Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to fall within the scope of the application.
In the description of the present application, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The following disclosure provides many different embodiments, or examples, for implementing different features of the application. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed.
The following describes the flow of the method for driving the mutual capacitance Touch screen in detail, and the method is executed by a Touch screen controller (or a Touch screen control device), wherein the Touch screen controller can be a micro control unit (Microcontroller Unit, abbreviated as MCU) in the Touch screen, a processor or a Touch control (Touch) integrated circuit (Integrated Circuit, abbreviated as IC) in the terminal equipment.
Referring to fig. 3, a schematic flow chart of a driving method of a mutual capacitive touch screen according to the present application is shown. The method comprises the following steps: s1, receiving a touch event, and starting a touch point positioning process; s2, setting a driving signal scanning mode adopted by the touch point positioning process, and obtaining a setting result; s3, if the set result is the first result, adopting a dichotomy iterative parallel scanning driving mode to acquire driving channels and sensing channels corresponding to all touch points in the touch event; and S4, if the set result is the second result, acquiring driving channels and sensing channels corresponding to all touch points in the touch event by adopting a progressive scanning driving mode.
Regarding step S1, a touch event is received, and a touch point positioning process is started.
When a Touch event occurs on the Touch screen, the sensing channel can feed back the capacitance change to the Touch screen controller (such as Touch IC) in real time; and the touch screen controller starts a touch point positioning process according to the received touch event information.
And S2, setting a driving signal scanning mode adopted by the touch point positioning process, and obtaining a setting result.
In one embodiment, step S2 further includes: setting a driving signal scanning mode according to the number of simultaneous touch points allowed by the touch screen, and obtaining the setting result; and if the number of simultaneous touch points allowed by the touch screen is smaller than or equal to a preset touch point threshold, acquiring a first result as a set result, otherwise, acquiring a second result as the set result. That is, in real application, an appropriate scanning manner may be set according to actual needs: for the situation of fewer touch points, the scanning time can be greatly reduced by adopting a dichotomy iterative parallel scanning driving mode for scanning, and the more channels of the touch screen, the more obvious the dichotomy advantages are; for the case of more touch points, the existing progressive scanning driving mode is more beneficial. Therefore, the touch screen controller can preset the driving signal scanning mode according to the application set by the terminal equipment (whether multi-touch control is performed or not and the number of allowed simultaneous touch points).
In another embodiment, step S2 further comprises: receiving real-time point reporting rate, if the point reporting rate is smaller than or equal to a preset point reporting rate threshold value, switching a driving signal scanning mode, and acquiring the driving signal scanning mode after switching as the setting result; the driving signal scanning mode before and after switching is selected from the dichotomy iterative parallel scanning driving mode and the progressive scanning driving mode. The touch screen controller reports touch point information after scanning a touch point (to a terminal equipment processor), and if the point reporting rate is reduced to a lower value (smaller than or equal to the preset point reporting rate threshold), the switching of the scanning mode of the driving signal is required (the switching can be completed by the terminal equipment processor); for example, currently, a dichotomy iterative parallel scanning driving mode is adopted, but according to the judgment of the real-time point reporting rate, the point reporting rate is smaller than a preset point reporting rate threshold, and then the progressive scanning driving mode is adopted. The switching of the driving signal scanning modes can realize the complementary advantages of the two driving modes.
Regarding step S3, if the set result is the first result, a driving method of binary iterative parallel scanning is adopted to obtain driving channels and sensing channels corresponding to all touch points in the touch event.
Specifically, step S3 further includes: s31, setting a cycle number threshold according to the number of simultaneous touch points allowed by the touch screen, and setting an initial scanning channel number according to the actual channel number of a driving channel of the touch screen, wherein the initial scanning channel number is larger than or equal to the actual channel number; s32, dividing the driving channel into two continuous target parts according to the initial scanning channel number, transmitting driving signals to all driving channels of the target parts in parallel, identifying whether mutual capacitance is changed or not through the sensing channels, updating the initial scanning channel number to be the channel number of the driving channel of the target part if the mutual capacitance is changed, repeatedly executing the step S32 until a touch point is identified, executing the step S33, and executing the step S35 if no mutual capacitance is changed; s33, recording the identified touch points, recording the driving channels and the sensing channels where the identified touch points are located, closing the recorded driving channels, and updating the cycle detection times; s34, judging whether the cycle detection times reach the cycle times threshold, if so, executing the step S37, otherwise, returning to execute the step S32; s35, judging whether the identified touch point is recorded, if so, executing the step S36, otherwise, returning to the step S32; s36, opening all driving channels.
The method further comprises the steps of: and outputting all touch point information (a driving channel and a sensing channel corresponding to the touch point), and reporting to a host (such as a terminal equipment processor) for processing. The lateral coordinate corresponding to the driving channel where the identified touch point is located is the lateral coordinate corresponding to the current touch point. When the driving channel scans (emits electrostatic field) in parallel, the sensing channel adopts a mode of simultaneously and completely receiving sensing signals (electrostatic field) in parallel; therefore, when the touch point is scanned, the sensing circuit of the touch screen controller can detect the capacitance change of the mutual capacitance on a certain sensing channel corresponding to the touch point, and the longitudinal coordinate corresponding to the sensing channel with the capacitance change is the longitudinal coordinate corresponding to the current touch point.
In a further embodiment, the initial number of scan channels satisfies the following constraint:
wherein N is the actual channel number, and M is the initial scan channel number. Namely, the initial scanning channel number M is a number corresponding to the smallest power of 2 among the numbers larger than or equal to the actual channel number N. Such as: when n=250, m=28 ＝256。
In a further embodiment, the channels corresponding to the number of channels of the initial scan channel exceeding the number of actual channels are complemented by virtual channels. For example, for the actual channel number n=250, the initial scan channel number m=256 is set, and 6 channels with M more than N are complemented by virtual channels; i.e. channels 251-256 employ virtual channels. This ensures that no odd numbers will appear during the Dichotomy (Dichotomy) scan.
In a further embodiment, step S32 further includes: s321, driving signals are sent to all driving channels of one target part in parallel, whether the mutual capacitance of all driving channels of the one target part is changed or not is identified through an induction channel, if the mutual capacitance is changed, the initial scanning channel number is updated to be the channel number of the driving channels of the target part, the step S321 is repeatedly executed until a touch point is identified, the step S33 is executed, and if no mutual capacitance is changed, the step S322 is executed; s322, driving signals are sent to all driving channels of another target portion in parallel, whether the mutual capacitance of all driving channels of the other target portion is changed or not is identified through the sensing channels, if the mutual capacitance of all driving channels of the other target portion is changed, the initial scanning channel number is updated to be the channel number of the driving channels of the target portion, the step S322 is repeatedly executed until a touch point is identified, the step S33 is executed, and if no mutual capacitance is changed, the step S35 is executed.
Referring to fig. 4, a flowchart of a method for driving a mutual capacitive touch screen according to an embodiment of the application is shown. According to the actual application requirement, a scanning mode is set. If a progressive scanning driving mode is adopted, scanning all driving channels N in sequence to obtain driving channels and sensing channels corresponding to all touch points in a touch event; if a bisection iterative parallel scanning driving mode is adopted, setting a threshold value W of the cycle times and the number M of the initial scanning channels; then scanning the driving channels 1-M/2 at the same time, and feeding back whether the mutual capacitance changes or not in real time by the sensing channel, Y: there is a mutual capacitance change, N: no mutual capacitance change; if the driving channels 1-M/2 are scanned simultaneously, the sensing channels feed back mutual capacitance changes (Y) in real time, then the driving channels 1-M/4 are continuously scanned simultaneously, and the sensing channels feed back the mutual capacitance changes in real time, if the driving channels 1-M/2+1-M are not scanned simultaneously, and if the mutual capacitance changes are not fed back in real time by the sensing channels; so, a dichotomy iteration is adopted, the identified touch point and the driving channel where the identified touch point is located are found and recorded, the driving channel is closed (so as to find other touch points), and the cycle detection times Q (Q=Q+1) are updated; and judging whether the cycle times threshold value is reached (Q is larger than or equal to W. If the scanning driving channels 1-M/2 have no mutual capacitance change, and the scanning driving channels M/2+1-M have no mutual capacitance change, judging whether the identified touch points are recorded, if so, opening all driving channels, ending the touch point positioning process, otherwise, returning to the rescanning start. Further, if all driving channels corresponding to the target portion where the initial feedback of the sensing channel has the mutual capacitance change do not identify the touch point (shown by the dotted line with an arrow in the figure), an operation of judging whether the identified touch point is recorded is performed.
That is, the two target portions are generally first driven in parallel for scanning the middle and front target portions. For the single-point touch mode, firstly, carrying out parallel driving scanning on a front target part, and if the mutual capacitance is changed, continuing to carry out dichotomy iteration until a touch point is identified; if the front target part is subjected to parallel driving scanning and the mutual capacitance is not changed, the rear target part is continuously subjected to parallel driving scanning. For the multi-point touch mode, firstly, carrying out parallel driving scanning on a front target part, if the mutual capacitance is changed, continuing to carry out dichotomy iteration until a touch point is identified, closing driving channels identified to the touch point, and carrying out dichotomy iteration on all driving channels again until all driving channels are identified or the cycle times meet the cycle times threshold value required by the multi-point touch mode; if the front target part is subjected to parallel driving scanning and the mutual capacitance is not changed, the rear target part is continuously subjected to parallel driving scanning. That is, in the dichotomy iterative parallel scanning driving mode provided by the application, the driving signal of the next time is determined according to the feedback information of the sensing channel, so that the time taken for determining the position of the touch point is related to the position of the touch point; the time spent is minimal if the touch point is in the first row of the scan and maximal if the touch point is in the last row.
In a further embodiment, step S32 further includes: when the mutual capacitance is changed, if the step S32 is repeatedly performed until the touch point is not recognized after the last driving channel that can be iterated, the step S35 is performed. That is, the mutual capacitance is fed back to the sensing channel to change, and by performing the dichotomy iterative parallel driving scanning on all driving channels of the target portion with the mutual capacitance to change, if no touch point is found, step S35 is performed to determine whether an identified touch point is recorded, if yes, step S36 is performed to open all driving channels, and the touch point positioning process is ended, otherwise, step S32 is performed again to restart scanning. Through the arrangement of the step, mutual capacitance change caused by sudden short-time touch points can be eliminated; for example, noise signals such as false touches may be masked causing random and short-term mutual capacitance variations.
According to the mutual capacitance type touch screen driving method, a proper scanning mode is set according to actual application requirements: for the condition of fewer touch points, the scanning time can be greatly reduced by adopting a dichotomy iterative parallel scanning driving mode for scanning; for the case of more touch points, the conventional progressive scan driving method is adopted. The application can realize the complementary advantages of the two driving modes, effectively shorten the scanning time, improve the point reporting rate and enable the touch experience of the user to be more comfortable and smooth.
The application is further illustrated by the following examples.
Referring to fig. 5, a scanning schematic diagram of a driving method according to a first embodiment of the application is shown.
The present embodiment is described with 8-channel single-point touch as an example. Assuming that a Touch event occurs at an A1 point on the Touch screen, the sensing channel feeds back capacitance change to the Touch IC in real time, and the Touch IC sends a driving signal in a dichotomy iterative parallel scanning driving mode according to the received information, and carries out 1 cycle, so that the Touch point is found finally.
Specifically, in the first cycle, all channels are firstly divided into two parts, namely TX1 to TX4 and TX5 to TX8, respectively; transmitting driving signals to TX1-TX 4 in parallel in t1 time, wherein the induction channel can recognize that the capacitance on the RX5 channel is changed; in the time t2, continuously dividing TX1 to TX4 into two parts, and transmitting driving signals to TX1 to TX2 in parallel, wherein the sensing channel has capacitance change; in the time t3, dividing TX1 and TX2 into two parts, and transmitting a driving signal to TX1, wherein the induction channel is unchanged; at time t4, a drive signal is sent to TX2, where the sense channel changes, so far it has been possible to determine the location of touch point A1, i.e. the intersection of TX2 and RX 5. After the touch point A1 is recognized, the driving channel TX2 is temporarily turned off until the next entirely new scan starts. Only 1 cycle is required due to the single touch.
If t represents the time for scanning one driving channel once, by adopting the mutual capacitance type touch screen driving method, the scanning time of the position of the touch point A1 in the touch screen is determined to be 4t by adopting a bisection iterative parallel scanning driving mode; and if the existing progressive scanning driving mode is adopted, the scanning time for determining the position of the touch point in the touch screen is 8t. The application can effectively shorten the scanning time and improve the point reporting rate.
Referring to fig. 6, a scanning schematic diagram of a driving method according to a second embodiment of the application is shown.
The present embodiment is described with reference to 22-channel single-touch control. For a typical 5 inch touch screen, the capacitive matrix is typically 22 x 9 (22 drive channels, 9 sense channels). Assuming that a touch event occurs at an A2 point on the touch screen, the sensing channel feeds back the capacitance change to TouchIC, touchIC in real time according to the received information, and the driving signal is sent in a dichotomy iteration parallel scanning driving mode to perform 1 cycle, so that the touch point is found finally.
Specifically, in the first cycle, all channels are firstly divided into two parts, namely TX1 to TX16 and TX17 to TX32, respectively; transmitting driving signals to TX1-TX 16 in parallel in t1 time, wherein the induction channel can recognize that the capacitance on the RX5 channel is changed; in the time t2, continuously dividing TX1 to TX16 into two parts, and transmitting driving signals to TX1 to TX8 in parallel, wherein the sensing channel has capacitance change; in the time t3, dividing TX1 to TX8 into two parts, and transmitting driving signals to TX1 to TX4 in parallel, wherein the induction channel is unchanged; in the time t4, driving signals are transmitted to TX5 to TX8 in parallel, and at the moment, the sensing channel has capacitance change; in the time t5, continuously dividing the TX5 to TX8 into two parts, and transmitting driving signals to the TX5 to TX6 in parallel, wherein the induction channel is unchanged; in the time t6, driving signals are transmitted to TX7 to TX8 in parallel, and at the moment, the sensing channel has capacitance change; during time t7, TX7 and TX8 are divided into two parts, and a driving signal is sent to TX7, where the sense channel changes, so far it has been possible to determine the location of touch point A2, i.e. the intersection of TX7 and RX 5. After the touch point A2 is recognized, the driving channel TX7 is temporarily turned off until the next entirely new scan starts. Only 1 cycle is required due to the single touch.
If t represents the time for scanning one driving channel once, the scanning time of the touch point A2 position in the touch screen is determined to be 7t by adopting a bisection iterative parallel scanning driving mode by adopting the mutual capacitance type touch screen driving method; and if the existing progressive scanning driving mode is adopted, the scanning time for determining the position of the touch point in the touch screen is 22t. The application can effectively shorten the scanning time and improve the point reporting rate.
Referring to fig. 7, a scanning schematic diagram of a driving method according to a third embodiment of the application is shown.
The present embodiment is described by taking two-touch control of 22 channels as an example. Assuming that a Touch event occurs at the point A3 and the point B3 on the Touch screen, the sensing channel feeds back the capacitance change to the Touch IC in real time, and the Touch IC sends a driving signal in a dichotomy iteration parallel scanning driving mode according to the received information, and carries out 2 cycles, so that the Touch point is found finally.
Specifically, in the first cycle, all channels are firstly divided into two parts, namely TX1 to TX16 and TX17 to TX32, respectively; transmitting driving signals to TX1-TX 16 in parallel in t1 time, wherein the induction channel can recognize that the capacitance on the RX7 channel is changed; in the time t2, continuously dividing TX1 to TX16 into two parts, and transmitting driving signals to TX1 to TX8 in parallel, wherein the sensing channel has capacitance change; in the time t3, dividing TX1 to TX8 into two parts, and transmitting driving signals to TX1 to TX4 in parallel, wherein the sensing channel has capacitance change; in the time t4, continuously dividing TX1 to TX4 into two parts, and transmitting driving signals to TX1 to TX2 in parallel, wherein the induction channel is unchanged; in the time t5, driving signals are transmitted to TX 3-TX 4 in parallel, and at the moment, the sensing channel has capacitance change; in the time t6, dividing TX3 and TX4 into two parts, and transmitting a driving signal to TX3, wherein the induction channel is unchanged; at time t7, a drive signal is sent to TX4, where the sense channel changes, so far it has been possible to determine the location of touch point A3, i.e. the intersection of TX4 and RX 7. After the touch point A3 is recognized, the driving channel TX4 is temporarily turned off until the next entirely new scan starts.
And (5) a second cycle, and carrying out dichotomy iteration again in the same way to find other touch points. At time t8, driving signals are sent to TX1 to TX16 (TX 4 is closed at the moment), and the induction channel is unchanged at the moment; at time t9, driving signals are sent to TX17 to TX32 (wherein TX23 to TX32 are virtual channels), and the sensing channel recognizes that the capacitance on RX3 is changed; in the time t10, dividing TX17 to TX32 into two parts, and transmitting driving signals to TX17 to TX24, wherein the induction channel is changed; at time t11, dividing TX17 to TX24 into two parts, and transmitting driving signals to TX17 to TX20, wherein the sensing channel is changed; at time t12, dividing TX17 to TX20 into two parts, and transmitting driving signals to TX17 to TX18, wherein the sensing channel is changed; at time t13, TX17 and TX18 are divided into two parts, and a driving signal is sent to TX17, where the sense channel changes, so far it has been possible to determine the location of touch point B3, i.e. the intersection of TX17 and RX 3. After the touch point position is identified, the drive channel TX17 is temporarily turned off to find other touch points until the next completely new scan starts. Only 2 cycles are needed due to the two-touch.
One touch point can be identified after one cycle is completed, a plurality of touch points can be identified after a plurality of cycles, and when a set cycle number threshold is reached or all touch points are identified, the process is ended. And finally, outputting all the touch point information, and reporting to a host for processing.
If t represents the time for scanning one driving channel once, by adopting the mutual capacitance type touch screen driving method, the scanning time of the positions of the touch points A3 and B3 in the touch screen is determined to be 13t by adopting a bisection iterative parallel scanning driving mode; and if the existing progressive scanning driving mode is adopted, the scanning time for determining the position of the touch point in the touch screen is 22t. The application can effectively shorten the scanning time and improve the point reporting rate.
If the two touch points are in the same row, the multi-touch position in the same row can be identified through RX sensing information by one cycle.
The method is suitable for large-screen touch and aims at the situation that the quantity of driving channels TX is large. Because the driving signal of the next time is determined according to the feedback information of the sensing channel, the time spent for determining the position of the touch point is related to the position of the touch point, if the touch point is in the first row of the scanning, the time spent is the least, and if the touch point is in the last row, the time spent is the most. The conventional driving mode and the driving mode of the present application are compared with 128-channel number and 256-channel number. Assuming that the time taken to scan a row is t, the following table compares the time taken to scan 128 channels and 256 channels for different scanning modes.
TABLE 1.128 channel scan time contrast
Table 2.256 channel scan time contrast
From the above table, for the case of fewer touch points, the scan time can be greatly reduced by adopting the dichotomy iterative parallel scan driving mode to scan, and the more channels, the more obvious the advantages.
Based on the same inventive concept, the application also provides a mutual capacitance type touch screen driving device.
Referring to fig. 8, a schematic diagram of a capacitive touch screen driving device according to the present application is shown. The device comprises: a receiving unit 81, a setting unit 82, a first scanning driving unit 83, and a second scanning driving unit 84.
The receiving unit 81 is configured to receive a touch event and start a touch point positioning process. The setting unit 82 is configured to set a driving signal scanning manner adopted by the touch point positioning process, and obtain a setting result. The first scan driving unit 83 is configured to obtain driving channels and sensing channels corresponding to all touch points in a touch event by adopting a bisection iterative parallel scan driving mode when the setting result of the setting unit 82 is a first result. The second scan driving unit 84 is configured to acquire driving channels and sensing channels corresponding to all touch points in the touch event by adopting a progressive scan driving manner when the setting result of the setting unit 82 is the second result.
In a further embodiment, the setting unit 82 sets a driving signal scanning mode according to the number of simultaneous touch points allowed by the touch screen, and obtains the setting result; and if the number of simultaneous touch points allowed by the touch screen is smaller than or equal to a preset touch point threshold, acquiring a first result as a set result, otherwise, acquiring a second result as the set result.
In a further embodiment, the setting unit 82 receives a real-time point reporting rate, and if the point reporting rate is less than or equal to a preset point reporting rate threshold, performs switching of the driving signal scanning mode, and obtains the driving signal scanning mode after switching as the setting result; the driving signal scanning mode before and after switching is selected from the dichotomy iterative parallel scanning driving mode and the progressive scanning driving mode.
In a further embodiment, the scan driving manner of the first scan driving unit 83 and the second scan driving unit 84 can refer to the descriptions of fig. 3-4, and will not be repeated here.
According to the mutual capacitance type touch screen driving device, a proper scanning mode is set according to actual application requirements: for the condition of fewer touch points, the scanning time can be greatly reduced by adopting a dichotomy iterative parallel scanning driving mode for scanning; for the case of more touch points, the conventional progressive scan driving method is adopted. The application can realize the complementary advantages of the two driving modes, effectively shorten the scanning time, improve the point reporting rate and enable the touch experience of the user to be more comfortable and smooth.
Based on the same inventive concept, the application also provides a terminal device.
Referring to fig. 9, a schematic structural diagram of a terminal device according to the present application is shown. As shown in fig. 9, the terminal device 90 includes: a touch screen 91; and a touch screen controller 92 connected to the touch screen 91. The touch screen controller 92 has one or more computer executable instructions stored therein; wherein the executable instructions, when executed by the touch screen controller 92, cause the mutual capacitive touch screen driving method of the present application to be performed.
The terminal device provided by the embodiment and the mutual capacitance type touch screen driving method provided by the embodiment belong to the same application conception; technical details which are not described in detail in the present embodiment can be seen in the above embodiments, and the present embodiment has the same advantageous effects as the execution of the mutual capacitive touch screen driving method.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments.
In the above, it should be apparent to those skilled in the art that various other modifications and variations can be made in accordance with the technical solution and the technical idea of the present application, and all such modifications and variations are intended to fall within the scope of the claims of the present application.