TWI807481B - Adaptive capacitive touch detection method, capacitive touch chip, touch display device and information processing device - Google Patents

Abstract

An adaptive capacitive touch detection method is implemented by a control circuit, which includes: recording at least one preliminary qualified touch point among a plurality of sensing points of a capacitive touch plane; enclosing an evaluation pane in the capacitive touch plane with each said preliminary qualified touch point as the center, and calculating the sum of the difference between the sensing value at the center of the evaluation pane and other sensing points in the evaluation pane to obtain an evaluation value; and judging whether the evaluation value of each of the preliminary qualified touch points is less than an evaluation threshold , and filter out the preliminary qualified touch points smaller than the evaluation threshold to remove ghost points.

Description

Adaptive capacitive touch detection method, capacitive touch chip, touch display device and information processing device

The present invention relates to a capacitive touch detection method, in particular to an adaptive capacitive touch detection method that can adjust judgment criteria according to different pressure paths.

Please refer to FIG. 1a and FIG. 1b together, wherein FIG. 1a shows a cross-sectional view of an existing capacitive touch screen, which includes a glass cover layer 11, a transparent adhesive layer 12, a color filter layer 13, a sensing electrode layer 14, and a TFT (thin film transistor; thin film transistor) layer 15 from top to bottom;

The working principle of the capacitive touch screen is: there is a basic capacitance between each sensing electrode 14a and the ground, and when a finger presses the glass cover 11, the finger will generate a parallel capacitance on the basic capacitance of the corresponding plurality of sensing electrodes 14a. At this time, a capacitance sensing circuit can generate a sensing signal according to a capacitance variation value to notify a control circuit.

However, during the actual pressing operation, the sensing electrode layer 14 will be deformed and the sensing electrodes 14a around the pressing area will be lifted, so that the sensing values of the unpressed sensing electrodes 14a will increase due to the closer distance to the finger, thereby possibly generating ghost points (that is, untouched points become touch broadcast points because their sensing values are greater than a predetermined threshold).

In order to solve the above problems, there is an urgent need in the art for a novel adaptive capacitive touch detection method.

The main purpose of the present invention is to disclose an adaptive capacitive touch detection method, which can adjust the size of an evaluation pane according to different pressing pressure paths, and perform an evaluation calculation on a plurality of sensing values in the evaluation pane to determine whether the center of the evaluation pane is a ghost point (the sensing value is greater than a pre-judgment) Threshold of untouched points).

Another object of the present invention is to disclose a capacitive touch chip, which can filter out ghost points by implementing the aforementioned adaptive capacitive touch detection method, so as to avoid untouched points being regarded as touched points.

Another object of the present invention is to disclose a touch display device, which can improve the reliability of its touch operation by using the above-mentioned capacitive touch chip.

Another object of the present invention is to disclose an information processing device, which can improve the touch experience of its touch screen by using the above-mentioned capacitive touch chip.

To achieve the aforementioned purpose, an adaptive capacitive touch detection method is proposed, which is realized by a control circuit and includes:

Recording at least one tentatively qualified touch point among a plurality of sensing points of a capacitive touch plane;

In the capacitive touch plane, an evaluation pane is circled around each of the preliminary qualified touch points, and the sum of the sensing value differences between the sensing point at the center of the evaluation pane and other sensing points in the evaluation pane is calculated to obtain an evaluation value; and

It is judged whether the evaluation value of each preliminary qualified touch point is less than an evaluation threshold, and the preliminary qualified touch points smaller than the evaluation threshold are filtered out.

In one embodiment, the preliminary qualified touch point is the sensing point whose sensing value is greater than a sensing threshold.

In one embodiment, the size of the evaluation pane for each of the preliminary qualified touch points is positively correlated with the sensing value of each of the preliminary qualified touch points.

In one embodiment, the evaluation threshold is proportional to the maximum of the sensing values of the sensing points of the capacitive touch plane.

To achieve the aforementioned purpose, the present invention further proposes a capacitive touch chip, which has a control circuit to perform an adaptive capacitive touch detection method, the method comprising:

Recording at least one tentatively qualified touch point among a plurality of sensing points of a capacitive touch plane;

In the capacitive touch plane, circle each of the preliminary qualified touch points as the center an evaluation pane, and calculating the sum of the differences of the sensing values between the sensing point at the center of the evaluation pane and other sensing points in the evaluation pane to obtain an evaluation value; and

It is judged whether the evaluation value of each preliminary qualified touch point is less than an evaluation threshold, and the preliminary qualified touch points smaller than the evaluation threshold are filtered out.

In one embodiment, the preliminary qualified touch point is the sensing point whose sensing value is greater than a sensing threshold.

In one embodiment, the size of the evaluation pane for each of the preliminary qualified touch points is positively correlated with the sensing value of each of the preliminary qualified touch points.

In one embodiment, the evaluation threshold is proportional to the maximum of the sensing values of the sensing points of the capacitive touch plane.

To achieve the aforementioned purpose, the present invention further proposes a touch display device, which has a capacitive touch screen and a touch drive circuit for driving the capacitive touch screen, characterized in that the touch drive circuit has at least one capacitive touch chip as described above.

In one embodiment, the capacitive touch screen has a display module, and the display module can be a liquid crystal display module, a micro light emitting diode display module, a mini light emitting diode display module, a quantum dot light emitting diode display module or an organic light emitting diode display module.

To achieve the aforementioned purpose, the present invention further proposes an information processing device, which has a central processing unit and the aforementioned touch display device, wherein the central processing unit is used to communicate with the touch display device.

In one embodiment, the capacitive touch screen has a display module, and the display module is a display module selected from a group consisting of a liquid crystal display module, a micro light emitting diode display module, a mini light emitting diode display module, a quantum dot light emitting diode display module and an organic light emitting diode display module.

In a possible embodiment, the information processing device may be a smart phone, a portable computer, a vehicle computer, a wearable electronic device or an access control device.

In order to enable your examiners to further understand the structure, features and purpose of the present invention, drawings and detailed descriptions of preferred specific embodiments are hereby attached.

11: Glass cover layer

12: transparent glue layer

13: Color filter layer

14: Induction electrode layer

14a: Sensing electrode

15: TFT layer

100: Touch display device

110: capacitive touch screen

110a: Touch Sensing Image

110b: touch sensing image

120: Touch drive circuit

121: Capacitive touch chip

121a: control circuit

121b: drive circuit

200: information processing device

210: central processing unit

220: touch display device

Step a: Recording at least one tentatively qualified touch point among a plurality of sensing points of a capacitive touch plane

Step b: in the capacitive touch plane, circle an evaluation pane centered on each of the preliminary qualified touch points, and calculate the sum of the sensing value difference between the sensing point at the center of the evaluation pane and other sensing points in the evaluation pane to obtain an evaluation value

Step c: judging whether the evaluation value of each of the preliminary qualified touch points is less than an evaluation threshold, and filtering out the preliminary qualified touch points smaller than the evaluation threshold

FIG. 1a shows a cross-sectional view of a conventional capacitive touch screen.

FIG. 1b illustrates a structure of a sensing electrode layer of the capacitive touch screen shown in FIG. 1a.

FIG. 2 is a block diagram of an embodiment of the touch display device of the present invention.

FIG. 3 is a flowchart of an embodiment of an adaptive capacitive touch detection method of the present invention.

FIG. 4a illustrates a frame of a touch sensing image with a ghost point.

Fig. 4b shows the removed touch-sensing image of Fig. 4a after being processed by the method of the present invention. One frame of the ghost point is a touch sensing image.

FIG. 5 is a block diagram of an embodiment of an information processing device of the present invention.

Please refer to FIG. 2 , which is a block diagram of an embodiment of the touch display device of the present invention. As shown in FIG. 2 , a touch display device 100 has a capacitive touch screen 110 and a touch drive circuit 120 for driving the capacitive touch screen 110, wherein the touch drive circuit 120 has at least one capacitive touch chip 121, and the capacitive touch chip 121 has a control circuit 121a and a drive circuit 121b. The number of capacitive touch chips 121 is directly proportional to the size of the capacitive touch screen 110 , that is, the larger the size of the capacitive touch screen 110 , the more the number of capacitive touch chips 121 .

The control circuit 121a is used to control the operation of the driving circuit 121b to obtain capacitance sensing values of a plurality of sensing points in a sensing area from the capacitive touch screen 110, and perform an adaptive capacitive touch detection process on these capacitance sensing values, which includes:

(1) Recording at least one tentatively qualified touch point among a plurality of sensing points in the sensing area, wherein the tentatively qualified touch point is a sensing point whose capacitance sensing value is greater than a sensing threshold;

(2) In the sensing area, an evaluation pane is circled around each of the preliminary qualified touch points as the center, and the sum of the difference between the sensing point at the center of the evaluation pane and the capacitance sensing value between other sensing points in the evaluation pane is calculated to obtain an evaluation value, wherein the size of the evaluation pane is positively correlated with the capacitance sensing value of each of the preliminary qualified touch points; and

(3) Judging whether the evaluation value of each of the preliminary qualified touch points is less than an evaluation value threshold, and filter out the preliminary qualified touch points that are smaller than the evaluation threshold, wherein the evaluation threshold is proportional to the maximum of the capacitance sensing values of the sensing points in the sensing area.

In detail, assuming that the capacitive sensing value of a tentatively qualified touch point with coordinates (i, j) is a _i,j , and i, j are both positive integers, the present invention assigns it an evaluation pane that is positively correlated with the capacitive sensing value, and the evaluation pane can be represented by a matrix A _i,j :

，其中，矩陣A_i,j之大小為(2n+1)*(2k+1)，n,k皆為正整數。

, wherein, the size of matrix A _{i, j} is (2n+1)*(2k+1), and n, k are both positive integers.

In addition, the evaluation value of the evaluation pane can be expressed as:

，其中，EVA為所述評估值。

, where EVA is the evaluation value.

In addition, the evaluation threshold can be expressed as Adj = αS _max , wherein α is a positive real number, and S _max is the maximum of the capacitive sensing values of the sensing points in the sensing area. In detail, α = r (2n+1)(2k+1), where 0<r<1.

Accordingly, if EVA<Adj, the preliminary qualified touch point is filtered out; if EVA>Adj, the preliminary qualified touch point is regarded as a touch broadcast point.

In addition, the capacitive touch screen 110 can have a display module, and the display module can be a liquid crystal display module, a micro light emitting diode display module, a mini light emitting diode display module, a quantum dot light emitting diode display module or an organic light emitting diode display module.

According to the above description, the present invention provides an adaptive capacitive touch detection method. Please refer to FIG. 3 , which shows a flowchart of an embodiment of an adaptive capacitive touch detection method of the present invention, which is implemented by a control circuit. As shown in Figure 3, the method includes: recording at least one tentatively qualified touch point in a plurality of sensing points of a capacitive touch plane (step a); in the capacitive touch plane, circle an evaluation pane centered on each of the tentatively qualified touch points, and calculate the center of the evaluation pane The sum of the difference of the sensing value between the sensing point and other sensing points in the evaluation pane to obtain an evaluation value (step b); and determine whether the evaluation value of each of the preliminary qualified touch points is less than an evaluation threshold, and filter out the preliminary qualified touch points smaller than the evaluation threshold (step c).

In step a, the preliminary qualified touch point is the sensing point whose sensing value is greater than a sensing threshold.

In step b, the size of the evaluation pane of each of the preliminary qualified touch points is positively correlated with the sensing value of each of the preliminary qualified touch points, that is, when the sensing value of a preliminary qualified touch point is larger, it means that there are more lifting sensing points around the touch point, and the size of the evaluation pane must be larger to ensure that all ghost points are filtered out.

In step c, the evaluation threshold is proportional to the maximum of the sensing values of the sensing points of the capacitive touch plane.

Please refer to FIGS. 4a and 4b together, wherein FIG. 4a shows a frame of touch sensing image 110a with a ghost point; FIG. 4b shows a frame of touch sensing image 110b with the ghost point removed after the touch sensing image 110a of FIG. 4a is processed by the method of the present invention.

According to the above description, the present invention further provides an information processing device. Please refer to FIG. 5 , which shows a block diagram of an embodiment of the information processing device of the present invention. As shown in FIG. 5, an information processing device 200 has a central processing unit 210 and a touch display device 220, wherein the touch display device 220 is realized by the touch display device 100 shown in FIG. In addition, the information processing device 200 can be a smart phone, a portable computer, a vehicle computer, a wearable electronic device or an access control device.

With the design disclosed above, the present invention has the following advantages:

1. The adaptive capacitive touch detection method of the present invention can adjust the size of an evaluation pane according to different pressing pressure paths, and perform an evaluation calculation on a plurality of sensing values in the evaluation pane to determine whether the center of the evaluation pane is a ghost point (an untouched point whose sensing value is greater than a predetermined threshold).

2. The capacitive touch chip of the present invention can filter out ghost points by implementing the aforementioned adaptive capacitive touch detection method, so as to avoid untouched points being regarded as touched points.

3. The touch display device of the present invention can improve its performance by the above-mentioned capacitive touch chip. Reliability of touch operation.

4. The information processing device of the present invention can improve the touch experience of its touch screen through the above-mentioned capacitive touch chip.

What is disclosed in this case is a preferred embodiment. For example, any partial changes or modifications derived from the technical ideas of this case and easily deduced by those who are familiar with the technology are within the scope of the patent right of this case.

To sum up, regardless of the purpose, means and efficacy of this case, it shows that it is very different from the conventional technology, and its first invention is practical, and indeed meets the patent requirements of the invention. I sincerely hope that your examination committee will be aware of it, and grant a patent as soon as possible to benefit the society. This is the highest prayer.

Step a: Recording at least one tentatively qualified touch point among a plurality of sensing points of a capacitive touch plane

Step b: in the capacitive touch plane, circle an evaluation pane centered on each of the preliminary qualified touch points, and calculate the sum of the sensing value difference between the sensing point at the center of the evaluation pane and other sensing points in the evaluation pane to obtain an evaluation value

Step c: judging whether the evaluation value of each of the preliminary qualified touch points is less than an evaluation threshold, and filtering out the preliminary qualified touch points smaller than the evaluation threshold

Claims (7)

An adaptive capacitive touch detection method is implemented by a control circuit, which includes: recording at least one preliminary qualified touch point among a plurality of sensing points of a capacitive touch plane; enclosing an evaluation pane in the capacitive touch plane with each of the preliminary qualified touch points as the center, and calculating the sum of the difference between the sensing value at the center of the evaluation pane and other sensing points in the evaluation pane to obtain an evaluation value; and judging whether the evaluation value of each of the preliminary qualified touch points is less than an evaluation threshold , and filter out the preliminary qualified touch points that are smaller than the evaluation threshold; wherein, the size of the evaluation pane of each of the preliminary qualified touch points is positively correlated with the sensing value of each of the preliminary qualified touch points, and the evaluation threshold is proportional to the maximum of the sensing values of the sensing points of the capacitive touch plane; wherein the preliminary qualifying touch point is the sensing point whose sensing value is greater than a sensing threshold. A capacitive touch chip, having a control circuit to perform an adaptive capacitive touch detection method, the method comprising: recording at least one tentatively qualified touch point among a plurality of sensing points of a capacitive touch plane; enclosing an evaluation pane centered on each of the tentatively qualified touch points in the capacitive touch plane, and calculating the sum of the difference between the sensing value at the center of the evaluation pane and other sensing points in the evaluation pane to obtain an evaluation value; and judging the evaluation value of each of the tentatively qualified touch points Whether it is less than an assessment threshold, and filtering out the preliminary qualified touch points that are less than the assessment threshold; Wherein, the size of the evaluation pane of each of the preliminary qualified touch points is positively correlated with the sensing value of each of the preliminary qualified touch points, and the evaluation threshold is proportional to the maximum of the sensing values of the sensing points of the capacitive touch plane; wherein, the preliminary qualified touch point is the sensing point whose sensing value is greater than a sensing threshold. A touch display device having a capacitive touch screen and a touch drive circuit for driving the capacitive touch screen, characterized in that the touch drive circuit has at least one capacitive touch chip as described in item 2 of the scope of the patent application. The touch display device described in item 3 of the scope of the patent application, wherein the capacitive touch screen has a display module, and the display module is a display module selected from a group consisting of a liquid crystal display module, a micro light emitting diode display module, a mini light emitting diode display module, a quantum dot light emitting diode display module and an organic light emitting diode display module. An information processing device has a central processing unit and the touch display device as described in item 3 of the scope of the patent application, wherein the central processing unit is used to communicate with the touch display device. The information processing device described in item 5 of the scope of the patent application, wherein the capacitive touch screen has a display module, and the display module is a display module selected from a group consisting of a liquid crystal display module, a micro light emitting diode display module, a mini light emitting diode display module, a quantum dot light emitting diode display module and an organic light emitting diode display module. The information processing device described in item 5 of the scope of the patent application is a device selected from the group consisting of a smart phone, a portable computer, a vehicle computer, a wearable electronic device and an access control device.

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