TWM483489U - Self-capacitance multipoint touch structure - Google Patents

Description

Self-capacitance multi-touch structure

This creation is about a structure of a display screen with a touch panel, especially a self-capacitance multi-touch structure.

The capacitive touch panel has transparent conductor lines or transparent conductor electrode points arranged in a vertical and horizontal direction. The principle of the capacitive touch panel technology is that when a finger or other medium contacts the transparent conductor line or the transparent conductor electrode point of the touch panel, the electrostatic coupling between the arranged transparent conductor line or the transparent conductor electrode point and the human body causes a capacitance change. . The coordinates of the touch point are detected from the generated current or voltage by the change in capacitance.

In general, the capacitive touch panel driving method senses the capacitance of each conductor line to ground, and determines whether an object is close to the capacitive touch panel by changing the capacitance value of the ground. This is a conventional self capacitance. Sensing. Among them, self-capacitance or capacitance to ground is not a physical capacitor, which is the parasitic and stray capacitance of each conductor line. Figure 1 is a schematic diagram of conventional self capacitance sensing. During the first time period, the first direction of the conductor line is driven by the first direction driving and sensor 110 to charge the self-capacitance of the conductor line in the first direction. In the second time period, drive and The sensor 110 detects the voltage on the conductor line in the first direction. Further in a third time period, the second direction of the conductor line is driven by the second direction drive and sensor 120 for charging the self-capacitance of the conductor line in the second direction. In a fourth time period, the driver and sensor 120 detects the voltage on the conductor line in the second direction.

A conventional self capacitance sensing method in FIG. The driving circuit and the sensing circuit are connected to the same conductor line at the same time. After driving the conductor line, the same conductor line is sensed by the amount of change of the signal to determine the self-capacitance. The advantage is that the amount of data is small, and the single frame of the touch panel has only m+n pen data (assuming that there are m conductor lines in the first direction and n conductor lines in the second direction), but Save on hardware costs. Since the amount of data processing is small, it has a low power consumption. The disadvantage of the self-capacitance sensing method is that when there is multi-touch on the touch panel, there is a ghost point effect, which makes it difficult for the self-capacitance sensing method to support multi-touch applications.

As shown in FIG. 1 , when two fingers touch the point B and the point C on the capacitive touch panel at the same time, the driving and sensor 110 detects the conductor line in the first direction at Y1 and Y2. The voltage is different from the voltage on other conductor lines. The drive and sensor 120 detects that the voltage on the conductor line in the second direction is different from the voltage on the other conductor line at X1 and X2, and therefore determines the points A, B, C, and D. There are touch points, but the points A and D are actually not touched and are called ghost points. Therefore, the self-capacitance sensing method has a ghost phenomenon in multi-touch. Therefore, there is still room for improvement in the conventional multi-touch structure.

The main purpose of this creation is to provide a self-capacitance multi-touch structure that avoids ghost points generated during touch detection to improve the accuracy of sensing.

According to one of the features of the present invention, the present invention provides a self-capacitance multi-touch structure including a panel, a plurality of first sensing electrode lines, a plurality of second sensing electrode lines, a first switch group, and a second switching. Group, and a controller. The plurality of first sensing electrode lines are disposed on the panel according to a first direction. The plurality of second sensing electrode lines are disposed on the panel according to a second direction. The first switcher group has a plurality of first switchers, a first end of each of the first switchers is connected to a corresponding first sense electrode line, and a second end of each first switcher is connected to the first switcher Common first output. The second switcher group has a plurality of second switchers, a first end of each of the second switchers is connected to a corresponding second sense electrode line, and a second end of each second switcher is connected to the second switcher Common second output. The controller is connected to a control end of each first switch of the first switch group, a control end of each second switch of the second switch set, the common first output, and the a common second output terminal for controlling whether the plurality of first switches are electrically connected to the common first output terminal, and controlling whether the plurality of second converters are electrically connected to the common second output terminal; wherein the control Setting a control end of the plurality of switchers to electrically connect a first sensing electrode line of the plurality of first sensing electrode lines to a second sensing electrode line of the plurality of second sensing electrode lines Touch sensing.

110‧‧‧Driver and sensor in the first direction

120‧‧‧Driver and sensor in the second direction

200‧‧‧ self-capacitor multi-touch structure

210‧‧‧ panel

220‧‧‧first sensing electrode line

230‧‧‧Second sensing electrode line

240‧‧‧First switcher group

250‧‧‧Second switcher group

260‧‧‧ Controller

241‧‧‧ first switcher

251‧‧‧Second switcher

Com1‧‧‧ common first output

Com2‧‧‧Common second output

A‧‧‧first end

B‧‧‧second end

c‧‧‧Control terminal

310‧‧‧ pins

320‧‧‧resistance

330‧‧‧First Diode

340‧‧‧second diode

350‧‧‧ switch

241-3‧‧‧First switcher

251-2‧‧‧Second switcher

220-1, 220-2, 220-3, 220-4, 220-5, 220-M‧‧‧ first sensing electrode line

230-1, 230-2, 230-3, 230-N‧‧‧ second sensing electrode line

A, B, C, D, E, F, G, H, I, J‧‧ Circle

S610~S690‧‧‧Steps

S810~S890‧‧‧Steps

The conventional self-capacitance sensing method in FIG.

Figure 2 is a block diagram of a self-capacitance multi-touch structure of the present invention.

Figure 3 is a circuit diagram of the author switcher.

Fig. 4 is a schematic view showing the connection of the sensing electrode lines of the present invention.

FIG. 5 is a schematic diagram of the sensing point detection of the present invention.

Figure 6 is a flow chart of the touch detection of the present creation.

7A to 7C are another schematic diagrams of the sensing point detection of the present invention.

FIG. 8 is another flow chart of the touch detection of the present creation.

This creation is about a self-capacitance multi-touch structure. FIG. 2 is a block diagram of an example of a self-capacitance multi-touch structure 200. The self-capacitance multi-touch structure 200 includes a panel 210, a plurality of first sensing electrode lines 220, and a plurality of second sensing electrodes. Line 230, a first switcher group 240, a second switcher group 250, and a controller 260.

The plurality of first sensing electrode lines 220 are disposed on the panel 210 according to a first direction (X). The plurality of second sensing electrode lines 230 are disposed on the panel 210 according to a second direction (Y). There are M first sensing electrode lines 220 in the first direction and N second sensing electrode lines 230 in the second direction, where M and N are integers greater than 1.

The first switcher group 240 has a plurality of first switches 241. A first end a of each of the first switches 241 is connected to a corresponding first sensing electrode line 220, and a second end b of each of the first switches 241 is connected to a common first output terminal com1.

The second switcher group 250 has a plurality of second switches 251. A first end a of each second switch 251 is connected to a corresponding second sensing electrode line 230, and a second end b of each second switch 251 is connected to a common second output end com2.

The controller 260 is connected to a control terminal c of each of the first switchers 241 of the first switcher group 240, a control terminal c of each of the second switchers 250, and a control terminal c of the second switcher 251. a common first output terminal com1 and the common second output terminal com2 to control whether the plurality of first switchers 241 are electrically connected to the common first output terminal com1, and control whether the plurality of second converters 251 are electrically connected To the common second output terminal com2. The controller 260 sets the control ends of the plurality of switches 241 and 251 such that one of the plurality of first sensing electrode lines 220 and one of the plurality of second sensing electrode lines 230 The second sensing electrode line 230 is electrically connected, and the touch sensing is performed.

The controller 260 sets the control ends of the plurality of first switchers 241 and the plurality of second switches 251 such that the one first sensing electrode line 220 and the one second sensing electrode line 230 are inside the controller 260. Electrical connection, 俾 for touch sensing.

The hard systems of the first switch 241 and the second switch 251 are the same. FIG. 3 is a circuit diagram of an example of the authoring switch 241, 251. The switch includes a pin 310, a resistor 320, and a first diode 330. A second diode 340 and a switch 350.

The pin 310 is connected to a corresponding sensing electrode line 220, 230 as a first end a of the switch 241, 251, and one end of the resistor 320 is connected to the pin 310. The anode of the first diode 330 is connected to the other end of the resistor 320, and its cathode is connected to a high potential (V+). The cathode of the second diode 340 is connected to the other end of the resistor 320, and its anode is connected to a low potential (V-). One end of the switch 350 is connected to the other end of the resistor 320, and the other end is connected to the common output end com1 or com2 as the second end b of the switch 241, 251, and the control end 351 serves as the switch 241. The control terminal c of 251 is connected to the controller 260.

The controller 260 is connected to the control end 351 of each of the plurality of switches 241, 251 to control whether the first end a of the plurality of switches 241, 251 is electrically connected to the common output com1 , com2.

Fig. 4 is a schematic view showing the connection of the sensing electrode lines of the present invention. The controller 260 sets the control terminal 351 of the plurality of switches 241, 251. At a point in time, only one first sensing electrode line 220-3 is electrically connected to the common first output terminal com1 via the first switch 241-3, and only one second sensing electrode line 230-2 is via the second The switch 251-2 is electrically connected to the common second output terminal com2. The controller 260 electrically connects the common first output terminal com1 and the common second output terminal com2 internally to make the first sensing electrode line 220-3 and the second sensing electrode line 230-2 The controller 260 is internally electrically connected to cause the controller 260 to perform self capacitance touch sensing. In other embodiments, the first sensing electrode line 220-3 and the second sensing electrode line 230-2 may also be electrically connected outside the controller 260.

As shown in FIG. 4, although the first sensing electrode line 220-3 and the second sensing electrode line 230-2 are not directly electrically connected, the first sensing electrode line 220-3 is switched by the first switching. The device 241-3 is electrically connected to the common first output terminal com1, and is internally connected to the common second output terminal com2 via the controller 260, and is connected to the second sensing electrode line 230 via the second switch 251-2. -2. As shown at circle A in Figure 4, this can form a sensing point on the panel 210.

At different time points, the second sensing electrode lines 230-1, 230-2, ..., 230-N and the first sensing electrode lines 220-1, 220-2, 220-3, ..., 220, respectively -M electrical connection, resulting in a plurality of sensing points. When the controller 260 controls the first sensing electrode line 220 and the second sensing electrode line 230 to perform electrical connection for touch detection, it takes a time of microsecond (μs) level, and a user's finger motion It is hundreds of milliseconds (ms) to even a few seconds. Although only one second sensing electrode line 230 is electrically connected to a first sensing electrode line 220 at a specific time, the controller 260 can control all of the first ones on the plane 210 during a touch of a user's finger. The sensing electrode line 220 and all of the second sensing electrode lines 230 are electrically connected one by one. Since there are M first sensing electrode lines in the first direction and N second sensing electrode lines in the second direction, M×N sensing points can be formed, where M and N are integers greater than 1. The M x N sensing points may form a touch sensing plane.

When a touch point is located at the intersection of the ith first sensing electrode line and the jth second sensing electrode line, the first sensing electrode line is located at the ith first The electrical signal sensed by the sensing point of the jth second sensing electrode line is larger than the electrical signal sensed by the touch point at the first sensing electrode line of the i-th but different from the intersection of the sensing point. Similarly, the electrical signal sensed by the touch point at the sensing point of the ith first sensing electrode line and the jth second sensing electrode line is located at the jth second sensing electrode line but different from the touch point. The electrical signals sensed by other locations at the intersection of the sensing points are large.

When a sensing point is located at the intersection of the ith first sensing electrode line and the jth second sensing electrode line, the touch point is located at the ith first sensing electrode line but different from the sensing point intersection. The electrical signal sensed at other places is greater than the electrical signal detected by the touch point at the first sensing electrode line other than the ith first sensing electrode line and not the jth second sensing electrode line; and the touch point is located The electrical signal detected by the j-th second sensing electrode line but different from the other portion of the sensing point intersection is located at a position other than the first sensing electrode line other than the first sensing electrode line and not the j-th article The electrical signal sensed at the second sensing electrode line is large.

FIG. 5 is a schematic diagram of the sensing point detection of the present invention. As shown in FIG. 5, the second sensing electrode line 230-2 is electrically connected to the first sensing electrode line 220-3. When a touch point (finger) is located at a different position, the intersection of the ith first sensing electrode line (220-3) and the jth second sensing electrode line (230-2) (circle B) is located The sensing signal (circle B) of the first sensing electrode line (220-3) and the jth second sensing electrode line (230-2) induces an electrical signal that is higher than the first sensing electrode located at the ith first The line (220-3) is different from the other points (circle E, circle J) of the sensing point (circle B). At the same time, the electrical signal sensed by the sensing point (circle B) of the first sensing electrode line (220-3) and the second sensing electrode line (230-2) of the ith strip is higher than that of the Two sensing electrode lines (230-2) The electrical signal induced by the other points (circle C, circle D, circle A, circle H) different from the sensing point (circle B) is large. That is, SigB>SigC and SigB>SigE, where SigB is the electrical signal sensed by the touch point for circle B, SigC is the electrical signal sensed by the touch point for circle C, and SigE is the touch point for circle E. Inductive electrical signal.

When a touch point (finger) is located at a different position, the intersection of the ith first sensing electrode line (220-3) and the jth second sensing electrode line (230-2) (circle B) is located The first sensing electrode line (220-3) of the i-th sense is different from the other sensing point (circle B) (the circle E) senses an electrical signal that is different from the first sensing electrode line that is not the i-th ( 220-3) and the electrical signal induced by the second sensing electrode line (230-2) of the jth (circle F) is large, and is located at the jth second sensing electrode line (230-2) but different from The other part of the sensing point (circle B) (circle C) induces an electrical signal that is greater than the first sensing electrode line (220-3) that is not the i-th and not the j-th second sensing electrode line ( The electrical signal sensed at 230-2) (circle F) is large. That is, SigE>SigF and SigC>SigF, among which SigF is an electrical signal sensed by the touch point being the circle F. Similarly, SigB>SigH, SigB>SigJ, SigB>SigA, SigB>SigD, SigE>SigI, SigE>SigG, SigE>SigF>SigG, among which SigX is the electrical signal sensed by the circle X.

As can be seen from the foregoing description, when a touch point is located at the circle B, the electrical signal induced by it is larger than the electrical signal induced by the surrounding touch point, and is also much larger than the sensing point that is not touched. Or the electrical signal that the touch point is not sensing on the detected electrode line. Therefore, the touch detection of the panel 210 can be performed in a time-sharing manner according to the foregoing principle. At the same time, the first direction and the second direction only need to intersect an angle. In this embodiment, the first Preferably, the direction is perpendicular to the second direction.

Figure 6 is a flow chart of the touch detection of the present creation. First, in step S610, the controller 260 initializes the index variables m, n, where m is a positive integer and 1 ≦ m ≦ M, n is a positive integer and 1 ≦ n ≦ N, the controller in this step The 260 system initializes the index variables m and n to 1.

In step S620, the controller 260 sets the mth first switch 241 to connect the mth first sensing electrode line 220 to the common first output terminal com1.

In step S630, the controller 260 sets the nth second switch 251 to connect the nth second sensing electrode line 230 to the common second output terminal com2.

In step S640, the controller 260 performs self-capacitance touch sensing on the sensing points formed at the intersection of the mth first sensing electrode line 220 and the nth second sensing electrode line 230.

In step S650, the controller 260 determines whether the index variable n is less than or equal to N. If yes, step S660 is executed to increment the index variable n by one, and then step S630 is performed. If not, step S670 is performed.

In step S670, the controller 260 determines whether the index variable m is less than or equal to M. If yes, step S680 is executed to increment the index variable m by one, and then step S620 is performed, and if no, step S690 is performed.

In step S690, the controller 260 performs touch detection. Accordingly, the controller 260 can obtain MxN touch detection values. In the MxN touch detection values, if there is more than one threshold, the corresponding sensing point can be considered as a touch. Thereby the controller 260 can complete the touch on the panel 210 Touch detection, but also avoid ghosts.

7A to 7C are another schematic diagrams of the sensing point detection of the present invention. It performs touch detection for a single sensing point location. As shown in FIG. 7A, the controller 260 sets the switches 241, 251 at the first time (T1) to electrically connect the first sensing electrode line 220-3 with the second sensing electrode line 230-2. The controller 260 performs self-capacitance touch sensing to obtain a sensing value Sig_cross.

As shown in FIG. 7B, the controller 260 sets the switches 241, 251 at a second time (T2) to electrically connect the first sensing electrode line 220-3 to the common first output terminal com1, and the second The sensing electrode line 230-2 is disconnected from the common second output terminal com2. The controller 260 performs self-capacitance touch sensing on the first sensing electrode line 220-3 to obtain a sensing value Sig_single1.

As shown in FIG. 7C, the controller 260 sets the switches 241, 251 at a third time (T3) to disconnect the first sensing electrode line 220-3 from the common first output terminal com1, and the second sensing The electrode line 230-2 is electrically connected to the common second output terminal com2. The controller 260 performs self-capacitance touch sensing on the second sensing electrode line 230-2 to obtain a sensing value Sig_single2.

When the finger touches the circle B, the sensed value Sig_cross is greater than the sensed values Sig_single1, Sig_single2. The controller 260 determines whether |Sig_cross-Sig_single1|>Th1 and |Sig_cross-Sig_single2|>Th1 are all established. If all of them are established, the controller 260 can determine that there is a touch point at the circle B, and Th1 is a threshold. value.

When there is no touch point at the circle B, the sensed value Sig_cross is not much different from the sensed values Sig_single1 and Sig_single2, so |Sig_cross- Sig_single1|>Th1, |Sig_cross-Sig_single2|>Th1 cannot be established at the same time. Therefore, when Sig_single1|>Th1, |Sig_cross-Sig_single2|>Th1 cannot be established at the same time, the controller 260 can determine that there is no touch point at the circle B.

FIG. 8 is another flow chart of the touch detection of the present creation. It is based on the touch detection technology of FIGS. 7A to 7C. First, in step S810, the controller 260 initializes the index variables m, n, where m is a positive integer and 1 ≦ m ≦ M, n is a positive integer and 1 ≦ n ≦ N, the controller in this step The 260 system initializes the index variables m and n to 1.

In step S820, the controller 260 sets the mth first switch 241 to connect the mth first sensing electrode line 220 to the common first output terminal com1. The controller 260 sets the nth second switch 251 to connect the nth second sensing electrode line 230 to the common second output terminal com2. The controller 260 performs self-capacitance touch sensing to obtain a sensed value Sig_cross.

In step S830, the controller 260 sets the mth first switch 241 to connect the mth first sensing electrode line 220 to the common first output terminal com1. The controller 260 sets the nth second switch 251 to disconnect the nth second sensing electrode line 230 from the common second output terminal com2. The controller 260 performs self-capacitance touch sensing to obtain a sensing value Sig_single1.

In step S840, the controller 260 sets the mth first switch 241 to disconnect the mth first sensing electrode line 220 from the common first output terminal com1. The controller 260 sets the nth second switch 251 to connect the nth second sensing electrode line 230 to the common second output end. Com2. The controller 260 performs self-capacitance touch sensing to obtain a sensing value Sig_single2.

In step S850, the controller 260 performs a touch point determination. The controller 260 determines whether |Sig_cross-Sig_single1|>Th1 and |Sig_cross-Sig_single2|>Th1 are all true, and if yes, the controller 260 can determine the mth first sensing electrode line 220 and the nth There is a touch point at the intersection of the two sensing electrode lines 230. If the non-uniformity is established, the controller 260 can determine that there is no touch point at the intersection of the mth first sensing electrode line 220 and the nth second sensing electrode line 230.

In step S860, the controller 260 determines whether the index variable n is less than or equal to N. If yes, step S870 is executed to increment the index variable n by one, and then step S820 is performed. If not, step S880 is performed.

In step S880, the controller 260 determines whether the index variable m is less than or equal to M. If yes, step S890 is executed to increment the index variable m by one, and then step S820 is performed, and if not, the flow is ended.

It can be seen from the foregoing description that the self-capacitance multi-touch structure utilizes the first switcher group and the second switcher group to electrically connect the first sensing electrode line and the second sensing electrode line, and form MxN on the panel. A sensing point that avoids the ghost points generated when the touch is detected, thereby improving the correctness of the sensing.

The above-described embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

200‧‧‧ self-capacitor multi-touch structure

210‧‧‧ panel

220‧‧‧first sensing electrode line

230‧‧‧Second sensing electrode line

240‧‧‧First switcher group

250‧‧‧Second switcher group

260‧‧‧ Controller

241‧‧‧ first switcher

251‧‧‧Second switcher

Com1‧‧‧ common first output

Com2‧‧‧Common second output

A‧‧‧first end

B‧‧‧second end

c‧‧‧Control terminal

Claims (10)

A self-capacitance multi-touch structure includes: a panel; a plurality of first sensing electrode lines are disposed on the panel according to a first direction; and a plurality of second sensing electrode lines are disposed according to a second direction a first switcher group having a plurality of first switchers, a first end of each of the first switchers being connected to a corresponding first sense electrode line, and a second of each first switcher The end is connected to a common first output; a second switcher group has a plurality of second switches, and a first end of each second switch is connected to a corresponding second sensing electrode line, each of the first a second end of the second switch is connected to a common second output; and a controller is connected to a control end of each of the first switchers of the first switcher group, and each of the second switcher groups a control terminal of the second switch, the common first output terminal, and the common second output terminal, to control whether the plurality of first switchers are electrically connected to the common first output terminal, and control the plurality of Whether the second converter is electrically connected to the common a second output end, wherein the controller sets a control end of the plurality of switchers to enable a second sensing of the first sensing electrode line of the plurality of first sensing electrode lines and the plurality of second sensing electrode lines The electrode wires are electrically connected and the touch sensing is performed. The self-capacitance multi-touch structure according to claim 1, wherein the controller sets the control ends of the plurality of first switches and the plurality of second switches to make the first sensing electrode The line and the one second sensing electrode line are electrically connected inside or outside the controller to perform touch sensing. The self-capacitance multi-touch structure of claim 2, wherein the controller generates a touch driving signal to the first sensing electrode line and the second sensing electrode line, and the first sensing The electrode line and the second sensing electrode line receive the sensed electrical signal for self-capacitance touch sensing. The self-capacitance multi-touch structure of claim 3, wherein there are M first sensing electrode lines in the first direction and N second sensing electrode lines in the second direction, The intersection of the M first sensing electrode lines and the N second sensing electrode lines is non-electrically connected, and the intersections overlap to form M×N sensing points, where M and N are integers greater than 1. The self-capacitance multi-touch structure according to claim 4, wherein when a touch point is located at the intersection of the ith first sensing electrode line and the jth second sensing electrode line, The electrical signals sensed by the sensing points of the first sensing electrode line and the jth second sensing electrode line are located at the intersection of the first sensing electrode line of the i-th but different from the sensing point. The electrical signal sensed by the location is large. When the touch point is located at the sensing point of the ith first sensing electrode line and the jth second sensing electrode line, the electrical signal induced by the touch point is located at the jth second. The electrical signal sensed by the sensing electrode line but different from the other locations where the sensing point meets is large. The self-capacitance multi-touch structure according to claim 5, wherein when a sensing point is located at the intersection of the ith first sensing electrode line and the jth second sensing electrode line, the touch The electrical signal sensed when the point is located at the first sensing electrode line of the i-th but different from the intersection of the sensing point is located at the first sensing electrode line other than the first sensing electrode line than the touch point and is not the j-th The electrical signal sensed at the second sensing electrode line is large; and the electrical signal sensed when the touch point is located at the jth second sensing electrode line but different from the intersection of the sensing point is more than the touch The electrical signal that is located at the first sensing electrode line other than the ith first sensing electrode line and not at the jth second sensing electrode line is large. The self-capacitance multi-touch structure of claim 1, wherein each switch comprises a pin, a resistor, a first diode, a second diode, and a switch. The self-capacitance multi-touch structure according to claim 7, wherein the pin is connected to a corresponding sensing electrode line, and one end of the resistor is connected to the pin, and the anode of the first diode is connected. To the other end of the resistor, the cathode is connected to a high potential, the cathode of the second diode is connected to the other end of the resistor, the anode is connected to a low potential, and one end of the switch is connected to the other end of the resistor. The other end is connected to the common output, and its control end is connected to the controller. The self-capacitance multi-touch structure of claim 2, wherein the first direction intersects the second direction by an angle. The self-capacitance multi-touch structure according to claim 9, wherein the first direction is perpendicular to the second direction.