Active stylus, touch control method, and display device

Abstract

The application provides an active handwriting pen, a touch control method and a display device. The active handwriting pen comprises: a handwriting pen body; a capacitive pen tip arranged at one end of the handwriting pen body; a touch sensor in transmission connection with the capacitive pen tip, used for detecting a touch state of the capacitive pen tip; an electromagnetic induction coil arranged in the handwriting pen body; and a control circuit board in electrical connection with the touch sensor and the electromagnetic induction coil, configured to drive the electromagnetic induction coil to receive / transmit electromagnetic touch signals according to a detection result of the touch sensor. The active handwriting pen of the embodiment can simultaneously perform touch control in a capacitive touch mode and an electromagnetic interaction mode during a touch process, which helps to improve the touch control effect.

Description

Technical Field

[0001] This application relates to the field of touch technology, and more particularly to an active stylus, a touch control method, and a display device. Background Technology

[0002] Due to their ease of use, styluses are increasingly in demand in office settings, drawing, and other scenarios. Current styluses mainly include capacitive and electromagnetic types. Capacitive styluses can interfere with the display function; therefore, to avoid affecting normal display, they need to be divided into multiple intervals. This results in discontinuous capacitive touch data, affecting accuracy, especially at high refresh rates. Electromagnetic styluses, on the other hand, can perform continuous recognition, unaffected by display time. However, electromagnetic touch products cannot be controlled by fingers, making them less convenient to use. Therefore, current styluses are generally less convenient to use. Summary of the Invention

[0003] This invention provides an active stylus, a touch control method, and a display device to improve the convenience of handwriting operations via a stylus.

[0004] To solve the above problems, the present invention is implemented as follows:

[0005] In a first aspect, the present invention provides an active stylus, comprising:

[0006] The stylus itself;

[0007] A capacitive pen tip is disposed at one end of the stylus body;

[0008] A touch sensor, connected to the capacitive pen tip, is used to detect the touch state of the capacitive pen tip.

[0009] An electromagnetic induction coil is disposed in the stylus body;

[0010] A control circuit board is electrically connected to the touch sensor and the electromagnetic induction coil. The control circuit board is configured to drive the electromagnetic induction coil to receive / transmit electromagnetic touch signals based on the detection result of the touch sensor.

[0011] In some embodiments, a pen tip holder is also included for holding the capacitive pen tip, the end of the pen tip holder away from the capacitive pen tip abutting against the touch sensor.

[0012] In some embodiments, the electromagnetic induction coil is fixed to the capacitive pen tip between the end of the capacitive pen tip away from the pen tip holder and the pen tip holder.

[0013] Secondly, embodiments of the present invention provide a touch control method applied to a display device, the method comprising the following steps:

[0014] Receive touch operations on the display device;

[0015] The touch operation responds to the touch control command of the stylus, wherein the control command includes capacitive touch command and electromagnetic touch command, and the stylus is an active stylus as described in any one of the first aspects.

[0016] In some embodiments, each frame display period of the display device includes at least one capacitive touch sub-period and at least one electromagnetic touch sub-period, wherein the display device responds to capacitive touch commands during the capacitive touch sub-period and electromagnetic touch commands during the electromagnetic touch sub-period.

[0017] In some embodiments, each frame display period of the display device includes a plurality of capacitive touch sub-periods and a plurality of electromagnetic touch sub-periods arranged alternately in sequence.

[0018] In some embodiments, after responding to a handwritten pen touch control command based on the touch operation, the method further includes:

[0019] The capacitive touch handwriting corresponding to the capacitive touch command and the electromagnetic touch handwriting corresponding to the electromagnetic touch command are identified respectively.

[0020] If the handwriting difference between the capacitive touch handwriting and the electromagnetic touch handwriting is greater than a preset difference threshold, the duration ratio of the capacitive touch sub-segment and the electromagnetic touch sub-segment is iteratively adjusted until the handwriting difference is no greater than the preset difference threshold.

[0021] In some embodiments, after receiving a touch operation on the display device, the method further includes:

[0022] If no valid response is received from the stylus, the touch recognition mode is switched to capacitive touch mode, in which the duration of the electromagnetic touch sub-period in each frame display period of the display device is 0.

[0023] In some embodiments, after receiving a touch operation on the display device, the method further includes:

[0024] Determine the refresh rate of the display device;

[0025] When the refresh rate is greater than a preset frequency threshold, the touch recognition mode is switched to electromagnetic touch mode. In electromagnetic touch mode, the duration of the capacitive touch sub-period in each frame display period of the display device is 0.

[0026] When the refresh rate is not greater than the preset frequency threshold, the step of responding to the pen touch control command written according to the touch operation is executed.

[0027] Thirdly, embodiments of the present invention provide a display device configured to perform the touch control method described in any one of the second aspects.

[0028] The active stylus of this invention, by setting a capacitive pen tip and an electromagnetic induction coil, can simultaneously perform touch control using both capacitive touch and electromagnetic interaction during the touch process, which helps to improve the touch control effect. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of an active stylus in one embodiment of the present invention;

[0031] Figure 2 This is a flowchart illustrating a touch control method according to an embodiment of the present invention;

[0032] Figure 3 This is a touch timing diagram of a display device according to an embodiment of the present invention;

[0033] Figure 4 This is a touch timing sequence in another embodiment of the present invention;

[0034] Figure 5 This is a flowchart illustrating a touch control method in another embodiment of the present invention;

[0035] Figure 6 This is a flowchart illustrating the touch control method in another embodiment of the present invention;

[0036] Figure 7 This is a flowchart illustrating the touch control method in another embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In the embodiments of this invention, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices. Additionally, the use of "and / or" in this application indicates at least one of the connected objects, such as A and / or B and / or C, representing seven possibilities: including A alone, B alone, C alone, and the presence of both A and B, both B and C, both A and C, and the presence of A, B, and C.

[0039] This invention provides an active stylus.

[0040] like Figure 1 As shown, in one embodiment, the active stylus 100 includes a stylus body, one end of which is provided with a capacitive pen tip 101. The capacitive pen tip 101 can transfer charge to the touch block of the touch display panel through voltage coding to achieve capacitive touch control.

[0041] The capacitive pen tip 101 is driven to the touch sensor 104. In one embodiment, the active stylus 100 also includes a pen tip holder 103 for holding and fixing the capacitive pen tip 101. The pen tip holder 103 is connected to the touch sensor 104, with one end of the pen tip holder 103 away from the capacitive pen tip 101 abutting against the touch sensor 104, thereby realizing the drive connection between the capacitive pen tip 101 and the touch sensor 104.

[0042] The touch sensor 104 is used to detect the touch state of the capacitive pen tip 101. It can be understood that when the user performs a touch operation with the stylus, the capacitive pen tip 101 contacts the display panel and applies a force to the pen tip holder 103. In this way, the touch sensor 104 can detect the touch state by detecting the force between itself and the pen tip holder 103.

[0043] In some embodiments, to avoid the touch sensor 104, a sensor protector 105 may be provided to support and protect the touch sensor 104.

[0044] The active stylus 100 also includes an electromagnetic induction coil 102, which can generate a signal frequency through an internal LC (inductor-capacitor) oscillation circuit, and transmit data with the display device through an agreed phase and determine the pen tip landing point by the position of the electromagnetic touch block, and transmit pressure-sensitive information through an agreed protocol, thereby realizing electromagnetic touch control.

[0045] It can be understood that the technical solution of this embodiment adds an electromagnetic induction coil 102 to the pen tip holder 103 to achieve the working process of electromagnetic capacitive dual touch control, and can realize electromagnetic capacitive dual communication.

[0046] In some embodiments, an electromagnetic induction coil 102 is fixed to the capacitive pen tip 101 at one end of the capacitive pen tip 101 away from the pen tip holder 103 and between the pen tip holder 103 and the capacitive pen tip 101.

[0047] The active stylus 100 also includes a control circuit board 106, which is electrically connected to a touch sensor 104 and an electromagnetic induction coil 102. The control circuit board 106 is configured to drive the electromagnetic induction coil 102 to receive / transmit electromagnetic touch signals based on the detection result of the touch sensor 104.

[0048] It should be understood that the active stylus 100 can communicate with the display device via the control circuit board 106, and for example, data transmission can be performed via means including but not limited to Bluetooth.

[0049] Generally, data transmission between the display device and the active stylus 100 is typically performed using a square wave. During the uplink data transmission from the display device to the active stylus 100, 8-bit source code is usually used for DSSS extended instruction transmission. In practice, the manufacturer matches the spread spectrum with the source code bit width to form the extended code, which mainly transmits screen refresh rate information and operating frequency selection, among other things.

[0050] In one embodiment, the specific frequency control selection settings are shown in Table 1 below:

[0051] Table 1: Data Transmission Frequency

[0052] Hea3 Hea2 Hea1 Hea0 F2 F1 F0 Mode Hz Setting 1 * * * * 0 0 0 * 60 Setting 2 * * * * 0 0 1 * 90 Setting 3 * * * * 0 1 0 * 120 Setting 4 * * * * 0 1 1 * 144 Setting 5 * * * * 1 0 0 * 165

[0053] Hea2 and Hea3 are reserved extension instructions. During touch point calibration, the operating frequency is selected based on Hea0 & Hea1, primarily adjusted using the crystal oscillator multiplier and system frequency divider of the active stylus 100. The number and spacing of touch pits are configured according to F0-F1, assigning different pit positions. The first and last bits of the DSSS spread spectrum are used for clock calibration, aligning the clock between the touch device and the touch controller to achieve timed sampling. The voltage is set to a capacitor coding voltage ≥40V, and the electromagnetic touch sensing voltage is TTL level.

[0054] In the downlink data transmission process from the active stylus 100 to the display device, BPSK, QDPSK, and other encoding methods are typically used for transmission. The downlink transmission protocol of the active stylus 100 should generally include pressure sensitivity information, button information, and pen battery level information, with the pressure sensitivity information being transmitted via a dual capacitive and electromagnetic protocol.

[0055] In one embodiment, the capacitive touch protocol and the electromagnetic touch protocol can be set with reference to Tables 2 and 3. Obviously, during implementation, the corresponding touch protocols can be adjusted as needed.

[0056] Table 2: Capacitive Touch Protocol

[0057]

[0058]

[0059] Table 3: Electromagnetic Touch Protocol

[0060]

[0061]

[0062] Interactive control commands can be transmitted within the BLK range, and can also be transmitted according to the reserved positions in the protocol.

[0063] By rationally allocating different data into the electromagnetic capacitor protocol, and with hardware support, all data can be transmitted at double the rate.

[0064] In Tables 2 and 3 above, both capacitive and electromagnetic touch protocols are 3-bit protocols. During implementation, these can be adjusted as needed; that is, the corresponding transmission protocol is not limited to 3 bits. To ensure data transmission stability, each TP pit can transmit 12 bits of data to meet different expansion requirements. This protocol includes a CRC file to ensure the integrity of the data packets. It is important to understand that electromagnetic and capacitive touch protocols can transmit different bits of data for the same function to ensure the transmission of more valid data.

[0065] This invention provides a touch control method applied to a display device.

[0066] like Figure 2 As shown, in one embodiment, the method includes the following steps:

[0067] Step 201: Receive a touch operation on the display device;

[0068] Step 202: Respond to the touch control command of the stylus according to the touch operation, wherein the control command includes capacitive touch command and electromagnetic touch command, and the stylus is an active stylus as described in any one of the first aspects.

[0069] In the technical solution of this embodiment, since the active stylus includes a capacitive pen tip and an electromagnetic induction coil, the active stylus can combine electromagnetic touch and capacitive touch. By utilizing the display segment, electromagnetic and capacitive protocol touch can be alternated, enabling pressure sensitivity complementarity and reporting rate complementarity, thereby increasing the amount of effective data. At the same time, it can also identify disturbances and calibrate handwriting by comparing electromagnetic touch data and capacitive touch data, thereby achieving touch pit adjustment, reducing interference and improving touch control effect.

[0070] In some embodiments, each frame display period of the display device includes at least one capacitive touch sub-period and at least one electromagnetic touch sub-period, wherein the display device responds to capacitive touch commands during the capacitive touch sub-period and electromagnetic touch commands during the electromagnetic touch sub-period.

[0071] like Figure 3 As shown, in this embodiment, the time period for transmitting touch data is divided into several touch sub-time periods, where CT is the capacitive touch sub-time period and ET is the electromagnetic touch sub-time period. The capacitive touch sub-time period needs to be adjusted according to the display time period to avoid affecting the normal display state of the display device. The time period outside the capacitive touch sub-time period can be used as the electromagnetic touch sub-time period for transmitting electromagnetic touch data. In this way, the display time can be fully utilized for the transmission of touch data, realizing the combination of capacitive touch and electromagnetic touch.

[0072] In practice, the display time period of the display device will be divided into several time blocks, which will be used as capacitive touch sub-time periods and electromagnetic touch sub-time periods. The entire touch segment will be processed equally according to the specific display refresh rate.

[0073] In some embodiments, the durations of capacitive touch sub-segments and electromagnetic touch sub-segments are equal, and each frame display period includes multiple capacitive touch sub-segments and multiple electromagnetic touch sub-segments that are alternately set in sequence.

[0074] To achieve capacitive touch functionality, the time setting for capacitive touch sub-segments must be ≤180µs, and the electromagnetic touch time must be evenly divided among the remaining time segments.

[0075] To ensure display quality, the capacitive touch pits are designed with a maximum of 180µs. The operating frequency of the capacitive touch control is 100K to 500K. Theoretically, each touch pit has 18 to 90 square wave signals. Each pit transmits data at a frequency agreed upon by the capacitive pen, but no specific limit is made here.

[0076] Based on the 500K operating frequency of the electromagnetic touch device, the maximum data transmission per slot (evenly distributing the remaining space) is 500 square wave signals. Similarly, the maximum amount of data propagated is calculated based on the touch slot time at different refresh rates. The electromagnetic capacitor can use two different frequencies for data transmission to ensure the maximum touch performance of the product.

[0077] like Figure 3 As shown, in an exemplary embodiment, CT1 to CT13 have a minimum CT touch time period of 10; the touch data window varies depending on the refresh rate. For example, when the refresh rate of the display device is 60Hz or 90Hz, the capacitive touch sub-time period of each frame image can be set to 13; when the refresh rate of the display device is 120Hz, the capacitive touch sub-time period of each frame image can be set to 10.

[0078] Taking 60Hz data transmission as an example, the whole frame time is 16666.7us, the instruction interval is about 614 (+200us margin)us, the CT time is 180*13=2340us, the ET time is 13512.7us, the time occupied by each electromagnetic touch pit is 1039.4us, and a margin of 20us is reserved for each pit.

[0079] This embodiment features a dual-touch setup combining capacitive and electromagnetic touch, ensuring a sufficient touch duration and making full use of the entire display time. The design is compatible with finger touch, and when in contact with other electromagnetic devices, the capacitive-electromagnetic touch protocol allows for full utilization of the entire display time, theoretically doubling the touch data. This significantly improves effective touch data, resulting in a substantial increase in pressure sensitivity and handwriting reporting accuracy.

[0080] In some embodiments, after receiving a touch operation on the display device, the method further includes:

[0081] Determine the refresh rate of the display device;

[0082] When the refresh rate is greater than a preset frequency threshold, the touch recognition mode is switched to electromagnetic touch mode. In electromagnetic touch mode, the duration of the capacitive touch sub-period in each frame display period of the display device is 0.

[0083] When the refresh rate is not greater than the preset frequency threshold, the step of responding to the pen touch control command written according to the touch operation is executed.

[0084] like Figure 4 As shown, for example, in one embodiment, the preset frequency threshold can be 120Hz. When the refresh rate of the display device is greater than 120Hz, such as 144Hz or 165Hz, the duration of each frame is too short to meet the duration requirements of capacitive touch. In this case, the touch mode is switched to electromagnetic scanning. That is, electromagnetic touch is used throughout the entire time, and the reception time of the touch screen is consistent with the data transmission time of the stylus. Clock calibration is performed through the uplink protocol, and each frame is synchronized to ensure stable data reception.

[0085] In some embodiments, after responding to a handwritten pen touch control command based on the touch operation, the method further includes:

[0086] The capacitive touch handwriting corresponding to the capacitive touch command and the electromagnetic touch handwriting corresponding to the electromagnetic touch command are identified respectively.

[0087] If the handwriting difference between the capacitive touch handwriting and the electromagnetic touch handwriting is greater than a preset difference threshold, the duration ratio of the capacitive touch sub-segment and the electromagnetic touch sub-segment is iteratively adjusted until the handwriting difference is no greater than the preset difference threshold.

[0088] like Figure 5 As shown, in the technical solution of this embodiment, capacitive touch and electromagnetic touch respectively transmit effective data.

[0089] When a stylus calibration operation is required, the handwriting data of different transmission methods is first identified and compared. If the difference between the handwriting data of the two methods is large, the touch controller sends a command to the stylus to control the stylus to adjust the working frequency, that is, to adjust the duration of the capacitive touch sub-segment and the electromagnetic touch sub-segment until the handwriting difference fluctuation is minimized. At this time, the touch controller stores the optimal working frequency for subsequent transmission to other touch devices.

[0090] If no calibration is required, the saved default configuration can be used directly.

[0091] like Figure 6 and Figure 7As shown in this embodiment, when the display device detects a touch operation, it sends a search command to find the stylus. If the stylus is found, it interacts with the stylus as described in the above embodiment, such as sending instructions on the display's working status to the stylus. The stylus responds to the instructions, allocates a touch time period according to the agreement, and receives touch data to perform touch control.

[0092] In some embodiments, after receiving a touch operation on the display device, the method further includes:

[0093] If no valid response is received from the stylus, the touch recognition mode is switched to capacitive touch mode, in which the duration of the electromagnetic touch sub-period in each frame display period of the display device is 0.

[0094] If the stylus does not respond effectively, i.e., the stylus does not respond or the response times out, it is confirmed as passive capacitive touch. The display device switches the detection mode. This state can be understood as the user performing a touch operation with their finger, which can be recognized as a conventional capacitive touch operation.

[0095] This invention provides a display device configured to execute any of the touch control methods described above.

[0096] The display device in this embodiment can work with an active stylus to implement the various steps of the above-described touch control method embodiment and achieve the same or similar technical effects, which will not be described in detail here.

[0097] The above description represents the preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles described herein, and these improvements and modifications should also be considered within the scope of protection of this disclosure.

Claims

1. A touch control method applied to a display device, characterized in that, The method includes the following steps: Receive touch operations on the display device; The touch operation responds to the touch control commands of the stylus, wherein the control commands include capacitive touch commands and electromagnetic touch commands; Each frame display period of the display device includes at least one capacitive touch sub-period and at least one electromagnetic touch sub-period. The display device responds to capacitive touch commands during the capacitive touch sub-period and electromagnetic touch commands during the electromagnetic touch sub-period. After responding to the handwritten pen touch control command based on the touch operation, the method further includes: The capacitive touch handwriting corresponding to the capacitive touch command and the electromagnetic touch handwriting corresponding to the electromagnetic touch command are identified respectively. If the handwriting difference between the capacitive touch handwriting and the electromagnetic touch handwriting is greater than a preset difference threshold, the duration ratio of the capacitive touch sub-segment and the electromagnetic touch sub-segment is iteratively adjusted until the handwriting difference is no greater than the preset difference threshold.

2. The method as described in claim 1, characterized in that, Each frame display period of the display device includes multiple capacitive touch sub-periods and multiple electromagnetic touch sub-periods arranged alternately in sequence.

3. The method according to any one of claims 1 to 2, characterized in that, After receiving a touch operation on the display device, the method further includes: If no valid response is received from the stylus, the touch recognition mode is switched to capacitive touch mode, in which the duration of the electromagnetic touch sub-period in each frame display period of the display device is 0.

4. The method according to any one of claims 1 to 2, characterized in that, After receiving a touch operation on the display device, the method further includes: Determine the refresh rate of the display device; When the refresh rate is greater than a preset frequency threshold, the touch recognition mode is switched to electromagnetic touch mode. In electromagnetic touch mode, the duration of the capacitive touch sub-period in each frame display period of the display device is 0. When the refresh rate is not greater than the preset frequency threshold, the step of responding to the pen touch control command written according to the touch operation is executed.

5. The method as described in claim 1, characterized in that, The stylus includes: The stylus itself; A capacitive pen tip is disposed at one end of the stylus body; A touch sensor, connected to the capacitive pen tip, is used to detect the touch state of the capacitive pen tip; An electromagnetic induction coil is disposed in the stylus body; A control circuit board is electrically connected to the touch sensor and the electromagnetic induction coil. The control circuit board is configured to drive the electromagnetic induction coil to receive / transmit electromagnetic touch signals based on the detection result of the touch sensor.

6. The method as described in claim 5, characterized in that, The stylus also includes a pen tip holder for holding the capacitive pen tip, and the end of the pen tip holder away from the capacitive pen tip abuts against the touch sensor.

7. The method as described in claim 6, characterized in that, The electromagnetic induction coil is fixed to the capacitive pen tip between the end of the capacitive pen tip away from the pen tip holder and the pen tip holder.

8. A display device, characterized in that, The display device is configured to perform the touch control method according to any one of claims 1 to 7.

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