TWI727662B - Resistive touch device and resistive touch-sensing method - Google Patents

Abstract

A resistive touch-sensing method includes providing a bias voltage to one of adjacent two first electrodes and measuring the other of the adjacent two first electrodes and two second electrodes to obtain a first and a second voltage signals corresponding to two touch points and a third voltage signal corresponding to one of the two touch points, calculating a first resistance ratio of a first resistor, a second resistor, and a third resistor according to the bias voltage, the first voltage signal, the second voltage signal, and the third voltage signal, and generating coordinates of the two touch points according to the first resistance ratio. Herein, the two touch points occur simultaneously at the junction of the two first electrodes, and the first resistor, the second resistor and the third resistor are formed by dividing the first electrode by the two touch points.

Description

Resistive touch device and resistive touch sensing method

The present invention relates to a resistive touch technology, in particular to a resistive touch device and a resistive touch sensing method.

Commonly used touch technologies on touch devices can be divided into two categories: resistive touch technologies and capacitive touch technologies according to their sensing methods. Although the current mainstream is projected capacitive touch technology, its cost is high, it is not suitable for thick gloves, and its ability to resist noise is poor. However, there are many noise sources in the application of touch devices, such as power noise, radio frequency signal noise, liquid crystal display (LCD) noise, mechanism deformation noise, water or liquid noise, etc. . Relatively speaking, the performance of Analog Matrix Resistive (AMR) touch technology in the face of the aforementioned noise is better than that of projected capacitive touch technology. In certain industrial or military defense applications, anti-interference ability and coordinate reporting accuracy are the first considerations, so the analog matrix resistive touch technology is the first choice.

The resistive touch device is composed of upper and lower two ITO (Indium Tin Oxide, indium tin oxide) conductive films laminated together. The two ITO conductive films are planar resistors and do not touch each other in a natural state. When the user applies force to touch the resistive touch device, the positions of the two ITO conductive films corresponding to the touch points will touch each other, and thus the coordinates of the touch points are obtained. Currently, most resistive touch devices have a single-touch detection architecture, and it is difficult to implement multi-touch operations.

In one embodiment, a resistive touch sensing method includes: providing a bias voltage to one of two adjacent first electrodes and measuring the other of the two second electrodes and the two first electrodes to obtain A first voltage signal and a second voltage signal corresponding to two contact pressure points and a third voltage signal corresponding to one of the two contact pressure points, according to the bias voltage, the first voltage signal, the second voltage signal, and the third voltage The signal calculates a first resistance ratio of a first resistance, a second resistance and a third resistance, and generates the coordinates of the two contact pressure points according to the first resistance ratio. Wherein, the two contact pressure points occur at the junction of the two first electrodes at the same time, and the first resistance, the second resistance and the third resistance are formed by dividing the first electrode by the two contact pressure points.

In one embodiment, a resistive touch device includes: a plurality of first electrodes, a plurality of second electrodes, and a control circuit. The first electrodes are arranged along a first direction. The second electrodes are arranged along a second direction. The second electrode overlaps the first electrode at intervals. Here, the first direction is substantially perpendicular to the second direction. The junction of two adjacent first electrodes among the plurality of first electrodes simultaneously touches two second electrodes among the plurality of second electrodes to form two contact points. The control circuit is coupled to the first electrode and the second electrode, and the control circuit is used to perform: provide a bias voltage to one of the two adjacent first electrodes and measure the two second electrodes corresponding to the two contact pressure points and the adjacent The other of the two first electrodes is used to obtain a first voltage signal and a second voltage signal corresponding to the two contact pressure points and a third voltage signal corresponding to one of the two contact pressure points, according to the bias voltage and the first voltage The signal, the second voltage signal, and the third voltage signal calculate a first resistance ratio of a first resistance, a second resistance, and a third resistance, and generate coordinates of two contact pressure points according to the first resistance ratio. Wherein, the first resistor, the second resistor, and the third resistor are formed by dividing the first electrode by two contact pressure points.

To sum up, according to the resistive touch device and resistive touch sensing method of the present invention, three-point voltage signals (ie, the first voltage signal, the second voltage signal, and the third voltage signal) are used, and there is no need to The additional fourth point of voltage information is used to generate the correct coordinates of the two contact pressure points occurring at the junction of two adjacent electrodes. In some embodiments, according to the resistive touch device and resistive touch sensing method of the present invention, only one end of the electrode to be measured needs to be connected to the analog-to-digital converter, and both ends are not required to be connected to the analog-to-digital converter. Analog-to-digital converters, so there is no need to increase the use of multiplexers, or use a control chip (IC) with less hardware functions and a cheaper price, thereby reducing the area size of the control board (ie control circuit) and reducing the hardware Body cost.

First, the resistive touch sensing method according to any embodiment of the present invention can be adapted to resistive touch devices, such as but not limited to smart phones, navigation devices (PND), and e-books. ), the user interface of electronic devices such as notebooks, tablets or pads or smart home appliances. In some embodiments, the resistive touch device can be integrated with the display to form a touch screen. In addition, the touch of the resistive touch device may be a touch element such as a hand, a stylus pen, or a touch brush.

1, a resistive touch device includes a control circuit 12 and a signal sensor 14. The signal sensor 14 is connected to the control circuit 12. The signal sensor 14 includes two sensing layers in a superimposed configuration, and each sensing layer has a plurality of electrodes. Taking an eight-wire resistive signal sensor as an example, the signal sensor 14 includes a plurality of first electrodes Y1 to Y8 (ie, one sensing layer) and a plurality of second electrodes X1 to X8 (ie, another sensing layer). Each of the first electrodes Y1 to Y8 extends along a first direction (ie, the X-axis direction), and the first electrodes Y1 to Y8 are arranged parallel to each other along a second direction (ie, the Y-axis direction). The second electrodes X1 to X8 extend along the second direction, and the second electrodes X1 to X8 are arranged parallel to each other along the first direction. Wherein, the first direction is substantially perpendicular to the second direction. Here, the first electrodes Y1 to Y8 overlap the second electrodes X1 to X8 at intervals. For example, the first electrodes Y1 to Y8 are located above the second electrodes X1 to X8 at intervals.

Under normal operation, the control circuit 12 sequentially applies a bias voltage to the first electrodes Y1~Y8 and measures the second electrodes X1~X8 to detect the coordinates of the touch point in the second direction (ie, Y-axis coordinates) . Then, the control circuit 12 sequentially applies a bias voltage to the second electrodes X1 to X8 and measures the first electrodes Y1 to Y8 to detect the coordinates of the touch point in the first direction (ie, the X-axis coordinates). In some embodiments, the control circuit 12 includes a driving and measuring circuit 121 and a processing unit 123. The driving and measuring circuit 121 is coupled to the first electrodes Y1 to Y8 and the second electrodes X1 to X8. The processing unit 123 is used for controlling the driving and measuring circuit 121 to drive and measure the electrodes.

When the signal sensor 14 is touched, the first electrode Yi and the second electrode Xj at the touched position touch each other to form a touched point. Wherein, i is a positive integer from 1 to 8, and j is a positive integer from 1 to 8. When the driving and measuring circuit 121 applies a bias voltage to the first electrode Yi corresponding to the contact pressure point (that is, one end of the first electrode Yi is coupled to the power supply voltage, and the other end of the first electrode Yi is coupled to the ground), The driving and measuring circuit 121 can measure a voltage signal from the second electrode Xj corresponding to the contact pressure point, and generate the coordinates of the contact pressure point in the second direction according to the voltage signal. When the driving and measuring circuit 121 applies a bias voltage to the second electrode Xj corresponding to the contact point (that is, one end of the second electrode Xj is coupled to the power supply voltage, and the other end of the second electrode Xj is coupled to the ground), The driving and measuring circuit 121 can measure a voltage signal from the first electrode Yi corresponding to the contact pressure point, and generate the coordinates of the contact pressure point in the first direction according to the voltage signal.

In other words, referring to FIGS. 1 and 2, when the control circuit 12 detects the touch point of the signal sensor 14, under the control of the processing unit 123, the driving and measuring circuit 121 first applies a bias voltage to the first electrode Y1 (Step S11) and measure the second electrodes X1~X8 (Step S12) to confirm whether a voltage signal is measured from any of the second electrodes (Step S13). At this time, the rest of the first electrodes Y2 to Y8 are floating. After the measurement, under the control of the processing unit 123, the driving and measurement circuit 121 then applies a bias voltage to the next first electrode Y2 (step S11) and measures the second electrodes X1~X8 (step S12) to confirm whether A voltage signal is measured from any second electrode (step S13). At this time, the remaining first electrodes Y1, Y3~Y8 are floating. After the measurement, under the control of the processing unit 123, the driving and measurement circuit 121 applies a bias voltage to the next first electrode Y3 (step S11) and measures the second electrodes X1~X8 (step S12) to confirm whether A voltage signal is measured from any second electrode (step S13). At this time, the remaining first electrodes Y1~Y2, Y4~Y8 are floating. And so on, until under the control of the processing unit 123, the driving and measuring circuit 121 applies a bias voltage to the last first electrode Y8 (step S11) and measures the second electrodes X1~X8 (step S12) to confirm whether A voltage signal is measured from any second electrode (step S13). At this time, the rest of the first electrodes Y1 to Y7 are floating.

Wherein, when the driving and measuring circuit 121 measures a voltage signal from a second electrode (one of X1~X8) (that is, the voltage signal measured from the second electrode is greater than 0 volts), it means the current driving A contact pressure point occurs on the first electrode; at this time, the driving and measuring circuit 121 further generates the coordinates of the contact pressure point in the second direction (ie, Y-axis coordinates) according to the measured voltage signal (step S15). Conversely, when the voltage measured by the driving and measuring circuit 121 from the second electrode (one of X1 to X8) is 0 volts, it means that there is no contact pressure point on the first electrode that is currently driven.

After completing the measurement of the second electrodes X1~X8 under the driving of each first electrode, referring to Figs. 1 and 3, under the control of the processing unit 123, the driving and measuring circuit 121 then applies a bias voltage to the second electrode X1 ( Step S21) and measure the first electrodes Y1 to Y8 (step S22) to confirm whether a voltage signal is measured from any of the first electrodes (step S23). At this time, the rest of the second electrodes X2 to X8 are floating. Then, under the control of the processing unit 123, the driving and measuring circuit 121 applies a bias voltage to the next second electrode X2 (step S21) and measures the first electrodes Y1 to Y8 (step S22) to confirm whether any A first electrode measures the voltage signal (step S23). At this time, the rest of the second electrodes X1, X3~X8 are floating. Then, under the control of the processing unit 123, the driving and measuring circuit 121 applies a bias voltage to the next second electrode X3 (step S21) and measures the first electrodes Y1 to Y8 (step S22) to confirm whether any A first electrode measures the voltage signal (step S23). At this time, the rest of the second electrodes X1~X2, X4~X8 are floating. And so on, until under the control of the processing unit 123, the driving and measuring circuit 121 applies a bias voltage to the last second electrode X8 (step S21) and measures the first electrodes Y1~Y8 (step S22) to confirm whether A voltage signal is measured from any first electrode (step S23). At this time, the rest of the second electrodes X1 to X7 are floating.

Wherein, when the driving and measuring circuit 121 measures the voltage signal from the first electrode (one of Y1 to Y8) (that is, the voltage signal measured from the first electrode is greater than 0 volts), it represents the current driving A contact pressure point occurs on the two electrodes; at this time, the driving and measuring circuit 121 further generates the coordinates of the contact pressure point in the first direction (ie, X-axis coordinates) according to the measured voltage signal (step S25). Conversely, when the voltage measured by the driving and measuring circuit 121 from the first electrode (one of Y1 to Y8) is 0 volts, it means that there is no contact pressure point on the second electrode that is currently driven.

For example, when a single finger or pen is pressed on the signal sensor 14, the dot in the middle of the two sensing layers is squeezed so that the upper and lower electrodes Xj and Yi at the pressed position are turned on, that is, a touch pressure The point occurs, as shown in Figure 4.

Assume that a touch pressure point Ta occurs on the signal sensor 14, as shown in FIG. 5.

At this time, when the driving and measuring circuit 121 applies a bias voltage to the first electrode Y3 (ie i=3) corresponding to the contact pressure point, the driving and measuring circuit 121 can switch from the second electrode X5 (ie j=5) The voltage signal corresponding to the touch point Ta is read, and the coordinate in the second direction, namely the Y coordinate, is generated accordingly. In other words, referring to FIG. 6, the two ends of the first electrode Y3 are respectively coupled to the power supply voltage VCC and the ground GND to drive the first electrode Y3. Here, the other first electrodes Y1, Y2, Y4~Y8 are floating. When the first electrode Y3 is driven, the second electrode X5 is coupled to an analog-to-digital converter (ADC) 1211 to read a voltage signal from the second electrode X5. At this time, the circuit model of the signal sensor 14 is shown in FIG. 7; wherein, the resistance Ry1 represents the impedance and wiring of the section of the first electrode Y3 between the contact pressure point Ta and the power supply voltage VCC (such as a control board). The sum of the impedances of traces and silver paste traces, etc. The resistance Ry2 represents the impedance and traces (such as control board traces and silver paste traces) of the section of the first electrode Y3 from the contact pressure point Ta to the ground GND The sum of the impedance of the wire, etc.) and the resistance Rx represent the sum of the impedance of the section from the contact pressure point Ta to the second electrode X5 between the analog-to-digital converter 1211 and the impedance of the trace. Therefore, the driving and measuring circuit 121 can obtain the Y coordinate according to the measured voltage signal by using the principle of resistance voltage division.

Similarly, when the driving and measuring circuit 121 applies a bias voltage to the second electrode X5 (that is, j=5) corresponding to the contact pressure point, the driving and measuring circuit 121 can start from the first electrode Y3 (that is, i=3). The voltage signal corresponding to the touch point Ta is read, and the coordinate in the first direction, that is, the X coordinate, is generated accordingly. In other words, referring to FIG. 8, the two ends of the second electrode X5 are respectively coupled to the power supply voltage VCC and the ground GND to drive the second electrode X5. Here, the other second electrodes X1~X4, X6~X8 are floating. When the second electrode X5 is driven, the first electrode Y3 is coupled to an analog-to-digital converter (ADC) 1211 to read a voltage signal from the second electrode X5. At this time, the circuit model of the signal sensor 14 is shown in FIG. 9; wherein, the resistance Rx1 represents the sum of the impedance of the section of the second electrode X5 between the contact pressure point Ta and the power supply voltage VCC and the impedance of the trace. , The resistance Rx2 represents the sum of the impedance of the section of the second electrode X5 from the contact pressure point Ta to the ground GND and the impedance of the trace, and the resistance Ry represents the resistance between the contact pressure point Ta and the analog-to-digital converter 1211 The sum of the impedance of the section of the first electrode Y3 and the impedance of the trace. Therefore, the driving and measuring circuit 121 can obtain the X coordinate according to the measured voltage signal by using the principle of resistance voltage division.

When the driving and measuring circuit 121 applies a bias voltage to an electrode extending in one direction (that is, one of the first direction and the second direction), the measurement is performed in the other direction (that is, the one in the first direction and the second direction). Another) When the extended electrode measures two voltage signals (that is, the voltage of the two electrodes is greater than 0 volts), it means that two contact pressure points occur simultaneously on the signal sensor 14, and the processing unit 123 will execute Coordinate correction program. For example, when the driving and measuring circuit 121 applies a bias voltage to a first electrode (one of Y1 to Y8), it measures the second electrodes X1 to X8 and measures two voltage signals, that is, reads two voltage signals. When the voltage of the second electrode (two of X1 to X8) is greater than 0 volts, the control circuit 12 will execute the Y coordinate calibration procedure (step S16). Similarly, when the driving and measuring circuit 121 applies a bias voltage to a second electrode (one of X1 to X8), the first electrode Y1 to Y8 is measured and the voltage signal is measured, that is, the second electrode is read. When the voltage of the electrodes (two of Y1 to Y8) is greater than 0 volts, the control circuit 12 will execute the coordinate correction procedure of the X coordinate (step S26).

The two contact pressure points occur on the signal sensor 14 at the same time. If the two contact pressure points happen to occur at the junction of two horizontal or vertical electrodes, for example, two fingers simultaneously press on the junction of two adjacent first electrodes Y2 and Y3 To form two contact pressure points Ta, Tb (as shown in Figure 10), or two fingers simultaneously press on the junction of two adjacent second electrodes X7, X8 to form two contact pressure points Ta, Tb (such as , Shown in Figure 12), the aforementioned circuit model in Figure 7 or Figure 9 is no longer valid.

Taking Figure 10 as an example, if the two contact pressure points Ta and Tb happen to be at the junction of two adjacent first electrodes Y2 and Y3, the dots between the two adjacent first electrodes Y2 and Y3 are formed by dots. The resistance varies with the pressure of the finger or pen, and the two adjacent first electrodes Y2 and Y3 form a parallel loop.

Here, referring to FIGS. 1, 2 and 11, when the driving and measuring circuit 121 applies a bias voltage to a first electrode Y2 to drive the first electrode Y2 (step S11), the circuit model of the signal sensor 14 is as follows Shown in Figure 14. In FIG. 14, since the impedance between the contact pressure points Ta and Tb and the analog-to-digital converter 1211 is a constant value, it is ignored. In this example, the resistance RT represents the resistance formed by the dot spacers between two adjacent first electrodes Y2 and Y3, and the resistance RU represents the distance between the end of the first electrode Y2 coupled to the power supply voltage VCC and the power supply voltage VCC. The resistance of the line, the resistance R1 represents the impedance of the section between the first electrode Y2 from the contact point Ta to the end of the first electrode Y2 coupled to the power supply voltage VCC (hereinafter referred to as the first resistance R1), and the resistance R2 represents the first electrode The impedance of the section Y2 between the two contact pressure points Ta and Tb (hereinafter referred to as the second resistance R2), the resistance R3 represents the first electrode Y2 from the contact pressure point Tb to the other end of the first electrode Y2 coupled to the ground GND The impedance of the middle section (hereinafter referred to as the third resistor R3), the resistor RD represents the impedance of the wiring between the other end of the first electrode Y2 coupled to the ground GND and the ground GND, and the resistor R4 represents the first electrode Y3 in the two The impedance of the section between the contact pressure points Ta and Tb (hereinafter referred to as the fourth resistor R4). Here, the second resistor R2 is substantially equal to the fourth resistor R4. In addition, the resistance Ra represents the sum of the resistance RU and the first resistance R1, that is, the impedance of the wiring between one end of the first electrode Y2 coupled to the power supply voltage VCC and the power supply voltage VCC and the first electrode Y2 from the contact pressure point Ta to the first electrode Y2 One electrode Y2 is coupled to the sum of the impedances of the section at one end of the power supply voltage VCC. The resistance Rb represents the sum of the resistance RD and the third resistance R3, that is, the impedance of the wiring between the other end of the first electrode Y2 coupled to the ground GND and the ground GND and the first electrode Y2 from the contact pressure point Tb to the first electrode Y2 The sum of the impedances of the segments coupled to the other end of the ground GND. The resistance Rbar represents the sum of the first resistance R1, the second resistance R2, and the third resistance R3, that is, the impedance of the first electrode Y2.

For example, one end of the first electrode Y2 is coupled to the power supply voltage (VCC), and the other end of the first electrode Y2 is coupled to the ground, so as to drive the first electrode Y2. At this time, the two ends of the other first electrodes Y1, Y3 to Y8 are floating.

When the first electrode Y2 is driven, the driving and measuring circuit 121 measures the second electrodes X1~X8 (step S12), and measures the voltages corresponding to the two contact pressure points Ta and Tb from the two second electrodes X2 and X6 Signal (hereinafter referred to as the first voltage signal VA and the second voltage signal VB). That is, the driving and measuring circuit 121 reads that the voltages of the second electrodes X2 and X6 are greater than 0 volts, and the driving and measuring circuit 121 reads that the voltages of the other second electrodes X1, X3 to X5, X7, and X8 are 0 volts. At this time, the control circuit 12 starts to execute the coordinate correction program of the Y coordinate.

In the coordinate calibration procedure, the driving and measuring circuit 121 measures the adjacent first electrode Y3 when the first electrode Y2 is driven, and measures the voltage signal corresponding to the contact pressure point Ta (hereinafter referred to as the third voltage Signal VC) (step S161).

The processing unit 123 calculates the resistance ratio of the first resistor R1, the second resistor R2 and the third resistor R3 according to the bias voltage, the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC (hereinafter referred to as the first resistance ratio) (Step S162). In some embodiments, the processing unit 123 calculates the resistance ratio of the two traces of the two ends of the first electrode Y2 and the first electrode Y2 according to the bias voltage, the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC ( Hereinafter referred to as the second resistance ratio). Then, the processing unit 123 calculates the first resistance ratio based on the resistance value of the two wires (that is, the resistance value of the resistance RD, RU), the resistance value of the first electrode Y2 (that is, the resistance value of the resistance RD, RU), and the second resistance ratio. .

For example, the two ends of the first electrode Y2 are respectively coupled to the power supply voltage VCC and the ground GND, and then the second electrode X2, the second electrode X6, and the first electrode Y3 are connected to the analog-to-digital converter in turn, so that the analog-to-digital converter can The first voltage signal VA, the second voltage signal VB and the third voltage signal VC are obtained respectively. With reference to Figure 14, the following derivation formula can be obtained according to the circuit principle.

式1

Formula 1

Among them, Ra:R2:Rb represents the second resistance ratio. I1 is the current flowing through the resistor Ra. I2 is the current shunted by the current I1 to the resistor RT. I3 is the current that the current I1 shunts to the resistor R2.

In other words, the processing unit 123 can calculate the second resistance ratio (Ra:R2:Rb) using the bias voltage (here, the power supply voltage VCC), the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC according to Equation 1. .

Here, the sum of the resistance values of the impedances of the first electrode Y2 and the traces at its two ends, (i.e., RU+Rbar+RD) (i.e., the sum of the resistance values of the impedance between the power supply voltage VCC and the ground GND) is A known. For example, when the signal sensor 14 does not generate a contact pressure point, the driving and measuring circuit 121 applies a bias voltage to the first electrode Y2, and the driving and measuring circuit 121 obtains the first electrode Y2 when the first electrode Y2 is driven. The voltage value is obtained at the two ends of electrode Y2. In addition, the sum of the resistance values of the impedance of the first electrode Y2 and its two ends is measured in advance, so the processing unit 123 can use the voltage value of the two ends of the first electrode Y2 and the power supply voltage VCC according to the ohm definition and the principle of resistance division The sum of the resistance values of the impedance between grounding and GND (RU+Rbar+RD) is calculated to obtain the resistance value of the first electrode Y2 (that is, the resistance value of the resistance Rbar) and the resistance RU of the two ends of the first electrode Y2 , RD resistance value. In another example, the resistance value of the first electrode Y2 (that is, the resistance value of the resistance Rbar) and the resistance values of the resistances RU and RD of the two ends of the first electrode Y2 can also be designed in the signal sensor 14 The time is derived by the designer through theory and pre-stored in the storage unit.

Next, the processing unit 123 can use the known resistance value of the impedance of the first electrode Y2 (that is, the resistance value of the resistance Rbar) and the known resistance value of the wiring impedance (that is, the resistance RU) according to the following equations 2 to 4. , RD resistance value) and the second resistance ratio (Ra:R2:Rb) to calculate the first resistance ratio (R1:R2:R3).

式2

Formula 2

式3

Formula 3

式4

Formula 4

After obtaining the first resistance ratio (R1:R2:R3) (step S162), the processing unit 123 can generate the coordinates of the two contact pressure points Ta and Tb in the second direction (ie, the Y coordinate) according to the first resistance ratio. (Step S163).

In one embodiment, when the adjacent first electrode Y3 is measured while the first electrode Y2 is driven, after the coordinate correction is completed (that is, step S163), the driving and measuring circuit 121 then drives the phase The next first electrode Y4 next to the first electrode Y3 is used to detect whether there is a touch point.

In another embodiment, after the coordinate correction is completed (ie, step S163), the driving and measuring circuit 121 then detects the coordinates of the touch points Ta and Tb in the first direction (ie, the X coordinate), that is, The subsequent first electrodes Y3 to Y8 are not driven.

Similarly, taking Fig. 12 as an example, if the two contact pressure points Ta and Tb happen to be at the junction of two adjacent second electrodes X7 and X8, the point spacer between the two adjacent second electrodes X7 and X8 The resistance formed by (dot) will change its resistance value according to the pressure of the finger or pen, and the two adjacent second electrodes X7 and X8 will form a parallel circuit. 1, 3, and 13, when the driving and measuring circuit 121 applies a bias voltage to the second electrode X7 to drive the second electrode X7 (step S21), the circuit model of the signal sensor 14 is also shown in FIG. 14. Show. In this example, the resistance RT represents the resistance formed by the dot spacers between two adjacent second electrodes X7 and X8, and the resistance RU represents the distance between the end of the second electrode X7 coupled to the power supply voltage VCC and the power supply voltage VCC. The first resistance R1 represents the impedance of the section between the contact pressure point Ta of the second electrode X7 and the end of the second electrode X7 coupled to the power supply voltage VCC, and the second resistance R2 represents the second electrode X7 in the second contact The impedance of the section between the pressure points Ta and Tb, the third resistance R3 represents the impedance of the section between the second electrode X7 from the pressure point Tb to the other end of the second electrode X7 coupled to the ground GND, and the resistance RD represents The second electrode X7 is coupled to the impedance of the trace between the other end of the ground GND and the ground GND, and the fourth resistor R4 represents the impedance of the section of the second electrode X7 between the two contact points Ta and Tb. Here, the second resistor R2 is also substantially equal to the fourth resistor R4. Moreover, the resistance Ra represents the sum of the resistance RU and the first resistance R1, that is, the impedance of the wiring between the end of the second electrode X7 coupled to the power supply voltage VCC and the power supply voltage VCC and the second electrode X7 from the contact pressure point Ta to the first resistance The two electrodes X7 are coupled to the sum of impedances of one end of the power supply voltage VCC. The resistance Rb represents the sum of the resistance RD and the third resistance R3, that is, the impedance of the wiring between the other end of the second electrode X7 coupled to the ground GND and the ground GND and the second electrode X7 from the contact pressure point Tb to the second electrode X7 The sum of the impedances of the segments coupled to the other end of the ground GND. The resistance Rbar represents the sum of the first resistance R1, the second resistance R2, and the third resistance R3, that is, the impedance of the second electrode X7.

For example, one end of the second electrode X7 is coupled to the power supply voltage (VCC), and the other end of the second electrode X7 is coupled to the ground, so as to drive the second electrode X7. At this time, the two ends of the other second electrodes X1 to X6 and X8 are floating.

At this time, when the driving and measuring circuit 121 measures the first electrodes Y1 to Y8 under the driving of the second electrode X7 (step S22), the driving and measuring circuit 121 can measure the two voltage signals (ie, the first voltage). The signal VA and the second voltage signal VB), that is, it is read that the voltage of the two first electrodes Y3 and Y7 is greater than 0 volts. Therefore, the control circuit 12 executes the coordinate correction procedure of the X coordinate (step S26).

In the coordinate calibration procedure, the driving and measuring circuit 121 measures the adjacent second electrode X8 under the driving of the second electrode X7, and measures the voltage signal corresponding to the contact pressure point Ta (hereinafter referred to as the third voltage Signal VC) (step S261).

Then, the processing unit 123 calculates the resistance ratio of the first resistor R1, the second resistor R2, and the third resistor R3 based on the bias voltage, the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC (hereinafter referred to as the first resistor Proportion) (step S262). In some embodiments, the processing unit 123 calculates the resistance ratio of the two wires at the two ends of the second electrode X7 and the second electrode X7 according to the bias voltage, the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC ( Hereinafter referred to as the second resistance ratio). Then, the processing unit 123 calculates the first resistance ratio based on the resistance value of the two wires (ie the resistance value of the resistors RU and RD), the resistance value of the second electrode X7 (ie the resistance value of the resistors RU and RD) and the second resistance ratio. . For example, the processing unit 123 can calculate the second resistance ratio (Ra:R2) using the bias voltage (here, the power supply voltage VCC), the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC according to the aforementioned formula 1. : Rb), and then use the known resistance value of the impedance of the second electrode X7 (ie, the resistance value of the resistance Rbar), the resistance value of the known trace resistance RU and RD according to the aforementioned formulas 2 to 4, and The second resistance ratio (Ra:R2:Rb) calculates the first resistance ratio (R1:R2:R3).

After obtaining the first resistance ratio (R1:R2:R3) (step S262), the processing unit 123 can generate the coordinates of the two contact pressure points Ta and Tb in the first direction (ie, the X coordinate) according to the first resistance ratio. (Step S263).

In some embodiments, the driving and measuring circuit 121 may include a multiplexer (not shown), a voltage source (that is, it provides a power supply voltage VCC), a ground GND, and an analog-to-digital converter 1211. In normal operation, the processing unit 123 controls the operation of the multiplexer, so that the two ends of the electrode are coupled to the voltage source and the ground GND through the multiplexer; at this time, the driving and measuring circuit 121 can provide a bias voltage by the voltage source Give the coupled electrode to drive this electrode. In addition, under the driving of the electrodes in one direction, the processing unit 123 controls the operation of the multiplexer so that the electrodes extending in the other direction are coupled to the analog-to-digital converter 1211 through the multiplexer; at this time, the analog-to-digital converter 1211 can The voltage signal of the electrode corresponding to the contact pressure point is received and the corresponding coordinate is generated accordingly. In the coordinate calibration procedure, the processing unit 123 controls the operation of the multiplexer, so that the two ends of the electrodes are coupled to the voltage source and the ground GND through the multiplexer; at this time, the driving and measuring circuit 121 can be biased by the voltage source. Press the coupled electrode to drive the electrode. Moreover, under the driving of the electrodes in one direction, the processing unit 123 controls the operation of the multiplexer, so that the electrodes extending in the other direction are coupled to the processing unit 123 via the multiplexer; at this time, the processing unit 123 can receive the corresponding touch pressure According to the voltage signal of the electrode of the point, the aforementioned calculation is performed.

In some embodiments, the processing unit 123 may be a microprocessor, a microcontroller, a digital signal processor, a central processing unit, a programmable logic controller, an analog circuit, a digital circuit, or any analog and/or operation signal based on operation instructions. Or digital device.

In some embodiments, one or more storage units may be provided inside and/or outside the processing unit 123. Here, the storage unit is used to store related software/firmware programs, data, data, and combinations thereof. Each storage unit can be realized by memory.

It should be clear that the "first" and "second" mentioned in the aforementioned terms are only used to distinguish two elements of the same term, and are not used to limit a specific element. For example, under the same operating principle, X1~X8 can also be renamed as the first electrode, and Y1~Y8 can be renamed as the second electrode.

In summary, according to the resistive touch device and resistive touch sensing method of the present invention, three-point voltage signals (ie, the first voltage signal VA, the second voltage signal VB, and the third voltage signal VC) are used , There is no need for additional fourth point voltage information to generate the correct coordinates of the two contact pressure points Ta and Tb occurring at the junction of two adjacent electrodes. In some embodiments, according to the resistive touch device and resistive touch sensing method of the present invention, only one end of the electrode to be measured needs to be connected to the analog-to-digital converter, and both ends are not required to be connected to the analog-to-digital converter. Analog-to-digital converter, so there is no need to increase the use of multiplexers, or use a control chip (IC) with fewer hardware functions and a cheaper price, thereby reducing the area of the control board (ie, the control circuit 12) and reducing Hardware cost.

12: Control circuit 14: Signal sensor 121: drive and measurement circuit 123: Processing Unit 1211: Analog-to-digital converter X1~X8: second electrode Y1~Y8: first electrode Xj: second electrode Yi: first electrode Ta: contact point Tb: contact point VCC: power supply voltage GND: Ground Rx: resistance Ry1: resistance Ry2: resistance Rx1: resistance Rx2: resistance Ry: resistance RT: resistance RU: Resistance R1: resistance R2: resistance R3: resistance R4: resistance RD: Resistance Ra: resistance Rb: resistance Rbar: resistance VA: The first voltage signal VB: second voltage signal VC: third voltage signal I1: current I2: current I3: current S11~S16: steps S161~S163: steps S21~S26: steps S261~S263: steps

FIG. 1 is a schematic diagram of a resistive touch device according to an embodiment. FIG. 2 is a flowchart of a resistive touch sensing method according to an embodiment. FIG. 3 is a flowchart of a resistive touch sensing method according to another embodiment. FIG. 4 is a schematic diagram of forming contact pressure points according to an embodiment. FIG. 5 is a schematic diagram of a first exemplary example when the signal sensor of FIG. 1 is touched and pressed. FIG. 6 is a schematic diagram of an example of Y coordinate detection of the signal sensor of FIG. 5. FIG. FIG. 7 is a schematic diagram of a circuit model of the signal sensor of FIG. 6. FIG. FIG. 8 is a schematic diagram of an exemplary embodiment of the X-coordinate detection of the signal sensor of FIG. 5. FIG. FIG. 9 is a schematic diagram of an exemplary example of the circuit model of the signal sensor of FIG. 8. FIG. FIG. 10 is a schematic diagram of a second exemplary embodiment when the signal sensor of FIG. 1 is touched. FIG. 11 is a schematic diagram of an exemplary example when the signal sensor of FIG. 10 applies pressure. FIG. 12 is a schematic diagram of a third example of the signal sensor of FIG. 1 when it is pressed. FIG. 13 is a schematic diagram of an exemplary example when the signal sensor of FIG. 12 applies pressure. FIG. 14 is a schematic diagram of an exemplary example of the circuit model of the signal sensor of FIG. 11 or FIG. 13.

S11~S16: steps

S161~S163: steps

Claims (5)

A resistive touch sensing method includes: providing a bias voltage to one of two adjacent first electrodes and measuring all the second electrodes and the other one of the two adjacent first electrodes so as to obtain information from all the second electrodes. Two second electrodes among the electrodes obtain a first voltage signal and a second voltage signal corresponding to two contact pressure points, and obtain a third voltage signal corresponding to one of the two contact pressure points from the other first electrode, The two contact pressure points occur at the junction of the two first electrodes at the same time; according to the bias voltage, the first voltage signal, the second voltage signal, and the third voltage signal, a first resistance and a second resistance are calculated. A first resistance ratio of resistance to a third resistance, wherein the first resistance, the second resistance, and the third resistance are formed by dividing the first electrode by the two contact pressure points; and according to the first resistance ratio Generate the coordinates of the two contact pressure points. The resistive touch sensing method according to claim 1, wherein the first resistance, the second resistance and the third voltage signal are calculated according to the bias voltage, the first voltage signal, the second voltage signal, and the third voltage signal The step of the first resistance ratio of the third resistor includes: calculating the two ends of the first electrode and the first electrode according to the bias voltage, the first voltage signal, the second voltage signal, and the third voltage signal A second resistance ratio of the wire; and calculating the first resistance ratio according to the two resistance values of the two wires, a resistance value of the first electrode and the second resistance ratio. The resistive touch sensing method according to claim 2, wherein the first electrode and the first electrode are calculated according to the bias voltage, the first voltage signal, the second voltage signal, and the third voltage signal The step of the second resistance ratio of the two traces at the two ends is calculated according to the following formula:

, Where Ra represents the sum of the trace of one of the two ends of the first electrode and the first resistance, R2 represents the second resistance, and Rb represents the other of the two ends of the first electrode The sum of the trace and the third resistance, VCC represents the bias voltage, VA represents the first voltage signal, VB represents the second voltage signal, and VC represents the third voltage signal. The resistive touch sensing method according to claim 1, wherein each of the first electrodes extends in a first direction, and each of the second electrodes extends in a second direction, and the first direction is substantially perpendicular to the first direction. In two directions, each first electrode overlaps each second electrode at intervals, and the coordinates of the two contact pressure points are coordinates in the second direction. A resistive touch device includes: a plurality of first electrodes arranged along a first direction; a plurality of second electrodes arranged along a second direction, overlapping with the plurality of first electrodes at intervals, wherein the first direction is substantially Perpendicular to the second direction, the junction of two adjacent first electrodes of the plurality of first electrodes simultaneously touches two second electrodes of the plurality of second electrodes to form two contact pressure points; and a control circuit, coupled Connect the plurality of first electrodes and the plurality of second electrodes to perform: provide a bias voltage to one of the two adjacent first electrodes and measure the second electrode and the other of the two adjacent first electrodes Obtain a first voltage signal and a second voltage signal corresponding to the two contact pressure points from the two second electrodes corresponding to the two contact pressure points, and obtain one of the two contact pressure points from the other first electrode Calculate a first resistance ratio of a first resistance, a second resistance and a third resistance based on the bias voltage, the first voltage signal, the second voltage signal and the third voltage signal , Where the The first resistance, the second resistance and the third resistance are formed by dividing the first electrode by the two contact pressure points; and the coordinates of the two contact pressure points are generated according to the first resistance ratio.

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