of a second operation mode are controlled The pixel charging time is substantially equivalent, and the step of making the brightness of the screen uniform includes: controlling a plurality of gate driving signals of the entire picture, so that the enabling time of each of the gate driving signals is substantially the same.

A method for uniformly driving a brightness of an embedded touch display panel according to a preferred embodiment of the present invention, and a driving circuit using the same, wherein a pixel charging time of a scan line of a first operation mode and a scan line of a second operation mode are controlled The pixel charging time is substantially equivalent, and the steps of making the brightness of the screen uniform include: enabling a plurality of gate driving signals; and sending a source driving signal of the corresponding pixel when each gate driving signal is enabled, and fixing the source The time when the pole drive signal is sent is such that the time of the source drive signal of each scan line is substantially the same.

The spirit of the present invention is to control the pixel charging time in each touch operation mode, so that the embedded touch display panel has substantially the same pixel charging time during scanning regardless of which touch operation mode is operated. Therefore, the brightness of the display can be consistent when the embedded touch display panel driving circuit switches the operation mode. Thereby, the display quality of the touch display panel can be improved.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

301‧‧‧Touch display timing drive circuit

302‧‧‧Embedded touch display panel

303‧‧‧Source drive circuit

304‧‧‧ gate drive circuit

S401~S404‧‧‧ steps of a uniform brightness driving method for an embedded touch display panel according to a preferred embodiment of the present invention

FIG. 1A is a schematic diagram of vertical blank touch sensing (V-blanking TP term) for the prior art embedded touch panel.

FIG. 1B is a schematic diagram showing a horizontal blank touch sensing (H-blanking TP term) of the prior art embedded touch panel.

FIG. 1C is a schematic diagram of hybrid touch sensing performed by the prior art embedded touch panel.

FIG. 2A is a timing diagram of a vertical blank touch sensing mode according to a preferred embodiment of the present invention.

FIG. 2B is a timing diagram of a hybrid touch sensing mode according to a preferred embodiment of the present invention.

FIG. 2C is a timing diagram of a hybrid touch sensing mode according to a preferred embodiment of the present invention.

FIG. 3 is a block diagram of a system of an embedded touch display device according to a preferred embodiment of the present invention.

FIG. 3A is a schematic diagram showing the waveform of controlling the charging time of the pixel by controlling the time when the gate driving circuit 302 turns on the scanning line according to a preferred embodiment of the present invention.

FIG. 3B is a schematic diagram showing the waveform of controlling the charging time of the pixel by controlling the time of the source driving circuit 303 to the data according to a preferred embodiment of the present invention.

FIG. 4 is a flow chart showing a method for uniformly driving the brightness of the embedded touch display panel according to a preferred embodiment of the present invention.

In the prior art, when the operation mode of the touch sensing is switched, the brightness of the screen changes, which is observed by the user and affects the display quality. However, the reason for this phenomenon in detail has not been explored and improved in the prior art. The applicant uses the following analysis to find out the cause of the change in brightness of the screen and further proposes an improved technique.

FIG. 2A is a timing diagram of a vertical blank touch sensing mode according to a preferred embodiment of the present invention. Please refer to FIG. 2A. In the vertical blank touch sensing mode, the driving time of one screen is about 16.67 ms. During the touch sensing period TP, the time of one touch screen of the continuous touch sensing 201 is about 1 ms. Therefore, the total time available for display is approximately 15.67 ms. For a panel with a resolution of 1280×800, each scan line has a driving time of 15.67ms ÷ 1280=12.23us, and the hold time required for each scan line is 1.2us, so this operation is performed. Mode, the maximum pixel charging time for each line is approximately 11.03us.

FIG. 2B is a timing diagram of a hybrid touch sensing mode according to a preferred embodiment of the present invention. Please refer to FIG. 2B. In the hybrid touch sensing mode, the driving time of one screen is about 16.67 ms, and the continuous touch sensing 201 takes 1 ms for one screen, and each interrupt shows a partial map between the scanning drivers. The frame touch detection 202 requires 300 us, and a total of three partial frame touch detections 202 are required. Therefore, the total time available for display is about 14.77 ms. For a panel with a resolution of 1280×800, each scan line has a drive time of 14.77ms ÷ 1280=11.53us, and the hold time required for each scan line is 1.2us, so this operation is performed. Mode, the maximum pixel charging time for each line is approximately 10.3us.

FIG. 2C is a timing diagram of a hybrid touch sensing mode according to a preferred embodiment of the present invention. Please refer to FIG. 2C. In the hybrid touch sensing mode, the driving time of one screen is about 16.67 ms, and the continuous touch sensing 201 takes 1 ms for one screen, and each interrupt shows a partial map between the scanning drivers. The frame touch detection 202 requires 250 us, and a total of five partial touch detections 202 are required. Therefore, the total time that the remaining display is actually possible is about 14.42 ms. For a panel with a resolution of 1280×800, each scan line has a driving time of 14..42ms ÷ 1280=11.26us, and the holding time required for each scanning line is 1.2us, so in this operation mode, The maximum pixel charging time for each line is approximately 10.0us.

Assume that in the low power mode, the embedded touch panel will use vertical blank touch sensing. At this time, since the touch sensing is performed during or after each vertical synchronization, the touch sensing of 60 pictures is performed every second. When a finger touch is detected, it switches to the hybrid touch sensing mode. At this time, in addition to sensing before and after the vertical synchronization time, the touch sensing also inserts a touch between the display scan line and the line. Sensing, that is, touch sensing of 120 pictures per second. In other words, the reporting rate can be increased by 2 times. In the embedded display touch panel, if the ratio of the display driving time and the touch scanning time is dynamically adjusted, the display time changes accordingly, thereby changing the charging time of the liquid crystal pixels of the source driving circuit, which may cause the human eye to The observed change in brightness.

FIG. 3 is a block diagram of a system of an embedded touch display device according to a preferred embodiment of the present invention. Referring to FIG. 3 , the embedded touch display device includes a touch display timing driving circuit 301 , an embedded touch display panel 302 , a source driving circuit 303 , and a gate driving circuit 304 . The touch display timing driving circuit 301 is coupled to the embedded touch display panel 302, the source driving circuit 303, and the gate driving circuit 304. The touch display timing driving circuit 301 controls the operation timing of the source driving circuit 303 and the gate driving circuit 304 in addition to the touch detection of the embedded touch display panel 302.

In this embodiment, during the display process, the system dynamically adjusts the display and the touch scan mode, and the switching sequence is, for example, a mode in which the mode of FIG. 2C is changed to the mode of the second FIG. As can be seen from the above description, in each of the above three modes, the pixel charging time of each mode is different. Therefore, in the present invention, the charging time of each mode for the pixels is substantially the same, and the brightness of the screen can be made uniform. For example, since the mode of Figure 2C has the shortest charging time (10.0 us) for each line of pixels. Therefore, when the system operates in the mode of FIG. 2B and the mode of FIG. 2A, the touch display timing driving circuit 301 sets the pixel charging time of each scanning line to be 10.0 us, in order to match the pixel in the mode of FIG. 2C. Charging time.

In addition, in the present invention, there are at least two methods for controlling the pixel charging time of each scanning line. The first mode is the time when the touch display timing driving circuit 301 controls the source driving circuit 303 to the pixel data, and the second type. The manner is that the touch display timing driving circuit 301 controls the time when the gate driving circuit 302 turns on the scan line. FIG. 3A is a schematic diagram showing the waveform of controlling the charging time of the pixel by controlling the time when the gate driving circuit 302 turns on the scanning line according to a preferred embodiment of the present invention. Please refer to FIG. 3A. 31 denotes the gate signal of the Nth line in the mode of FIG. 2A, and 32 denotes the gate signal of the Nth line in the mode of FIG. 2C. As can be seen from the figure, even if the source is still giving data, the gate driving circuit 301 is controlled by the touch display timing driving circuit 301 to make the gate time of the two modes consistent, so that the switching mode can be switched. When the brightness does not change.

FIG. 3B is a schematic diagram showing the waveform of controlling the charging time of the pixel by controlling the time of the source driving circuit 303 to the data according to a preferred embodiment of the present invention. Please refer to FIG. 3B, 33 indicates the gate signal of the Nth line in the mode of FIG. 2A; 34 indicates the gate signal of the Nth line in the mode of FIG. 2C; and 35 indicates the mode of FIG. 2A. The data signal of the Nth line; 36 indicates the data signal of the Nth line in the mode of Fig. 2C. As can be seen from the figure, even if the gate is still enabled, the source driving circuit 303 is controlled by the touch display timing driving circuit 301 so that the data supply time of the two modes is the same, and the brightness can be switched when the mode is switched. Will not change.

It can be seen from the above embodiment that even if the enable time length of the gate driving signal is different, the data driven by the source driving circuit is driven for the same time, so the charging time for the liquid crystal is substantially equal. Therefore, when switching modes, the brightness can be maintained evenly without changing. However, in some cases, even if the pixel charging time is the same, there is a possibility that the brightness is uneven. The brightness of each mode can be measured by the instrument to find the pixel charging time of the other mode and the brightness of the mode of the 2C picture. In general, the most influential effect on brightness is the pixel charging time, so the pixel charging time of other modes and the pixel charging time of the mode of the 2C figure are not much different, but may still be different. In addition, the circuit may also have errors. Therefore, the present invention does not limit the pixel charging time to be completely equal. As long as the switching mode can be substantially achieved, the time at which the brightness is uniform is within the scope of the present invention.

In addition, the three operation modes used in the above-mentioned 2A, 2B, and 2C are merely examples for describing the spirit of the present invention, and are not intended to limit the present invention. As long as there are two modes, it is within the spirit of the present invention to use substantially the same pixel charging time.

FIG. 4 is a flow chart showing a method for uniformly driving the brightness of the embedded touch display panel according to a preferred embodiment of the present invention. Referring to FIG. 4, the brightness uniform driving method of the embedded touch display panel includes the following steps:

Step S401: Start.

Step S402: determining an operation mode. Since the focus of the case is not in the judgment of the operation mode, the switching judgment of the operation mode may be a system determination, or may be a decision after the touch, and the application of the present invention requires at least two modes. Therefore, the embodiment only cites two modes of operation, and this step is not described in detail.

Step S403: In the first operation mode, one scan line is charged with a fixed time length. This step can be selected to control the turn-on time of each scan line by the gate drive circuit 304. In this step, the source driving circuit 303 can also be used to charge the pixels of the scanning line at a fixed time after the scanning line is turned on.

Step S404: In the second operation mode, one scan line is charged with the same fixed time length as the first operation mode. Similarly, this step can select the gate drive circuit 304 to control the turn-on time of each scan line. In this step, the source driving circuit 303 can also be used to charge the pixels of the scanning line at a fixed time after the scanning line is turned on.

Since the first operational mode and the second operational mode have different maximum pixel charging times for each scan line, the present invention selects a smaller maximum pixel charging time as the pixel charging time of the scan line for each mode. Therefore, no matter what mode is switched, the transmittance of the liquid crystal pixels can be uniform, and the brightness can be kept uniform.

In summary, the spirit of the present invention is to control the pixel charging time in each touch operation mode, so that the embedded touch display panel is charged in the pixel charging time regardless of which touch operation mode is operated. To be essentially the same. Therefore, the brightness of the display can be consistent when the embedded touch display panel driving circuit switches the operation mode.

The specific embodiments of the present invention are intended to be illustrative only and not to limit the invention to the above embodiments, without departing from the spirit of the invention and the following claims. The scope of the invention and the various changes made are within the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (10)

 A method for uniformly driving a brightness of an embedded touch display panel, comprising: performing a first operation mode, comprising: performing a continuous display scan driving for one picture time of an embedded touch display panel; After the continuous display scan driver completes one screen, performing a full frame touch detection; performing a second operation mode, including: performing a plurality of non-continuous display for one screen time of an embedded touch display panel Scanning driving; and performing at least a portion of the frame touch detection between the at least one pair of adjacent non-continuous display scan drivers; and controlling a pixel charging time of the scan line of the first operation mode and a scan line of the second operation mode The pixel charging time is substantially equivalent, so that the brightness of the picture is uniform.    The brightness uniform driving method of the embedded touch display panel according to the first aspect of the invention, wherein the pixel charging time of the scan line of the first operation mode and the pixel charging time of the scan line of the second operation mode are controlled. Substantially equivalent, the brightness of the picture is uniform, including: controlling a plurality of gate driving signals of the entire picture, so that the enabling time of each of the gate driving signals is substantially the same.    The method of uniformly driving the brightness of the embedded touch display panel according to the first aspect of the invention, wherein the second operation mode further comprises: after the non-continuous display scan driving completes one picture, performing the whole picture Frame touch detection.    The brightness uniform driving method of the embedded touch display panel according to the first aspect of the invention, wherein the pixel charging time of the scan line of the first operation mode and the pixel charging time of the scan line of the second operation mode are controlled. Substantially equivalent, the brightness of the picture is uniform, including: enabling a plurality of gate driving signals; and sending a source driving signal of the corresponding pixel when each of the gate driving signals is enabled, and fixing the source The time when the drive signal is sent is such that the source drive signals of each scan line are substantially the same time.    The method for uniformly driving the brightness of the embedded touch display panel as recited in claim 1, further comprising: performing the first mode operation in a low power consumption mode; and performing the Two mode operation.    The driving circuit of the embedded touch display panel is configured to drive an embedded touch display panel. The driving circuit of the embedded touch display panel comprises: a touch display timing driving circuit coupled to the embedded touch display The panel, wherein the touch display timing driving circuit includes a first operating mode and a second operating mode, the first operating mode includes: performing a continuous display for one time of the embedded touch display panel a scan driver; and after the continuous display scan driver completes a screen, performing a full frame touch detection, wherein the second operation mode comprises: performing a screen time for an embedded touch display panel a plurality of non-continuous display scan drivers; and a portion of the frame touch detection between at least one pair of adjacent non-continuous display scan drivers; and wherein the touch display timing drive circuit controls the scan of the first operation mode The pixel charging time of the line is substantially equivalent to the pixel charging time of the scan line of the second operation mode, so that the brightness of the screen is both Evenly consistent.    The driving circuit of the embedded touch display panel as described in claim 6 further includes: a gate driving circuit comprising a plurality of scanning line driving ends and a control terminal, wherein the gate driving circuit is controlled The touch-control display timing driving circuit is coupled to the gate driving line of the embedded touch display panel, wherein the touch display timing driving circuit controls the gate The pole drive circuit enables the enable time of the plurality of gate drive signals outputted by the scan line driving terminals to be substantially the same in the first operation mode and the second operation mode.    The driving circuit of the embedded touch display panel according to the sixth aspect of the invention, wherein the touch display timing driving circuit further comprises: the touch display timing driving circuit in the second operating mode After the non-continuous display scan driver completes one screen, the entire frame touch detection is performed.    The driving circuit of the embedded touch display panel as described in claim 6 further includes: a source driving circuit comprising a plurality of pixel driving ends and a control terminal, wherein the control terminal of the source driving circuit The pixel display driving circuit of the source driving circuit is coupled to the data line of the embedded touch display panel, wherein the touch display timing driving circuit controls the source driving circuit The output time of the data signal output by the pixel driving terminals is substantially the same in the first operation mode and the second operation mode.    The driving circuit of the embedded touch display panel according to the sixth aspect of the invention, wherein the touch display timing driving circuit performs the first mode operation in a low power consumption mode; and the touch display timing driving The second mode operation is performed after the circuit detects the touch.