CN101866241B - Method for reducing noise for touch panel - Google Patents

Abstract

The method for reducing the noise of the touch panel is to take a synchronous reference signal during the test of the display, and determine the sampling signal with the largest and smallest intensity among the multiple sampling signals at the test position within the first predetermined time and the intensity difference between the two , to generate the noise estimation signal; when the strength of the noise estimation signal is lower than the strength of the noise estimation signal with the smallest signal strength, updating the relevant information of the noise estimation signal with the smallest signal strength to the relevant information of the noise estimation signal; On the contrary, maintain the relevant information of the noise estimation signal with the minimum signal strength; repeat the above steps with the second predetermined time as the time interval until the end of the third predetermined time; drive according to the relevant information of the synchronization reference signal and the noise estimation signal with the minimum signal strength The data line of the display panel, so as to avoid the noise caused by the data coupling of the data line from interfering with the detection and judgment of the touch command on the touch panel at any time during other tests of the display or during the use of the user.

Description

Methods of Reducing Touch Panel Noise

technical field

The present invention relates to a method for reducing the noise of a touch panel, in particular to a method for determining the best charge of the capacitor on the touch panel by sampling the signal on the touch panel and finding the time point with the minimum noise. Discharge time, a method of reducing noise on the touch panel. the

Background technique

Please refer to FIG. 1 , which is a partial schematic diagram of a display 100 generally having a touch panel. As shown in FIG. 1 , the display 100 includes a touch panel 110 and a display panel 120 . The display panel 120 is covered with gate lines (not shown) and data lines (such as the data lines D1, D2, D3, D4 shown in FIG. The transmitted clock pulse signal and the data signal transmitted by the data line display pixel data on the display panel 120 . The touch panel 110 itself has a capacitance, and by sensing the change of the capacitance value on the touch panel 110, the display 100 can accurately know the position on the touch panel 110 triggered by the user, and then judge each position triggered by the user. A single-touch command or a multi-touch command. However, since the touch panel 110 and the display panel 120 are very likely to generate data coupling (Data Coupling) due to the coupling capacitance between the two (such as the capacitances C1, C2, and C3 shown in FIG. 1 ), the data line The transmitted data signal will interfere with the capacitive detection performed on the touch panel 110 in the form of noise, thereby affecting the accuracy of the display 100 when judging touch commands or displaying pixel data. If in order to avoid this kind of data coupling, it would be feasible to reduce the detection frequency of the capacitance value detection on the touch panel 110 to avoid the time for the data line to transmit the data signal, but this will make the touch panel unable to Real-time 110 senses the touch command triggered by the user. the

Contents of the invention

The invention discloses a method for reducing noise of a touch panel. The method includes (a) determining a synchronous reference signal from at least one clock pulse signal used on a display panel; (b) using a touch panel corresponding to the display panel within a first predetermined time A sensor on a test position of the test position performs signal sampling for multiple times to generate multiple sampled signals; (c) determine the maximum sampled signal with the highest intensity and the minimum sampled signal with the smallest intensity among the multiple sampled signals sampling signal; (d) determining the intensity difference between the maximum sampled signal and the minimum sampled signal to generate a noise estimate signal; (e) comparing the intensity of the noise estimate signal with the intensity of the noise estimate signal with the smallest signal intensity ; When the strength of the noise estimation signal is lower than the strength of the noise estimation signal with the smallest signal strength, update the strength of the noise estimation signal with the smallest signal strength to the strength of the noise estimation signal to minimize the signal strength The phase difference of the noise estimation signal corresponding to the synchronization reference signal is updated as the phase difference of the noise estimation signal corresponding to the synchronization reference signal; according to the phase difference of the noise estimation signal corresponding to the synchronization reference signal and The time point of occurrence of the synchronous reference signal determines and records the time point of appearance of the noise estimation signal with the smallest signal strength; when the strength of the noise estimation signal is not lower than the strength of the noise estimation signal with the smallest signal strength, Maintain the strength of the noise estimation signal with the smallest signal strength and the phase difference corresponding to the synchronization reference signal; (f) take a second predetermined time as a time interval, and execute steps (b), (c), ( d), (e), until the end of a third predetermined time, wherein the third predetermined time covers a plurality of the first predetermined time and a plurality of the second predetermined time; and (g) according to the synchronization reference signal and The occurrence time point of the currently recorded minimum noise estimation signal is used to drive a plurality of data lines of the display panel to transmit data to the display panel. the

Description of drawings

Fig. 1 is a partial schematic diagram of a display generally having a touch panel;

Fig. 2 is the flowchart of the method for reducing the noise on the touch panel disclosed by the present invention;

Fig. 3 is the timing diagram of signal sampling when implementing the steps described in Fig. 2, wherein the horizontal axis represents the time, and the vertical axis represents the strength of the signal;

FIG. 4 is a timing diagram of various clock pulse signals used in the display panel shown in FIG. 1 . the

Among them, reference signs

100 Displays

110 Touch Panel

120 Display Panel

D1, D2, D3, D4 Data cable

C1, C2, C3 Capacitors

202-222 Steps

t1, t2, t3, t_delay, t_min Time

s_min, s_max Signals

err noise estimation signal

YCLK Gate Line Clock Pulse Signal

YOE Gate Line Switch Signal

YV1C Edge adjustment signal

XPOL Polarity Reversal Signal

XSTB Data write control signal

Detailed ways

In order to solve the problem in the prior art that the data coupling between the touch panel and the display panel affects the detection of touch commands or the display of pixel data on the display, the present invention discloses a method for sampling signals on the touch panel. , and then find out the time point with the minimum noise to determine the best charging and discharging time of the capacitor on the touch panel, so as to reduce the noise on the touch panel. the

Please refer to FIG. 2 , which is a flowchart of a method for reducing noise on a touch panel disclosed in the present invention. As shown in Figure 2, the method disclosed in the present invention comprises steps as follows:

Step 202: Determine a synchronous reference signal from at least one clock pulse signal used on a display panel, and execute step 204;

Step 204: within a first predetermined time, use a sensor on a test position corresponding to a touch panel on the display panel to sample a signal at the test position to generate a sampling signal, and execute Step 206;

Step 206: Determine within the first predetermined time, among the plurality of sampled signals that have been sampled so far, a maximum sampled signal with the highest intensity and a minimum sampled signal with the smallest intensity, and perform step 208;

Step 208: Determine whether the first predetermined time has ended; when the first predetermined time has ended, execute step 210, otherwise execute step 204;

Step 210: Determine the intensity difference between the maximum sampled signal and the minimum sampled signal to generate a noise estimation signal, and perform step 212;

Step 212: Compare the strength of the noise estimation signal with the strength of a current minimum noise estimation signal, and determine the strength of the current minimum noise estimation signal according to the comparison result; when the noise estimation signal strength is lower than the current minimum When the strength of the noise estimation signal, execute step 214, otherwise execute step 216;

Step 214: updating the strength of the noise estimation signal to the strength of the current minimum noise estimation signal, and corresponding the noise estimation signal to the phase difference of the synchronization reference signal and the occurrence time point of the synchronization reference signal, Determine and record as the time point of occurrence of the current minimum noise estimate signal;

Step 216: Wait for a second predetermined time, and execute step 218;

Step 218: Confirm whether a third predetermined time has ended, wherein the third predetermined time covers a plurality of the first predetermined time and a plurality of the second predetermined time; when the third predetermined time has ended, execute step 220 , otherwise execute step 204;

Step 220 : Drive a plurality of data lines of the display panel to transmit data to the display panel according to the synchronous reference signal and the occurrence time point of the currently recorded minimum noise estimation signal. the

In order to clearly explain the steps described in FIG. 2, please also refer to FIG. 3. FIG. 3 is a timing diagram of signal sampling when the steps described in FIG. 2 are implemented, wherein the horizontal axis represents time, and the vertical axis represents signal intensity. FIG. 3 shows the signal strength detected by a sensor of the touch panel 110 at the corresponding test position on the display panel 120 . The steps described in FIG. 2 use the signal strength as a reference for judging the noise level. the

When the method described in FIG. 2 is applied to the display 100 shown in FIG. 1 , in step 202, a time point t_min (as shown in FIG. 3 ) with the smallest noise needs to be tested within a certain period of time, as the subsequent drive data line The time t3 shown in FIG. 3 is the fixed time period compared with the standard time point for transmitting data to the display panel. However, the start time point of time t3 also needs to be determined in advance to find out the phase difference t_delay between the start point and time point t_min, and when the display 100 is actually started later, as long as the start time of time t3 can be known Point and phase difference t_delay, the position on the time axis of the time point t_min representing the minimum noise can be estimated. The starting time point of the time t3 is determined by finding a synchronous reference signal among different types of clock pulse signals on the display panel 120 , and subsequent tests will be performed using the synchronous reference signal as a starting point. Please refer to FIG. 4 , which is a timing diagram of various clock pulse signals used on the display panel 120 shown in FIG. 1 . FIG. 4 shows a timing sequence of a gate line clock pulse signal YCLK, a gate line switch signal YOE, an edge adjustment signal YV1C, a polarity inversion signal XPOL, and a data writing control signal XSTB, wherein each signal is only The enable/disable status is represented by high and low potentials. The gate line clock pulse signal YCLK represents the clock pulse used by each gate line on the display panel 120, and the gate line switch signal YOE is used to control whether the gate line clock pulse signal YCLK is effective for triggering the gate lines, in other words, When the gate line clock pulse signal YCLK and the gate line control signal YOE are enabled at the same time, the gate lines on the display panel 120 can be triggered and started. The polarity inversion signal XPOL is used to control the LEDs mounted on the display panel 120 to implement polarity inversion of the display panel 120 . The data writing control signal XSTB is used to control the timing when the data lines on the display panel 120 are turned on, so as to write pixel data on the display panel 120 . Observing Figure 4, it can be seen that there are different phase differences between the various clock pulse signals. If one of the clock pulse signals cannot be used as a synchronization reference signal to determine the starting point of time t3, even if the size of the phase difference t_delay is known. Used for the operation of the display 100 to reduce noise. In a preferred embodiment of the present invention, as shown in FIG. 4 , a period of time when the edge adjustment signal YC1C is not enabled (ie, a duty cycle (Duty Cycle)) is used as the time t3 shown in FIG. 3 . the

Steps 204 - 208 correspond to time t1 shown in FIG. 3 , and time t1 is used as a signal sampling time for a single test position on the touch panel 110 . As shown in FIG. 3 , at time t1, the sensor on the touch panel 110 corresponding to a specific test position on the display panel 120 is used for signal sampling to obtain a plurality of discrete sampling signals (as shown at time t1 in FIG. 3 ). The four signals covered). In step 206 , a signal with the largest signal strength and a signal with the smallest signal strength are found from the signals (maybe not all four signals covered in FIG. 3 ) that have been sampled at the time t1. In step 208, when the time t1 is over, that is, when the four signals covered by the time t1 shown in FIG. The signal s_max and the signal s_min with the smallest intensity. the

In step 210, the intensity difference between the signals s_max and s_min is determined as a noise estimation signal err, which is used as a signal group covered by time t1 as shown in FIG. 3 (ie, as shown in FIG. 3 The set of four signals covered by time t1) represents the noise. The general situation before executing step 212 is that the display 100 has already collected the respective noise estimation signals err in a plurality of the above-mentioned signal groups, and has found out the noise estimation signal err with the smallest signal strength as the A current minimum noise estimation signal is made, and the state of the current minimum noise estimation signal before the end of time t3 is variable. In this way, when a new noise estimation signal err is obtained after executing step 210, in step 212, the signal strengths of the new noise estimation signal and the current minimum noise estimation signal will be compared Compare. When the comparison result shows that the signal strength of the new noise estimation signal err is smaller than the current minimum noise estimation signal, the relevant information of the current minimum noise estimation signal will be updated to the new noise estimation signal err in step 214. Relevant information, such as updating the strength of the current minimum noise estimation signal and the corresponding phase difference t_delay to the time difference between the strength of the new noise estimation signal err and the starting point corresponding to time t3 (that is, the phase difference), etc. . Conversely, when the comparison result shows that the signal strength of the new noise estimation signal err is not smaller than the current minimum noise estimation signal, then maintain the relevant information of the current minimum noise estimation signal, for example, maintain the current minimum noise estimation signal Intensity and its phase difference with respect to the synchronous reference signal. the

Observing FIG. 3, it can be seen that in the present invention, the same test position on the touch panel 110 will be sampled in units of signal groups, and there will be a fixed time t2 between the signal groups; the waiting period described in step 216 The second predetermined time is the time t2 shown in FIG. 3 , and no matter whether the new noise estimation signal err sampled in step 212 is smaller than the current minimum noise estimation signal, it will wait for a period of time t2 as shown in FIG. 3 . Observing FIG. 3 , it can be seen that the time t3 covers multiple times t1 and t2 , and in general, the length of the time t1 is much shorter than the length of the time t2 . In step 218 , it is determined whether the time t3 is over, so as to determine whether to stop sampling the test position on the touch panel 110 . When the time t3 has not yet ended, it means that the test position needs to be continuously sampled, and step 202 is executed; otherwise, it means that the relevant information (such as the time point of occurrence) of the current minimum noise estimation signal at the test position has been obtained, And execute step 220 . Step 220 represents that when the display 100 is manufactured or a subsequent performance test is performed, the capacitance on the touch panel 110 can be driven according to the time point of the current minimum noise estimation signal obtained so far, so as to minimize the estimated noise Next, charge and discharge the touch panel 110, thereby avoiding the noise interference brought by the data coupling to the touch panel as described in the prior art, so as to reduce the noise on the touch panel and improve the ability of the touch panel to detect touch commands. time accuracy. the

Please note that the time t2 and t3 shown in FIG. 3 can be determined according to the preset setting in the process or test or the user's own setting after purchasing the display 100, and the length of the time t1 is much shorter than the time t2. Dense signal sampling in a very short time. the

The invention discloses a method for reducing noise on a touch panel. In the method disclosed in the present invention, a synchronous reference signal is determined, and the starting point of the synchronous reference signal is used as the criterion to find out the time point when the signal with the least noise appears during the test, so that other related tests or During the user's use, the noise caused by the data coupling of the data line can be avoided at any time to interfere with the detection and judgment of the touch command on the touch panel. the

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should belong to the scope of protection of the appended claims of the present invention. the

Claims (3)

1. a method that reduces noise for touch panel is characterized in that, comprises:

(a) by determining a synchronous reference signal in the employed at least a clock pulse signal on the display panel;

(b) in one first schedule time,, this test position is carried out the multiple signal sampling, to produce a plurality of sampled signals with the inductor of a contact panel on a pairing test position on this display panel;

(c) determine a maximum maximum sampled signal and the minimum minimum sample signal of intensity of intensity in these a plurality of sampled signals;

(d) determine the intensity difference of this maximum sampled signal and this minimum sample signal, to produce a noise estimating signal;

(e) intensity of the minimum noise estimating signal of the intensity of this noise estimating signal and signal intensity relatively;

When the intensity of this noise estimating signal is lower than the intensity of the minimum noise estimating signal of this signal intensity; The intensity of the noise estimating signal that this signal intensity is minimum is updated to the intensity of this noise estimating signal, and the phase differential that the noise estimating signal that this signal intensity is minimum corresponds to this synchronizing datum signal is updated to the phase differential that this noise estimating signal corresponds to this synchronizing datum signal; Correspond to the phase differential of this synchronizing datum signal and the time of occurrence point of this synchronizing datum signal according to this noise estimating signal, determine and write down the time of occurrence point of the minimum noise estimating signal of this signal intensity;

When the intensity of this noise estimating signal is not lower than the intensity of the minimum noise estimating signal of this signal intensity, keep the intensity of the minimum noise estimating signal of this signal intensity and corresponding to the phase differential of this synchronizing datum signal;

(f) be a time interval with one second schedule time, execution in step (b), (c), (d), (e) once more, till one the 3rd schedule time finished, wherein the 3rd schedule time was contained had a plurality of these first schedule times and a plurality of this second schedule time; And

(g), drive many data lines of this display panel, to transfer data on this display panel according to this synchronizing datum signal and the time of occurrence point that writes down the minimum noise estimating signal of this signal intensity at present.

2. method according to claim 1 is characterized in that,

Wherein this at least a clock pulse signal comprises one edge adjustment signal, and this edge adjustment signal is used for adjusting the sequential that the data line of these display panel both sides reads, with prevent and the central area of this display panel between the time for reading of data line poor;

Wherein step (a) comprises:

With this edge adjustment signal deciding is this synchronizing datum signal;

Wherein the length of the 3rd schedule time determines according to a dutycycle of this edge adjustment signal.

3. method according to claim 1 is characterized in that, the time span of this second schedule time and the 3rd schedule time determines according to a default settings and/or a user's setting.

Images