Detection method of active pen, touch control chip, touch control screen and touch control device with active pen

Abstract

The invention discloses a detection method of an active pen, a touch control chip, a touch control screen and a touch control device with the active pen, the touch control screen comprises a plurality of transmitting electrodes, a plurality of receiving electrodes and a plurality of AFE circuits, the transmitting electrodes and the receiving electrodes are arranged in a crossed mode, and each AFE circuit is connected with one transmitting electrode or one receiving electrode. The AFE circuit is used for converting an electric signal of the electrode into a detection signal; the detection method comprises the following steps: obtaining a detection data frame according to detection signals output by a plurality of AFE circuits at first scanning time; when it is judged that an active pen exists on the touch screen according to the previous detection data frame, entering a pen detection state; wherein in the pen detection state, the touch screen scans detection signals of all the transmitting electrodes and the receiving electrodes according to second scanning time; extracting pen data of the active pen from the current detection data frame; demodulating the pen data to obtain a signal amplitude corresponding to the signal frequency of the active pen; and obtaining the contact state, the contact position or the inclination angle of the active pen according to the signal amplitude.

Description

Technical Field

[0001] This application relates to the field of touch technology, specifically to a method for detecting an active pen, a touch chip, a touch screen, and a touch device with an active pen. Background Technology

[0002] With the widespread adoption of smartphones and tablets, more and more applications require styluses for high-precision touch input, placing increasingly higher demands on stylus performance. Active styluses, with their advantages of high precision, low cost, and excellent user experience, have become the most mainstream type of stylus. Unlike passive styluses, active styluses are themselves signal transmitters. The touchscreen's sensors can then receive these signals and calculate the stylus's coordinates, achieving an effect similar to writing on paper with a stylus. However, current touchscreens supporting active styluses require additional detection circuitry, increasing manufacturing costs. Summary of the Invention

[0003] In view of this, this application provides a method for detecting an active pen, a touch chip, a touch screen, and a touch device with an active pen, to reduce the manufacturing cost of touch screens and enable touch screens with AFE circuits to also realize active pen touch applications. The technical solution of this application is as follows: This application provides a method for detecting an active pen, applied to a touchscreen. The touchscreen includes multiple transmitting electrodes, multiple receiving electrodes intersecting with the transmitting electrodes, and multiple AFE circuits. Each AFE circuit is connected to one of the transmitting electrodes or the receiving electrodes. The AFE circuit converts the electrical signals of the electrodes into detection signals, which are used to detect finger touches on the touchscreen. The detection method includes: obtaining a detection data frame based on the detection signals output by the multiple AFE circuits at a first scan time; entering a pen detection state when it is determined that an active pen exists on the touchscreen based on the previous detection data frame; wherein, in the pen detection state, the touchscreen scans the detection signals of all the transmitting electrodes and the receiving electrodes according to a second scan time; extracting pen data of the active pen from the current detection data frame; demodulating the pen data to obtain the signal amplitude corresponding to the signal frequency of the active pen; and obtaining the contact state, touch position, or tilt angle of the active pen based on the signal amplitude.

[0004] In one embodiment of this application, the second scan time is less than or equal to the first scan time.

[0005] In one embodiment of this application, the active pen includes a first terminal disposed at the pen tip and a second terminal disposed at the pen head, wherein the first terminal and the second terminal are driven by signals of different frequencies; the step of demodulating the pen data to obtain the signal amplitude corresponding to the signal frequency of the active pen includes: obtaining the pen data component corresponding to the signal frequency of the active pen from the pen data; and performing IQ demodulation processing on multiple pen data components to obtain the signal amplitude corresponding to each signal frequency of the active pen.

[0006] In one embodiment of this application, the active pen is used to output a signal of a first frequency through the first terminal and a signal of a second frequency through the second terminal when the pen tip contacts the touch screen; the pen data components include a first data component of the first frequency and a second data component of the second frequency; the signal amplitude includes a first signal amplitude of the first frequency and a second signal amplitude of the second frequency; obtaining the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude includes: determining that the active pen is in a pen tip contact state when the first signal amplitude and the second signal amplitude are obtained; obtaining the first terminal coordinates of the first terminal on the touch screen based on the first signal amplitude, as the contact point position; obtaining the second terminal coordinates of the second terminal on the touch screen based on the second signal amplitude; and obtaining the normal angle and the horizontal angle based on the first terminal coordinates and the second terminal coordinates, as the tilt angle.

[0007] In one embodiment of this application, the active pen is used to output a signal of a third frequency through the first terminal and a signal of a fourth frequency through the second terminal when it is suspended above the touch screen; the pen data component further includes a third pen data component of the third frequency and a fourth pen data component of the fourth frequency; the signal amplitude includes a third signal amplitude of the third frequency and a fourth signal amplitude of the fourth frequency; obtaining the contact state, contact point position or tilt angle of the active pen based on the signal amplitude further includes: determining that the active pen is in a pen tip suspension state when the third signal amplitude and the fourth signal amplitude are obtained.

[0008] In one embodiment of this application, the active pen includes a third terminal disposed at the end of the pen. The active pen is used to output a signal of a fifth frequency through the third terminal when the end of the pen contacts the touch screen. The pen data component includes a fifth pen data component of the fifth frequency, and the signal amplitude includes a fifth signal amplitude of the fifth frequency. Obtaining the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude includes: determining that the active pen is in a pen end contact state when the fifth signal amplitude is obtained.

[0009] In one embodiment of this application, after determining the touch point position of the active pen, the method further includes: determining the target transmitting electrode and the target receiving electrode corresponding to the local area of ​​the touch screen according to the touch point position and a preset number; scanning the detection signals of the target transmitting electrode and the target receiving electrode according to the second scanning time to obtain the next detection data frame.

[0010] In one embodiment of this application, it further includes: controlling the transmitting electrode and / or the receiving electrode to transmit an uplink signal according to a preset period, the uplink signal being used to interact with the active pen; the step of determining that the active pen exists on the touch screen based on the previous detection data frame includes: determining that the active pen exists on the touch screen when a downlink signal of the active pen is detected from the detection data frame.

[0011] A second aspect of this application provides a touch chip, the touch chip including a plurality of AFE circuits, each AFE circuit being connected to one of the transmitting electrodes or receiving electrodes of a touch screen, the touch chip further including a digital sampling circuit, a preset number of digital bandpass filters, and a preset number of demodulators, the digital sampling circuit being connected to the AFE circuit, the digital bandpass filters being connected to the digital sampling circuit, and each demodulator being connected to one of the digital bandpass filters; the digital sampling circuit being used to scan the detection signal according to a first scan time or a second scan time to obtain the detection data frame; the digital bandpass filters being used to obtain the pen data component corresponding to the signal frequency of the active pen from the pen data; the demodulators being used to perform IQ demodulation processing on the pen data component to obtain the signal amplitude corresponding to the signal frequency of the active pen.

[0012] In one embodiment of this application, a digital bandpass filter and a corresponding demodulator constitute a demodulation path, and the touch chip includes four demodulation paths; wherein each demodulation path is used to demodulate the pen data components corresponding to the following four signals to obtain a first signal amplitude, a second signal amplitude, a third signal amplitude, and a fourth signal amplitude, the four signals being: a first frequency signal output through the first terminal of the pen tip and a second frequency signal output through the second terminal of the pen tip when the pen tip touches the touch screen; and the active pen is used to output a third frequency signal through the first terminal and a fourth frequency signal through the second terminal when it is suspended above the touch screen.

[0013] In one embodiment of this application, any one of the demodulation paths multiplexes the pen data component corresponding to the demodulated fifth signal to obtain the amplitude of the fifth signal. The fifth signal is a signal of the fifth frequency output by the third terminal of the pen tail when the active pen touches the touch screen.

[0014] A third aspect of this application provides a touch screen, including multiple transmitting electrodes, multiple receiving electrodes intersecting with the transmitting electrodes, and the touch chip; the touch chip is also used to perform the detection method.

[0015] A fourth aspect of this application provides a touch device with an active pen, including an active pen and the touch screen. The active pen is used to output a first frequency signal through a first terminal of the pen tip and a second frequency signal through a second terminal of the pen tip when the pen tip contacts the touch screen; and the active pen is used to output a third frequency signal through the first terminal and a fourth frequency signal through the second terminal when it is suspended above the touch screen.

[0016] It is understood that the active pen detection method of this application, when determining the presence of an active pen on the touch screen based on the detection data frame, reuses the AFE circuit of the touch screen to scan the detection signals of all transmitting and receiving electrodes in the touch screen according to the second scan time, obtains the detection data frames of all transmitting and receiving electrodes, extracts the pen data of the active pen from the detection data frame, obtains the signal amplitude corresponding to all electrodes by demodulating the pen data, and finally obtains the contact state, touch point position or tilt angle of the active pen through the signal amplitude of all electrodes. Thus, the touch screen does not need to design an additional active pen detection circuit to detect the active pen, reducing the manufacturing cost of the touch screen, and enabling touch screens with AFE circuits to realize the touch application of active pen. Attached Figure Description

[0017] Figure 1 This is a schematic block diagram of a touch screen provided in an embodiment of this application.

[0018] Figure 2 This is a flowchart illustrating an active pen detection method provided in an embodiment of this application.

[0019] Figure 3 This is a flowchart illustrating a method for demodulating pen data according to an embodiment of this application.

[0020] Figure 4 This is a schematic block diagram of an active pen provided in an embodiment of this application.

[0021] Figure 5 This is a flowchart illustrating a method for obtaining the contact state, contact point position, and tilt angle of an active pen according to an embodiment of this application.

[0022] Figure 6 This is a flowchart illustrating another method for obtaining the active pen contact state, contact point position, and tilt angle provided in an embodiment of this application.

[0023] Figure 7This is a schematic block diagram of another active pen provided in the embodiments of this application.

[0024] Figure 8 This is a flowchart illustrating the third method for obtaining the active pen contact state, contact point position, and tilt angle provided in the embodiments of this application.

[0025] Figure 9 This is a flowchart illustrating another active pen detection method provided in an embodiment of this application.

[0026] Figure 10 This is a schematic block diagram of a touch screen provided in an embodiment of this application.

[0027] Figure 11 This application provides a schematic block diagram of a touch chip. Detailed Implementation

[0028] It should be noted that in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or sequence.

[0029] It should also be noted that the methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchanged, and some steps can also be deleted.

[0030] With the widespread adoption of smartphones and tablets, more and more applications require styluses for high-precision touch input, leading to increasingly demanding performance requirements for styluses. Active styluses, with their advantages of high precision, low cost, and excellent user experience, have become the most mainstream type of stylus. Unlike passive styluses, active styluses are themselves signal transmitters. The touchscreen's sensors can then receive these signals and calculate the stylus's coordinates, achieving an effect similar to writing on paper. However, current touchscreens supporting active styluses require additional complex detection circuitry, resulting in higher manufacturing costs.

[0031] This application provides an active pen detection method, a touch chip, a touch screen, and a touch device with an active pen, which are used to reduce the manufacturing cost of touch screens and enable touch screens with AFE circuits to also realize active pen touch applications.

[0032] Please refer to Figure 1 , Figure 1 This is a schematic block diagram of a touch screen provided in an embodiment of this application. The touch screen 100 includes multiple transmitting electrodes TX, multiple receiving electrodes RX that are intersected with the transmitting electrodes TX, and multiple AFE circuits 111 (AFE, Analog Front-End).

[0033] In this embodiment, each AFE circuit 111 is connected to one of the transmitting electrodes TX or receiving electrodes RX. The AFE circuit 111 is used to convert the electrical signals of the electrodes into detection signals, which are used to detect finger touch points on the touchscreen 100. When the touchscreen 100 enters the pen detection state, it receives the pen signal from the active pen 200 through the receiving electrode RX and the transmitting electrode TX. The AFE circuit 111 is also used to multiplex the pen signal into a detection signal when the touchscreen 100 enters the pen detection state, so that the touchscreen 100 can detect active pen touch points on the touchscreen 100 based on the detection signal. The touchscreen 100 also includes a touch chip, which includes the AFE circuit 111.

[0034] Next, combine Figure 1 This application introduces an active pen detection method based on an embodiment. Please refer to [link / reference]. Figure 2 Specifically, it includes the following steps: Step S21: Obtain a detection data frame based on the detection signals output by multiple AFE circuits during the first scan time.

[0035] It is understood that when the stylus approaches the touchscreen, the signal transmitting area of ​​the stylus forms a mutual capacitance with the receiving and transmitting electrodes of the touchscreen. This mutual capacitance can be received by the AFE circuit and output as a detection signal. In this embodiment, the touchscreen chip can scan the detection signals output by each AFE circuit according to the first scan time during the current detection cycle to obtain the corresponding detection data frame. For example, a digital sampling circuit can be provided in the touchscreen chip. The digital sampling circuit is connected to the AFE circuit. By scanning the detection signals output by each AFE circuit according to the first scan time, the above-mentioned detection data frame is obtained. The detection data frame is a digital signal.

[0036] Step S22: When it is determined that there is an active pen on the touch screen based on the previous detection data frame, enter the pen detection state.

[0037] In this embodiment, the touch chip can perform pen monitoring during a preset time period of the first scanning time. When the data in the detection data frame during this time period detects the mutual capacitance generated by the active pen and the touch electrode, it is determined that there is an active pen on the touch screen.

[0038] When the touch chip determines that there is an active pen on the touch screen based on the detection data frame of the previous detection cycle, it enters the pen detection state in the current detection cycle to reuse the AFE circuit to convert the pen signal transmitted by the active pen into a detection signal and obtain the corresponding detection data frame.

[0039] In some embodiments, the touch chip can also control the transmitting electrode and / or receiving electrode to transmit uplink signals according to a preset period, the uplink signals being used to interact with the active pen. The process of determining the presence of an active pen on the touch screen based on the previous detection data frame may further include: determining that an active pen is present on the touch screen when a downlink signal of the active pen is detected from the detection data frame.

[0040] In this embodiment, during pen detection, the touchscreen scans the detection signals of all transmitting and receiving electrodes according to a second scan time. The second scan time is less than or equal to the first scan time. For example, within one frame scan time, the touch chip can divide the detection data into different time segments and allocate them to different touch detection states. These touch detection modes include self-capacitance detection, mutual capacitance detection, and the aforementioned pen detection state. Therefore, upon entering the pen detection state, the scan time can be shortened to the second scan time to obtain the required detection data frame, thereby reducing the computational load of the touch chip and improving detection efficiency.

[0041] Furthermore, in pen detection mode, the touch chip can control all AFE circuits to output detection signals to obtain detection data frames for each receiving electrode and each transmitting electrode. For example, in Figure 1 The touch screen 100 shown includes 4 transmitting electrodes TX and 5 receiving electrodes RX, which can obtain 4 detection data frames in the first direction and 5 detection data frames in the second direction, wherein the first direction is the distribution direction of the transmitting electrodes TX and the second direction is the distribution direction of the receiving electrodes RX.

[0042] Step S23: Extract the pen data of the active pen from the current detection data frame.

[0043] In this embodiment, after entering the pen detection state, the touch chip acquires the detection data frame of the current detection period and can extract the pen data of the active pen from the detection data frame. For example, a sampling window with a preset time period can be set in the touch chip, and pen data can be extracted from the detection data frame according to the sampling window.

[0044] It is understandable that if the second scan time is set to be less than the first scan time, and the detection data required to obtain the pen detection status through the second scan time is the detection data frame, then the current detection data frame can be directly used as pen data, thus eliminating the need to set a sampling window to extract pen data from the detection data frame, thereby improving detection efficiency.

[0045] Step S24: Demodulate the pen data to obtain the signal amplitude corresponding to the signal frequency of the active pen.

[0046] In this embodiment, after the touch chip obtains the pen data corresponding to each receiving electrode and each transmitting electrode from multiple detection data frames, it performs digital domain demodulation processing on all the pen data to obtain multiple signal amplitudes corresponding to the signal frequency of the active pen.

[0047] For example, the signal frequency of the active pen can be preset in the touch chip, or the touch chip can obtain the signal frequency of the active pen from the downlink signal of the active pen. Based on the signal frequency, the pen data is first bandpass filtered to obtain the data corresponding to the signal frequency. Then, the data is quadrature demodulated to finally obtain the signal amplitude corresponding to each receiving electrode and each transmitting electrode.

[0048] Step S25: Obtain the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude.

[0049] In this embodiment of the application, after obtaining the signal amplitude corresponding to all electrodes, the touch chip obtains the contact state, touch position or tilt angle of the active pen according to the signal amplitude. For example, the contact state of the active pen is determined according to the maximum value of the signal amplitude, and the touch position and tilt angle are determined according to the distribution of the signal amplitude in the first direction and the second direction.

[0050] It is understood that the active pen detection method of this application embodiment, when determining that an active pen exists on the touch screen based on the detection data frame, reuses the AFE circuit of the touch screen to scan the detection signals of all transmitting electrodes and receiving electrodes in the touch screen according to the second scan time, obtains the detection data frames of all transmitting electrodes and receiving electrodes, extracts the pen data of the active pen from the detection data frame, obtains the signal amplitude corresponding to all electrodes by demodulating the pen data, and finally obtains the contact state, touch point position or tilt angle of the active pen through the signal amplitude of all electrodes. Thus, the touch screen does not need to design an additional active pen detection circuit to detect the active pen, reduces the manufacturing cost of the touch screen, and enables the touch screen with the AFE circuit to realize the touch application of the active pen.

[0051] Please refer to Figure 3 , Figure 3 A flowchart illustrating a method for demodulating pen data, provided in this application embodiment, specifically includes the following steps: Step S31: Obtain the pen data component corresponding to the signal frequency of the active pen from the pen data.

[0052] In this embodiment, a digital bandpass filter corresponding to the signal frequency of the active pen can be set in the touch chip. After obtaining pen data, the touch chip can input the pen data into the digital bandpass filter to obtain the corresponding pen data component output by the digital bandpass filter.

[0053] In some embodiments, when the signal transmission area of ​​the active pen includes multiple terminals for transmitting signals, and each terminal transmits signals at different frequencies, multiple digital bandpass filters corresponding to these signal frequencies can be configured in the touch chip. For example, when the active pen includes two terminals, a pen tip and a pen nib, that transmit signals at different frequencies, two corresponding digital bandpass filters can be configured in the touch chip.

[0054] Step S32: Perform IQ demodulation on multiple pen data components to obtain the signal amplitude corresponding to each signal frequency of the active pen.

[0055] In this embodiment, after obtaining multiple pen data components, the touch chip performs IQ demodulation processing on each pen data component to obtain the signal amplitude corresponding to each signal frequency of the active pen. For example, an IQ demodulator can be provided in the touch chip. After obtaining the pen data components of the current electrode, the pen data components can be input into the IQ demodulator to obtain the I-path and Q-path components of the pen data components, and finally obtain the corresponding signal amplitude based on the I-path and Q-path components.

[0056] Please refer to Figure 4 , Figure 4 This is a schematic block diagram of an active pen provided in an embodiment of this application. The active pen 200 includes a first terminal 210 disposed at the pen tip and a second terminal 220 disposed at the pen head.

[0057] In this embodiment, the active pen 200 outputs a signal at a first frequency via a first terminal 210 and a signal at a second frequency via a second terminal 220 when the pen tip contacts the touchscreen. The pen data components include a first data component at the first frequency and a second data component at the second frequency. The signal amplitude includes a first signal amplitude at the first frequency and a second signal amplitude at the second frequency.

[0058] The active pen 200 also includes a first contact sensor disposed at the pen tip, which is used to detect whether the pen tip is in contact with or hovering over the touchscreen. In some embodiments, the first contact sensor includes a pressure sensor.

[0059] Please refer to Figure 5 , Figure 5 A flowchart illustrating a method for obtaining the contact state, contact point position, and tilt angle of an active pen, as provided in this application embodiment, specifically includes the following steps: Step S51: When the amplitude of the first signal and the amplitude of the second signal are obtained, the active pen is determined to be in pen tip contact state.

[0060] In this embodiment, the touch chip may be equipped with a first frequency digital bandpass filter and a second frequency digital bandpass filter to obtain a first data component and a second data component based on the pen data components. When the touch chip performs IQ demodulation processing on the first and second data components and obtains a non-zero first signal amplitude and a non-zero second signal amplitude, it determines that the active pen is in a pen tip contact state.

[0061] In some embodiments, after the touch chip obtains the first signal amplitude and the second signal amplitude corresponding to all electrodes, it can also determine the largest first target amplitude from all the first signal amplitudes and the largest second target amplitude from all the second signal amplitudes. When it is determined that both the first target amplitude and the second target amplitude are greater than the preset amplitude, the active pen is determined to be in pen tip contact state, so as to avoid misjudgment of pen tip contact state.

[0062] Step S52: Obtain the coordinates of the first terminal on the touch screen based on the amplitude of the first signal, and use them as the touch point position.

[0063] It is understood that when the pen tip touches the touch screen, there is a horizontal distance between the first terminal and each transmitting electrode and receiving electrode. The magnitude of the first signal amplitude follows a normal distribution along the horizontal distance. The maximum value of the normal distribution curve corresponds to the first actual amplitude of the signal output by the first terminal at the first frequency. Therefore, the coordinates of the first terminal can be obtained based on the maximum value of the first signal amplitude, the first actual amplitude, and the coordinate information of the transmitting electrode and the receiving electrode.

[0064] For example, after obtaining the first signal amplitude corresponding to each transmitting electrode and receiving electrode, the touch chip determines the largest first amplitude from the first signal amplitudes of all transmitting electrodes and the largest second amplitude from the first signal amplitudes of all receiving electrodes. Based on the first amplitude, the second amplitude, the coordinate information of the transmitting electrode corresponding to the first amplitude, the coordinate information of the receiving electrode corresponding to the second amplitude, and the aforementioned first actual amplitude, the first terminal coordinates are obtained.

[0065] Step S53: Obtain the coordinates of the second terminal on the touch screen based on the amplitude of the second signal.

[0066] Similarly, there is a horizontal distance between the second terminal and each transmitting electrode and receiving electrode, and the magnitude of the second signal amplitude follows a normal distribution along the horizontal distance. The maximum value of the normal distribution curve corresponds to the second actual amplitude of the signal at the second frequency output by the second terminal. Therefore, the coordinates of the second terminal can be obtained based on the maximum value of the second signal amplitude, the second actual amplitude, and the coordinate information of the transmitting electrode and the receiving electrode.

[0067] For example, after obtaining the second signal amplitude corresponding to each transmitting electrode and receiving electrode, the touch chip determines the largest third amplitude from the second signal amplitudes of all transmitting electrodes and the largest fourth amplitude from the second signal amplitudes of all receiving electrodes. Based on the third amplitude, the fourth amplitude, the coordinate information of the transmitting electrode corresponding to the third amplitude, the coordinate information of the receiving electrode corresponding to the fourth amplitude, and the aforementioned second actual amplitude, the second terminal coordinates are obtained.

[0068] Step S54: Obtain the normal angle and horizontal angle based on the coordinates of the first terminal and the second terminal, and use them as the tilt angle.

[0069] In this embodiment, the angle between the active stylus and the touchscreen includes a normal angle and a horizontal angle. Obtaining the normal angle and horizontal angle based on the first terminal coordinates and the second terminal coordinates specifically includes: inputting the first terminal coordinates and the second terminal coordinates into a preset multidimensional interpolation function to obtain the normal angle and horizontal angle. The multidimensional interpolation function can be preset in the touch chip. The first terminal coordinates include first direction coordinates and second direction coordinates on the touchscreen surface, and the second terminal coordinates also include first direction coordinates and second direction coordinates on the touchscreen surface. The first direction is the distribution direction of the transmitting electrodes, and the second direction is the distribution direction of the receiving electrodes.

[0070] In some embodiments, the active pen 200 is configured to output a signal of a third frequency via a first terminal 210 and a signal of a fourth frequency via a second terminal 220 when hovering above the touchscreen. The pen data components also include a third data component of the third frequency and a fourth data component of the fourth frequency. The signal amplitude includes a third signal amplitude of the third frequency and a fourth signal amplitude of the fourth frequency.

[0071] like Figure 6 As shown, the method for obtaining the active pen contact state, contact point position, and tilt angle also includes the following steps: Step S55: When the amplitude of the third signal and the amplitude of the fourth signal are obtained, determine that the active pen is in a pen tip floating state.

[0072] In this embodiment, the touch chip may further include a third-frequency digital bandpass filter and a fourth-frequency digital bandpass filter to obtain the third and fourth data components based on the pen data components. When the touch chip performs IQ demodulation on the third and fourth data components and obtains non-zero third and fourth signal amplitudes, it determines that the active pen is in a pen tip contact state.

[0073] In some embodiments, the touch chip acquires a first signal amplitude, a second signal amplitude, a third signal amplitude, and a fourth signal amplitude through a digital bandpass filter and IQ demodulation processing. When the first and second signal amplitudes are determined to be non-zero, and the third and fourth signal amplitudes are zero, the active pen is determined to be in a pen tip contact state. When the first and second signal amplitudes are determined to be zero, and the third and fourth signal amplitudes are determined to be non-zero, the active pen is determined to be in a hovering state.

[0074] Please refer to Figure 7 , Figure 7 This is a schematic block diagram of another active pen provided in an embodiment of this application, wherein the active pen 200 further includes a third terminal 230 disposed at the end of the pen.

[0075] In this embodiment, the active pen 200 outputs a signal at a fifth frequency via the third terminal 230 when the pen tip contacts the touchscreen. The pen data component includes a fifth pen data component at the fifth frequency, and the signal amplitude includes a fifth signal amplitude at the fifth frequency. Since the first terminal can be used for the touchscreen's drawing function, the third terminal can be used for the touchscreen's drawing and erasing function.

[0076] In some embodiments, the active pen 200 further includes a second contact sensor disposed at the end of the pen, which is used to detect contact between the pen end and the touchscreen. The second contact sensor includes a pressure sensor.

[0077] like Figure 8 As shown, the method for obtaining the active pen contact state, contact point position, and tilt angle also includes the following steps: Step S56: When the amplitude of the fifth signal is obtained, determine that the active pen is in pen tail contact state.

[0078] In this embodiment, the touch chip may also include a digital bandpass filter with a fifth frequency to obtain a fifth data component based on the pen data components. When the touch chip performs IQ demodulation on the fifth data component and obtains a non-zero fifth signal amplitude, it determines that the active pen is in a pen tail contact state.

[0079] In this embodiment, the touch device defaults to calling the eraser function when the pen tip touches the screen. Of course, more practical operations can be triggered based on system settings or custom application logic, allowing users to switch to preset tools (such as markers, highlighters, shape tools, etc.) with a single click in drawing / note-taking applications.

[0080] In some embodiments, when the touch chip determines that the amplitudes of the first signal, the second signal, the third signal, the fourth signal, and the fifth signal are all zero and remain so for a preset duration, it determines that there is no active pen application, and can exit the pen detection state and enter the normal detection state to perform self-capacitive or mutual-capacitive finger touch detection through the AFE circuit.

[0081] Please refer to Figure 9 , Figure 9 A flowchart illustrating another active pen detection method provided in this application embodiment, specifically including the following steps: Step S91: Obtain a detection data frame based on the detection signals output by multiple AFE circuits during the first scan time.

[0082] Step S92: When it is determined that an active pen exists on the touchscreen based on the previous detection data frame, enter the pen detection state. In the pen detection state, the touchscreen scans the detection signals of all transmitting and receiving electrodes according to the second scan time.

[0083] Step S93: Extract the pen data of the active pen from the current detection data frame.

[0084] Step S94: Demodulate the pen data to obtain the signal amplitude corresponding to the signal frequency of the active pen.

[0085] Step S95: Obtain the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude.

[0086] Step S96: Determine the target transmitting electrode and target receiving electrode corresponding to the local area of ​​the touch screen based on the touch point location and preset quantity.

[0087] In this embodiment, the touch chip first determines the first transmitting electrode and the first receiving electrode closest to the touch point, then selects the remaining transmitting electrodes adjacent to the first transmitting electrode according to a preset number, and selects the remaining receiving electrodes adjacent to the first receiving electrode according to a preset number, thereby determining the target transmitting electrode and the target receiving electrode corresponding to the aforementioned local area.

[0088] Among them, the number of target transmitting electrodes is less than the number of global transmitting electrodes of the touch screen, and the number of target receiving electrodes is less than the number of global receiving electrodes of the touch screen.

[0089] Step S97: Scan the detection signals of the target transmitting electrode and the target receiving electrode according to the second scan time to obtain the next detection data frame.

[0090] It is understandable that since the number of target transmitting electrodes is less than the number of global transmitting electrodes on the touch screen, and the number of target receiving electrodes is less than the number of global receiving electrodes on the touch screen, the number of detection data frames in the next detection cycle can be reduced, thereby reducing the computational load of the touch chip and thus reducing the power consumption of the touch screen.

[0091] Please refer to Figure 10 , Figure 10 This is a schematic block diagram of a touch screen provided in an embodiment of this application. The touch screen 100 includes multiple transmitting electrodes TX, multiple receiving electrodes RX that are intersected with the transmitting electrodes TX, and a touch chip 110.

[0092] In this embodiment, the touch chip 110 includes multiple AFE circuits 111, each AFE circuit 111 being connected to a transmitting electrode TX or a receiving electrode RX. The AFE circuit 111 converts the electrical signals of the electrodes into detection signals, and the touch chip 110 detects finger touches on the touchscreen 100 based on these detection signals. The touch chip 110 is also used to execute the detection methods of any of the above embodiments.

[0093] It is understood that the beneficial effects of the touch screen 100 in the embodiments of this application can be referred to the beneficial effects of the active pen detection method in the foregoing embodiments, and will not be repeated here.

[0094] Please refer to Figure 11 , Figure 11 This application provides a schematic block diagram of a touch chip 110, which includes multiple AFE circuits 111, digital sampling circuits 112, a preset number of digital bandpass filters 113, and a preset number of demodulators 114. Figure 11 The default number of examples is 4.

[0095] In this embodiment, the digital sampling circuit 112 is connected to the AFE circuit 111, the digital bandpass filter 113 is connected to the digital sampling circuit 112, and each demodulator 114 is connected to one of the digital bandpass filters 113.

[0096] The digital sampling circuit 112 is used to scan the detection signal according to the first scan time or the second scan time to obtain a detection data frame. The digital bandpass filter 113 is used to obtain the pen data component corresponding to the signal frequency of the active pen from the pen data. The demodulator 114 is used to perform IQ demodulation processing on the pen data component to obtain the signal amplitude corresponding to the signal frequency of the active pen.

[0097] In this circuit, a digital bandpass filter 113 and a corresponding demodulator constitute a demodulation path, meaning the touch chip 110 includes four demodulation paths. Each demodulation path is used to demodulate and obtain the aforementioned first, second, third, and fourth signal amplitudes. Furthermore, any one of the demodulation paths can be multiplexed to obtain the aforementioned fifth signal amplitude. Based on this circuit architecture, the first, second, third, and fourth signal amplitudes can be acquired simultaneously. Therefore, the processing based on these four signals in the embodiments of this application can be performed simultaneously or sequentially according to the computational arrangement.

[0098] This application embodiment also provides a touch device with an active pen, including an active pen and a touch screen of any of the above embodiments. The active pen is used to output a first frequency signal through a first terminal of the pen tip and a second frequency signal through a second terminal of the pen tip when the pen tip touches the touch screen. The active pen is also used to output a third frequency signal through the first terminal and a fourth frequency signal through the second terminal when it is suspended above the touch screen.

[0099] It is understood that the beneficial effects of the touch chip, touch screen and touch device with active pen in the embodiments of this application can be referred to the beneficial effects of the active pen detection method in the foregoing embodiments, and will not be repeated here.

[0100] This application also provides a computer storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the above-described active pen detection method.

[0101] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer storage medium or transmitted through the computer storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0102] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and its implementation can be combined arbitrarily.

[0103] The embodiments described above are merely preferred embodiments of this application and are not intended to limit the scope of this application. Any modifications and improvements made by those skilled in the art to the technical solutions of this application without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A method for detecting an active pen, applied to a touch screen, the touch screen including multiple transmitting electrodes, multiple receiving electrodes intersecting with the transmitting electrodes, and multiple AFE circuits, each AFE circuit being connected to one of the transmitting electrodes or the receiving electrodes, the AFE circuit being used to convert the electrical signals of the electrodes into detection signals, the detection signals being used to detect finger touches on the touch screen; Its features are, The detection method includes: A detection data frame is obtained based on the detection signals output by the plurality of AFE circuits during the first scan time; When the active pen is determined to be present on the touch screen based on the detection data frame described above, the touch screen enters the pen detection state; wherein, in the pen detection state, the touch screen scans the detection signals of all the transmitting electrodes and the receiving electrodes according to the second scanning time; Extract the pen data of the active pen from the current detection data frame; The pen data is demodulated to obtain the signal amplitude corresponding to the signal frequency of the active pen; The contact state, contact point position, or tilt angle of the active pen are obtained based on the signal amplitude.

2. The detection method as described in claim 1, characterized in that, The second scan time is less than or equal to the first scan time.

3. The detection method as described in claim 1, characterized in that, The active pen includes a first terminal disposed at the pen tip and a second terminal disposed at the pen head, wherein the first terminal and the second terminal are driven by signals of different frequencies; The step of demodulating the pen data to obtain the signal amplitude corresponding to the signal frequency of the active pen includes: Obtain the pen data component corresponding to the signal frequency of the active pen from the pen data; IQ demodulation is performed on multiple pen data components to obtain the signal amplitude corresponding to each signal frequency of the active pen.

4. The detection method as described in claim 3, characterized in that, The active pen is used to output a signal of a first frequency through the first terminal and a signal of a second frequency through the second terminal when the pen tip touches the touch screen. The data component includes a first data component at the first frequency and a second data component at the second frequency; the signal amplitude includes a first signal amplitude at the first frequency and a second signal amplitude at the second frequency. The step of obtaining the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude includes: Upon determining that the first signal amplitude and the second signal amplitude have been obtained, it is determined that the active pen is in a pen tip contact state; The coordinates of the first terminal on the touch screen are obtained based on the first signal amplitude, and are used as the touch point position; The coordinates of the second terminal on the touch screen are obtained based on the amplitude of the second signal. The normal angle and horizontal angle are obtained based on the coordinates of the first terminal and the coordinates of the second terminal, and are used as the tilt angle.

5. The detection method as described in claim 3, characterized in that, The active pen is used to output a signal of a third frequency through the first terminal and a signal of a fourth frequency through the second terminal when it is suspended above the touch screen. The data component also includes a third data component at the third frequency and a fourth data component at the fourth frequency; the signal amplitude includes a third signal amplitude at the third frequency and a fourth signal amplitude at the fourth frequency. The step of obtaining the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude further includes: When the amplitude of the third signal and the amplitude of the fourth signal are obtained, the active pen is determined to be in a pen tip suspension state.

6. The detection method as described in claim 3, characterized in that, The active pen includes a third terminal disposed at the end of the pen, and the active pen is used to output a signal of a fifth frequency through the third terminal when the end of the pen contacts the touch screen; The data component includes the fifth data component at the fifth frequency, and the signal amplitude includes the fifth signal amplitude at the fifth frequency. The step of obtaining the contact state, contact point position, or tilt angle of the active pen based on the signal amplitude includes: When the amplitude of the fifth signal is obtained, the active pen is determined to be in a pen tail contact state.

7. The detection method as described in claim 1, characterized in that, After determining the contact point position of the active pen, the method further includes: Based on the location and preset number of the touch points, determine the target transmitting electrode and the target receiving electrode corresponding to the local area of ​​the touch screen; The detection signals of the target transmitting electrode and the target receiving electrode are scanned according to the second scan time to obtain the next detection data frame.

8. The detection method as described in claim 1, characterized in that, Also includes: The transmitting electrode and / or the receiving electrode are controlled to transmit uplink signals according to a preset cycle. The uplink signals are used to interact with the active pen. The step of determining the presence of the active pen on the touchscreen based on the previously described detection data frame includes: When it is determined that the downlink signal of the active pen is detected from the detection data frame, it is determined that the active pen exists on the touch screen.

9. A touch chip, the touch chip comprising a plurality of AFE circuits, characterized in that, Each of the AFE circuits is connected to one of the transmitting or receiving electrodes of the touch screen. The touch chip also includes a digital sampling circuit, a preset number of digital bandpass filters, and a preset number of demodulators. The digital sampling circuit is connected to the AFE circuit, the digital bandpass filters are connected to the digital sampling circuit, and each demodulator is connected to one of the digital bandpass filters. The digital sampling circuit is used to scan the detection signal according to a first scan time or a second scan time to obtain the detection data frame; The digital bandpass filter is used to obtain the pen data component corresponding to the signal frequency of the active pen from the pen data; The demodulator is used to perform IQ demodulation processing on the pen data components to obtain the signal amplitude corresponding to the signal frequency of the active pen.

10. The touch chip as described in claim 9, characterized in that, A digital bandpass filter and a corresponding demodulator constitute a demodulation path, and the touch chip includes four demodulation paths; Each of the demodulation paths is used to demodulate the data components corresponding to the following four signals to obtain the amplitude of a first signal, a second signal, a third signal, and a fourth signal, wherein the four signals are: The active pen is used to output a first frequency signal through a first terminal of the pen tip and a second frequency signal through a second terminal of the pen tip when the pen tip touches the touch screen; and the active pen is used to output a third frequency signal through the first terminal and a fourth frequency signal through the second terminal when it is suspended above the touch screen.

11. The touch chip as described in claim 10, characterized in that, Any one of the demodulation paths multiplexes the pen data component corresponding to the demodulated fifth signal to obtain the amplitude of the fifth signal. The fifth signal is a signal of the fifth frequency output by the third terminal of the pen tail when the active pen touches the touch screen.

12. A touch screen, characterized in that, It includes multiple transmitting electrodes, multiple receiving electrodes intersecting with the transmitting electrodes, and the touch chip as described in claim 9; The touch chip is also used to perform the detection method as described in any one of claims 1 to 8.

13. A touch device with an active stylus, characterized in that, The device includes an active pen and a touch screen as described in claim 12. The active pen is used to output a first frequency signal through a first terminal of the pen tip and a second frequency signal through a second terminal of the pen tip when the pen tip contacts the touch screen. The active pen is also used to output a third frequency signal through the first terminal and a fourth frequency signal through the second terminal when it is suspended above the touch screen.

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