CN103902127B - The localization method and capacitive touch screen of touch location on a kind of capacitive touch screen - Google Patents

Abstract

The invention relates to the field of capacitive touch, and discloses a method for locating a touch position on a capacitive touch screen and the capacitive touch screen. In the present invention, the capacitance variation of all touch sensing Sensors of the capacitive touch screen is detected; the capacitive touch screen includes N first touch sensing Sensors and N second touch sensing Sensors, N is a natural number, and one first The touch sensing Sensor and a second touch sensing Sensor symmetrically form a rectangular sensing unit; according to the relative change in the capacitance of the first touch sensing Sensor and the second touch sensing Sensor, the position of the touch point in the X-axis direction is positioned, And locate the position of the touch point in the Y-axis direction according to the capacitance variation of the plurality of sensing units; the X-axis direction is the broad side direction of the capacitive touch screen, and the Y-axis direction is the long side direction of the capacitive touch screen. Since the sensing unit is a rectangle, and the relative change trend of the capacitance of the first touch sensing Sensor and the second touch sensing Sensor is symmetrical, the calculation is more accurate, and the touch point positioning of the capacitive touch screen is more accurate.

Description

A method for locating a touch position on a capacitive touch screen and a capacitive touch screen

technical field

The invention relates to the field of capacitive touch, in particular to a method for locating a touch position on a capacitive touch screen and the capacitive touch screen.

Background technique

At present, capacitive touch screens should be widely used in color and black and white TFT (Thin Film Transistor Thin Film Field Effect Transistor) displays. computers), etc.) and industrial products.

Most capacitive touch screens use multilayer ITO (Indium-Tin Oxide, indium tin oxide) films. At present, the mainstream design schemes of capacitive touch screens are strip pattern and mesh pattern. Strip pattern and mesh pattern must use double-layer ITO film.

For example, a bar pattern used in a capacitive touch screen is shown in FIG. 1 . In FIG. 1 , the horizontal touch sensor (Sensor) is a sensor that senses coordinates in the X-axis direction, and the vertical Sensor is a Sensor that senses coordinates in the Y-axis direction. These Sensors form capacitance with the ground, and this capacitance is commonly referred to as self-capacitance, that is, capacitance to ground. When a finger touches the capacitive touch screen, the capacitance of the finger will be superimposed on the capacitance of the screen body, causing the capacitance of the screen body to change. During touch detection, the capacitive screen detects the horizontal and vertical Sensor arrays in turn, and determines the abscissa and ordinate of the touch position, that is, the coordinates of the touch position, according to the change in capacitance before and after the touch, so as to locate the touch position.

Although the capacitive touch screen with a strip pattern has high positioning accuracy for the touch position, when making the Sensor in the capacitive touch screen, the lamination process usually used for the double-layer ITO film is very complicated.

A capacitive touch screen using a single-layer ITO film emerged as the times require, as shown in Figure 2. This capacitive touch screen includes two sets of triangular (or approximately triangular) Sensors, wherein the width of one set of Sensors decreases along the width direction of the capacitive touch screen (such as the positive direction of the X axis), and the width of the other set of Sensors decreases. Increments along the positive direction of the X axis.

Although the process is simple, the accuracy of touch point positioning needs to be further improved.

Contents of the invention

The object of the present invention is to provide a method for locating a touch position on a capacitive touch screen and the capacitive touch screen, so that the capacitive touch screen can locate a touch point more accurately.

In order to solve the above technical problems, the present invention provides a method for locating a touch position on a capacitive touch screen, wherein the capacitive touch screen includes N first touch sensing Sensors and N second touch sensing Sensors, one of which The first touch-sensing Sensor and the second touch-sensing Sensor form a rectangular sensing unit; the width of the first touch-sensing Sensor decreases along the positive direction of the X-axis, and the second touch-sensing Sensor The width increases along the positive direction of the X-axis; the positive direction of the X-axis is the broadside direction of the capacitive touch screen, and from left to right, and the Y-axis direction is the direction of the capacitive touch screen Long side direction, and perpendicular to the X-axis; wherein, N is a natural number greater than or equal to 1;

The positioning method of the touch position on the capacitive touch screen comprises the following steps:

Detecting capacitance variations of all touch sensing Sensors of the capacitive touch screen;

Locating the position of the touch point in the X-axis direction according to the relative change of the capacitance variation of the first touch sensing Sensor and the capacitance variation of the second touch sensing Sensor;

The position of the touch point in the Y-axis direction is located according to the capacitance variation of the plurality of sensing units.

The present invention also provides a capacitive touch screen, comprising: several touch sensing sensors Sensors;

Wherein, the touch sensing Sensor is divided into several groups, each group is a sensing unit, and the sensing unit is rectangular; wherein, each of the sensing units includes a first touch sensing Sensor and a second sensing unit. A touch-sensing Sensor, the width of the first touch-sensing Sensor decreases along the positive direction of the X-axis, and the width of the second touch-sensing Sensor increases along the positive direction of the X-axis;

The positive direction of the X-axis is the width direction of the capacitive touch screen, and is from left to right, and the Y-axis direction is the long side direction of the capacitive touch screen, and is perpendicular to the X-axis.

Compared with the prior art, the embodiment of the present invention firstly detects the capacitance variation of all touch sensing Sensors of the capacitive touch screen; wherein, the capacitive touch screen includes N first touch sensing Sensors and N second Touch sensor, N is a natural number greater than or equal to 1, a first touch sensor and a second touch sensor symmetrically form a rectangular sensing unit, the width of the first touch sensor is along the X-axis The positive direction decreases, and the width of the second touch sensing Sensor increases along the positive direction of the X axis; and then the touch point is located according to the relative change of the capacitance change of the first touch sensing Sensor and the capacitance change of the second touch sensing Sensor. position in the X-axis direction, and locate the position of the touch point in the Y-axis direction according to the capacitance variation of multiple sensing units. Since all touch sensing sensors are grouped, each group of touch sensing sensors is a rectangular sensing unit, the shape of the sensing unit is regular and symmetrical, and the calculation based on the sensing unit is more accurate, so the positioning is based on the capacitance change of multiple sensing units The position of the touch point in the Y-axis direction makes the capacitive touch screen locate the touch point in the Y-axis direction more precisely; moreover, because in each group of sensing units that are touched, the capacitance of the first touch sensing Sensor The variation curve of the variation with the movement trajectory of the touch point and the variation curve of the capacitance variation of the second touch sensing Sensor with the movement trajectory of the touch point are approximately axisymmetric, that is to say, the variation trends of the two are opposite. This symmetry is determined by the symmetrical structure of the touch-sensing Sensor. The coincidence position of the finger and the two touch-sensing Sensors changes with the movement on the X-axis, and the overlapping part of a touch-sensing Sensor increases, correspondingly The amount of change in the sensing capacitance of the touch sensor also increases, and the overlapping part of the other touch sensor Sensor and the finger will decrease accordingly, and the corresponding amount of change in the sensing capacitance will also decrease. The position of the finger in the X direction can be accurately positioned by utilizing the capacitance change values of one or more pairs of touch sensing Sensors. To sum up, the method for locating the touch position on the capacitive touch screen of the present invention enables the capacitive touch screen to locate the touch point more accurately.

In addition, in the step of locating the position of the touch point in the Y-axis direction according to the capacitance variation of the plurality of sensing units, the following sub-steps are included:

The position of the touch point in the direction of the Y-axis is positioned after a differential operation is performed on capacitance variations of the plurality of sensing units.

When touching, a linear equation is made in the Y-axis direction according to the capacitance variation of multiple sensing units to perform difference calculation to locate the touch point. The capacitive screen is divided into pairs of rectangular or approximately rectangular units into equidistant areas, so that a linear difference operation can be performed on the capacitance change of the sensing unit, and the positioning of the touch point in the Y-axis direction can be performed. more accurate.

In addition, in the step of locating the position of the touch point in the X-axis direction using a linear interpolation method, the following sub-steps are also included:

Select the capacitance variation ΔC1 of the first touch sensing Sensor with the largest capacitance variation and the capacitance variation ΔC2 of the second touch sensing Sensor with the largest capacitance variation among the two sets of touch sensing Sensors opposite to it;

The position of the touch point in the X-axis direction is located according to the values of the ΔC1 and the ΔC2.

By selecting the capacitance variation ΔC1 of the first touch sensing Sensor with the largest capacitance variation and the capacitance variation ΔC2 of the second touch sensing Sensor with the largest capacitance variation among the two symmetrical and adjacent touch sensing Sensors To locate the position of the touch point in the X-axis direction, since the capacitance change of the touch sensor Sensor with the largest capacitance change is selected for calculation (because the touch sensor closest to the touch point has the largest capacitance change), the calculation The amount is small, so the energy consumption of the capacitive touch screen is low, and the positioning of the touch point is fast and efficient.

In addition, in the step of locating the position of the touch point in the X-axis direction using a linear interpolation method, the following sub-steps are also included:

Select respectively the capacitance changes ΔC1 and ΔC3 of the first touch sensing Sensor with the largest capacitance change and the second largest capacitance change, and the second touch with the largest and second largest capacitance change at the corresponding positions of the two touch sensing Sensors. Sensing the capacitance change of the Sensor ΔC2, ΔC4;

The position of the touch point in the X-axis direction is located according to the values of the ΔC1, the ΔC2, the ΔC3 and the ΔC4.

By selecting the capacitance variation ΔC1 and ΔC3 of the first touch sensing Sensor with the largest capacitance variation and the second largest capacitance variation and the second touch sensor with the largest capacitance variation and the second largest capacitance variation among the adjacent touch sensing Sensors that are symmetrical to them, The capacitance changes ΔC2 and ΔC4 of the touch sensor can locate the position of the touch point in the X-axis direction. Although the capacitance change of the touch sensor closest to the touch point is the largest, a touch action may span more than two Touch sensing Sensor, so the capacitance change of the touch sensing Sensor with the largest capacitance change and the second largest capacitance change is selected at the same time for calculation. The positioning is more accurate and reliable. At the same time, the calculation amount is relatively small and the energy consumption is low. .

In addition, in the step of locating the position of the touch point in the X-axis direction according to the relative change of the capacitance variation of the first touch sensing Sensor and the capacitance variation of the second touch sensing Sensor, further comprising The following substeps:

Sum the capacitance changes of all the first touch sensing Sensors and the capacitance changes of the second touch sensing Sensor respectively, and obtain the sum ΔS1 of the capacitance changes of all the first touch sensing Sensors and all The sum ΔS2 of capacitance changes of the second touch sensing Sensor;

The position of the touch point in the X-axis direction is located according to the values of the ΔS1 and the ΔS2.

Sum the capacitance changes of all the first touch sensors and the capacitance changes of the second touch sensors respectively, and obtain the sum ΔS1 of the capacitance changes of all the first touch sensors and all the second touch sensors and ΔS2 of the capacitance change, and then locate the position of the touch point in the X-axis direction according to ΔS1 and ΔS2, since the capacitance change caused by all touched touch sensors is considered comprehensively (because a touch action may span multiple touch sensing sensors), and locate the touch point according to the symmetry between the first touch sensing sensor and the second touch sensing sensor, so that the positioning of the touch point is more reliable.

In addition, in the step of locating the position of the touch point in the X-axis direction according to the relative change of the capacitance variation of the first touch sensing Sensor and the capacitance variation of the second touch sensing Sensor, further comprising The following substeps:

Positioning the touch point in the X-axis direction after eliminating the systematic error in the X-axis direction.

When touching, the capacitive touch screen will inevitably introduce systematic errors, resulting in inaccurate positioning of the touch point in the X-axis direction. The system error is generated by a fixed bias. Therefore, when positioning the touch point in X The system error in the X-axis direction is eliminated when the position in the X-axis direction is determined, so that the positioning of the touch position in the X-axis direction is more accurate.

Description of drawings

Fig. 1 is a schematic diagram of a strip pattern adopted by a touch sensing Sensor of a double-layer ITO film capacitive touch screen according to the prior art;

Fig. 2 is a schematic diagram of a pattern adopted by a touch sensing Sensor of a single-layer ITO film capacitive touch screen according to the prior art;

3 is a schematic diagram of a pattern adopted by a touch sensing Sensor of a corresponding single-layer ITO film capacitive touch screen in a method for locating a touch position on a capacitive touch screen according to a first embodiment of the present invention;

FIG. 4 is a schematic diagram of capacitance variations of all touch sensing Sensors according to a fourth embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, various embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that, in each implementation manner of the present invention, many technical details are provided for readers to better understand the present application. However, even without these technical details and various changes and modifications based on the following implementation modes, the technical solution claimed in each claim of the present application can be realized.

The first embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen, and the specific steps are as follows:

First, detect the capacitance variation of all touch sensing Sensors of the capacitive touch screen. Wherein, the capacitive touch screen includes N first touch sensing Sensors and N second touch sensing Sensors, where N is a natural number greater than or equal to 1; a first touch sensing Sensor is symmetrical to a second touch sensing Sensor form a rectangular or approximately rectangular sensing unit; the width of the first touch sensing Sensor decreases along the positive direction of the X axis, and the width of the second touch sensing Sensor increases along the positive direction of the X axis; the positive direction of the X axis is the direction of the wide side of the capacitive touch screen, and is from left to right, and the direction of the Y axis is the direction of the long side of the capacitive touch screen, and is perpendicular to the X axis.

Specifically, when a finger touches the capacitive touch screen, the capacitance of the touch sensor on the capacitive touch screen will change due to the bioelectricity carried on the finger. According to the capacitance caused by the touched touch sensor The delta can locate the position of the touch point.

In this embodiment, firstly, all the touch sensing sensors included in the capacitive touch screen are divided into several groups, each group is a sensing unit, and the sensing unit is rectangular, as shown in FIG. 3 . Each sensing unit includes a first touch-sensing Sensor whose width gradually decreases along the positive direction of the X-axis and a second touch-sensing Sensor whose width gradually increases along the positive direction of the X-axis. Wherein, the shapes of the first touch sensing Sensor and the second touch sensing Sensor can be triangular, trapezoidal, or similar to triangular or trapezoidal, depending on the processing technology.

Since the touch sensing sensors of the capacitive touch screen are grouped, each group of touch sensing sensors is a rectangular or approximately rectangular sensing unit. The shape of the sensing unit is regular and symmetrical, and the calculation based on the sensing unit is more accurate.

Then, according to the relative change of the capacitance variation of the first touch sensing Sensor and the capacitance variation of the second touch sensing Sensor and the capacitance variation of the touch sensing Sensor attached to the first touch sensing Sensor and the second touch sensing Sensor Locating the position of the touch point in the X-axis direction, and locating the position of the touch point in the Y-axis direction according to the capacitance variation of the plurality of sensing units. In this embodiment, the position of the touch point in the X-axis direction is marked as X ₀ ; the position of the touch point in the Y-axis direction is marked as Y ₀ .

Because in each group of sensing units that are touched, the change curve of the capacitance variation of the first touch sensing Sensor with the trajectory of the touch point and the variation curve of the capacitance variation of the second touch sensing Sensor with the trajectory of the touch point The curve is approximately axisymmetric, that is to say, the change trend of the two is opposite. According to the relative change of the symmetry, this symmetry is determined by the symmetrical structure of the touch sensing Sensor. Fingers and two The overlapping position of the touch sensing Sensor changes with the movement on the X-axis. The overlapping part of one touch sensing Sensor increases, and the corresponding change in sensing capacitance also increases, while the overlapping part of the other touch sensing Sensor and the finger changes. Correspondingly, the variation of the corresponding inductive capacitance also decreases. The position of the finger in the X direction can be accurately positioned by using the capacitance change values of one or more pairs of touch sensing Sensors, that is, the position X ₀ of the touch point in the X-axis direction can be positioned more precisely. Moreover, since all touch sensing sensors are grouped, each group of touch sensing sensors is a rectangular or approximately rectangular sensing unit, the shape of the sensing unit is regular and symmetrical, and the calculation based on the sensing unit is more accurate. The capacitance variation locates the position Y ₀ of the touch point in the Y-axis direction, so that the capacitive touch screen can more accurately position the touch point in the Y-axis direction.

To sum up, the method for locating the touch position on the capacitive touch screen of the present invention enables the capacitive touch screen to locate the touch point more accurately.

Compared with the prior art, the touch sensing Sensors of the capacitive touch screen are grouped, each group is a sensing unit, and the sensing unit is rectangular or approximately rectangular, wherein each sensing unit contains a first touch sensor Sensing the Sensor and a second touch-sensing Sensor, the width of the first touch-sensing Sensor decreases along the positive direction of the X-axis, and the width of the second touch-sensing Sensor increases along the positive direction of the X-axis. Since the shape of the sensing unit is regular and symmetrical, the calculation based on the sensing unit is more accurate, so the position of the touch point in the Y-axis direction is located according to the capacitance variation of multiple sensing units, so that the capacitive touch screen can accurately control the position of the touch point in the Y-axis direction. The positioning is more accurate, and, in each group of sensing units that are touched, the change curve of the capacitance change of the first touch sensor Sensor with the movement track of the touch point is the same as the change curve of the capacitance change of the second touch sensor Sensor with the touch point The change curve of the motion track is approximately axisymmetric. According to the relative change with symmetry, this symmetry is determined by the symmetrical structure of the touch sensing Sensor. The overlapping position of the finger and the two touch sensing Sensors varies with the Changes with the movement on the X-axis, the overlapping part of one touch sensor sensor increases, and the corresponding change in sensing capacitance also increases, while the overlapping part of the other touch sensing Sensor and the finger will decrease accordingly, and the corresponding sensing capacitance The amount of variation is also reduced. The position of the finger in the X direction can be accurately positioned by using the capacitance change values of one or more pairs of touch sensing Sensors, that is, the position of the touch point in the X-axis direction can be positioned more accurately.

The second embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen. The second embodiment is a further refinement of the first embodiment, and provides a specific positioning method of the touch position in the Y-axis direction. In the second embodiment of the present invention, the position of the touch point in the Y-axis direction is positioned after performing difference calculations on the capacitance changes of multiple sensing units. Since the linear difference calculation is performed on the capacitance changes of the sensing units, the The capacitive touch screen is more accurate in the positioning of the touch point in the Y-axis direction.

Specifically, in the step of locating the position of the touch point in the Y-axis direction according to the capacitance changes of the multiple sensing units, the following sub-steps are included: performing difference calculations on the capacitance changes of the multiple sensing units and then locating the touch point position in the Y-axis direction. In this embodiment, the position of the touch point in the Y-axis direction is denoted as Y ₁ .

When touching, a linear equation is made in the Y-axis direction according to the capacitance variation of multiple sensing units to perform difference calculation to locate the touch point. Wherein, the linear equation is F(y)=ΔS ₁ ·y ₁ +ΔS ₂ ·y ₂ +ΔS ₃ ·y ₃ +...ΔS _N ·y _N , N is the number of induction units, also That is, the number of groups of touch sensing Sensors, F(y) is the calculated Y-axis coordinate value of the finger touch, ΔS ₁ , ΔS ₂ , ΔS ₃ ,..., ΔS _N are obtained according to the capacitance change of each sensing unit y ₁ , y ₂ , y ₃ , . . . , y _N are the Y-axis coordinate values corresponding to each sensing unit. According to the above linear equation, the position Y ₁ of the touch point in the Y-axis direction can be calculated.

The capacitive screen is divided into pairs of rectangular or approximately rectangular units into equidistant areas, so that a linear difference operation can be performed on the capacitance change of the sensing unit, instead of directly using the touch sensor with gradually changing width. The difference calculation is performed on the capacitance change amount, and the shape of the rectangular sensing unit is regular, so that the capacitive touch screen can locate the touch point in the Y-axis direction more accurately.

The third embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen. The third embodiment is a further refinement of the first embodiment, and provides a specific positioning method of the touch position in the X-axis direction. In the third embodiment of the present invention, the linear interpolation method is used to locate the position of the touch point in the X-axis direction. Specifically, the capacitance change ΔC1 of the first touch sensing Sensor with the largest capacitance change is selected to correspond to it. The capacitance variation ΔC2 of the second touch sensing Sensor with the largest capacitance variation among the two groups of touch sensing Sensors is determined, and the position X ₁ of the touch point in the X-axis direction is located according to the values of ΔC1 and ΔC2 . Since the capacitance change of the touch sensor with the largest capacitance change is selected for calculation, the amount of calculation is small, so that the energy consumption of the capacitive touch screen is low, and the positioning of the touch point is fast and efficient.

Specifically, in the step of using the linear interpolation method to locate the position of the touch point in the X-axis direction, the following sub-steps are also included:

Firstly, select the capacitance change ΔC1 of the first touch sensing Sensor with the largest capacitance change and the capacitance change of the second touch sensing Sensor with the largest capacitance change among the two adjacent touch sensing Sensors that are symmetrical to it. The amount ΔC2. For the convenience of description, we stipulate that according to the direction from top to bottom, the capacitance change of the first touch sensing Sensor of the capacitive touch screen is recorded as Δc1, Δc3, Δc5, ..., Δc(2N-1), and the capacitance The capacitance variation of the second touch sensor of the touch screen is denoted as Δc2, Δc4, Δc6, . . . , Δc(2N). For example, at a certain moment, the capacitance changes of all touch sensing Sensors of the capacitive touch screen are shown in FIG. 4 . In FIG. 4 , the horizontal axis is the number of touch sensing Sensors, represented by Num, and the vertical axis is the capacitance variation. In FIG. 4 , the capacitance variation Δc3 of the first touch sensing Sensor has the largest value, which is selected as ΔC1; the capacitance variation Δc4 of the second touch sensing Sensor has the largest value, and is selected as ΔC2.

Next, locate the position X ₁ of the touch point in the X-axis direction according to the values of ΔC1 and ΔC2 . Among them, the formula for calculating X1 is _: x ₁ and x ₂ are the X-axis coordinate values corresponding to the two touch sensing Sensors, or the maximum or minimum value of the X-axis coordinate values.

By selecting the capacitance change ΔC1 of the first touch sensing Sensor with the largest capacitance change and the capacitance change ΔC2 of the second touch sensing Sensor with the largest capacitance change among the two sets of touch sensing Sensors opposite to it, the touch point is The position in the X-axis direction is positioned, since the capacitance change of the touch sensing Sensor with the largest capacitance change is selected for calculation (because the closer to the touch point, the capacitance change of the touch sensing Sensor is greater, that is, The touch sensor with the largest capacitance change is closest to the touch point), and the amount of calculation is small, so the energy consumption of the capacitive touch screen is low, and the positioning of the touch point is fast and efficient.

The fourth embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen. The fourth embodiment is further improved on the basis of the third embodiment. The main improvement is that in the fourth embodiment, when locating the position of the touch point in the X-axis direction, not only the capacitance change value is selected The largest touch-sensing sensor also selects the touch-sensing sensor with the second largest capacitance change value, which improves the positioning accuracy.

Specifically, in the step of using the linear interpolation method to locate the position of the touch point in the X-axis direction, the following sub-steps are also included:

First, respectively select the capacitance changes ΔC1 and ΔC3 of the first touch sensing Sensor with the largest capacitance change and the second largest capacitance change, and the second touch sensor with the largest and second largest capacitance change at the positions corresponding to the two touch sensing Sensors. Control and sense the capacitance changes of the Sensor ΔC2, ΔC4. As shown in Figure 4, the value of the capacitance change Δc3 of the first touch sensing Sensor is the largest, which is selected as ΔC1, and the value of the capacitance change Δc4 of the second touch sensing Sensor is the largest, which is selected as ΔC2; The capacitance variation Δc5 of the touch sensing Sensor is the second largest, which is selected as ΔC3, and the capacitance variation Δc6 of the second touch sensing Sensor is the second largest, and is selected as ΔC4.

Next, the position X ₂ of the touch point in the X-axis direction is located according to the values of ΔC1 , ΔC2 , ΔC3 and ΔC4 . Among them, the _formula for calculating X2 is: x ₃ and x ₄ are X-axis coordinate values of the touch sensing Sensor corresponding to ΔC3 and ΔC4, which may be the same as or different from x1 and x2.

By selecting the capacitance changes ΔC1 and ΔC3 of the second largest first touch sensor with the largest capacitance change and the second largest second touch sensor with the largest capacitance change at the positions corresponding to the two touch sensors The capacitance changes ΔC2 and ΔC4 of the Sensor locate the position of the touch point in the X-axis direction. Although the touch sensor closest to the touch point has the largest capacitance change, a touch action may span more than two touch points. Sensing Sensor, so at the same time select the capacitance change of the touch sensing Sensor with the largest capacitance change and the next largest capacitance change for calculation, the positioning is more accurate and reliable, and at the same time, the calculation amount is relatively small and the energy consumption is low.

The fifth embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen. The fifth embodiment is further improved on the basis of the fourth embodiment. The main improvement is that: in the fifth embodiment, when locating the position of the touch point in the X-axis direction, all the touch-sensing Sensors are selected. The amount of capacitance change, and the position of the touch point in the X-axis direction is positioned according to the symmetry of the touch sensing Sensor. In this way, the capacitance change caused by all touched touch sensing Sensors is considered comprehensively, and the positioning is more reliable.

Specifically, in the step of locating the position of the touch point in the X-axis direction according to the relative change of the capacitance variation of the first touch sensing Sensor and the capacitance variation of the second touch sensing Sensor, the following sub-steps are also included:

First, sum the capacitance changes of all first touch sensors and the capacitance changes of the second touch sensors to obtain the sum ΔS1 of the capacitance changes of all first touch sensors and all second touch sensors. The sum ΔS2 of the sensor capacitance change. Wherein, ΔS1=Δc1+Δc3+Δc5+...+Δc(2N-1), ΔS2=Δc2+Δc4+Δc6+...+Δc(2N).

Next, the position X ₃ of the touch point in the X-axis direction is located according to the values of ΔS1 and ΔS2 . Wherein, the formula for calculating _X3 is: x ₄ and x ₅ are the reference X-axis coordinate values corresponding to ΔS1 and ΔS2, such as the maximum or minimum value of the X-axis coordinate value. Due to the consistency of all touch sensor structures, even if ΔS1 and ΔS2 are multiple touch sensor The combination of Sensor variation and reference value can also only select two.

Sum the capacitance changes of all the first touch sensors and the capacitance changes of the second touch sensors respectively, and obtain the sum ΔS1 of the capacitance changes of all the first touch sensors and all the second touch sensors and ΔS2 of the capacitance change, and then locate the position of the touch point in the X-axis direction according to ΔS1 and ΔS2, since the capacitance change caused by all touched touch sensors is considered comprehensively (because a touch action may span multiple touch sensing sensors), and locate the touch point according to the symmetry between the first touch sensing sensor and the second touch sensing sensor, so that the positioning of the touch point is more reliable.

The sixth embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen. The sixth embodiment is a further refinement of the first embodiment, and provides a specific positioning method of the touch position in the X-axis direction. In the sixth embodiment of the present invention, the positions X ₁ , X ₂ , and X ₃ of the touch point in the X-axis direction are first acquired through the methods described in the third embodiment, the fourth embodiment, and the fifth embodiment, respectively, and then X ₁ , X ₂ and X ₃ are weighted to obtain the position X ₄ of the touch point in the X-axis direction, so that the position of the touch point in the X-axis direction can be positioned more accurately by comprehensively considering the influence of various factors.

Specifically, in the step of locating the position of the touch point in the X-axis direction according to the relative change of the capacitance variation of the touched first touch-sensing Sensor and the capacitance variation of the touched second touch-sensing Sensor, Also includes the following substeps:

First, the positions X ₁ , X ₂ and X ₃ of the touch point in the X-axis direction are obtained through the methods described in the fourth embodiment, the fifth embodiment, and the sixth embodiment, respectively.

Next, X ₁ , X ₂ and X ₃ are weighted to obtain the position X ₄ of the touch point in the X-axis direction. Among them, the formula for obtaining X ₄ is X ₄ =w ₁ ·X ₁ +w ₂ ·X ₂ +w ₃ ·X ₃ , w ₁ , w ₂ and w ₃ are the weighting coefficients of X ₁ , X ₂ and X ₃ respectively , representing the weights of the positions X ₁ , X ₂ and X ₃ of the touch point in the X-axis direction acquired by the methods described in the fourth embodiment, the fifth embodiment, and the sixth embodiment respectively, and the weights of the three are It is obtained through a pre-calibration method, and the calculation accuracy of the three calculation methods is different for different positions on the screen. The weighted value will be adjusted according to the size of the results obtained by the three calculation methods.

In this way, since the influence of various factors is comprehensively considered, the location of the touch point in the X-axis direction is more accurate.

The seventh embodiment of the present invention relates to a method for locating a touch position on a capacitive touch screen. The seventh embodiment is further improved on the basis of the first embodiment, the main improvement is: in the seventh embodiment, when locating the position of the touch point in the X-axis direction, the system in the X-axis direction is eliminated The error makes the positioning of the touch position in the X-axis direction more accurate.

Specifically, in the step of locating the position of the touch point in the X-axis direction according to the relative change of the capacitance variation of the first touch sensing Sensor and the capacitance variation of the second touch sensing Sensor, the following sub-steps are also included: After eliminating the systematic error in the X-axis direction, locate the position of the touch point in the X-axis direction.

In detail, firstly, the position X ₀ of the touch point in the X-axis direction is obtained according to the method described in the first embodiment; then, the systematic error x ₀ (or in other words, the inherent bias) in the X-axis direction is eliminated by using the following formula Shift), to obtain the touch position X ₅ after eliminating the system error: Among them, the system error x ₀ is obtained through a formula calibration method. For example, one calibration method is to scan all positions on the screen and obtain the minimum capacitance change of the touch sensing Sensor when there is a touch.

Since the capacitive touch screen will inevitably introduce a system error when touching, wherein the system error is generated by a fixed bias, resulting in inaccurate positioning of the touch point in the X-axis direction, so when locating the touch point in For the position in the X-axis direction, the system error in the X-axis direction is eliminated by offsetting a calibrated value for the capacitance change, so that the touch position positioning in the X-axis direction is more accurate.

The division of steps in the above methods is only for the sake of clarity of description. During implementation, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they contain the same logical relationship, they are all within the scope of protection of this patent. ; Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but not changing the core design of the algorithm and process are all within the scope of protection of this patent.

The eighth embodiment of the present invention relates to a capacitive touch screen, and the capacitive touch screen includes: several touch sensing Sensors.

Among them, the touch sensing Sensor is divided into several groups, each group is a sensing unit, and the sensing unit is rectangular; wherein, each sensing unit includes a first touch sensing Sensor and a second touch sensing Sensor, the second The width of the first touch sensor sensor decreases along the positive direction of the X-axis, and the width of the second touch sensor Sensor increases along the positive direction of the X-axis; the positive direction of the X-axis is the width direction of the capacitive touch screen, and points from the left Right, the direction of the Y axis is the direction of the long side of the capacitive touch screen, and is perpendicular to the X axis.

It is worth mentioning that, in order to highlight the innovative part of the present invention, this embodiment does not introduce units that are not closely related to solving the technical problems proposed by the present invention, but this does not mean that there are no other elements in this embodiment. unit.

It is not difficult to find that this embodiment is a system embodiment corresponding to the first embodiment, and this embodiment can be implemented in cooperation with the first embodiment. The relevant technical details mentioned in the first embodiment are still valid in this embodiment, and will not be repeated here in order to reduce repetition. Correspondingly, the relevant technical details mentioned in this implementation manner can also be applied in the first implementation manner.

Those of ordinary skill in the art can understand that the above-mentioned embodiments are specific examples for realizing the present invention, and in practical applications, various changes can be made to it in form and details without departing from the spirit and spirit of the present invention. scope.

Claims (7)

1. on a kind of capacitive touch screen touch point localization method, it is characterised in that the capacitive touch screen comprising N number of first touch Control sensing Sensor and N number of second touch-control sensing Sensor, the first touch-control sensing Sensor and one described second Touch-control sensing Sensor constitutes the sensing unit of a rectangle；Pros of the width of the first touch-control sensing Sensor along X-axis To successively decreasing, the width of the second touch-control sensing Sensor is incremented by along the positive direction of the X-axis；The positive direction of the X-axis is institute State the broadside of capacitive touch screen, and point to right by left, Y direction is the long side direction of the capacitive touch screen, and vertically In the X-axis；Wherein, N is the natural number more than or equal to 1；

On the capacitive touch screen, the localization method of touch point is comprised the steps of：

Detect the capacitance change of all touch-control sensing Sensor of the capacitive touch screen；

Relative with the capacitance change of the second touch-control sensing Sensor according to the capacitance change of the first touch-control sensing Sensor Change positioning touch point position in the X-axis direction；

Position of the touch point in the Y direction is positioned according to the capacitance change of multiple sensing units.

2. on capacitive touch screen according to claim 1 touch point localization method, it is characterised in that many in the basis In the step of capacitance change of individual sensing unit positions position of the touch point in the Y direction, comprising following son Step：

The touch point is positioned after difference operation is carried out to the capacitance change of multiple sensing units in the Y direction Position.

3. on capacitive touch screen according to claim 1 touch point localization method, it is characterised in that described according to The change relative with the capacitance change of the second touch-control sensing Sensor of the capacitance change of one touch-control sensing Sensor positions institute In the step of stating position of the touch point in the X-direction, the touch point is positioned in the X-axis side using linear interpolation method Position upwards.

4. on capacitive touch screen according to claim 3 touch point localization method, it is characterised in that in the employing line Property interpolation method the step of position the position of the touch point in the X-direction in, also include following sub-step：

The capacitance change Δ C1 and on the other side two of capacitance change maximum first touch-control sensing Sensor is chosen respectively The capacitance change Δ C2 of the second maximum touch-control sensing Sensor of capacitance change in the second touch-control sensing Sensor of group；

Position of the touch point in the X-direction is positioned according to the value of the Δ C1 and Δ C2.

5. on capacitive touch screen according to claim 3 touch point localization method, it is characterised in that in the employing line Property interpolation method the step of position the position of the touch point in the X-direction in, also include following sub-step：

Choose respectively capacitance change maximum, secondary the first big touch-control sensing Sensor capacitance change Δ C1, Δ C3 with Capacitance change Δ C2, Δ C4 with the second touch-control sensing Sensor of the two touch-control sensings Sensor opposite positions；

According to the value of the Δ C1, the Δ C2, the Δ C3 and Δ C4 positioning touch point in the X-direction Position.

6. on capacitive touch screen according to claim 1 touch point localization method, it is characterised in that described according to The change relative with the capacitance change of the second touch-control sensing Sensor of the capacitance change of one touch-control sensing Sensor positions institute In the step of stating position of the touch point in the X-direction, also include following sub-step：

The capacitance change of all first touch-control sensing Sensor is become with the electric capacity of the second touch-control sensing Sensor Change amount is sued for peace respectively, obtains the capacitance change and Δ S1 and all described second of all first touch-control sensing Sensor The capacitance change of touch-control sensing Sensor and Δ S2；

Position of the touch point in the X-direction is positioned according to the value of the Δ S1 and Δ S2.

7. on capacitive touch screen according to claim 1 touch point localization method, it is characterised in that described according to The change relative with the capacitance change of the second touch-control sensing Sensor of the capacitance change of one touch-control sensing Sensor positions institute In the step of stating position of the touch point in the X-direction, also include following sub-step：

Position of the touch point in the X-direction is positioned after eliminating the systematic error in the X-direction.