Beacon signal detection method, touch input device and active pen
By using energy sliding window and energy accumulation curve techniques in beacon signal detection, the falling edge of the beacon signal can be accurately determined, solving the problem of inaccurate time synchronization caused by noise interference and distance changes, and achieving high-precision synchronization between touch input devices and active pens.
Patent Information
- Application Number
- CN202511746448.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-03-06
AI Technical Summary
In existing technologies, the energy variation of beacon signals is easily affected by noise and the energy variation varies with distance, resulting in low time synchronization accuracy.
By employing energy sliding window technology, the falling edge of the beacon signal is determined by receiving the beacon signal and performing energy accumulation processing, and the peak value of the energy accumulation curve is used to improve the detection accuracy of energy change edges and achieve system clock synchronization.
It improves the detection accuracy of beacon signal energy change edges, enhances time synchronization, and ensures the accuracy of collaborative operation between touch input devices and active pens.
Smart Images
Figure CN121614042A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of touch technology, specifically to a beacon signal detection method, a touch input device, and an active pen. Background Technology
[0002] In an active pen touch system, the touch input device and the active pen are two independent devices with their own system clocks. When the touch input device and the active pen work together, the system clocks of the two devices need to be synchronized to ensure that the working times of the touch input device and the active pen correspond one-to-one.
[0003] Currently, beacon signals are generally used to synchronize two system clocks. For example, a beacon signal is transmitted to a touch input device via an active pen, and the touch input device completes synchronization by detecting the energy change edges (including rising and falling edges) of the beacon signal.
[0004] In existing technologies, signal threshold detection is generally used to detect the energy change edge of beacon signals. However, since the energy change edge of beacon signals is easily affected by noise, and the energy of beacon signals varies with the distance between the active pen and the screen, the accuracy of detecting the energy change edge of beacon signals by setting a signal threshold is low, which in turn affects the time synchronization effect. Summary of the Invention
[0005] In view of this, this application provides a beacon signal detection method, a touch input device, and an active pen to improve the detection accuracy of beacon signal energy change edges, thereby improving the time synchronization effect. The technical solution of this application is as follows: The first aspect of this application provides a method for detecting a beacon signal, comprising: receiving a beacon signal sent by a target device; inputting the beacon signal into a preset energy sliding window to obtain an energy accumulation curve of the beacon signal accumulated through the energy sliding window; determining the falling edge of the beacon signal based on the peak value of the energy accumulation curve; and completing time synchronization with the target device based on the falling edge.
[0006] In one embodiment of this application, the duration of the energy sliding window is consistent with the duration of the beacon signal.
[0007] In one embodiment of this application, the start time of the energy sliding window is earlier than the start time of the beacon signal.
[0008] In one embodiment of this application, determining the falling edge of the beacon signal based on the peak value of the energy accumulation curve includes: determining the falling edge of the beacon signal based on the time point of the peak value of the energy accumulation curve; and determining the rising edge of the beacon signal based on the falling edge and the protocol time length of the beacon signal.
[0009] In one embodiment of this application, the step of synchronizing time with the target device based on the falling edge includes: comparing the moment of the rising edge with the expected moment of the system clock to obtain a time difference; and controlling the counting period of the system clock based on the time difference and a preset proportional-integral filter to synchronize the system clock with the time of the target device.
[0010] In one embodiment of this application, the step of inputting the beacon signal into a preset energy sliding window to obtain an energy accumulation curve of the beacon signal accumulated through the energy sliding window includes: performing down-conversion processing on the beacon signal to obtain a baseband signal; performing modulus calculation processing on the baseband signal to obtain the amplitude signal of the beacon signal; and inputting the amplitude signal into the energy sliding window to obtain the energy accumulation curve.
[0011] A second aspect of this application provides a touch input device, including a touch chip, the touch chip being used in the aforementioned detection method.
[0012] In one embodiment of this application, the target device includes an active pen, which is used to transmit the beacon signal.
[0013] A third aspect of this application provides an active pen, including a controller for performing the aforementioned detection method.
[0014] In one embodiment of this application, the target device includes a touch input device for transmitting the beacon signal.
[0015] A fourth aspect of this application provides a computer storage medium storing a computer program that, when executed by a processor, causes the processor to perform the detection method.
[0016] It is understood that, in this embodiment of the application, the beacon signal is input into a preset energy sliding window, thereby obtaining the energy accumulation curve corresponding to the beacon signal output by the energy sliding window after the accumulation process. The falling edge time of the beacon signal can be accurately determined by the peak value of the energy accumulation curve, thereby improving the detection accuracy of the energy change edge of the beacon signal and thus improving the time synchronization effect. Attached Figure Description
[0017] Figure 1 This is a schematic block diagram of an active pen touch system provided in an embodiment of this application.
[0018] Figure 2 This is a flowchart illustrating a beacon signal detection method provided in an embodiment of this application.
[0019] Figure 3 This is a schematic block diagram of an energy sliding window and a beacon signal provided in an embodiment of this application.
[0020] Figure 4 This is a schematic block diagram of an energy accumulation curve provided in an embodiment of this application.
[0021] Figure 5 This is a flowchart illustrating a method for determining the rising edge of a beacon signal provided in an embodiment of this application.
[0022] Figure 6 This is a flowchart illustrating a method for synchronizing time with a target device according to an embodiment of this application.
[0023] Figure 7 This is a flowchart illustrating a method for obtaining an energy accumulation curve according to an embodiment of this application. Detailed Implementation
[0024] 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.
[0025] 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.
[0026] In an active pen touch system, the touch input device and the active pen are two independent devices with their own system clocks. When the touch input device and the active pen work together, the system clocks of the two devices need to be synchronized to ensure that the working times of the touch input device and the active pen correspond one-to-one.
[0027] Currently, beacon signals are generally used to synchronize two system clocks. For example, a beacon signal is transmitted to a touch input device via an active pen, and the touch input device completes synchronization by detecting the energy change edges (including rising and falling edges) of the beacon signal.
[0028] In existing technologies, signal threshold detection is generally used to detect the energy change edge of beacon signals. However, since the energy change edge of beacon signals is easily affected by noise, and the energy of beacon signals varies with the distance between the active pen and the screen, the accuracy of detecting the energy change edge of beacon signals by setting a signal threshold is low, which in turn affects the time synchronization effect.
[0029] This application provides a beacon signal detection method, a touch input device, and an active pen to improve the detection accuracy of beacon signal energy change edges, thereby improving the time synchronization effect.
[0030] Please refer to Figure 1 , Figure 1 This is a schematic block diagram of an active pen touch system provided in an embodiment of this application, wherein the active pen touch system 100 includes a touch input device 110 and an active pen 120.
[0031] In this embodiment, the active pen 120 can transmit a first signal frame to the touch input device 110, and the touch input device 110 can transmit a second signal frame to the active pen 120. Information interaction between the active pen 120 and the touch input device 110 is completed through the first and second signal frames. The touch input device 110 includes a touchpad and various electronic devices equipped with touchscreens, such as mobile phones and tablets, etc., which are not limited here.
[0032] The first signal frame may include a beacon signal, a positioning signal, and a downlink communication signal, while the second signal frame may include an uplink communication signal. After receiving the first signal frame, the touch input device 110 establishes a unified time slot with the active pen 120 based on the beacon signal, thereby synchronizing its time with the active pen 120. It also detects the touch position of the active pen 120 based on the positioning signal and extracts the interactive information sent by the active pen 120 from the downlink communication signal. Upon receiving the second signal frame, the active pen 120 extracts the interactive information sent by the touch input device 110 based on the uplink communication signal.
[0033] In some embodiments, the first signal frame may include a positioning signal and a downlink communication signal, and the second signal frame may include a beacon signal and an uplink communication signal. That is, the touch input device 110 outputs the beacon signal, and the active pen 120 establishes system time synchronization based on the beacon signal.
[0034] In this embodiment, the active pen 120 internally includes a power supply, a first signal generation module, a first signal detection module, and a pressure detection module. The process by which the touch input device 110 detects the position of the pen tip touch point of the active pen 120 includes: the active pen 120 generates a first signal frame through the first signal generation module; when the pen tip contacts the touch input device 110, the first signal frame is transmitted to the touch electrode at the touch point position on the touch input device 110. The touch electrode of the touch input device 110 and the pen tip of the active pen 120 form a coupling capacitor, thereby generating charge information corresponding to the first signal frame on the touch electrode. Through the detection process of the coupling capacitor, the touch input device 110 can calculate the position of the pen tip of the active pen 120 on the touchscreen. The transmission time, frequency, waveform, and amplitude of the first signal frame are constrained by a protocol, enabling the touch input device 110 to distinguish between the active pen 120 and finger touch, allowing the active pen 120 and finger touch to operate collaboratively.
[0035] The touch input device 110 needs to send a second signal frame to the active pen 120 for communication. For example, transmitting the second signal frame may be to notify the active pen 120 to adjust the parameters of the first signal frame. Additionally, the second signal frame serves as a time window synchronization signal for the active pen 120. For instance, when the microprocessor or touch chip of the touch input device 110 detects interference with the frequency of the first signal frame sent by the active pen 120, the microprocessor or touch chip needs to notify the active pen 120 to perform frequency hopping via the second signal frame to avoid the interfering frequency, thereby improving the signal-to-noise ratio of the first signal frame of the active pen 120 and maintaining the accuracy of pen tip position detection. Specifically, the second signal frame uses a specific encoding method to transmit relevant information, such as the touch chip type, frequency hopping information, and detection window configuration information, through a coupling capacitor formed between the touch electrode and the pen tip of the active pen 120, thereby transmitting the information to the active pen 120 as charge information.
[0036] Please refer to Figure 2 , Figure 2 A flowchart illustrating a beacon signal detection method provided in this application embodiment specifically includes the following steps: Step S21: Receive the beacon signal sent by the target device.
[0037] In this application and subsequent embodiments, the target device is described in detail using an active pen as an example. The touch input device receives a first signal frame sent by the active pen through the touch screen. The touch chip of the touch input device processes the first signal frame and obtains the aforementioned beacon signal from the first signal frame.
[0038] Step S22: Input the beacon signal into the preset energy sliding window to obtain the energy accumulation curve of the beacon signal accumulated through the energy sliding window.
[0039] In this embodiment of the application, after receiving the beacon signal from the target device, the touch chip inputs the beacon signal into a preset energy sliding window, calculates the energy summation of the beacon signal at each moment of the energy sliding window, and obtains the above-mentioned energy summation curve.
[0040] The duration of the energy sliding window is the same as the duration of the beacon signal, and the start time of the energy sliding window is earlier than the start time of the beacon signal. Figure 3 The diagram shown is a schematic block diagram of an energy sliding window and a beacon signal provided in an embodiment of this application.
[0041] The energy sliding window 31 starts at time T1. The beacon signal 32 starts at time T2 and ends at time T4. The energy sliding window 31 slides forward along the timeline from time T1, accumulating the energy of the beacon signal 32 within the window, resulting in the output energy accumulation curve shown below. Figure 4 As shown.
[0042] Step S23: Determine the falling edge of the beacon signal based on the peak value of the energy accumulation curve.
[0043] In the embodiments of this application, Figure 4 In the energy accumulation curve 33 shown, P1 is the energy accumulation of the beacon signal 32 within the window at time T1, P2 is the energy accumulation of the beacon signal 32 within the window at time T2, and P3 is the energy accumulation of the beacon signal 32 within the window at time T3. Since the protocol sets the time length of the energy sliding window 31 to be consistent with the time length of the beacon signal 32, when the energy sliding window 31 slides to the point where the start time coincides with the start time of the beacon signal 32, the energy accumulation of the beacon signal 32 within the window reaches the peak value P2. Therefore, the end time of the beacon signal 32 can be obtained from the time of the peak value P2, which is also the time of the falling edge of the beacon signal 32.
[0044] In some embodiments, the duration of the energy sliding window may differ from the duration of the beacon signal. For example, the duration of the energy sliding window may be shorter than the duration of the beacon signal. In this case, the energy accumulation curve output by the energy sliding window includes a peak plateau and inflection points on both sides of the peak plateau. The falling edge of the beacon signal can be obtained from the time corresponding to the first inflection point. Alternatively, the duration of the energy sliding window may be longer than the duration of the beacon signal. In this case, the energy accumulation curve output by the energy sliding window also includes a peak plateau and inflection points on both sides of the peak plateau. The falling edge of the beacon signal can be obtained from the time corresponding to the later inflection point.
[0045] In this context, the touch chip of the touch input device can determine the falling edge of the beacon signal based on the peak value of the energy accumulation curve, and determine the rising edge of the beacon signal based on the falling edge. For example, the downlink communication signal of the first signal frame transmitted from the active pen to the touch input device includes time parameters specified by the beacon signal protocol. After obtaining the falling edge, the touch chip determines the rising edge of the beacon signal based on the falling edge and the time parameters.
[0046] Step S24: Complete time synchronization with the target device based on the falling edge.
[0047] In this embodiment, after receiving the falling edge of the beacon signal, the touch chip obtains the rising edge of the beacon signal based on the falling edge. After obtaining the rising edge of the beacon signal, the touch chip adjusts the system time of the touch input device according to the timing of the rising edge, thereby synchronizing the system time of the touch input device with the time of the target device. For example, the touch chip compares the timing of the rising edge with the expected timing in the system time to obtain a time difference, and uses this time difference to adjust the system time, ultimately synchronizing the touch input device with the active pen time.
[0048] It is understood that, in this embodiment of the application, the beacon signal is input into a preset energy sliding window, thereby obtaining the energy accumulation curve corresponding to the beacon signal output by the energy sliding window after the accumulation process. The falling edge time of the beacon signal can be accurately determined by the peak value of the energy accumulation curve, thereby improving the detection accuracy of the energy change edge of the beacon signal and thus improving the time synchronization effect.
[0049] Please refer to Figure 5 , Figure 5 A flowchart illustrating a method for determining the rising edge of a beacon signal, provided in this application embodiment, specifically includes the following steps: Step S51: Determine the falling edge of the beacon signal based on the peak time of the energy accumulation curve.
[0050] In the embodiments of this application, such as Figure 3 and Figure 4 As shown, after obtaining the energy accumulation curve based on the energy sliding window, the touch chip can first detect the peak value of the energy accumulation curve, determine the moment of the peak value of the energy accumulation curve, and then determine the falling edge moment of the beacon signal.
[0051] Step S52: Determine the rising edge of the beacon signal based on the falling edge and the protocol duration of the beacon signal.
[0052] In this embodiment of the application, the protocol duration can be obtained from the first signal frame transmitted by the target device. For example, when the target device is an active pen, the touch input device can obtain the protocol duration information from the downlink communication signal of the first signal frame after receiving the first signal frame transmitted by the active pen.
[0053] In this context, the touch chip of the touch input device obtains the rising edge time of the beacon signal by subtracting the falling edge time from the protocol time length.
[0054] Please refer to Figure 6 , Figure 6 A flowchart illustrating a method for synchronizing time with a target device, as provided in this application embodiment, specifically includes the following steps: Step S61: Compare the time of the rising edge with the expected time of the system clock to obtain the time difference.
[0055] In this embodiment, the touch input device is equipped with a system clock, and the touch chip controls the local signal frame of the touch input device according to the count of the system clock. A predetermined time corresponding to the rising edge of the beacon signal can be preset in the system clock. By adjusting the predetermined time to match the rising edge time, the touch input device is synchronized with the active pen, thereby synchronizing the local signal frame of the touch input device with the signal frame of the active pen.
[0056] In this context, the touch chip of the touch input device can compare the rising edge of the beacon signal with the expected time of the system clock after obtaining the rising edge. For example, it can use the difference between the rising edge and the expected time to obtain the time difference between the rising edge and the expected time.
[0057] Step S62: Based on the time difference and the preset proportional-integral filter, the counting period of the system clock is controlled to synchronize the system clock with the time of the target device.
[0058] In this embodiment, after obtaining the time difference, the touch chip uses the time difference as the deviation value of a preset proportional-integral filter and inputs it to the proportional-integral filter to finely adjust the counting period of the system clock, so that the system clock gradually synchronizes with the clock of the active pen, and finally synchronizes the touch input device with the active pen in time.
[0059] Please refer to Figure 7 , Figure 7 A flowchart illustrating a method for obtaining an energy accumulation curve, provided in this application embodiment, specifically includes the following steps: Step S71: Down-convert the beacon signal to obtain the baseband signal.
[0060] In this embodiment of the application, after receiving the beacon signal, the touch chip of the touch input device first performs down-conversion processing on the beacon signal to obtain the baseband signal corresponding to the beacon signal.
[0061] Step S72: Perform modulus calculation on the baseband signal to obtain the amplitude signal of the beacon signal.
[0062] In this embodiment of the application, since the baseband signal is a complex signal, after the touch chip obtains the baseband signal, it performs modulus calculation on the baseband signal to calculate the amplitude of the baseband signal, thereby outputting the amplitude signal of the beacon signal.
[0063] Step S73: Input the amplitude signal into the energy sliding window to obtain the energy accumulation curve.
[0064] In this embodiment, after obtaining the amplitude signal corresponding to the beacon signal, the touch chip inputs the amplitude signal to the energy sliding window to obtain the energy accumulation curve of the beacon signal.
[0065] This application also provides a touch input device, wherein the touch input device includes a touch chip, and the touch chip is used to execute the beacon signal detection method of any of the above embodiments.
[0066] It is understood that when the touch chip of the touch input device performs the beacon signal detection method, the target device includes an active pen, which is used to send beacon signals to the touch input device.
[0067] This application also provides an active pen, wherein the active pen includes a controller, the controller being used to execute the beacon signal detection method of any of the above embodiments.
[0068] It is understood that when the beacon signal detection method is executed together with the control of the active pen, the target device includes a touch input device, which is used to send the beacon signal to the active pen.
[0069] It is understood that the beneficial effects of the aforementioned touch input device or active pen can be compared with the beneficial effects of the beacon signal detection method in the foregoing embodiments, and will not be repeated here.
[0070] This application also provides a computer storage medium storing a computer program that, when executed by a processor, causes the processor to perform the aforementioned beacon signal detection method.
[0071] 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)).
[0072] 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.
[0073] 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 of detecting a beacon signal, characterized by, The method comprises: receiving a beacon signal sent by a target device; inputting the beacon signal into a preset energy sliding window to obtain an energy cumulative curve of the beacon signal after the energy sliding window cumulative sum; determining a falling edge of the beacon signal according to a peak value of the energy cumulative curve; completing time synchronization with the target device according to the falling edge.
2. The detection method of claim 1, wherein, The time length of the energy sliding window is consistent with the time length of the beacon signal.
3. The detection method as described in claim 1, characterized in that, The starting time of the energy sliding window is earlier than the starting time of the beacon signal.
4. The detection method as described in claim 1, characterized in that, The determination of the falling edge of the beacon signal according to the peak value of the energy cumulative curve comprises: determining the falling edge of the beacon signal according to the time point of the peak value of the energy cumulative curve; and determining a rising edge of the beacon signal according to the falling edge and the protocol time length of the beacon signal.
5. The detection method of claim 4, wherein, The time synchronization with the target device according to the falling edge comprises: comparing the time point of the rising edge with an expected time point of a system clock to obtain a time difference value; and feeding back the time difference value and a preset proportional integral filter to control the counting period of the system clock, so as to synchronize the system clock with the time of the target device.
6. The method of claim 1, wherein, The inputting of the beacon signal into the preset energy sliding window to obtain the energy cumulative curve of the beacon signal after the energy sliding window cumulative sum comprises: performing down-conversion processing on the beacon signal to obtain a baseband signal; performing modulus processing on the baseband signal to obtain an amplitude signal of the beacon signal; and inputting the amplitude signal into the energy sliding window to obtain the energy cumulative curve.
7. A touch input device, comprising: The touch chip is used to execute the detection method in any one of claims 1 to 6.
8. The touch input device of claim 7, wherein, The target device comprises a stylus, and the stylus is used to send the beacon signal.
9. A stylus, characterized by The controller is used to execute the detection method in any one of claims 1 to 6.
10. A ballpoint pen as claimed in claim 9, characterized in that The target device comprises a touch input device, and the touch input device is used to send the beacon signal.