CN101667086A - Touch screen and coordinate positioning method - Google Patents

Abstract

The invention relates to a touch screen and a coordinate positioning method. The sensing array layer comprises M multiplied by N capacitive sensors, wherein M columns of capacitive sensors are arranged along the first axis direction, and N rows of capacitive sensors are arranged along the second axis direction. The microprocessor comprises a plurality of pins correspondingly coupled with the capacitive sensor. When the touch screen is touched to cause at least one sensing value of the capacitive sensor in the sensing array layer to change, the microprocessor performs interpolation calculation by using the sensing value sensed by the capacitive sensor to determine a touched coordinate. The invention can realize the coordinate positioning which can be carried out by the traditional method only needing two induction layers only by one induction layer. Not only improves the sensing resolution, but also further reduces the manufacturing cost of the printed circuit board or the indium tin oxide glass in the prior art.

Description

Touch screen and coordinate positioning method

technical field

The present invention relates to a touch technology, and in particular to a touch screen and a coordinate positioning method.

Background technique

In recent years, due to the rapid development of technology, handheld devices, such as smart phones, digital personal assistants (Personal Digital Assistant, PDA), satellite navigation systems (Global Position System, GPS), etc., are becoming more and more popular. Since the above-mentioned devices all use touch screens, the technology of touch sensors becomes very important. In traditional technologies, touch sensors generally use resistive sensors. This kind of resistive sensor must rely on pressure to sense the coordinates of the indicator on the screen. Since such hand-held devices usually use liquid crystal screens at present, the resistive sensor must overlap with the liquid crystal screen. Therefore, when the pressure is applied to the resistive sensor, the corresponding pressure is applied to the LCD screen. Over time, the LCD screen may be damaged. In addition, the resolution of the resistive sensor is low, and the coordinate positioning is often inaccurate.

In the prior art, there is another kind of touch sensor, which is a capacitive touch panel. Capacitive touch panels are currently widely used in touch screens of handheld devices. However, the traditional capacitive touch panel must use a four-layer layout in the circuit layout of the touch panel. FIG. 1 is a cross-sectional view of the structure of a traditional capacitive touch panel. Please refer to FIG. 1 , the capacitive touch panel includes a Y-axis sensing layer 101, an X-axis sensing layer 102, a grounding layer 103, and an electronic components layer 104, wherein the electronic components layer 104 is used for placing and disposing electronic components. Connections (including control IC, resistors, capacitors, etc. components). 2 and 3 respectively illustrate the structures of the X-axis sensing layer 102 and the Y-axis sensing layer 101 . Please refer to FIG. 2 and FIG. 3 , the Y-axis sensing layer 101 and the X-axis sensing layer 102 respectively include a plurality of parallel sensing electrodes X00 and Y00 .

In addition, the traditional capacitive touch panel has another structure, which is a six-layer indium tin oxide (Indium Tin Oxide, ITO) glass structure. FIG. 4 is a structural cross-sectional view of a capacitive touch panel with a traditional ITO glass structure. Please refer to Fig. 4, its first layer 401 is a silicon dioxide (SiO2) layer, used to protect the Y-axis sensing layer; its second layer 402 is a Y-axis sensing layer; its third layer 403 is a glass layer; its fourth Layer 404 is an X-axis sensing layer; the fifth layer 405 is a silicon dioxide layer for protecting the X-axis sensing layer; the sixth layer 406 is a noise shielding layer for isolating noise.

However, in order to apply sensing on a two-dimensional plane, a traditional capacitive touch panel needs to wire a printed circuit board or an ITO glass structure into a two-dimensional plane, which complicates the manufacturing process. Relatively, the cost requirements are relatively high.

Contents of the invention

In view of this, an object of the present invention is to provide a coordinate positioning method and a touch screen using it, which mainly uses a one-dimensional sensing method to obtain two-dimensional plane coordinates, which not only improves the resolution of the sensing, but also further Reduced fabrication costs for printed circuit boards or indium tin oxide (ITO) glass.

Another object of the present invention is to provide a method for calibrating the coordinates of the touch screen to convert the coordinates of the capacitive sensor into the coordinates of the display panel.

To achieve the above and other objectives, the present invention provides a touch screen, which includes a sensing array layer and a microprocessor. The sensing array layer includes M×N capacitive sensors, wherein M columns of capacitive sensors are arranged along the first axis direction, and N rows of capacitive sensors are arranged along the second axis direction. The microprocessor includes a plurality of pins, correspondingly coupled to the capacitive sensor. When the touch screen is touched, causing at least one sensing value of the capacitive sensor in the sensing array layer to change, the microprocessor uses the sensing value sensed by the capacitive sensor to perform interpolation calculations to determine A touched coordinate.

In addition, the present invention proposes a coordinate positioning method. The method includes the following steps: providing a touch screen; in the above touch screen, providing a sensing array layer including M×N capacitive sensors, wherein M columns of capacitive sensors are arranged along the first axis direction , configure N rows of capacitive sensors along the direction of the second axis; provide multiple reference coordinates corresponding to the above-mentioned capacitive sensors, each reference coordinate includes a first-axis coordinate and a second-axis coordinate; when the above-mentioned touch screen is touched , when at least one sensing value of the capacitive sensor in the sensing array layer changes, using the sensing value sensed by the capacitive sensor and the first axis coordinate and the second axis coordinate of its corresponding reference coordinates, An interpolation calculation is performed to determine a touched coordinate.

According to the touch screen described in a preferred embodiment of the present invention, the touch screen further includes an electronic component layer and a ground layer, wherein the ground layer is disposed between the sensing array layer and the electronic component layer. In another embodiment, the touch screen further includes a first silicon oxide layer and a second silicon oxide layer, wherein the sensing array layer is disposed between the first silicon oxide layer and the second silicon oxide layer.

The spirit of the present invention is to configure a sensing array layer in a touch panel, wherein, the sensing array layer is configured with M×N capacitive sensors, wherein, along the direction of the first axis, M columns of capacitive sensors are configured , along the direction of the second axis, N rows of capacitive sensors are configured, and each capacitive sensor is coupled to a microprocessor. Therefore, as long as the touch panel is touched, the sensing value of the capacitive sensor at the corresponding position will change, and the touched position can be known through calculation. Because this structure is obviously different from the traditional touch panel, the present invention only needs one sensing layer to achieve coordinate positioning that traditionally requires two sensing layers. It not only improves the resolution of sensing, but also further reduces the manufacturing cost of printed circuit board or indium tin oxide (ITO) glass in the prior art.

Description of drawings

FIG. 1 is a cross-sectional view of the structure of a traditional capacitive touch panel.

FIG. 2 illustrates the structure of the X-axis sensing layer 102 of a conventional capacitive touch panel.

FIG. 3 illustrates the structure of the Y-axis sensing layer 101 of a conventional capacitive touch panel.

FIG. 4 is a structural cross-sectional view of a capacitive touch panel with a traditional ITO glass structure.

FIG. 5 is a circuit structure diagram of a touch screen according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a method for determining coordinates in the X-axis direction of a capacitive touch screen according to an embodiment of the present invention.

7 is a schematic diagram of a method for determining coordinates in the Y-axis direction of a capacitive touch screen according to an embodiment of the present invention.

FIG. 8 is a coordinate configuration of a capacitive touch screen according to an embodiment of the present invention.

FIG. 9 is another coordinate configuration of a capacitive touch screen according to an embodiment of the present invention.

FIG. 10 is a structural diagram of a capacitive touch screen according to an embodiment of the present invention.

FIG. 11 is a schematic diagram illustrating a sensing method for multiple fingers or conductive material contacts according to an embodiment of the present invention.

FIG. 12 is a structural cross-sectional view of a capacitive touch screen according to an embodiment of the present invention.

FIG. 13 is a flowchart of a coordinate positioning method according to an embodiment of the present invention.

FIG. 14 is a schematic diagram of wiring impedance of a capacitive touch screen according to an embodiment of the present invention.

FIG. 15 is a schematic diagram of sensing values sensed by the capacitive sensor C50 on the capacitive touch screen in the same state according to an embodiment of the present invention.

Figure number:

101, 402: Y-axis sensing layer

102, 405: X-axis sensing layer

103: Ground layer

104: Electronic component layer

X00, Y00: sensing electrodes

401, 404: silica

403: glass layer

501: Induction array layer

502: Microprocessor

C50: capacitive sensor

1201: the first layer of the touch screen according to the embodiment of the present invention

1202: the second layer of the touch screen according to the embodiment of the present invention

1203: the third layer of the touch screen according to the embodiment of the present invention

S1300-S1306: steps in the embodiment of the present invention

Detailed ways

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

FIG. 5 is a structural diagram of a capacitive touch screen according to an embodiment of the present invention. Please refer to FIG. 5 , the capacitive touch screen includes a sensing array layer 501 and a microprocessor 502 . In this embodiment, the sensing array layer 501 includes 12 capacitive sensors C50 arranged in a 3×4 array. Each capacitive sensor C50 is coupled to the microprocessor 502 . And each capacitive sensor C50 has a coordinate (0,0)˜(3,2) representing it.

When the finger of the human body or any material with conductive properties is not in contact with the capacitive touch screen, the capacitance value of the above-mentioned capacitive sensor C50 will not have any change, therefore, each capacitance received by the microprocessor 502 The sensing value will not change. Generally speaking, the microprocessor 502 provides an initial value (BaseValue) corresponding to each capacitive sensor C50, which is generally 0. When a finger or any conductive material touches the capacitive touch screen of this embodiment, the capacitive sensing value ( ADCValue) will change. And microprocessor 502 can carry out following judgment:

(ADCValue-BaseValue)>Th,

Among them, Th represents the threshold value.

When it is determined that the above value is greater than the above threshold value, the microprocessor 502 determines that a finger or any conductive material touches the capacitive sensor C50 at this time.

FIG. 6 is a schematic diagram of a method for determining coordinates in the X-axis direction of a capacitive touch screen according to an embodiment of the present invention. Please refer to FIG. 6. In this embodiment, when the X-axis coordinate is to be judged, the microprocessor 502 scans the capacitive sensing value corresponding to the capacitive sensor C50 according to the following sequence:

(0,0)→(1,0)→(2,0)→(3,0)→(0,1)→(1,1)→(2,1)→(3,1)... .→→(3,2).

When it is detected that the capacitive sensing values corresponding to two adjacent capacitive sensors C50 are greater than the threshold value, an interpolation calculation is performed to obtain the coordinates touched by the touching object (such as a conductor or a finger). This interpolation is calculated as follows:

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; S</span>}$

Among them, X_position is the determined X coordinate; i and i+1 are the X coordinates of the adjacent capacitive sensor C50 respectively; K is the capacitive sensing value detected by the ith X coordinate; L is the i+1th X The capacitive sensing value detected by the coordinate; S is the coordinate interval number between two X coordinates.

For example, assume that the built-in coordinate interval number of the X coordinate of each capacitive sensor C50 of the capacitive touch screen is 32. When the finger touches between the capacitive sensor C50 whose coordinates are (1,0) and (2,0), the capacitive sensing value detected by the capacitive sensor C50 whose coordinates are (1,0) is 70, and The capacitive sensing value detected by the capacitive sensor C50 with coordinates (2,0) is 80, then the X coordinate is:

(70×1+80×2)×32÷(70+80)＝49.067≈49.

For the same reason, FIG. 7 is a schematic diagram of a method for determining coordinates in the Y-axis direction of a capacitive touch screen according to an embodiment of the present invention. Please refer to FIG. 7 , in this embodiment, when the Y-axis coordinate is to be judged, the microprocessor 502 scans the capacitive sensing value corresponding to the capacitive sensor C50 according to the following sequence:

(0,0)→(0,1)→(0,2)→(1,0)→(1,1)→(1,2)→(2,0)→(2,1)... .→→(3,2).

When it is detected that the capacitive sensing values corresponding to two adjacent capacitive sensors C50 are greater than the threshold value, an interpolation calculation is performed to obtain the coordinates touched by the touching object (such as a conductor or a finger). This interpolation is calculated as follows:

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; S</span>}$

Among them, Y_position is the judged Y coordinate; j and j+1 are the Y coordinates of the adjacent capacitive sensor C50 respectively; K is the capacitive sensing value detected by the jth Y coordinate; L is the j+1th Y The capacitive sensing value detected by the coordinate; S is the coordinate interval number between two coordinates.

For example, assume that the built-in number of coordinate intervals of the Y coordinates of each capacitive sensor C50 of the capacitive touch screen is 40. When the finger touches between the capacitive sensor C50 with coordinates (1, 1) and (1, 2), the capacitive sensing value detected by the capacitive sensor C50 with coordinates (1, 1) is 90, while The capacitive sensing value detected by the capacitive sensor C50 with coordinates (1, 2) is 150, then the Y coordinate is:

Y_position=(90×1+150×2)×40÷(90+150)=65.

Next, FIG. 8 is a coordinate configuration of a capacitive touch screen according to an embodiment of the present invention. FIG. 9 is another coordinate configuration of a capacitive touch screen according to an embodiment of the present invention. Please refer to FIG. 8 and FIG. 9 at the same time. FIG. 8 is a standard coordinate configuration in the above embodiment; FIG. 9 is another standard coordinate configuration. Generally speaking, according to the needs of customers or the encoding of firmware, the coordinate configuration can be changed as above. If the coordinate configuration in FIG. 9 is used, if the coordinate configuration in FIG. 8 is to be changed, a coordinate conversion calculation must be performed, wherein the coordinate conversion calculation can be performed by the microprocessor 502 .

Before explaining this coordinate transformation calculation, the following assumptions are made. Assume that the codes of the X coordinate and Y coordinate in FIG. 9 are X_position and Y_position respectively; the codes of the X coordinate and Y coordinate in FIG. 8 are Xo and Yo respectively; m and n represent the row number and the column number of the capacitive sensor C50 respectively. but

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; Xo</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; Yo</span>}\\ \mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; Xo</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; Yo</span>}\end{array}\right.$

Express the above simultaneous equations in matrix form:

$\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}\\ \mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; no</span>}\\ \mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="m"\; filenames="A2008102137540025H1.png,A2008102137540026H1.png"\; state="\{\{state\}\}">m</figure-callout></span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; Xo</span>}\\ \mathrm{<span\; class="notranslate">\; Yo</span>}\end{array}\right]$

Therefore, the mapping to the two-dimensional coordinates (Xo, Yo) can be obtained through the inverse matrix operation:

$\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; Xo</span>}\\ \mathrm{<span\; class="notranslate">\; Yo</span>}\end{array}\right]<span\; class="notranslate">\; =</span>{\left[\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; no</span>}\\ \mathrm{<span\; class="notranslate">\; m</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}\\ \mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}\end{array}\right]<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span>}\left[\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; no</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}\\ \mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}\end{array}\right]$

$<span\; class="notranslate">\; \&DoubleRightArrow;</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; Xo</span>}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; Yo</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; Y</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; position</span>}}{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\end{array}\right.$

FIG. 10 is a structural diagram of a capacitive touch screen according to an embodiment of the present invention. Please refer to FIG. 10. Although the above example uses a touch screen with 12 capacitive sensors C50 as an example, those skilled in the art should know that the larger the number of capacitive sensors C50, the higher the resolution, and the coordinate acquisition and calculation The location is more accurate. In addition, FIG. 11 is a schematic diagram of a sensing method for multiple fingers or conductive material contacts according to an embodiment of the present invention. Please refer to FIG. 11 , in this embodiment, we define the number of capacitive sensors touched by a single finger of the user as four adjacent capacitive sensors C50 as a group. Through the above process, the interpolation displacement point can be obtained by moving a finger or any conductive material between any two capacitive sensors.

It can be seen from the above several embodiments that the present invention only needs one sensing array layer to achieve the two-dimensional coordinate positioning that can be achieved in the prior art only requiring two sensing layers. FIG. 12 is a structural cross-sectional view of a capacitive touch screen according to an embodiment of the present invention. Please refer to FIG. 12 , if the method of the present invention is implemented in the touch screen process of a printed circuit board, only a 3-layer structure is required. The first layer 1201 is the sensor array layer of the embodiment of the present invention; the second layer 1202 is the ground layer; the third layer 1203 is the electronic component layer. In the same way, if the method of the present invention is implemented in the touch screen process of indium tin oxide (ITO), only a three-layer structure is required. The first layer 1201 is a silicon dioxide layer; the second layer 1202 is a sensing array layer according to the embodiment of the present invention; the third layer 1203 is a ionosphere; and the fourth layer 1204 is a noise shielding (Shielding) layer.

The above embodiments can be simply summarized into a coordinate positioning method. FIG. 13 is a flowchart of a coordinate positioning method according to an embodiment of the present invention. Referring to Figure 13, this method includes the following steps:

Step S1300: start.

Step S1301: Provide a touch screen.

Step S1302: In the above-mentioned touch screen, a sensing array layer is provided, which includes M×N capacitive sensors, wherein M columns of capacitive sensors are arranged along the first axis, and M columns are arranged along the second axis. N rows of capacitive sensors.

Step S1303: Provide a plurality of reference coordinates corresponding to the capacitive sensor, each reference coordinate includes a first axis coordinate and a second axis coordinate. For example the coordinate system of FIG. 8 or FIG. 9 described above.

Step S1304: Determine whether the touch screen is touched. This step can be determined by using the microprocessor 502 to detect whether the capacitive sensing value of the capacitive sensor C50 is greater than a threshold value. When the determination is negative, return to step S1304 and continue to make determinations.

Step S1305: When the touch screen is touched, causing at least one sensing value of the capacitive sensors in the sensing array layer to change, use the sensing value sensed by the capacitive sensor and its corresponding An interpolation calculation is performed on the first axis coordinate and the second axis coordinate of the reference coordinate to determine the touched coordinate. The part of the interpolation calculation has been described in detail in the above embodiments, so it will not be repeated here.

Step S1306: end.

FIG. 14 is a schematic diagram of wiring impedance of a capacitive touch screen according to an embodiment of the present invention. Please refer to Fig. 14, each point on Fig. 14 respectively represents the wiring resistance of the sensing line to which the 4 capacitive sensors C50 in the first column are coupled, and the 4 capacitive sensors C50 in the second column from left to right. The wiring resistance of the sensing line coupled to the sensor C50 and the wiring resistance of the sensing lines coupled to the four capacitive sensors C50 in the third column. In the embodiment of the present invention, the proposed one-dimensional capacitive sensor array is extended to a two-dimensional plane architecture, so each capacitive sensor C50 needs to have a corresponding sensing line to be coupled to the microprocessor 502, When the capacitive sensor C50 is farther away from the microprocessor 502, the wiring resistance of the corresponding sensing line is also larger, so that the sensing value sensed by the microprocessor 502 is also smaller, and if the capacitive sensor C50 is farther away from the microprocessor, The closer the 502 is, the smaller the wiring electrical group generated by the corresponding sensing line is, so that the sensing value obtained by the microprocessor 502 is also larger.

Next, please refer to FIG. 15 , which is a schematic diagram of sensing values sensed by the capacitive sensor C50 on the capacitive touch screen in the same state according to an embodiment of the present invention. As shown in FIG. 15 , in the case of uneven distribution of wiring resistance lengths, unevenly distributed induction values will be obtained. In order to obtain a good judgment effect, to judge whether there is a finger or a conductor placed on or close to the sensing plane, the present invention proposes two other implementations:

(1) Take the column as a unit, adjust the gain of the sensing value sensed by the capacitive sensor C50 of each column; If the electric group is smaller than the wiring resistance of the sensing line coupled to the capacitive sensor C50 in the column I+1, the sensing value of the I column will be greater than the sensing value of the I+1 column. Therefore, in design, the microprocessor 502 can set the gain of the I+1th column to be greater than the gain of the Ith column, so that the corresponding gain value of each capacitive sensor C50 can be given an appropriate gain according to the difference in the wiring resistance, so that It is achieved that under the same touch condition, the sensing values sensed by each capacitive sensor C50 are similar.

(2) Take the column as the unit, adjust the threshold value of the sensing value sensed by the capacitive sensor C50 of each column; as mentioned in the previous article, when the finger is placed on the sensing area, the microprocessor 502 will A sensing value (ADCVaule) is obtained, so when (ADCValue-BaseValue)>threshold (Threshold), it will be determined that there is a finger on the sensing area at this time. Therefore, in order to overcome the wiring resistance, in design, the microprocessor 502 can adjust the threshold value (Threshold) corresponding to the capacitive sensor C50 of each column in units of columns. For example, if the wiring resistance corresponding to the capacitive sensor C50 in the I column is smaller than the wiring resistance corresponding to the capacitive sensor C50 in the I+1 column, the sensing value corresponding to the capacitive sensor C50 in the I column will be greater than the sensing value corresponding to the capacitive sensor C50 in column I+1. Therefore, the threshold value (Threshold I+1) of the I+1 column built in the microcontroller 502 is properly designed to make it smaller than the threshold value (Threshold I) of the I column, so that each capacitive sensor C50 corresponds to The gain value is given an appropriate threshold value according to the wiring resistance, so that each column can correctly determine whether a finger or a conductor touches or approaches the capacitive sensor C50.

In summary, the spirit of the present invention is to use a touch panel to configure a sensing array layer, wherein, the sensing array layer is configured with M×N capacitive sensors, wherein, along the direction of the first axis, the M columns of capacitive sensors, N rows of capacitive sensors are configured along the second axis, and each capacitive sensor is coupled to a microprocessor. Therefore, as long as the touch panel is touched, the sensing value of the capacitive sensor at the corresponding position will change, and the touched position can be known through calculation. Because this structure is obviously different from the traditional touch panel, the present invention only needs one sensing layer to achieve coordinate positioning that traditionally requires two sensing layers. It not only improves the resolution of sensing, but also further reduces the manufacturing cost of printed circuit board or indium tin oxide (ITO) glass in the prior art.

The specific embodiments proposed in the detailed description of the preferred embodiments are only used to facilitate the description of the technical content of the present invention, rather than restricting the present invention to the above-mentioned embodiments in a narrow sense, without departing from the spirit of the present invention and the following claims The situation, the implementation of various changes, all belong to the scope of the present invention. Therefore, the protection scope of the present invention should be regarded as defined by the claims.

Claims (20)

1. A touch screen, comprising:

the sensing array layer comprises M multiplied by N capacitive sensors, wherein M rows of capacitive sensors are arranged along the first axis direction, and N rows of capacitive sensors are arranged along the second axis direction; and

and the microprocessor comprises a plurality of pins which are correspondingly coupled with the capacitive sensors, and when the touch screen is touched to cause that at least one sensing value of the capacitive sensors in the sensing array layer changes, the microprocessor performs interpolation calculation by using the sensing value sensed by the capacitive sensors to determine touched coordinates.

2. The touchscreen of claim 1, wherein the touchscreen further comprises:

an electronic element layer; and

and the grounding layer is configured between the induction array layer and the electronic element layer.

3. The touchscreen of claim 1, wherein the touchscreen further comprises:

a first silicon oxide layer; and

a second silicon dioxide layer; wherein,

the sensing array layer is configured between the first silicon oxide layer and the second silicon oxide layer.

4. The touchscreen of claim 1, wherein the coordinates of the capacitive sensor in the ith column and the jth row are represented as (i, j).

5. The touchscreen of claim 4, wherein when the touchscreen is touched, resulting in a change in the sensed values of the capacitive sensors in the ith row and the jth column and the sensed values of the capacitive sensors in the (i +1) th row and the jth column of the sensor array layer:

the microprocessor captures the sensing values of the capacitive sensors in the ith row and the jth row and the sensing values of the capacitive sensors in the (i +1) th row and the jth row, and performs the following interpolation calculation to obtain the first axis coordinate of the touched coordinate:

wherein, K represents the sensing value of the capacitive sensor in the ith row and the jth column, L represents the sensing value of the capacitive sensor in the (i +1) th row and the jth column, and S represents the number of spaced coordinates between each of the capacitive sensors.

6. The touchscreen of claim 4, wherein when the touchscreen is touched, resulting in a change in the sensed values of the capacitive sensors in the ith row and the jth column and the sensed values of the capacitive sensors in the ith row and the jth +1 column of the sensor array layer:

the microprocessor captures the sensing values of the capacitive sensors in the ith row and the jth row and the sensing values of the capacitive sensors in the ith row and the jth +1 row, and performs the following interpolation calculation to obtain a second axis coordinate of the touched coordinate:

wherein, K represents the sensing value of the capacitive sensor in the ith row and the jth column, L represents the sensing value of the capacitive sensor in the (i +1) th row and the jth column, and S represents the number of spaced coordinates between each of the capacitive sensors.

7. The touchscreen of claim 1, wherein the coordinates (x, y) of the capacitive sensor in row i and column j are represented as (i + nxj, mxi + j).

8. The touchscreen of claim 7, wherein the microprocessor further performs a coordinate transformation calculation as follows:

<math> <mrow> <mi>x</mi> <mn>0</mn> <mo>=</mo> <mfrac> <mrow> <mo>-</mo> <mi>x</mi> <mo>+</mo> <mi>N</mi> <mo>&times;</mo> <mi>y</mi> </mrow> <mrow> <mi>M</mi> <mo>&times;</mo> <mi>N</mi> <mo>-</mo> <mn>1</mn> </mrow> </mfrac> </mrow> </math>

<math> <mrow> <mi>y</mi> <mn>0</mn> <mo>=</mo> <mfrac> <mrow> <mi>M</mi> <mo>&times;</mo> <mi>x</mi> <mo>-</mo> <mi>y</mi> </mrow> <mrow> <mi>M</mi> <mo>&times;</mo> <mi>N</mi> <mo>-</mo> <mn>1</mn> </mrow> </mfrac> </mrow> </math>

where (x0, y0) are the transformed coordinates of the capacitive sensor.

9. The touchscreen of claim 1, wherein the touchscreen further comprises:

the M multiplied by N induction lines are respectively used for electrically connecting the M multiplied by N capacitive sensors and the microprocessor;

the microprocessor gives M multiplied by N gains corresponding to the M multiplied by N capacitive sensors according to the wiring resistance of each sensing wire.

10. The touchscreen of claim 1, wherein the touchscreen further comprises:

the M multiplied by N induction lines are respectively used for electrically connecting the M multiplied by N capacitive sensors and the microprocessor;

the microprocessor gives M × N threshold values corresponding to the M × N capacitive sensors according to the wiring resistance of each of the sensing lines, and determines whether the (I, J) -th capacitive sensor is touched according to whether the sensing value of the (I, J) -th capacitive sensor is greater than the threshold value of the (I, J) -th capacitive sensor.

11. The touchscreen of claim 1, wherein the touchscreen further comprises:

the M multiplied by N induction lines are respectively used for electrically connecting the M multiplied by N capacitive sensors and the microprocessor;

the microprocessor gives M × N threshold values corresponding to the M × N capacitive sensors according to the wiring resistance of each of the sensing lines, and determines whether the (I, J) -th capacitive sensor is touched according to whether the sensing value of the (I, J) -th capacitive sensor minus the basic value of the (I, J) -th capacitive sensor is greater than the threshold value of the (I, J) -th capacitive sensor.

12. A coordinate positioning method, characterized by comprising:

providing a touch screen;

providing an induction array layer in the touch screen, wherein the induction array layer comprises M multiplied by N capacitive sensors, M rows of capacitive sensors are configured along a first axis direction, and N rows of capacitive sensors are configured along a second axis direction;

providing a plurality of reference coordinates corresponding to the capacitive sensors, wherein each reference coordinate comprises a first axis coordinate and a second axis coordinate;

when the touch screen is touched to cause a change in at least one sensed value of the capacitive sensors in the sensor array layer, an interpolation calculation is performed by using the sensed value sensed by the capacitive sensor and the first axis coordinate and the second axis coordinate of the reference coordinate corresponding to the sensed value to determine the touched coordinate.

13. The coordinate locating method of claim 12, wherein the coordinates of the capacitive sensor in the ith column and the jth row are represented as (i, j).

14. The coordinate positioning method of claim 13, wherein when the touch screen is touched, which causes a change in the sensing value of the capacitive sensor in the ith row and the jth column and the sensing value of the capacitive sensor in the (i +1) th row and the jth column in the sensor array layer:

capturing the sensing values of the capacitive sensors in the ith row and the jth row and the sensing values of the capacitive sensors in the (i +1) th row and the jth row, and performing the following interpolation calculation to obtain a first axis coordinate of the touched coordinate:

wherein, K represents the sensing value of the capacitive sensor in the ith row and the jth column, L represents the sensing value of the capacitive sensor in the (i +1) th row and the jth column, and S represents the number of spaced coordinates between each of the capacitive sensors.

15. The coordinate positioning method of claim 13, wherein when the touch screen is touched, which causes a change in the sensing value of the capacitive sensor in the ith row and the jth column and the sensing value of the capacitive sensor in the ith row and the jth +1 column in the sensor array layer:

capturing the sensing values of the capacitive sensors in the ith row and the jth row and the sensing values of the capacitive sensors in the ith row and the jth +1 row, and performing the following interpolation calculation to obtain a second axis coordinate of the touched coordinate:

wherein, K represents the sensing value of the capacitive sensor in the ith row and the jth column, L represents the sensing value of the capacitive sensor in the (i +1) th row and the jth column, and S represents the number of spaced coordinates between each of the capacitive sensors.

16. The coordinate locating method of claim 12, wherein the coordinates (x, y) of the capacitive sensor in row i and column j are represented as (i + nxj, mxi + j).

17. The coordinate positioning method of claim 16 further comprising the steps of:

performing a coordinate transformation calculation, the coordinate transformation calculation comprising:

<math> <mrow> <mi>x</mi> <mn>0</mn> <mo>=</mo> <mfrac> <mrow> <mo>-</mo> <mi>x</mi> <mo>+</mo> <mi>N</mi> <mo>&times;</mo> <mi>y</mi> </mrow> <mrow> <mi>M</mi> <mo>&times;</mo> <mi>N</mi> <mo>-</mo> <mn>1</mn> </mrow> </mfrac> </mrow> </math>

<math> <mrow> <mi>y</mi> <mn>0</mn> <mo>=</mo> <mfrac> <mrow> <mi>M</mi> <mo>&times;</mo> <mi>x</mi> <mo>-</mo> <mi>y</mi> </mrow> <mrow> <mi>M</mi> <mo>&times;</mo> <mi>N</mi> <mo>-</mo> <mn>1</mn> </mrow> </mfrac> </mrow> </math>

where (x0, y0) are the transformed coordinates of the capacitive sensor.

18. The coordinate positioning method of claim 12, further comprising:

providing M multiplied by N sensing lines, wherein each sensing line is respectively used for electrically connecting the M multiplied by N capacitive sensors and a microprocessor; and

and giving M × N gains corresponding to the M × N capacitive sensors according to the wiring resistance of each sensing line.

19. The coordinate positioning method of claim 12, further comprising:

providing M multiplied by N sensing lines, wherein each sensing line is respectively used for electrically connecting the M multiplied by N capacitive sensors and a microprocessor;

according to the wiring resistance of each induction line, giving M multiplied by N threshold values corresponding to the M multiplied by N capacitance sensors; and

and determining whether the (I, J) -th capacitive sensor is touched according to whether the sensing value of the (I, J) -th capacitive sensor is larger than the threshold value of the (I, J) -th capacitive sensor.

20. The coordinate positioning method of claim 12, further comprising:

providing M multiplied by N sensing lines, wherein each sensing line is respectively used for electrically connecting the M multiplied by N capacitive sensors and a microprocessor;

according to the wiring resistance of each induction line, giving M multiplied by N threshold values corresponding to the M multiplied by N capacitance sensors; and

and determining whether the (I, J) -th capacitive sensor is touched according to whether the sensing value of the (I, J) -th capacitive sensor minus the basic value of the (I, J) -th capacitive sensor is larger than the threshold value of the (I, J) -th capacitive sensor.

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