Film recognition method and electronic device

Abstract

The present application provides a film recognition method and electronic device, which are applied to the field of touch technology. By comparing whether the ratio of a signal amount peak value to a second signal amount in a signal amount collected by the electronic device is less than or equal to a first threshold, it is determined whether the distribution of the signal amount collected by the electronic device conforms to the distribution characteristics after the film is applied, thereby realizing the recognition of whether the electronic device has a film applied.

Description

Technical Field

[0001] The present application relates to the field of touch technology, and in particular to a film recognition method and an electronic device. Background Art

[0002] With the development of touch technology, more and more electronic devices use touch for human-computer interaction. Users can operate the touch panel of the electronic device with a stylus (such as writing on the touch panel) to provide input to the electronic device, and the electronic device performs corresponding operations based on the input of the stylus.

[0003] In order to protect electronic devices, people usually like to stick a protective film (or called a film) on the touch panel of the electronic device. The protective film has a certain thickness. After the film is applied, the touch effect of the stylus on the touch panel of the electronic device is affected. However, it is currently impossible to identify whether an electronic device has a film. Summary of the invention

[0004] The present application provides a film identification method and an electronic device, which realizes the identification of whether the electronic device has a film by comparing whether the characteristic information of the signal quantity collected by the electronic device conforms to the characteristics after the film is applied.

[0005] In the first aspect, the present application provides a film recognition method, which is applied to an electronic device that realizes a touch function with a stylus pen. In the method, the electronic device collects at least one group of first signal quantities, and each group of first signal quantities includes a plurality of first signal quantities sensed by a coding signal from the stylus pen in a plurality of sensing areas on a touch panel of the electronic device. The electronic device obtains the maximum value of each group of first signal quantities in at least one group of first signal quantities, and obtains at least one signal quantity peak value corresponding to at least one group of first signal quantities. For any signal quantity peak value in at least one signal quantity peak value, if the signal quantity peak value is sensed at the center of any sensing area in the plurality of sensing areas, the electronic device obtains the first signal quantity sensed by the sensing area in the first preset area from a group of first signal quantities corresponding to the signal quantity peak value, and obtains the second signal quantity corresponding to the sensing area in the first preset area. Among them, the first preset area is an area on the touch panel of the electronic device centered on the first sensing area corresponding to the signal quantity peak value. If the ratio of the signal quantity peak value to the second signal quantity is less than or equal to the first threshold value, the electronic device recognizes that the electronic device is filmed.

[0006] In this solution, the first sensing area refers to the peak sensing area, that is, the sensing area where the peak signal amount is sensed. If the peak signal amount is sensed at the center of the first sensing area, then the ratio of the peak signal amount sensed by the electronic device with the film in the first sensing area to the second signal amount sensed by the sensing area in the first preset area is lower than the ratio of the peak signal amount sensed by the electronic device without the film in the first sensing area to the second signal amount sensed by the sensing area in the first preset area. The first threshold is extracted from the ratio of the size of the peak signal in the multiple groups of signal amounts obtained by the electronic device before the film is applied and the size of the signal around the peak signal (recorded as the first ratio) and the ratio of the size of the peak signal in the multiple groups of signal amounts obtained by the electronic device after the film is applied and the size of the signal around the peak signal (recorded as the second ratio). The first threshold is less than or equal to the first ratio and greater than the second ratio. Therefore, when the ratio of the peak signal amount to the second signal amount of the electronic device to be identified as having a film applied is less than or equal to the first threshold, the film is identified as being applied to the electronic device.

[0007] In another possible design of the first aspect, the signal amount peak is sensed at the center of any sensing area among the multiple sensing areas, including: a ratio between at least two third signal amounts is less than or equal to a second threshold value. The third signal amount is a first signal amount sensed by at least two second sensing areas in a group of first signal amounts corresponding to the signal amount peak, and the second sensing area is a sensing area in the multiple sensing areas that is equidistant from the first sensing area corresponding to the signal amount peak.

[0008] In this design, the electronic device extracts the peak signal amount sensed at the center of the first sensing area from the peak signal amount sensed in the first sensing area according to the characteristic that the ratio between the signal amounts of the signals around the peak signal is less than the second threshold value, that is, the peak signal amount not sensed at the center of the first sensing area is eliminated. Compared with screening the peak signal amount sensed at the center of the first sensing area according to the coordinates where the peak signal amount is sensed, directly screening the peak signal amount sensed at the center of the first sensing area by using the characteristic that the ratio between the signal amounts of the surrounding signals is less than the second threshold value has the effect of faster processing speed and more timely processing because it can be directly processed in the signal acquisition stage.

[0009] In another possible design manner of the first aspect, the number of third signal quantities is two. Before the ratio between at least two third signal quantities is less than or equal to the second threshold, the method further includes: the electronic device obtains first signal quantities sensed by at least two sensing areas closest to the first sensing area corresponding to the signal quantity peak value in a group of first signal quantities corresponding to the signal quantity peak value, to obtain at least two third signal quantities.

[0010] In this design, the signal amount of the signal around the peak signal corresponds to the signal amount sensed by at least two sensing areas that are closest to the first sensing area among the multiple sensing areas. Since the stylus writes at different positions on the screen, the magnitude of the signal amount peak sensed by the first sensing area corresponding to different positions is different, and the magnitude of the signal amount sensed by the sensing area around the first sensing area corresponding to different positions is also different. If the positions of at least two sensing areas that are equal to the first sensing area on the screen of the electronic device are far apart, the magnitude of the signal amount will also be affected, which may cause the difference between the signal amounts of the signals around the peak value of the signal amount sensed by the center of the first sensing area to be large. In order to avoid mistakenly screening out the signal amount peak in this case, it is necessary to set the second threshold to be larger, but this leads to greater requirements on the accuracy of the signal acquisition component (such as the touch panel of the electronic device), for example: the acquisition accuracy of the signal acquisition component is low, and the magnitude of the collected signal amount is not accurate enough, then the second threshold is set to be larger and the signal amount peak sensed in the center of the first sensing area cannot be eliminated. Therefore, by obtaining the signal amounts sensed by at least two sensing areas closest to the first sensing area as the third signal amount, the third signal amount is less affected by the position of the sensing area on the electronic device. Therefore, if the signal amount peak located at the center of the first sensing area is screened based on the ratio between at least two third signal amounts, the screening result is more accurate and the collection accuracy requirement for the signal acquisition component is also lower.

[0011] In another possible design of the first aspect, the method further includes: the electronic device obtains, for any signal amount peak value among the at least one signal amount peak value, a first signal amount sensed by a sensing area within a second preset area from a group of first signal amounts corresponding to the signal amount peak value, to obtain a fourth signal amount corresponding to the sensing area within the second preset area. The second preset area is an area on the touch panel of the electronic device centered on the first sensing area corresponding to the signal amount peak value.

[0012] The above-mentioned if the ratio of the signal amount peak value to the second signal amount is less than or equal to the first threshold, then the electronic device is identified as having a film, including: if the ratio of the signal amount peak value to the second signal amount is less than or equal to the first threshold, and the sum of the signal amount peak value and the fourth signal amount is less than or equal to the third threshold, then the electronic device is identified as having a film.

[0013] In this design, the electronic device combines the two conditions of the ratio being less than or equal to the first threshold and the sum being less than or equal to the third threshold to identify the electronic device film. The advantage of combining the ratio and the sum is that if there are abnormal signals in the multiple groups of first signal quantities, and the ratio is calculated using the abnormal signals, then although the ratio is greater than or equal to the first threshold, the identification result of the electronic device film is inaccurate. Therefore, combining the two conditions of the ratio being less than or equal to the first threshold and the sum being less than or equal to the third threshold to identify the electronic device film will obtain a more accurate identification result.

[0014] In another possible design manner of the first aspect, the obtaining of the first signal quantity sensed by the sensing area within the first preset area from a group of first signal quantities corresponding to the signal quantity peak value includes: the electronic device obtaining the minimum first signal quantity among the first signal quantities sensed by each sensing area within the first preset area from a group of first signal quantities corresponding to the signal quantity peak value.

[0015] Since the magnitudes of the second signal quantities sensed by the plurality of peripheral sensing regions of the first sensing region are similar, only the minimum value of the plurality of second signal quantities and the signal quantity peak value may be extracted for ratio calculation, which can reduce the amount of calculation.

[0016] In another possible design manner of the first aspect, the collecting of at least one set of first signal quantities includes: if the stylus pen performs a touch operation on the electronic device, the electronic device collects at least one set of first signal quantities.

[0017] Under this design, the signal amount collected by the electronic device when the stylus pen writes on the electronic device is used as the first signal amount. In other processes, such as the process in which the user operates the stylus pen to gradually approach the touch panel of the electronic device, the collected signal amount is not used as the first signal amount to identify whether the electronic device has a film, thereby reducing the interference of invalid signals on the calculation results.

[0018] In another possible design of the first aspect, the method further includes: the electronic device collects the pressure signal. If the stylus performs a touch operation on the electronic device, at least one set of first signal quantities is collected, including if the signal strength of the pressure signal is greater than or equal to a fourth threshold, the electronic device collects at least one set of first signal quantities.

[0019] In this design, whether the stylus is writing on the electronic device is determined by whether the signal strength of the pressure signal is greater than or equal to the fourth threshold. If the signal strength of the pressure signal is greater than or equal to the fourth threshold, that is, the stylus is writing on the electronic device, the electronic device starts to collect at least one set of first signal quantities. If the signal strength of the pressure signal is less than the fourth threshold, that is, the stylus is not writing on the electronic device, the electronic device does not collect the first signal quantity.

[0020] In another possible design of the first aspect, the size of the third threshold value corresponds to the position of the first sensing area corresponding to the signal amount peak value on the electronic device. The above method also includes: the electronic device obtains the position of the first sensing area corresponding to the signal amount peak value on the touch panel of the electronic device. Then the electronic device selects the third threshold value corresponding to the position from a plurality of third threshold values ​​of different sizes. The sum of the above signal amount peak value and the fourth signal amount is less than or equal to the third threshold value, including: the sum of the signal amount peak value and the fourth signal amount is less than or equal to the third threshold value corresponding to the position.

[0021] In this design, whether the sum value meets the condition that the electronic device is not filmed is judged by using thresholds of different sizes at different positions. The judgment fault tolerance rate is high and the accuracy requirement for signal quantity collection is low. It is not easy to cause wrong judgment when the accuracy of the collected signal quantity is low.

[0022] In another possible design manner of the first aspect, the method further includes: the electronic device presets a first quantity, and determines a first preset area with a first sensing area corresponding to a signal amount peak as the center, and the first preset area includes a first number of sensing areas.

[0023] In another possible design manner of the first aspect, the position of each sensing area on the touch panel of the electronic device corresponds to the position of an area formed by the intersection of the sensing electrodes and the driving electrodes in the electronic device.

[0024] In a second aspect, the present application provides a film identification method, in which the electronic device obtains a first signal amount sensed by a sensing area within a second preset area from a group of first signal amounts corresponding to the signal amount peak value for any signal amount peak value among at least one signal amount peak value, and obtains a fourth signal amount corresponding to the sensing area within the second preset area; wherein the second preset area is an area on the touch panel of the electronic device centered on the first sensing area corresponding to the signal amount peak value. If the sum of the signal amount peak value and the fourth signal amount is less than or equal to the third threshold value, a film is identified on the electronic device.

[0025] In a third aspect, the present application provides an electronic device, comprising: a touch panel, a processor, and a memory for storing instructions executable by the processor, wherein when the processor is configured to execute the instructions, the electronic device executes the method described in the first aspect and any possible design method thereof.

[0026] In a fourth aspect, the present application provides a computer-readable storage medium, which includes computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the method described in the first aspect and any possible design thereof.

[0027] In a fifth aspect, the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the method described in the first aspect and any possible design thereof.

[0028] In a sixth aspect, an embodiment of the present application provides a chip system, which includes at least one processor and at least one interface circuit. The interface circuit can read instructions stored in a memory in an electronic device and send the instructions to the processor. When the instructions are executed by the processor, the electronic device can execute the method described in the first aspect and any possible design thereof.

[0029] It can be understood that the beneficial effects that can be achieved by the method provided by the second invention, the electronic device of the third aspect, the computer-readable storage medium of the fourth aspect, the computer program product of the fifth aspect, and the chip system of the sixth aspect can be referred to the beneficial effects in the first aspect and any possible implementation manner thereof, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of electrode distribution in the related art;

[0031] Figure 2 Some schematic diagrams of comparison before and after film application provided in the embodiments of the present application;

[0032] Figure 3 A schematic diagram of a film identification method provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of a scenario provided for an embodiment of the present application;

[0034] Figure 5 A hardware interaction diagram of a tablet and a stylus provided in an embodiment of the present application;

[0035] Figure 6 A schematic diagram of a software architecture of a tablet provided in an embodiment of the present application;

[0036] Figure 7 A schematic diagram of the distribution of the sum of the signal quantities before and after film pasting provided in an embodiment of the present application;

[0037] Figure 8 A schematic diagram of the distribution of the signal quantity sensed at the center of the sensing area before and after film application provided in an embodiment of the present application;

[0038] Fig. 9 A flowchart of a film recognition method provided in an embodiment of the present application;

[0039] Fig.10A schematic diagram of a signal acquisition method provided in an embodiment of the present application;

[0040] Fig.11 A schematic diagram of the distribution of signal quantities sensed by the peripheral sensing areas of a first sensing area provided in an embodiment of the present application;

[0041] Fig.12 A schematic diagram of a sensing area provided in an embodiment of the present application;

[0042] Fig.13 A structural diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solution in the embodiment of the present application will be described below in conjunction with the drawings in the embodiment of the present application. In the description of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0044] In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second" and the like are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art can understand that the words "first", "second" and the like are only used for descriptive purposes, and do not limit the quantity and execution order, nor can they be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present embodiment, unless otherwise specified, the meaning of "multiple" is two or more. And the words "first", "second" and the like are not necessarily different. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present embodiment, unless otherwise specified, "at least one" means one or more, and the meaning of "multiple" is two or more.

[0045] In the embodiments of the present application, the words "exemplarily" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0046] Before describing the embodiments of the present application, a brief introduction to the technical terms involved in the present application is first given.

[0047] Signal quantity: The stylus pen and the electronic device generate a coupling signal in a coupling manner. The coupling signal can be used by the electronic device to draw handwriting, and the signal quantity is used to characterize the signal strength of the coupling signal. The signal quantity can be the actual strength value of the coupling signal, or it can be a quantized value obtained by converting the signal strength of the coupling signal according to specific rules. In the case where the coupling method between the stylus pen and the electronic device is capacitive coupling, the coupling signal can be called a capacitive signal. In the case where the coupling method between the stylus pen and the electronic device is electromagnetic coupling, the coupling signal can be called an electromagnetic signal. Among them, the capacitive signal includes a coding signal sent by the stylus pen to the electronic device, and the coding signal can be used by the electronic device to determine the position of the tip of the stylus pen on the touch panel of the tablet. The signal quantity appearing below is a quantized value that characterizes the signal strength of the capacitive signal.

[0048] The center of the sensing area is the center of the sensing channel of the touch sensor (touch panel sensor, TPsensor) used to detect the signal. For example, the touch panel of an electronic device is usually provided with two layers of electrodes, horizontally and vertically, such as Figure 1 As shown, Figure 1 Schematic diagram of electrode distribution in related art, which can be referred to as sensing electrode (or receive channel, RX channel) and driving electrode (or transmit channel, TX channel) respectively. When the stylus is close to or in contact with the touch panel of the electronic device, a capacitor will be formed at the intersection 101 of the TX channel and the RX channel, such as Figure 1 There are 16 intersections 101 on the touch panel that will form capacitance. The electronic device collects the signal of the capacitance formed by the 16 intersections 101 through 16 TP sensors, wherein each TP sensor corresponds to a sensing area, each sensing area corresponds to one intersection 101, and is used to collect the signal of the capacitance signal formed by the intersection 101 corresponding to the sensing area, and the center of the intersection 101 is called the center 102 of the sensing area.

[0049] In order to protect the touch panel of electronic devices, users often apply films to electronic devices, such as tempered films, paper-like films, hydrogel films, etc. However, after applying the film, the touch effect of the stylus on the electronic device with the film is poor. For example: in the scene of writing with a stylus, the writing effect of the stylus on the electronic device with the film is poor. The embodiment of the present application here uses test data to illustrate the impact of the film on the writing effect of the electronic device. Reference Figure 2 , which shows the writing effects of multiple electronic devices of the same brand and model before and after the film is applied. The writing effect can be characterized by the smoothness and continuity of the lines. For example, the higher the smoothness and / or the higher the continuity of the lines, the better the writing effect. Figure 2It can be seen that the lines written on the electronic device before the film is applied are smooth and continuous, so the writing effect is better, while the lines written on the electronic device after the film is applied are wavy and broken, so the writing effect is poor. Through comparison, it can be seen that whether the electronic device has a film will affect the writing effect of the electronic device.

[0050] Based on this, the embodiment of the present application provides a film recognition method, which is applied to an electronic device. The electronic device first collects a signal quantity (corresponding to Figure 3 The collected signal quantity) and extract the characteristic information of the signal quantity (corresponding to Figure 3 Then, based on the feature information, it is identified whether the electronic device is in the film-applied state (corresponding to Figure 3 The embodiment of the present application realizes the recognition of whether the electronic device has a film by comparing the characteristic information of the signal quantity collected by the electronic device to see whether it meets the characteristics after the film is applied. If it is recognized that the electronic device has a film, the coordinate calculation method corresponding to the film can be used to calculate the coordinate value of the touch operation performed by the stylus on the tablet, so as to reduce the writing problems such as line jitter and line breakage caused by the coordinate value deviation.

[0051] refer to Figure 4 , which provides a schematic diagram of a scenario applicable to the embodiment of the present application, in which a stylus 40 can perform touch operations on an electronic device, such as clicking, sliding, writing, drawing, etc. Among them, the electronic device can be a mobile phone 41, a tablet computer (can be referred to as a tablet) 42, a laptop computer 43, a wearable device 44, etc. that supports interaction with the stylus. The stylus 40 can be a capacitive stylus, an electromagnetic (inductive) stylus, a resistive stylus, etc.

[0052] The following will mainly describe the embodiments of the present application by taking the stylus pen being a capacitive stylus pen and the electronic device being a tablet as an example.

[0053] refer to Figure 5 , which shows a hardware interaction diagram between a tablet and a stylus provided in an embodiment of the present application.

[0054] like Figure 5 As shown, the tablet includes: a touch panel 501, a processor 502 and a first communication module 503. The touch panel 501 may further include a TP sensor (corresponding to Figure 5 A touch sensor in the device) 504 and a touch microelectronic device (integrated circuit, IC) chip 505.

[0055] Continue to refer Figure 5 The stylus pen includes: a micro controller unit (MCU) 506 , a sensor component 507 and a second communication module 508 .

[0056] The tablet can run the film recognition method provided in the embodiment of the present application through the processor 502 to realize the recognition of the tablet film. The processor 502 may include different devices, such as when a central processing unit (CPU) and a graphics processing unit (GPU) are integrated, the CPU and the GPU can cooperate to execute the film recognition method provided in the embodiment of the present application, such as part of the algorithm in the film recognition method is executed by the CPU, and the other part of the algorithm is executed by the GPU, so as to obtain faster recognition efficiency.

[0057] The tablet and the stylus establish a communication link through the first communication module 503 and the second communication module 508. For example, the communication link is a Bluetooth link, and the communication link can be used to transmit information between the tablet and the stylus. Exemplarily, the tablet can send an uplink signal to the stylus through the communication link, and the uplink signal is used to instruct the stylus to feed back a coding signal to the tablet through the communication link. The capacitive signal mentioned above includes the uplink signal and the coding signal.

[0058] The tablet can collect touch information through TP sensor 504, and the touch information may include: the above-mentioned coding signal, or also include pressure signal, signal generated by user (such as user's finger or knuckle) touching the touch panel, etc. The tablet can calculate the touch position based on the touch information through touch IC chip 505. In some embodiments, the tablet recognizes characteristic information of the signal quantity through touch IC chip 505.

[0059] The sensor component 507 of the stylus can be set at the tip of the stylus to collect the pressure signal of the tip. Exemplarily, when the tip of the stylus squeezes the touch panel of the tablet, the sensor component 507 collects the pressure signal generated by the touch panel squeezing the tip of the stylus. The stylus can feed back the pressure signal to the tablet through the communication link. The embodiment of the present application is suitable for detecting whether the tablet is filmed when the stylus is writing on the tablet, so the tablet receives the pressure signal in addition to the coding signal. In some embodiments, the tablet identifies whether the stylus is in the first state according to the pressure signal. Exemplarily, if the pressure signal meets the first condition, it is identified that the stylus is in the first state; if the pressure signal does not meet the first condition, the tablet identifies that the stylus is not in the first state. Among them, the first state indicates that the user is writing on the tablet with the stylus. The first condition includes: the signal strength of the pressure signal is greater than or equal to the fourth threshold, wherein the fourth threshold can be set according to actual needs, such as 0, 10, 20, etc. represented by a digital quantity.

[0060] The sensor component 507 of the stylus can also be used to collect the three-axis acceleration value of the stylus, and the three-axis acceleration value includes: the acceleration value on the X-axis, the acceleration value on the Y-axis, and the acceleration value on the Z-axis. MCU 506 receives the three-axis acceleration value sent by the sensor component 507, and identifies information such as the inclination angle and motion state of the stylus based on the three-axis acceleration value. The motion state is used to characterize whether the stylus is in a stationary state or a non-stationary state. In some embodiments, the tablet combines the pressure signal and the motion state to identify whether the stylus is in the first state. For example, if the pressure signal satisfies the first condition and the motion state characterizes that the stylus is in a non-stationary state, the tablet recognizes that the stylus is in the first state. Otherwise, the tablet recognizes that the stylus is not in the first state.

[0061] It should be understood that Figure 5 The hardware structure of the stylus pen and the hardware structure of the tablet are only examples. In actual implementation, modules can be added or reduced according to needs, or one or more of the above modules can be combined. As an example, the stylus pen can also be equipped with a vibrator, a data port, etc., and the tablet can also be equipped with a charging module, an audio module, a camera, etc., which are not specifically limited in the embodiments of the present application.

[0062] The above article introduces the hardware structure of the tablet and stylus. The following article describes the software structure of the tablet. The software system of the tablet can adopt a layered architecture, event-driven architecture, micro-kernel architecture, micro-service architecture, or cloud architecture. In this article, we will mainly focus on the layered architecture of Android TM Taking the system as an example, the software structure of the tablet is illustrated. The layered architecture divides the tablet's software system into several layers, each with a clear role and division of labor, and the layers communicate with each other through software interfaces.

[0063] As an example, refer to Figure 6 , which shows the software and hardware architecture of the tablet. The software and hardware architecture of the tablet from top to bottom are: application layer (application), application framework layer (application framework), hardware abstraction layer (kernel), driver layer and hardware layer.

[0064] The application layer can include applications such as camera, calendar, map, video, music, short message, gallery, call, desktop, video clip, system settings, etc. Among them, the system settings can be an independent application or an Android application package (Android TM application package, APK).

[0065] In some embodiments, the stylus pen can perform touch operations on the application interface of the application program, and the touch operations include clicking, sliding, writing, drawing, etc. The following will mainly describe the touch operation as writing as an example.

[0066] In some embodiments, the application can adaptively adjust the coordinate calculation method to calculate the coordinate value of the touch operation performed by the stylus on the tablet according to the recognition result of whether the film is applied, so as to reduce writing problems such as line jitter and line breakage caused by coordinate value deviation. For example, the system setting provides a control for turning writing optimization on and off, and the user can turn on or off the writing optimization function of the tablet by clicking the control. If the writing optimization function of the tablet is turned on, the tablet executes the method provided in the embodiment of the present application and outputs the recognition result. The system setting adaptively adjusts the coordinate calculation method according to the recognition result to achieve the purpose of writing optimization.

[0067] The application framework layer provides an application programming interface (API) and a programming framework for the applications in the application layer. The framework layer includes some predefined functions. The application framework layer may include an input flinger and a Bluetooth service.

[0068] As an example, inputflinger receives the recognition result from the bottom layer (such as the hardware abstraction layer) and reports the recognition result to the upper layer (such as the application layer). The recognition result includes the recognition of whether the tablet has a film.

[0069] In some embodiments, the recognition result indicates that the tablet has a film attached. For example, if the inputflinger reports the recognition result to the system setting, it means that the tablet has a film attached. If the recognition result is not reported, it means that the tablet has not been filmed. Accordingly, the system setting only needs to optimize writing when the recognition result is received, and still use the original coordinate calculation method when the recognition result is not received.

[0070] In other embodiments, when the recognition result is a film, it indicates that the tablet has a film, and vice versa, when the recognition result is no film, it indicates that the tablet has no film. Accordingly, the system is set to optimize writing when the recognition result is received and the recognition result is a film, and still use the original coordinate calculation method when the recognition result is received and the recognition result is no film.

[0071] The hardware abstraction layer may include an input subsystem and a touch daemon (TP daemon).

[0072] As an example, TP daemon can process feature information and pressure signals from the bottom layer (such as the driver layer) to obtain recognition results. The input subsystem can receive the recognition results processed by TP daemon and report the recognition results to the upper layer (such as the application framework layer).

[0073] The driver layer may include a Bluetooth driver, a human interface device (HID) driver, and an input driver.

[0074] As an example, the Bluetooth driver, HID driver, and input driver are used to report pressure signals to an upper layer (such as a hardware abstraction layer). The input driver is also used to report feature information to an upper layer (such as a hardware abstraction layer), wherein the feature information is extracted based on the signal amount of the coding signal.

[0075] The hardware layer can include touch IC chip, TP sensor (corresponding to Figure 6 touch sensor in the device) and a Bluetooth module.

[0076] As an example, the TP sensor receives the coding signal sent by the stylus and sends the coding signal to the touch IC chip. After the touch IC chip receives the coding signal sent by the TP sensor, it can calculate the touch position according to the coding signal and report the touch position to the upper layer (such as the driver layer). Figure 6 In addition, the touch IC chip can also calculate feature information based on the coding signal, and the feature information is used by the TP daemon to calculate the recognition result. The Bluetooth module can be used to transmit information transmitted via the Bluetooth link, such as the pressure signal sent by the stylus.

[0077] The method provided in the embodiment of the present application can be deployed in a tablet having the above-mentioned hardware and software structure. Before explaining the method in the embodiment of the present application, the improvement principle of the method is first introduced.

[0078] First, according to the principle of capacitive sensing: C represents capacitance, ε represents dielectric constant, S represents contact area between tablet and stylus, k represents electrostatic force constant, π represents pi, and d represents distance between tablet and stylus. It can be seen that when stylus is writing on tablet, ε, S, 4πk are fixed, C is inversely proportional to d, that is, the greater the distance between tablet (which can refer to the touch panel of tablet) and stylus, the smaller the signal amount of coding signal received by tablet. Based on this, when the same stylus touches the same position of tablet before and after film pasting, because the protective film has a certain thickness, compared with the distance between stylus and touch panel of tablet before film pasting, the distance between stylus and touch panel of tablet after film pasting increases, resulting in a decrease in coupling between the two. When the signal amount of coding signal sent by stylus to tablet before and after film pasting is the same, the signal amount of coding signal received by tablet after film pasting is less than the signal amount of coding signal received by tablet before film pasting.

[0079] Secondly, when the tablet is not covered with a film or the tablet is covered with a film, the signal amount of the coding signal sent by the stylus at the center of the sensing area received by the tablet is greater than the signal amount of the coding signal sent by the stylus at the edge of the sensing area received by the tablet. If the tablet receives the coding signal sent by the stylus at the center of the sensing area when it is not covered with a film, and receives the coding signal sent by the stylus at the edge of the sensing center when it is covered with a film, then there may be a situation where the signal amount received when the tablet is covered with a film is greater than or equal to the signal amount when the tablet is not covered with a film. In other words, the conclusion drawn above based on the principle of capacitive sensing is valid when the stylus is located at the center of the sensing area of ​​the tablet before or after the film is applied, or when the stylus is located at the edge of the sensing area, but it may not be valid when it cannot be guaranteed that the stylus is located at the center of the sensing area of ​​the tablet before or after the film is applied, or when the stylus is located at the edge of the sensing area.

[0080] Through the above two analysis points, it can be known that under the same state (before or after film pasting), the magnitude of the signal received by the tablet at different positions in the sensing area is different. However, the sum of the magnitudes of the signal received by the tablet in multiple sensing areas after film pasting will be smaller than the sum of the magnitudes of the signal received by the tablet in the multiple sensing areas before film pasting. Therefore, the first distribution feature of the coding signal can be determined: the sum of the peak value of the signal after film pasting and the signal sensed by the surrounding sensing areas of the corresponding sensing area is smaller than the sum of the peak value of the signal before film pasting and the signal sensed by the surrounding sensing areas of the corresponding sensing area, that is, after film pasting, the sum of the signal magnitudes becomes smaller.

[0081] The first distribution feature is described below. For example, after applying the film, the distribution of the amount of signals received by the tablet is shown in Table 1; before applying the film, the distribution of the amount of signals received by multiple sensing areas of the tablet is shown in Table 2.

[0082] In both Table 1 and Table 2, the signal in the third row and third column is the largest, that is, the signal in the third row and third column is the signal peak mentioned above. In Table 1, the tip of the stylus is at the center of the third column channel, and in Table 2, the tip of the stylus is at the edge of the second column channel and the third column channel. Therefore, according to the signal given in Table 1 and Table 2, the result obtained is that the peak signal after film application is greater than the peak signal before film application, which is contrary to the conclusion obtained by the capacitive sensing principle. Therefore, the recognition result obtained by determining whether the tablet has a film only by the size of the signal peak is not accurate enough.

[0083] Although it is impossible to control the signal peak to be collected at the center of the sensing area in actual applications, the relationship between the signal peaks before and after the film is applied can be obtained by comparing the sizes of multiple signal amounts before and after the film is applied. For example, although the signal peak (4000) after the film is applied in Table 1 is larger than the signal peak (2500) before the film is applied. However, when comparing the signal sizes, the embodiment of the present application not only obtains the signal peaks before and after the film is applied (corresponding to the signal in the third row and third column of Table 1 and the signal in the third row and third column of Table 2), but also obtains the signal amounts around the signal peaks before and after the film is applied (corresponding to the signals in the second row and second column, the second row and third column, the second row and fourth column, the third row and second column, the third row and fourth column, the fourth row and second column, the fourth row and third column, the fourth row and second column, the fourth row and fourth column in Table 2 and the signals in the second row and second column, the second row and third column, the second row and fourth column, the third row and second column, the fourth row and second column, the fourth row and second column, the fourth row and second column, the fourth row and second column, the fourth row and second column, the fourth row and second column, the fourth row and fourth column, the fourth row and second column, the fourth row and fourth column, the fourth row and second column, the fourth row and fourth column, the fourth row and second column, the fourth row and fourth column). Then compare the difference between the peak value of the signal before and after the film is applied and the sum of the surrounding signals.

[0084] Table 1: After film application

[0085] First column Second column Column 3 Fourth column Fifth column First row 50 100 300 100 50 Second row 100 500 700 600 150 Third row 150 800 4000 800 180 Fourth row 100 500 700 500 120 Fifth row 50 150 400 200 30

[0086] Table 2: Before film application

[0087] First column Second column Column 3 Fourth column Fifth column First row 50 100 300 100 50 Second row 100 720 800 420 150 Third row 450 2480 2500 500 400 Fourth row 350 700 800 420 300 Fifth row 65 320 450 350 70

[0088] Figure 7 The difference between the peak signal value and the sum of the surrounding signal value (or sum value, represented by sum) before and after film application is shown. The horizontal axis represents the sample number. If the horizontal axis is 1, the vertical axis represents the size of sum. If the horizontal axis is 1 and the vertical axis is 6000, it means that the sum value of sample number 1 is 6000. Figure 7The value on the ordinate corresponding to each horizontal axis in the value is that the sum corresponding to the screen protector before the film is applied is larger, and the sum corresponding to the screen protector after the film is applied is smaller. In other words, the first distribution feature can also be established when it cannot be guaranteed that the stylus is located at the same touch position (such as the center of the sensing area or the edge of the sensing area) before and after the screen protector is applied. Therefore, a value between the sum corresponding to the tablet before the screen protector is applied and the sum corresponding to the tablet after the screen protector is applied can be selected as the third threshold. The third threshold is any signal quantity between [5950, 6300], such as the third threshold is 6100. If it is detected that the sum corresponding to the tablet is less than or equal to the third threshold, it is recognized that the tablet has a screen protector. If it is detected that the sum corresponding to the tablet is greater than the third threshold, it is recognized that the tablet has no screen protector.

[0089] The first distribution feature of the coding signal is introduced above. The second distribution feature of the coding signal is described below.

[0090] Collect multiple groups of signal quantities, one group of signal quantities corresponds to one group of sampling objects, and the sampling objects may include tablets and styluses of the same brand and model, tablets and styluses of different brands, or tablets and styluses of the same brand but different models. One group of signal quantities includes the signal quantities of coding signals sent by the stylus in the group of sampling objects to different positions on the tablet before and after film application.

[0091] According to the distribution of each group of signal quantities in the multiple groups of signal quantities, the signal quantity shows a downward trend from the contact area between the tip of the stylus and the tablet (or the first sensing area corresponding to the signal quantity peak value) to the area around the contact area, and the downward trend corresponding to the tablet before the film is applied is greater than the downward trend corresponding to the tablet after the film is applied. Therefore, the second distribution feature of the signal quantity distribution is determined: when the stylus is at the center of the first sensing area, the ratio between the peak signal quantity after the film is applied and the signal quantity sensed by the sensing area around the corresponding sensing area is less than the ratio between the peak signal quantity before the film is applied and the signal quantity sensed by the sensing area around the corresponding sensing area.

[0092] The second distribution feature is described below. For example, the signal distribution in the center of the sensing area before and after film application is as follows: Figure 8As shown, the horizontal axis represents the sample number and the vertical axis represents the size of the signal. The ratio (represented as ratio1) of the peak signal amount at the center of the first sensing area after film application (represented as A) to the signal amount sensed by the peripheral sensing area of ​​the first sensing area (represented as C) is small, while the ratio (represented as ratio2) of the peak signal amount at the center of the first sensing area before film application (represented as B) to the signal amount sensed by the peripheral sensing area of ​​the first sensing area (represented as D) is large, that is, the corresponding descent speed of the flat plate before film application is greater than the corresponding descent speed of the flat plate after film application, that is, ratio2>ratio1. When the stylus is located at the center of the first sensing area, a value is selected as the first threshold value between the ratio of the peak signal amount after film application to the signal amount sensed by the peripheral sensing area and the ratio of the peak signal amount before film application to the signal amount sensed by the peripheral sensing area. The first threshold value can be a value between [5.5, 6.8], such as the first threshold value is 6. If the stylus is at the center of the first sensing area and the ratio of the signal peak to the signal sensed in the surrounding sensing area is greater than a first threshold, it is recognized that the tablet is not covered with a film; if the stylus is at the center of the first sensing area and the ratio of the signal peak to the signal sensed in the surrounding sensing area is less than or equal to the first threshold, it is recognized that the tablet is covered with a film.

[0093] The following will describe the film identification method provided by the embodiment of the present application based on the first distribution feature and the second distribution feature of the signal quantity distribution mentioned above. The method of using the first distribution feature and / or the second distribution feature to identify whether the tablet has a film can be summarized in four processes, namely data acquisition, sample screening, feature extraction, and film identification. The following will first describe the film identification method by taking whether the signal quantity distribution of the coding signal received by the tablet satisfies the signal quantity distribution of the tablet after the film is applied in the second distribution feature as an example.

[0094] First, the data acquisition in the film recognition method is explained. Data acquisition refers to obtaining the signal quantity of the capacitance signal. Data acquisition includes the following: Fig. 9 Shown:

[0095] S901. The tablet collects at least one set of first signal quantities.

[0096] Among them, at least one group of first signal quantities is used to identify whether the tablet has a film attached. At least one group of first signal quantities corresponds to at least one scanning cycle. A group of first signal quantities includes multiple first signal quantities obtained by the tablet scanning multiple sensing areas in one scanning cycle, and the multiple first signal quantities correspond to multiple sensing areas of the tablet. The multiple first signal quantities are the signal quantities sensed by the coding signal from the stylus pen in the multiple sensing areas of the tablet.

[0097] The sensing area of ​​the tablet is located at the intersection of the RX channel and the TX channel, and is used to sense the signal amount of the capacitive signal generated at the intersection. At the beginning of the scanning cycle, the tablet scans each sensing area (or sensing channel) in turn according to the preset scanning order. After the sensing area is scanned, a first signal amount sensed in the sensing area is sent. After the scanning cycle ends, the tablet collects the first signal amounts sensed by all sensing areas on the touch panel, obtains a group of first signal amounts, and enters the next scanning cycle. After the next scanning cycle ends, the tablet can collect another group of first signal amounts. And so on, after multiple scanning cycles end, the tablet collects multiple groups of first signal amounts.

[0098] The number of groups of the first signal quantity is a positive integer, such as 1, 10, 100, which means that the tablet collects 1 group of first signal quantities, 10 groups of first signal quantities, and 100 groups of first signal quantities. In actual applications, the tablet will collect more groups of first signal quantities, such as 100, 200, 1000 groups, etc., so that the collected multiple groups of first signal quantities can include first signal quantities that meet the following feature extraction conditions.

[0099] The scene of writing with the stylus on the tablet may include: starting the writing function of the stylus, the user operating the stylus to gradually approach the touch panel of the tablet, the user operating the stylus to write on the touch panel of the tablet, and completing the writing process, that is, the tablet can collect the signal amount of the coding signal in these processes. In order to improve the accuracy of the signal amount of the collected coding signal, in the embodiment of the present application, the signal amount collected by the tablet when the stylus is writing on the tablet is used as the first signal amount, and in other processes, such as the process of the user operating the stylus to gradually approach the touch panel of the tablet, the collected signal amount is not used as the first signal amount to identify whether the tablet is film-pasted.

[0100] Therefore, S901 can be replaced by: if the stylus pen is writing on the tablet, collect at least one set of first signal quantities. That is, in this embodiment, the tablet detects in real time whether the stylus pen starts writing on the tablet, and if the tablet detects that the stylus pen is writing on the tablet, the tablet collects at least one set of first signal quantities.

[0101] In some embodiments, the tablet identifies whether the stylus is writing on the tablet by detecting the size of the pressure signal.

[0102] As an example, the stylus can collect the pressure signal generated by the touch panel squeezing the pen tip through a sensor component (such as a pressure sensor). For example, when the stylus is close to the touch panel of the tablet or just touches the touch panel of the tablet but does not squeeze the tablet, the stylus cannot collect the pressure signal and will not send the pressure signal to the tablet. When the user uses the stylus to write on the touch panel of the tablet, the pen tip squeezes the touch panel, so the pen tip is also subjected to pressure from the touch panel, so the stylus collects the pressure signal and sends the pressure signal to the tablet.

[0103] As another example, a pressure sensor for sensing the pressure between the tip of the stylus pen and the touch panel of the tablet may also be disposed in the tablet, and the tablet collects pressure signals through the pressure sensor.

[0104] After the tablet collects the pressure signal, it determines whether the signal strength of the pressure signal is greater than or equal to the fourth threshold. Fig.10 As shown, if the signal strength of the pressure signal is greater than or equal to the fourth threshold, that is, the stylus is writing on the tablet, the tablet starts to collect at least one set of first signal quantities. If the signal strength of the pressure signal is less than the fourth threshold, that is, the stylus is not writing on the tablet, the tablet does not collect the first signal quantities.

[0105] Among them, the fourth threshold is the pressure intensity threshold, and the fourth threshold can be set according to actual needs. For example, it can be the pressure intensity expressed as a digital quantity, 0, 10, 20, etc., or it can also be an actual detection value, such as 0.98 Newton (N), 0.49N, etc.

[0106] The above describes the process of data acquisition. After the tablet collects at least one first signal, the following sample screening process is performed. Sample screening refers to screening the signal. Sample screening refers to screening the signal, such as screening the first signal, and screening the signal peak value in the first signal. Sample screening includes:

[0107] S902: The tablet obtains a signal amount peak value in each group of first signal amounts in at least one group of first signal amounts.

[0108] Take the case where there are x intersections of TX channels and RX channels (referred to as x sensing areas) on the touch panel of a tablet to sense the coding signal as an example. The tablet scans the signal quantities sensed by the x sensing areas in one scanning cycle to obtain the first signal quantities of the coding signal sensed by the x sensing areas. Among the x first signal quantities, the first signal quantity sensed by the sensing area closest to the tip of the stylus on the touch panel of the tablet is the largest, and this first signal quantity is called the signal quantity peak value.

[0109] When the stylus pen writes (such as drawing) on ​​the touch panel of the tablet, the distribution of the first signal quantity of each position of the pen tip on the touch panel of the tablet sensed by the tablet is as shown in Table 1 or Table 2, and the first signal quantity is arranged in an array. There is a signal quantity peak in each signal quantity array, and the sensing area corresponding to the signal quantity peak is called the first sensing area. According to the signal distribution of the first sensing area and the surrounding sensing areas, the position where the stylus pen tip writes on the touch panel of the tablet is calculated by a coordinate calculation method.

[0110] After filtering out the signal quantity peak value from the first signal quantity, the tablet determines whether the signal quantity peak value is sensed at the center of the first sensing area.

[0111] Since the first sensing area is an area, although the pen tip can be sensed by the first sensing area when it falls within the range of the first sensing area, the position of the pen tip in the first sensing area is different, and the magnitude of the signal peak is also different. When the stylus pen writes on the touch panel of the tablet, the stylus pen tip will pass through the edge of the first sensing area and the center of the first sensing area (or pass through the center of the first sensing area and the edge of the first sensing area in turn). Since the pen tip will pass through the center of the first sensing area and the edge of the first sensing area, the position of the stylus pen tip corresponding to the sensed signal peak may be at the center of the first sensing area or at the edge of the first sensing area.

[0112] According to the second distribution feature, when the pen tip falls on the center of the first sensing area, the ratio between the peak value of the signal after film application and the signal sensed by the surrounding sensing area of ​​the corresponding sensing area is smaller than the ratio between the peak value of the signal before film application and the signal sensed by the surrounding sensing area of ​​the corresponding sensing area. Therefore, after obtaining the peak value of the signal, it is determined whether the peak value of the signal is sensed at the center of the first sensing area. If the peak value of the signal is sensed at the center of the first sensing area, the following S903 is executed. If the peak value of the signal is not sensed at the center of the first sensing area, the peak value of the signal is eliminated.

[0113] As an example, the signal amount peak value sensed at the center of the first sensing area can be obtained in the following manner: the maximum value of each group of first signal amounts in at least one group of first signal amounts is obtained to obtain at least one signal amount peak value corresponding to at least one group of first signal amounts. For any signal amount peak value in at least one signal amount peak value, if the signal amount peak value is sensed at the center of any sensing area in multiple sensing areas, it means that the sample is valid, and the signal amount peak value is retained; if the signal amount peak value is not sensed at the center of multiple sensing areas, it means that the sample is invalid, and the signal amount peak value is discarded.

[0114] In this example, the signal peak value is sampled and screened based on whether the signal peak value is sensed at the center of the first sensing area, and the signal peak value sensed at the center of the first sensing area is obtained.

[0115] The following is an exemplary method for determining whether the signal peak is sensed at the center of the first sensing area.

[0116] When the touch sensors for sensing the signal quantity of the coding signal are arranged in an array, the distance between two adjacent touch sensors is equal (or equidistant in short). Then the signal quantities sensed in the peripheral sensing areas of the first sensing area of ​​the tablet have the characteristic of small difference in signal quantity (or close signal quantity). Fig.11 As shown, the tip of the stylus falls on the center 1101 of the first sensing area on the touch panel of the tablet, and the signal amount sensed at the center 1101 of the first sensing area is Fig.11 The vertical coordinate corresponding to point A in FIG. 1 and the signal amounts sensed by the peripheral sensing area 1102 at the position where the pen tip is located on the touch panel (i.e., the first sensing area) are respectively Fig.11 The ordinate corresponding to point B and the ordinate corresponding to point C in the figure. It can be seen that among points A, B and C, the signal amount at point A is the largest, and the difference between the signal amounts at points B and C is small. The small difference between the signal amounts at points B and C indicates that the signal amounts sensed by the peripheral sensing area 1102 are close in size, so whether the signal amount peak is sensed at the center of the first sensing area can be identified in the following way.

[0117] Obtain the first signal quantities sensed by at least two second sensing areas in a group of first signal quantities corresponding to the signal quantity peak value as the third signal quantity, wherein the second sensing area is a sensing area equidistant from the first sensing area corresponding to the signal quantity peak value. If the ratio between at least two third signal quantities is less than or equal to the second threshold, it means that the signal quantity peak value is sensed by the center of the first sensing area, and the signal quantity peak value is retained; if the ratio between at least two third signal quantities is greater than the second threshold, it means that the signal quantity peak value is not sensed by the center of the first sensing area, and the signal quantity peak value is discarded. The second threshold value is any value between [0.9, 1.1]. If the second threshold value is 1.1, then when the ratio between the two third signal quantities is less than or equal to 1.1, it is determined that the signal quantity peak value corresponding to the two third signal quantities is sensed at the center of the first sensing area of ​​the tablet.

[0118] Fig.12 The position of the first sensing area and the second sensing area on the touch panel of the tablet is shown. There are multiple sensing areas on the touch panel of the tablet. It can be seen that the sensing area where the tip of the stylus falls is the first sensing area 1201. Fig.12As shown in (a), there is a sensing area above the first sensing area 1201, below the first sensing area 1201, on the left side of the first sensing area 1201, and on the right side of the first sensing area 1201. These four sensing areas are equidistant from the first sensing area 1201, so they are called second sensing areas 1202. The second sensing area can be understood as the peripheral sensing area of ​​the first sensing area.

[0119] In addition to the above four sensing areas that can be used as the second sensing area 1202, Fig.12 In the sensing area shown in (b), the four sensing areas marked with slashes can also be used as the four second sensing areas 1202 corresponding to the first sensing area. Different from the four second sensing areas 1202 not marked with slashes, the four second sensing areas 1202 marked with slashes are not the sensing areas closest to the first sensing area and are not adjacent to the first sensing area.

[0120] In practical applications, multiple sensing areas that are closest to the first sensing area (ie, the closest to each other on the touch panel) can be selected as the second sensing area (eg Fig.12 The second sensing area 1202 shown in (a) of FIG. 1 may also be selected as a plurality of sensing areas not adjacent to the first sensing area (eg, Fig.12 The second sensing area 1202 shown in (b) of FIG. 1 is not limited in the present application. The two sensing areas being adjacent means that the two sensing areas are in the same row or column of the plurality of sensing areas arranged in an array, and there is no other sensing area between the two sensing areas.

[0121] In the embodiment of the present application, the signal amount sensed by the tablet in the second sensing area is referred to as the third signal amount. The third signal amount can be understood as the signal amount sensed by the peripheral sensing area of ​​the first sensing area corresponding to the signal amount peak value.

[0122] It should be noted that each signal amount peak value and its corresponding third signal amount are from the same group of first signal amounts, that is, the signal amount peak value and its corresponding third signal amount are signal amounts obtained by scanning the flat panel in the same scanning cycle. Then, if the ratio between the third signal amounts is less than or equal to the second threshold, it means that the magnitudes of the signal amounts sensed by the peripheral sensing areas of the first sensing area are close, and it is confirmed that the signal amount peak value is sensed at the center of the first sensing area. If the ratio between the third signal amounts is greater than the second threshold, it means that the magnitudes of the signal amounts sensed by the peripheral sensing areas of the first sensing area are not close, and it is confirmed that the signal amount peak value is not sensed at the center of the first sensing area. In this way, the signal amount peak value that meets the signal amount sensed at the center of the first sensing area can be screened out from multiple signal amount peak values ​​by taking advantage of the fact that the magnitudes of the signal amounts sensed by the peripheral sensing areas of the first sensing area are relatively small.

[0123] In some embodiments, the number of the second sensing areas is two. For example, two sensing areas adjacent to the first sensing area can be obtained as the second sensing areas. When the touch sensors are arranged in an array, the distances between two adjacent touch sensors are equal (or simply equidistant), then the two sensing areas adjacent to the first sensing area are equidistant from the first sensing area. In this embodiment, the ratio between the third signal quantities sensed by the two second sensing areas is compared with the second threshold.

[0124] In some other embodiments, the number of the second sensing areas is more than two. For example, all the sensing areas adjacent to the first sensing area on the touch panel of the tablet can be obtained as the second sensing areas. Fig.12 In (a), the first sensing area has four adjacent sensing areas, so there are four second sensing areas. The tablet obtains the ratio between the third signal quantities sensed by any two second sensing areas among the plurality of second sensing areas, and obtains six ratios. The six ratios are all compared with the second threshold. If the six ratios are all less than or equal to the second threshold, it is confirmed that the signal quantity peak is sensed at the center of the first sensing area.

[0125] The above describes the process of filtering out the signal amount peak value from each group of first signal amounts. The sample filtering also includes: S903, if the signal amount peak value is sensed at the center of the first sensing area, the tablet filters out the signal amount sensed by the peripheral sensing area of ​​the first sensing area from each group of first signal amounts as the second signal amount.

[0126] Exemplarily, when the signal peak is sensed at the center of the first sensing area, the tablet presets a first number, and determines the first preset area with the first sensing area corresponding to the signal peak as the center, and the first preset area includes the first number of sensing areas. If the first number is 3*3, then the first preset area is centered on the first sensing area and includes 9 sensing areas. Among the 9 sensing areas, in addition to the first sensing area corresponding to the signal peak, there are 8 sensing areas left. The first signal sensed by any of the 8 sensing areas can be used as the second signal corresponding to the sensing area in the first preset area. Among them, the sensing area in the first preset area does not include the first sensing area.

[0127] The samples obtained by screening through S902-S903 include the signal amount peak value sensed at the center of the first sensing area and the second signal amount sensed by the sensing area within the first preset area in a group of first signal amounts corresponding to the signal amount peak value.

[0128] After the samples are screened, the distribution characteristics of the signal quantity are extracted according to the screened samples, which is the feature extraction mentioned above. The process of feature extraction is described below in conjunction with S904.

[0129] S904: The tablet calculates a ratio of a signal amount peak value to a second signal amount in any group of the at least one group of first signal amounts.

[0130] The ratio feature of the signal quantity is extracted according to the second distribution feature of the signal quantity distribution, "when the stylus is at the center of the first sensing area, the ratio between the peak value of the signal quantity after the film is applied and the signal quantity sensed by the peripheral sensing area of ​​the corresponding sensing area is less than the ratio between the peak value of the signal quantity before the film is applied and the signal quantity sensed by the peripheral sensing area of ​​the corresponding sensing area". The ratio feature is the ratio of the peak value of the signal quantity in a group of first signal quantities to the second signal quantity in the group of first signal quantities.

[0131] The ratio feature reflects the amplitude of the decrease in the signal amount. A large ratio feature indicates that the ratio of the peak signal amount sensed in the first sensing area to the signal amount sensed in the surrounding sensing areas (i.e., the second signal amount) is large; a small ratio feature indicates that the ratio of the peak signal amount sensed in the first sensing area to the signal amount sensed in the surrounding sensing areas (i.e., the second signal amount) is small.

[0132] As an example, when there are multiple second signal quantities, the following methods can be used to calculate the ratio feature.

[0133] The first method is to obtain an average value of multiple second signal quantities, calculate the ratio between the signal quantity peak value and the average value of the multiple second signal quantities, and obtain a ratio feature.

[0134] The second method is to obtain the minimum value of multiple second signal quantities, calculate the ratio between the signal quantity peak value and the minimum value of the multiple second signal quantities, and obtain the ratio feature.

[0135] Since the magnitudes of the second signal quantities sensed by the plurality of peripheral sensing regions of the first sensing region are similar, the minimum value of the plurality of second signal quantities and the peak value of the signal quantity may be extracted for ratio calculation, which can reduce the amount of calculation.

[0136] The third method: obtaining the maximum values ​​of multiple second signal quantities, calculating the ratio between the signal quantity peak value and the maximum values ​​of the multiple second signal quantities, and obtaining the ratio feature.

[0137] A fourth method is to respectively calculate the ratio between the signal quantity peak value and each of the second signal quantities in the plurality of second signal quantities to obtain a plurality of ratio features.

[0138] After extracting the ratio features, the tablet performs the film recognition process.

[0139] S905: The tablet determines whether the ratio of the signal amount peak value to the second signal amount is less than or equal to a first threshold.

[0140] If the ratio is less than or equal to the first threshold, execute S906 ; if the ratio is greater than the first threshold, execute S907 .

[0141] In some embodiments, the ratio feature may be enlarged or reduced, such as enlarging the ratio feature by 100 times and then comparing it with the first threshold, or reducing the ratio feature by 100 times and then comparing it with the first threshold.

[0142] S906: The tablet recognizes the tablet film.

[0143] S907: The tablet recognizes that the tablet has no film attached.

[0144] For example, the second distribution feature of the signal quantity distribution mentioned above shows that the ratio feature of the signal quantity before the flat panel film is applied and the ratio feature of the signal quantity after the flat panel film is applied are distinguishable, so a value is obtained between the ratio feature of the signal quantity before the flat panel film is applied and the ratio feature of the signal quantity after the flat panel film is applied as the first threshold. For the flat panel to be identified as having a film applied, the ratio feature of the signal quantity of the flat panel is calculated, and then the ratio feature is compared with the first threshold.

[0145] If the ratio feature is less than or equal to the first threshold, it means that the ratio of the signal peak value sensed by the first sensing area to the signal peak value sensed by the surrounding sensing areas is small, which meets the second distribution feature of the signal distribution of the tablet after film application, and the tablet film application is recognized.

[0146] On the contrary, if the ratio feature is greater than the first threshold, it means that the ratio of the signal peak value sensed by the first sensing area to the signal peak value sensed by the surrounding sensing area is large, which meets the second distribution feature of the signal distribution of the unfilmed tablet, and the tablet is identified as not having a film.

[0147] As an example, multiple ratio features are calculated from at least one set of first signal quantities, and the multiple ratio features are compared with the first threshold respectively. If the results of multiple comparisons are that the ratio features are less than or equal to the first threshold, the flat film is identified. In this way, the results obtained by multiple comparisons have a higher accuracy rate.

[0148] In summary, the tablet extracts the ratio feature of the signal quantity from at least one group of first signal quantities collected, and compares the extracted ratio feature with the first threshold value based on the characteristic that the ratio feature of the tablet after the film is attached and the ratio feature of the tablet before the film is attached, so as to identify whether the tablet has a film attached. If it is recognized that the tablet has a film attached, the tablet can adjust the handwriting function of the touch panel to a functional mode that matches the film, wherein the functional mode that matches the film is achieved by adaptively adjusting the coordinate calculation method according to the recognition result. By adjusting the different functional modes of the touch panel, the influence of the film on writing can be compensated, so as to achieve the purpose of writing optimization.

[0149] The above only illustrates the implementation process of tablet film recognition by taking the example that the signal distribution of the tablet satisfies the second distribution feature. In actual applications, the signal distribution of the tablet also satisfies the first distribution feature, so whether the tablet has a film can be identified based on the first distribution feature.

[0150] The first distribution feature also involves the calculation of the signal quantity, so for the tablet that needs to be identified as having a film, the first step is to perform the data acquisition step. For details, please refer to the above description of data acquisition.

[0151] After at least one set of first signal quantities are collected, the following sample screening process is performed. In this embodiment, sample screening refers to screening the first signal quantities, and the sample screening process includes: S908-S910.

[0152] S908. For any first semaphore in each group of first semaphores, the tablet determines whether the first semaphore satisfies a second condition.

[0153] If the first semaphore satisfies the second condition, S909 is executed; if the first semaphore does not satisfy the second condition, S910 is executed.

[0154] S909: The tablet removes the first semaphore.

[0155] S910. The tablet reserves the first semaphore.

[0156] The second condition includes: a preset signal range, such as the preset signal range includes [400, 5000].

[0157] As an example, the two endpoint values ​​in the preset signal range are determined by analyzing the difference in signal quantity between noise signals and non-noise signals in the multiple sets of signal quantities collected for testing. For example, the signal quantity of the noise signal is distributed between 200 and 350 and 5200 and 5300, and the non-noise signal is distributed between 500 and 4800. Then, a value between 350 and 500 is taken as the minimum value in the signal range, and a value between 5200 and 4800 is taken as the maximum value of the signal range, to obtain the preset signal range.

[0158] The second condition is used to remove noise signals and retain valid signals. If the first signal quantity meets the second condition, it means that the first signal quantity is not a noise signal and the sample is valid, so the first signal quantity is retained; if the first signal quantity does not meet the second condition, it means that the first signal quantity is a noise signal and the sample is invalid, so the first signal quantity is removed.

[0159] After sample screening, the effective first signal quantity is retained, so that only the effective first signal quantity needs to be processed later, which reduces the processing cost and prevents noise signals from interfering with the recognition results.

[0160] After sample screening, the distribution characteristics of the signal quantity are extracted based on the screened samples, which is the feature extraction mentioned above.

[0161] Feature extraction includes: S911-S913.

[0162] S911. The tablet obtains a maximum value of the first signal quantity that meets the second condition from each group of first signal quantities, and obtains at least one signal quantity peak value corresponding to at least one group of first signal quantities.

[0163] The first semaphore that meets the second condition, that is, the reserved first semaphore, is hereinafter referred to as the first semaphore.

[0164] S912. For any signal amount peak value among the at least one signal amount peak value, the tablet obtains a first signal amount sensed by a sensing area within the second preset area from a group of first signal amounts corresponding to the signal amount peak value, and obtains a fourth signal amount corresponding to the sensing area within the second preset area.

[0165] S913. The tablet calculates a sum of a signal quantity peak value and a fourth signal quantity in any one group of first signal quantities in at least one group of first signal quantities.

[0166] Among them, the second preset area is an area on the touch panel centered on the first sensing area corresponding to the signal amount peak value. As an example, the second preset area can be set with the second number of preset areas as the range. If the second preset area is set to include 3*3 sensing areas, then the second preset area includes 9 sensing areas. Among the 9 sensing areas, in addition to the first sensing area corresponding to the signal amount peak value, there are 8 sensing areas left. The first signal amount sensed by any of the 8 sensing areas can be used as the fourth signal amount corresponding to the sensing area in the second preset area. Among them, the sensing area in the second preset area can be understood as the peripheral sensing area of ​​the first sensing area, the sensing area in the second preset area does not include the first sensing area, and the fourth signal amount can be understood as the signal amount around the signal amount peak value.

[0167] According to the first distribution feature of the signal quantity distribution, after the film is applied, the sum of the signal quantity peak value and the signal quantity around it becomes smaller, and the plate extracts the sum value feature of the signal quantity. The sum value feature is the sum value between the signal quantity peak value in a group of first signal quantities and the fourth signal quantity in the group of first signal quantities.

[0168] The sum feature reflects the size of the signal in the peak area (i.e., the first sensing area and the second preset area). A large sum feature indicates a large signal in the peak area, and a small sum feature indicates a small signal in the peak area. It should be understood that when the stylus is writing at the same position on the touch panel of the tablet, the peak signal collected by the tablet without a film is greater than the peak signal collected by the tablet with a film, so it is only through the relationship between the peak signal and the threshold that it is possible to identify whether the tablet has a film. In actual application, the position where the user writes on the touch panel of the tablet with the stylus is random. If you want to achieve film recognition for any position where the stylus is written on the touch panel of the tablet, you need to set a threshold for the peak signal at each position. When the stylus is detected writing on the touch panel of the tablet, the tablet first needs to detect the position where the stylus is written, and then find the threshold corresponding to each preset position based on the position of the pen to determine whether the peak signal generated by the position of the pen meets the peak signal feature when the film is applied. This method is quite complicated, so in this embodiment, the signal peak value is not directly compared with the threshold, but the sum feature is extracted. Compared with the solution of only extracting the signal peak value, this embodiment reduces the calculation process without causing erroneous judgment, so it is more suitable for the scenario of identifying tablet film when users write in daily life.

[0169] The above describes the steps of extracting the sum feature. After the sum feature is extracted, the tablet executes S914-S916 to realize the film recognition process.

[0170] S914. The tablet determines whether the sum of the signal quantity peak value and the fourth signal quantity is less than or equal to a third threshold.

[0171] If the sum is less than or equal to the third threshold, execute S915; if the sum is greater than the third threshold, execute S916.

[0172] S915. Identify the tablet film.

[0173] S916: Identify that the tablet is not filmed.

[0174] From the first distribution feature of the signal quantity distribution mentioned above, it can be known that the sum value feature of the signal quantity before the flat panel film is applied and the sum value feature of the signal quantity after the flat panel film is applied are distinguishable, so a value between the sum value feature of the signal quantity before the flat panel film is applied and the sum value feature of the signal quantity after the flat panel film is applied is taken as the third threshold. For the flat panel that needs to be identified whether it has a film applied, after calculating the sum value feature of the signal quantity of the flat panel, the sum value feature is compared with the third threshold.

[0175] If the sum feature is less than or equal to the third threshold, it means that the signal amount in the peak area is small, which meets the first distribution feature of the signal amount distribution of the tablet after film pasting, and the tablet film is identified.

[0176] On the contrary, if the sum feature is greater than the third threshold, it means that the signal amount in the peak area is large, which meets the second distribution feature of the signal amount distribution of the unfilmed flat panel, and the flat panel is identified as unfilmed.

[0177] In practical applications, the third threshold value can be set according to different positions of the peak area on the plate.

[0178] For example, since the stylus writes at different positions on the touch panel, the magnitudes of the signal peaks sensed by the first sensing areas corresponding to different positions are different, and the magnitudes of the fourth signal sensed by the sensing areas surrounding the first sensing areas corresponding to different positions are also different. The difference between the signal peak and the fourth signal indicates that the magnitudes of the signals in different peak areas are also different. In order to avoid the problem of low judgment tolerance and easy erroneous judgment caused by judging the magnitude of the signal in each peak area by only a third threshold without making any distinction, the tablet first obtains the signal peaks sensed in each sensing area on the touch panel, and the tablet records the magnitudes of the signal peaks sensed in each sensing area and the position information of the sensing area where the signal peak is sensed.

[0179] Based on the highest signal, the peak values ​​of the signals sensed in the other sensing areas are normalized and linearly fitted. The curve obtained by fitting reflects the trend of the signal peak value changing with the position. The position refers to the coordinates of the first sensing area corresponding to the signal peak value on the touch panel.

[0180] According to the curve obtained by fitting, the signal peak value is smaller in the upper half of the touch panel (corresponding to the driving distal end of the touch IC chip) and larger in the lower half of the touch panel (corresponding to the driving proximal end of the touch IC chip). That is, the signal peak value and the value of the peripheral signal sensed in the upper half of the touch panel are different from the signal peak value and the value of the peripheral signal sensed in the lower half of the touch panel. Therefore, if the first sensing area is located in the upper half of the touch panel, the preset third threshold is smaller, and if the first sensing area is located in the lower half of the touch panel, the preset third threshold is larger. In this way, by using different positions and thresholds of different sizes to judge whether the value characteristics meet the condition that the flat panel is not filmed, the judgment fault tolerance rate is higher, and the requirements for the accuracy of signal acquisition are lower, and it is not easy to cause wrong judgment when the accuracy of the collected signal is low.

[0181] In summary, the above only illustrates the implementation process of identifying a flat panel with a film by taking the case where the signal distribution of the flat panel satisfies the first distribution feature as an example. In practical applications, the first distribution feature and the second distribution feature of the signal distribution of the flat panel can be combined as a basis for identifying whether the flat panel has a film.

[0182] Exemplarily, after calculating the ratio feature and the sum feature above, the tablet compares the ratio feature with the first threshold and the sum feature with the third threshold. If the ratio feature is less than or equal to the first threshold and the sum feature is less than or equal to the third threshold, it is identified that the tablet has a film attached. On the contrary, if the ratio feature is greater than the first threshold or the sum feature is greater than the third threshold, it is identified that the tablet has no film attached. In this embodiment, when the distribution of the sensed signal quantity satisfies both the signal quantity distribution after film attachment in the first distribution feature and the signal quantity distribution after film attachment in the second distribution feature, the tablet is identified as having a film attached to improve the recognition accuracy.

[0183] Some other embodiments of the present application provide an electronic device, which may include: the above-mentioned touch panel, a memory and one or more processors. The touch panel, the memory and the processor are coupled. The memory is used to store computer program code, and the computer program code includes computer instructions. When the processor (or the touch panel with a processor) executes the computer instructions, the electronic device can execute the various functions or steps performed by the tablet in the above-mentioned method embodiment. The structure of the electronic device can refer to Figure 5 The structure of the plate shown.

[0184] The present application also provides a chip system, such as Fig.13 As shown, the chip system includes at least one processor 1301 and at least one interface circuit 1302. The processor 1301 and the interface circuit 1302 can be interconnected through a line. For example, the interface circuit 1302 can be used to receive signals from other devices (e.g., a memory of a tablet). For another example, the interface circuit 1302 can be used to send signals to other devices (e.g., the processor 1301).

[0185] For example, the interface circuit 1302 may read instructions stored in the memory of the tablet and send the instructions to the processor 1001. When the instructions are executed by the processor 1301, the tablet may execute the steps in the above embodiments.

[0186] An embodiment of the present application also provides a computer-readable storage medium, which includes computer instructions. When the computer instructions are executed on the above-mentioned electronic device, the electronic device executes each function or step executed by the mobile phone in the above-mentioned method embodiment.

[0187] The embodiment of the present application also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute each function or step executed by the mobile phone in the above method embodiment.

[0188] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0189] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0190] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0191] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0192] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0193] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A film recognition method, characterized in that: Electronic devices that are used to realize touch functions with a stylus pen include: Collecting at least one group of first signal quantities, each group of the first signal quantities includes a plurality of first signal quantities sensed by a coding signal from the stylus pen at a plurality of sensing areas on the touch panel of the electronic device; Obtaining a maximum value of each group of first signal quantities in the at least one group of first signal quantities, and obtaining at least one signal quantity peak value corresponding to the at least one group of first signal quantities; For any signal amount peak value among the at least one signal amount peak value, if the signal amount peak value is sensed at the center of any sensing area among the multiple sensing areas, a first signal amount sensed by a sensing area other than the first sensing area in a first preset area among a group of first signal amounts corresponding to the signal amount peak value is used as a second signal amount; wherein the first preset area includes the first sensing area on the touch panel of the electronic device and a peripheral sensing area centered on the first sensing area; the first sensing area is the sensing area corresponding to the signal amount peak value; If the ratio of the signal amount peak value to the second signal amount is less than or equal to a first threshold, the electronic device is identified as having a film.

2. The method according to claim 1, characterized in that The signal amount peak is sensed at the center of any sensing area among the multiple sensing areas, including: A ratio between at least two third signal quantities is less than or equal to a second threshold; The third signal quantity is a first signal quantity sensed by at least two second sensing areas in a group of first signal quantities corresponding to the signal quantity peak value, and the second sensing areas are sensing areas in the multiple sensing areas that are equidistant from the first sensing areas corresponding to the signal quantity peak value.

3. The method according to claim 2, characterized in that The number of the third signal quantities is two, and before the ratio between the at least two third signal quantities is less than or equal to the second threshold, the method further includes: The first signal quantities sensed by at least two sensing areas closest to the first sensing area corresponding to the signal quantity peak value in a group of first signal quantities corresponding to the signal quantity peak value are obtained to obtain at least two third signal quantities.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: For any signal amount peak value among the at least one signal amount peak value, a first signal amount sensed by a sensing area other than the first sensing area in a second preset area in a group of first signal amounts corresponding to the signal amount peak value is used as a fourth signal amount; wherein the second preset area includes the first sensing area on the touch panel of the electronic device and a peripheral sensing area centered on the first sensing area; If the ratio of the signal amount peak value to the second signal amount is less than or equal to a first threshold, identifying the electronic device film, comprises: If the ratio of the signal amount peak value to the second signal amount is less than or equal to the first threshold, and the sum of the signal amount peak value and the fourth signal amount is less than or equal to the third threshold, the electronic device film is identified.

5. The method according to any one of claims 1 to 3, characterized in that: The taking the first signal amount sensed by the sensing area other than the first sensing area in the first preset area in a group of first signal amounts corresponding to the signal amount peak as the second signal amount includes: The minimum first signal amount among the first signal amounts sensed by the sensing areas other than the first sensing area in the first preset area in a group of first signal amounts corresponding to the signal amount peak value is taken as the second signal amount.

6. The method according to any one of claims 1 to 3, characterized in that The collecting of at least one set of first signal quantities comprises: If the stylus performs a touch operation on the electronic device, at least one set of first signal quantities is collected.

7. The method according to claim 6, characterized in that The method further comprises: Collect pressure signals; If the stylus performs a touch operation on the electronic device, at least one set of first signal quantities is collected, including If the signal strength of the pressure signal is greater than or equal to a fourth threshold, at least one set of first signal quantities is collected.

8. The method according to claim 4, characterized in that The size of the third threshold value corresponds to the position of the first sensing area corresponding to the signal amount peak value on the electronic device; The method further comprises: Acquire a position of a first sensing area corresponding to the signal amount peak value on the touch panel of the electronic device; Selecting a third threshold value corresponding to the position from the plurality of third threshold values ​​of different sizes; The sum of the signal quantity peak value and the fourth signal quantity is less than or equal to a third threshold, including: A sum of the signal quantity peak value and the fourth signal quantity is less than or equal to a third threshold corresponding to the position.

9. The method according to any one of claims 1, 2, 3, 7 and 8, characterized in that: The method further includes: the electronic device presets a first quantity, and determines the first preset area with the first sensing area corresponding to the signal amount peak as the center, and the first preset area includes the first number of sensing areas.

10. The method according to any one of claims 1, 2, 3, 7 and 8, characterized in that: The position of each sensing area on the touch panel of the electronic device corresponds to the position of an area formed by the intersection of the sensing electrodes and the driving electrodes in the electronic device.

11. An electronic device, characterized in that: include: A touch panel, a processor, and a memory for storing instructions executable by the processor, wherein when the processor is configured to execute the instructions, the electronic device implements the method as claimed in any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that: The method comprises computer instructions, which, when executed on the electronic device, cause the electronic device to execute the method according to any one of claims 1 to 10.

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