An addressing-based capacitive touch screen touch detection method

Abstract

A kind of capacitive touch screen touch detection method based on addressing, comprising: in touch area, electrode group including M sensing electrodes is provided;Peripheral area is provided with signal line and gating circuit, the main body of gating circuit is M×N TFT array, each TFT row includes N TFTs with source electrode, drain electrode connected in series, each sensing electrode is connected with signal line by a TFT row;Each TFT column is equipped with first control line and second control line;Step (1) is controlled by the level input of the first control line and the second control line of each TFT column, the switch state of each TFT, so that certain or certain sensing electrode is in input or output state;Step (2) is electrically connected with signal line using external detection circuit based on the principle of capacitance, the response of sensing electrode is detected;Step (3) analyzes and obtains the touch position and touch action of finger.The present application can realize flexible gating to different sensing electrodes, improve the sensitivity and detection efficiency of detection.

Description

Technical Field

[0001] This invention relates to the field of touch screen technology, and more specifically to an addressing-based capacitive touch screen touch detection method. Background Technology

[0002] Existing capacitive touchscreens generally include a transparent substrate, which can be divided into a touch area and a peripheral area. The touch area has multiple sensing electrodes for sensing finger touches, while the peripheral area has multiple peripheral wires patterned from a metal layer, which are used to connect the sensing electrodes.

[0003] This type of capacitive touchscreen detects the position of a finger on the screen and its touch event by sensing changes in the capacitance (capacitance to ground or mutual capacitance) of a sensing electrode. However, each sensing electrode is typically connected to the detection circuit via a wire, and the number of peripheral leads is the same as the number of sensing electrodes. As the number of sensing electrodes increases, the number of peripheral leads also increases, eventually leading to overly dense peripheral leads, causing routing difficulties, and increasing interference between the circuits, resulting in reduced touchscreen sensitivity. Furthermore, existing capacitive touchscreens use an electrode-by-electrode scanning method, requiring scanning of each electrode in each detection cycle, resulting in low detection efficiency. As the number of sensing electrodes increases, the detection time also increases, thus reducing sensitivity and responsiveness. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide an addressing-based capacitive touchscreen touch detection method. This method enables flexible selection of different sensing electrodes in the capacitive touchscreen, reducing detection time and improving response speed, thereby increasing detection sensitivity and efficiency. The technical solution adopted is as follows: A capacitive touchscreen touch detection method based on addressing, characterized by comprising: A touch area and a peripheral area are provided on the substrate of a capacitive touch screen. The touch area is provided with an electrode group, which includes M sensing electrodes. The peripheral area is provided with at least one signal line and a gating circuit. The main body of the gating circuit is an M×N TFT array. The TFT array can be divided into M TFT rows or N TFT columns. Each TFT row includes N TFTs connected in series with their source and drain terminals connected end to end. Each sensing electrode is connected to the corresponding signal line through a TFT row. Each TFT column is equipped with a first control line and a second control line. Its TFTs can be divided into first TFTs and second TFTs. The gates of the first TFTs and second TFTs are connected to the first control line and the second control line, respectively. The first TFTs and second TFTs in different columns have different arrangements. In addition, the touch location and touch action of the fingers are detected through the following steps: Step (1) The switching state of each TFT is controlled by the level input of the first control line and the second control line of each TFT column, so as to realize the signal line and one or more corresponding sensing electrodes to be connected, thereby making one or more sensing electrodes of the capacitive touch screen in the input or output state. Step (2) uses an external detection circuit based on the principle of capacitance to be electrically connected to the signal line to detect the response of the sensing electrode in the input or output state. Step (3) Analyze the detection results of step (2) to obtain the touch position and touch action of the finger.

[0005] In the preferred embodiment, the first and second TFTs of a certain TFT column are defined as belonging to their first row set and second row set, respectively. Through the selective overlap of the first and second control lines, the intersection of any first or second row set of each TFT column contains only one TFT row. This ensures that the selection circuit can accurately select the M sensing electrodes.

[0006] In a more preferred embodiment, the relationship between the number of columns N and the number of rows M of the TFT array is: 2 (N-1) <M≤2 N In a further preferred embodiment, each column of the TFT array is identified by a non-zero natural number n not greater than N, and the first TFT and the second TFT in the nth column are consecutively numbered 2. n-1 Interleaved arrangement.

[0007] In the preferred embodiment, the number of sensing electrodes M=2 N N is a natural number not less than 3. For example, the number of sensing electrodes M can be 8, 16, 32, 64, 128, or 256.

[0008] In the aforementioned touch detection method, signal lines are electrically connected to sensing electrodes through rows of TFTs, and each TFT is controlled by first and second control lines. This enables the selection of signal lines between different sensing electrodes, facilitating further input or output, thereby detecting the position of a finger on the touchscreen and its touch events. Using this method, the number of control lines N is exponentially related to the number of sensing electrodes M. Even with a large number of sensing electrodes, signal input / output selection can be achieved with fewer control lines, thus reducing the number of peripheral leads. Furthermore, signal lines can simultaneously select multiple sensing electrodes in certain combinations to achieve more efficient detection, reduce detection time, and improve response speed, thereby increasing detection sensitivity and efficiency.

[0009] In a preferred embodiment, the TFT is a low-temperature polycrystalline silicon (LTPS) thin-film transistor or an oxide (such as IGZO) thin-film transistor. It has lower resistance in the on-state, making it more suitable for connecting in series to form the connection between the sensing electrode and the signal line.

[0010] Generally, when the gate of the TFT is input with a high level through the first control line or the second control line, the TFT is in the conducting state; otherwise, it is in the non-conducting state. In this specification, the high and low levels on the first and second control lines can be represented by 0 (low level) or 1 (high level), respectively.

[0011] In a preferred embodiment, in steps (1)-(3), the various sensing electrodes of the capacitive touchscreen are detected in multiple groups, and the touch position and touch action of the finger are analyzed based on the detection results of each group. That is, multiple detections are performed within a certain detection cycle, and different sensing electrode groups are selected for detection each time through a gating circuit, and the touch position and touch action of the finger are analyzed based on the detection results of each detection.

[0012] In a more preferred scheme, the group detection method is specifically as follows: Step (a) defines M'=2 N For M' sensing electrodes (considering that the number of sensing electrodes M may not be exactly 8, 16, 32, 64, etc., the above inequality 2 needs to be used). (N-1) <M≤2 N To determine the number of groupings N and the value of M', where M' is the number of sensing electrodes (including M actual electrodes and M'-M supplementary electrodes that do not actually exist), N groupings are performed. In the k-th (1≤k≤N) grouping, the sensing electrodes are divided into groups of 2 consecutive numbers. k-1 The first and second electrodes are arranged in an alternating manner; Step (b) 2N detections are performed within the detection period T, where k is defined as a non-zero natural number not greater than N. The first electrode of the k-th group is detected in the 2k-1th detection, and the second electrode of the k-th group is detected in the 2kth detection; Step (c) Based on the results of each detection, the sensing electrodes touched by the finger are analyzed.

[0013] In a further preferred embodiment, each responsive probe is recorded in step (b), and the intersection of their electrode groups is calculated in step (c) to obtain the touch position of the finger.

[0014] When the first TFT and the second TFT in the nth column are consecutively numbered 2 n-1 When the array is staggered, the above-mentioned group detection method can be implemented by inputting a low level to the first control line of the k-th column TFT in the 2k-1th detection while keeping other control lines at a high level, and inputting a low level to the second control line of the k-th column TFT in the 2k-th detection.

[0015] In a preferred embodiment, the electrode group is divided into an X electrode group and a Y electrode group. The X electrode group includes a plurality of X electrodes arranged in parallel along the X-axis, and the Y electrode group includes a plurality of Y electrodes arranged in parallel along the Y-axis. Each X electrode and each Y electrode are intersected on a working surface.

[0016] In a more preferred embodiment, the X electrode group is selected for conduction using the aforementioned gating circuit, and the Y electrode group is directly connected to the detection circuit via multiple channels for detection. Specifically, each X electrode is selected and input with a signal using the above method, and each Y electrode is individually connected to the detection circuit. Thus, the signal input through the X electrode is fed back to each Y electrode according to the mutual capacitance principle, and each Y electrode is independently detected, thereby forming the detection of the X and Y positions of the working surface.

[0017] In another preferred embodiment, the X electrode group and the Y electrode group are each selected to be turned on by the gating circuit and perform their own detection (each can be detected using the self-capacitance principle), thereby forming the detection of the X and Y positions of the working surface.

[0018] In another preferred embodiment, both the X electrode group and the Y electrode group are selected and turned on by the gating circuit. One detection period T includes two time periods, T1 and T2. In step (2), (2-1): during the T1 time period, all Y channels are fully opened and the X electrode group is selected. The mutual capacitance change between the X and Y signal lines is detected according to the mutual capacitance principle, thereby hitting a certain X electrode and recording it; (2-2): during the T2 time period, the signal is input to the hit X electrode and each Y electrode is detected. When a certain Y electrode is hit, the coordinates formed by its X electrode and Y electrode are output.

[0019] Compared with the prior art, the present invention has the following advantages: This capacitive touchscreen touch detection method, by setting a gating circuit in the peripheral area of ​​the capacitive touchscreen, can flexibly select different sensing electrodes, such as directly selecting a single sensing electrode or simultaneously selecting multiple sensing electrodes. This allows for a more efficient (or intelligent) detection method, enabling the selection of input or output from each sensing electrode in the capacitive touchscreen to detect the position of a finger on the screen and its touch events. Furthermore, it can reduce detection time and improve response speed, as well as reduce the number of peripheral leads, thereby improving detection sensitivity and efficiency. Attached Figure Description

[0020] Figure 1 These are circuit diagrams of the capacitive touchscreen in the preferred embodiments of the present invention, namely, Embodiment 1 and Embodiment 2.

[0021] Figure 2This is a circuit diagram of the capacitive touchscreen in the preferred embodiment of the present invention, Example 3.

[0022] Figure 3 This is a circuit diagram of the capacitive touchscreen in the preferred embodiment of the present invention, Example 4.

[0023] Figure 4 This is a schematic diagram of the structure of the capacitive touch screen in the preferred embodiment of the present invention, Example 4. Detailed Implementation

[0024] Example 1 like Figure 1 , Figure 2 As shown, this address-based capacitive touchscreen touch detection method includes: A touch area 101 and a peripheral area 102 are provided on the substrate 1 of the capacitive touch screen 100. The touch area 101 is provided with an electrode group, which includes M sensing electrodes 2. The peripheral area 102 is provided with at least one signal line 3 and a selection circuit 4. The main body of the selection circuit 4 is an M×N TFT array. The TFT array can be divided into M TFT rows 41 or N TFT columns 42. Each TFT row 41 includes N TFTs connected in series with their source and drain terminals connected end to end. Each sensing electrode 2 is connected to the corresponding signal line 3 through a TFT row 41. Each TFT column 42 is equipped with a first control line 43 and a second control line 44. Its TFTs can be divided into first TFTs 421 and second TFTs 422. The gates of the first TFTs 421 and the second TFTs 422 are connected to the first control line 43 and the second control line 44, respectively. The first TFTs 421 and the second TFTs 422 in different columns have different arrangements. The touch location and touch action of the finger are detected through the following steps: Step (1) The switching state of each TFT is controlled by the level input of the first control line 43 and the second control line 44 of each TFT column 42, so as to realize the signal line 3 and the corresponding one or more sensing electrodes 2 are connected, thereby making one or more sensing electrodes 2 of the capacitive touch screen in the input or output state. Step (2) uses an external detection circuit based on the principle of capacitance to be electrically connected to the signal line 3 to detect the response of the sensing electrode 2 which is in the input or output state. Step (3) Analyze the detection results of step (2) to obtain the touch position and touch action of the finger.

[0025] In this embodiment, the TFT is a low-temperature polycrystalline silicon (LTPS) thin-film transistor or an oxide (such as IGZO) thin-film transistor. Its resistance is lower in the on-state, making it more suitable for connecting in series to form the connection between the sensing electrode 2 and the signal line 3. When the gate of the TFT receives a high level input through the first control line 43 or the second control line 44, the TFT is in the on-state; otherwise, it is in the off-state. The high and low levels on the first control line 43 and the second control line 44 can be represented by 0 (low level) or 1 (high level), respectively.

[0026] In this embodiment, the number of sensing electrodes 2 is M=2 N N is a natural number not less than 3. The relationship between the number of columns N and the number of rows M in a TFT array is: 2 (N-1) <M≤2 N Each column of the TFT array is identified by a non-zero natural number n not greater than N. The first TFT421 and the second TFT422 in the nth column are consecutively numbered 2. n-1 The electrodes are arranged in an alternating pattern. In steps (1)-(3), the various sensing electrodes 2 of the capacitive touchscreen are detected in multiple groups. The touch position and touch action of the finger are analyzed based on the detection results of each group. That is, multiple detections are performed within a certain detection cycle. Each time, different sensing electrodes 2 are selected for detection by the selection circuit 4, and the touch position and touch action of the finger are analyzed based on the detection results of each group.

[0027] The specific method of group probing is as follows: (a) Define M'=2 N The M' sensing electrodes 2 are grouped into N types, where in the k-th (1≤k≤N) grouping, the sensing electrodes 2 are divided into groups of consecutive numbers 2 k-1 The first and second electrodes are arranged in an alternating pattern. For example: Capacitive touchscreen 100 has 16 sensing electrodes 2,2 3 <M≤2 4 Let N=4 and M'=2 4 =16=M. The first control line 43 and the second control line 44 use different overlaps in different TFT columns 42, specifically: the first TFT 421 and the second TFT 422 in the first TFT column 42 are connected in a consecutive number of 1 (i.e., 2) 0 The first TFT 421 and the second TFT 422 in the second TFT column 42 are arranged in an alternating pattern, with a consecutive number of 2 (i.e., 2...) 1 The TFTs in the third column 42 are arranged in an alternating pattern, with the first TFT 421 and the second TFT 422 arranged in a sequence of 4 consecutive times (i.e., 2). 2 (Alternating arrangement)

[0028] (b) 2N tests are performed within the detection period T, where k is defined as a non-zero natural number not greater than N. The first electrode of the k-th group is tested in the 2k-1 test, and the second electrode of the k-th group is tested in the 2k test. For example: the detection frequency is 200Hz, the detection period is 5ms, and the detection period is divided into multiple detection time periods as shown in the table below. In different time periods, the selection of different groups of electrodes is achieved by inputting the control lines (the rule is: while keeping other control lines high, a low level is input to the first control line 43 of the k-th column TFT in the 2k-1th detection, and a low level is input to the second control line 44 of the k-th column TFT in the 2k-th detection). (The rule for each group of electrodes is: in the k-th (1≤k≤N) grouping, the sensing electrode 2 is divided into groups of 2 consecutive numbers.) k-1 (The first and second electrodes are arranged in an alternating pattern).

[0029] (c) In each of the above detections, record each detection that has a response, and obtain the touch position of the finger by the intersection of its electrode groups.

[0030] For example, assuming the finger touches the position of the 3rd electrode, and the detection results are t1(1), t2(2), t1(3), and t1(4), the intersection of the corresponding electrode groups "1010101010101010", "0011001100110011", "1111000011110000", and "1111111100000000" is taken to obtain "0010000000000000", which means the finger touches the 3rd electrode. Based on the detection results, the finger's touch position can be analyzed, and the detection steps are significantly reduced. For example, the number of sensing electrodes 2 is 16, and the number of detections M is only 8.

[0031] Example 2 While all other parts remain the same as in Embodiment 1, the difference lies in the fact that, considering the possibility that the number M of sensing electrodes 2 may not be exactly 8, 16, 32, or 64, the aforementioned inequality 2 needs to be adopted. (N-1) <M≤2 N To determine the number of groupings N and the value of M', M' of the sensing electrodes 2 include M actual electrodes and M'-M supplementary electrodes that do not actually exist. In this embodiment, the capacitive touchscreen 100 has 15 sensing electrodes 2. 3 <M≤2 4 Similarly, let N=4 and M'=2 4 =16. M'-M=1. That is, there is 1 supplementary electrode.

[0032] Example 3 refer to Figure 2While all other parts are the same as in Embodiment 1, the difference is that the electrode group is divided into an X electrode group and a Y electrode group. The X electrode group includes a plurality of X electrodes 21 arranged in parallel along the X-axis, and the Y electrode group includes a plurality of Y electrodes 22 arranged in parallel along the Y-axis. Each X electrode 21 and each Y electrode 22 are intersected on a working surface.

[0033] In this embodiment, the X electrode group is selected and turned on by the corresponding gating circuit 4, and the Y electrode group is a multi-channel design and is independently detected by the detection circuit. Each X electrode 21 is selected and input with a signal using the above method, and each Y electrode 22 is individually connected to the detection circuit. Thus, the signal input through the X electrode 21 is fed back to each Y electrode 22 according to the mutual capacitance principle, and each Y electrode 22 is independently detected, thereby forming the detection of the X and Y positions of the working surface.

[0034] Example 4 refer to Figure 3 , 4 While all other parts are the same as in Embodiment 3, the difference is that there are two gating circuits 4. The X electrode group and the Y electrode group are each selected and turned on by gating circuits and are detected by themselves (they can be detected by self-capacitance principle), thereby forming the detection of the X and Y positions of the working surface.

[0035] In this embodiment, both the X electrode group and the Y electrode group are selected by a gating circuit. One detection period T includes two time periods, T1 and T2. In step (2), (2-1): during the T1 time period, each Y channel is fully opened and the X electrode group is selected. The mutual capacitance change between the X and Y signal lines is detected according to the mutual capacitance principle, thereby hitting a certain X electrode 21 and recording it. (2-2): during the T2 time period, the signal is input to the hit X electrode 21 to detect each Y electrode 22. A certain Y electrode 22 is hit and the coordinates formed by its X electrode 21 and Y electrode 22 are output.

[0036] Furthermore, it should be noted that the names of the various parts of the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this invention are included within the scope of protection of this invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this invention or exceed the scope defined in these claims, all of which should fall within the scope of protection of this invention.

Claims

1. A capacitive touchscreen touch detection method based on addressing, characterized in that... include: A touch area and a peripheral area are provided on the substrate of a capacitive touch screen. The touch area has an electrode group, which includes M sensing electrodes. The peripheral area has at least one signal line and a gating circuit. The main body of the gating circuit is an M×N TFT array. The TFT array can be divided into M TFT rows or N TFT columns. Each TFT row includes N TFTs connected in series with their source and drain terminals connected end-to-end. Each sensing electrode is connected to the corresponding signal line through a TFT row. Each TFT column is equipped with a first control line and a second control line. Its TFTs can be divided into first TFTs and second TFTs. The gates of the first TFTs and second TFTs are connected to the first control line and the second control line, respectively. The first TFTs and second TFTs in different columns have different arrangements. The touch location and touch action of the finger are detected through the following steps: Step (1) The switching state of each TFT is controlled by the level input of the first control line and the second control line of each TFT column, so as to realize the signal line and one or more corresponding sensing electrodes to be connected, thereby making one or more sensing electrodes of the capacitive touch screen in the input or output state. Step (2) uses an external detection circuit based on the principle of capacitance to be electrically connected to the signal line to detect the response of the sensing electrode in the input or output state. Step (3) Analyze the detection results of step (2) to obtain the touch position and touch action of the finger.

2. The addressing-based capacitive touchscreen touch detection method according to claim 1, characterized in that: Define the first TFT and the second TFT of a certain TFT column as their first row set and second row set, respectively. By selectively overlapping the first control line and the second control line, the intersection of any first row set or second row set of each TFT column contains only one TFT row.

3. The addressing-based capacitive touchscreen touch detection method according to claim 2, characterized in that: The relationship between the number of columns N and the number of rows M of the TFT array is: 2 (N-1) <M≤2 N .

4. The addressing-based capacitive touchscreen touch detection method according to claim 3, characterized in that: Each column of the TFT array is identified by a non-zero natural number n, not greater than N. The first and second TFTs in the nth column are consecutively set to 2. n-1 Interleaved arrangement.

5. The addressing-based capacitive touchscreen touch detection method according to claim 1, characterized in that: The number of inductive electrodes is M=2 N N is a natural number not less than 3.

6. The addressing-based capacitive touchscreen touch detection method according to claim 1, characterized in that: The TFT is a low-temperature polycrystalline silicon thin-film transistor or an oxide thin-film transistor.

7. A capacitive touchscreen touch detection method based on addressing according to any one of claims 1-6, characterized in that: In steps (1)-(3), the various sensing electrodes of the capacitive touch screen are detected in multiple groups, and the touch position and touch action of the finger are analyzed based on the detection results of each group.

8. The addressing-based capacitive touchscreen touch detection method according to claim 7, characterized in that: The specific method of group probing is as follows: Step (a) Define M'=2 N The M' sensing electrodes are grouped into N different groups, where in the k-th (1≤k≤N) group, the sensing electrodes are divided into groups of 2 consecutive numbers. k-1 The first and second electrodes are arranged in an alternating manner; Step (b) 2N detections are performed within the detection period T, where k is defined as a non-zero natural number not greater than N. The first electrode of the k-th group is detected in the 2k-1th detection, and the second electrode of the k-th group is detected in the 2kth detection; Step (c) Based on the results of each detection, the sensing electrodes touched by the finger are analyzed.

9. The addressing-based capacitive touchscreen touch detection method according to claim 8, characterized in that: In step (b), each responsive probe is recorded, and in step (c), the intersection of their electrode groups is calculated to obtain the touch position of the finger.

10. A capacitive touchscreen touch detection method based on addressing according to any one of claims 1-6, characterized in that: The multiple sensing electrodes are divided into an X electrode group and a Y electrode group. The X electrode group includes multiple X electrodes arranged in parallel along the X-axis, and the Y electrode group includes multiple Y electrodes arranged in parallel along the Y-axis. Each X electrode and each Y electrode are intersected on a working surface.

11. The addressing-based capacitive touchscreen touch detection method according to claim 10, characterized in that: The X electrode group is selected for conduction using the aforementioned gating circuit, while the Y electrode group is directly connected to the detection circuit via multiple channels for detection.

12. The addressing-based capacitive touchscreen touch detection method according to claim 10, characterized in that: The X electrode group and Y electrode group are each selected and activated by the gating circuit and are detected by themselves, thereby forming the detection of the X and Y positions of the working surface.

13. The addressing-based capacitive touchscreen touch detection method according to claim 10, characterized in that: The X electrode group and Y electrode group are both selected and turned on by the gating circuit. One detection cycle T includes two time periods, T1 and T2. In step (2), (2-1): During the T1 time period, all Y channels are fully opened and the X electrode group is selected. The mutual capacitance change between the X and Y signal lines is detected according to the mutual capacitance principle. Thus, a certain X electrode is hit and recorded. (2-2): During the T2 time period, the signal is input to the hit X electrode and each Y electrode is detected. A certain Y electrode is hit and the coordinates formed by its X electrode and Y electrode are output.

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