A capacitive stylus device

Abstract

This invention relates to a capacitive stylus device. The capacitive stylus device includes a drive receiving circuit, a pen tip conductive structure, and a pen tail conductive interface connected to the drive receiving circuit. The drive receiving circuit outputs downlink signals to the pen tip and pen tail conductive structures. These downlink signals are received by a capacitive touchscreen. The capacitive touchscreen detects and calculates the writing position of the capacitive stylus device by sensing the position of the downlink signals. This invention, by incorporating two independent receiving / transmitting units and using independent receiving parameters, enables the pen tip and pen tail to simultaneously receive uplink signals. This significantly accelerates the response speed of the active pen with a tail electrode in receiving uplink signals. It also allows for independent adjustment of the output voltage of the pen tip and pen tail, ensuring that the signal strength of the pen tip and pen tail remains consistent. This is beneficial for the capacitive touchscreen to receive downlink signals with the same signal strength, thereby reducing power consumption.

Description

Technical Field

[0001] This invention relates to the field of touch control, and more particularly to a capacitive stylus device. Background Technology

[0002] Currently, active capacitive pens (referred to as active pens) are finding increasingly diverse applications, penetrating into laptops, e-readers, and mobile phone login scenarios. Active pens, primarily based on bidirectional protocols, offer a superior user experience. They receive uplink signals from tablet devices and then transmit high-voltage signals, enabling bidirectional interaction. However, to meet customers' writing needs, the pen's end also needs to support active pen functionality. But implementing a bidirectional protocol for receiving signals at the pen's end is challenging; therefore, how to enable active pen functionality at the pen's end is a problem that requires current consideration. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a capacitive stylus device that solves the deficiencies of the prior art.

[0004] The objective of this invention is achieved through the following technical solution: a capacitive stylus device, the capacitive main control stylus device including a drive receiving circuit, and a pen tip conductive structure and a pen tail conductive structure connected to the drive receiving circuit;

[0005] The driving receiving circuit outputs downlink signals to the pen tip conductive structure and the pen tail conductive structure. These downlink signals are received by the capacitive touch screen. The capacitive touch screen detects and calculates the writing position of the capacitive stylus device by sensing the position of the downlink signals.

[0006] The capacitive stylus device operates in a time-division multiplexing mode, receiving mode and transmitting mode. During writing, the capacitive touch screen sends uplink signals into space. The capacitive stylus device first operates in receiving mode to receive the uplink signals and then switches to transmitting mode to send downlink signals. This allows the capacitive touch screen to detect and identify the signal position of the capacitive stylus device, thereby completing two-way interaction.

[0007] The driving receiving circuit includes two independent receiving units and transmitting units, as well as a processor. One receiving unit and transmitting unit is connected to the pen tip conductive structure, and the other receiving unit and transmitting unit is connected to the pen tail conductive structure. Both sets of receiving units and transmitting units are connected to the processor.

[0008] The uplink signal sent by the capacitive touch screen enters the pen tip conductive structure and the pen tail conductive structure, and is then amplified, converted from analog to digital and decoded by the receiving unit before being sent to the processor. The transmitting unit converts the signal from digital to analog and generates the reference voltage required for the digital-to-analog conversion. Based on the digital value output by the processor, it generates the waveform required by the protocol and transmits it to the pen tip conductive structure and the pen tail conductive structure to form the downlink signal.

[0009] The receiving unit includes a DC blocking capacitor, a variable gain amplifier, an analog-to-digital converter, and a decoder connected in sequence. The uplink signal emitted by the capacitive touch screen enters the pen tip conductive structure and the pen tail conductive structure, and then enters the variable gain amplifier through the DC blocking capacitor. The variable gain amplifier controls the amplification factor of the signal. After amplification, the signal enters the analog-to-digital converter to convert the analog signal into a digital signal. The digital signal enters the decoder to obtain the decoding result of the uplink signal, and then sends it to the processor.

[0010] The transmitting unit includes a digital-to-analog converter and a boost unit connected thereto; the boost unit generates a high voltage as a reference voltage for the digital-to-analog converter and generates the waveform required by the protocol according to the digital value output by the processor, which is transmitted to the pen tip conductive structure and the pen tail conductive structure to form a downlink signal.

[0011] The processor compares the decoding results of the two uplink signals to determine which uplink signal is stronger, and then connects to the transmitting unit corresponding to the one with the stronger uplink signal.

[0012] When a capacitive stylus device sends a downlink signal, whichever of the two receiving units receives the signal first will have its corresponding pen tip conductive structure or pen tail conductive structure transmit the downlink signal.

[0013] The processor adjusts the boost voltage of the boost unit in the two transmitting units, thereby adjusting the reference voltage of the digital-to-analog converter and adjusting the amplitude of its output waveform. This makes the output waveforms of the pen tip conductive structure and the pen tail conductive structure consistent, so as to avoid large differences in the signal amount of the downlink signal received by the capacitive touch screen.

[0014] This invention offers the following advantages: A capacitive stylus device, through the built-in dual independent receiving / transmitting units and the use of independent receiving parameters, enables simultaneous uplink signal reception at both the pen tip and the pen tail. This significantly accelerates the response speed of an active pen with a tail electrode in receiving uplink signals. Furthermore, the output voltage of the pen tip and the pen tail can be independently adjusted, ensuring consistent signal strength between them. This is beneficial for capacitive touchscreens to receive downlink signals with identical signal strength. Compared to traditional solutions that use the same coding voltage at both the pen tip and the pen tail, this method offers higher consistency and reduces power consumption by lowering the coding voltage at the pen tail. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the bidirectional signal interaction of the present invention;

[0017] Figure 3 A schematic diagram of the structure for driving the receiving power supply;

[0018] Figure 4 This is a schematic diagram of the processor comparing signals.

[0019] In the diagram: 101-Capacitive stylus device, 102-Drive receiving circuit, 103-Stylus tip conductive structure, 104-Capacitive touch screen, 105-Downlink signal, 106-Stylus tail conductive structure, 201-Uplink signal, 301-Receiver unit, 302-Transmitter unit, 303-Variable gain amplifier, 304-Analog-to-digital converter unit, 305-Decoder, 306-Processor, 307-DC blocking capacitor, 308-Digital-to-analog converter unit, 309-Boost unit. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of this application provided below with reference to the accompanying drawings is not intended to limit the scope of protection of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The present invention will be further described below with reference to the accompanying drawings.

[0021] This invention specifically discloses a capacitive stylus device that simultaneously receives uplink signals through multiple channels. It enables the pen tip and pen tail to simultaneously receive uplink signals from the tablet device and achieve asynchronous decoding. This ensures that the pen tip and pen tail have independent detection configurations and do not interfere with each other, which greatly improves the response speed of the pen tail electrode and the writing experience.

[0022] like Figure 1 As shown, the capacitive master pen device 101 includes a drive receiving circuit 102, and a pen tip conductive structure 103 and a pen tail conductive structure 106 connected to the drive receiving circuit.

[0023] The driving receiving circuit 102 outputs downlink signals 105 to the pen tip conductive structure 103 and the pen tail conductive structure 106. These downlink signals 105 are received by the capacitive touch screen 104. The capacitive touch screen 104 detects and calculates the writing position of the capacitive stylus device 101 by sensing the position of the downlink signals 105.

[0024] like Figure 2As shown, the capacitive stylus device 101 operates in a time-division multiplexing mode, receiving mode and transmitting mode. During writing, the capacitive touch screen 104 sends an uplink signal 201 into space. The capacitive stylus device 101 first operates in receiving mode to receive the uplink signal 201 and then switches to transmitting mode to send a downlink signal 105. This allows the capacitive touch screen 104 to detect and identify the signal position of the capacitive stylus device 101, thus completing a two-way interaction.

[0025] Furthermore, such as Figure 3 As shown, the driving receiving circuit 102 includes two independent receiving units 301 and transmitting units 302. The receiving unit 301 is responsible for signal reception. The uplink signal 201 emitted by the capacitive touchscreen 104 enters the pen tip conductive structure 103 and the pen tail conductive structure 106, then passes through the DC blocking capacitor 307 and enters the variable gain amplifier 303. The variable gain amplifier can control the signal amplification factor. After amplification, the signal enters the analog-to-digital converter unit 304 (ADC). After passing through the ADC, the analog signal is converted into a digital signal. The digital signal enters the decoder 305 to obtain the decoding result of the uplink signal 201, and is further sent to the processor 306.

[0026] The transmitting unit 302 mainly consists of a digital-to-analog converter 308 and a boost unit 309. The boost unit 309 is mainly used to generate high voltage. In order for the tablet to receive a sufficiently strong pen tip signal, a relatively high transmitting voltage is generally required. The typical transmitting voltage is 10-80V. The high voltage generated by the boost unit 309 serves as the reference voltage for the digital-to-analog converter 308. Based on the digital value output by the processor 306, it generates the waveform required by the protocol and further transmits it to the pen tip conductive structure 103 and the pen tail conductive structure 106 to form a downlink signal 105, which is then sent to the capacitive touch screen 104.

[0027] Furthermore, such as Figure 4 As shown, the processor 306 compares the decoding results of the two uplink signals 201 to determine which uplink signal 201 is stronger. If the uplink signal 201 of the pen tip conductive structure 103 is stronger, then only the transmitting unit 302 connected to the pen tip conductive structure 103 needs to be used; similarly, if the uplink signal 201 of the pen tail conductive structure 106 is stronger, then only the transmitting unit 302 connected to the pen tail conductive structure 106 needs to be used. This allows for precise control over whether the pen tip or pen tail is used for coding, which helps save power. At the same time, since both receiving units 301 are working simultaneously, the one that receives the signal first transmits the downlink signal 105. This method improves the response speed by 100% compared to the traditional pen tip / pen tail time-division detection method, effectively improving the user's writing experience.

[0028] Since the conductive structures 103 at the tip and 106 at the tail of a typical active pen are often designed with different shapes, the MCU can adjust the boost voltage of the boost unit 309 in these two transmitting units 302 to further adjust the reference voltage of the digital-to-analog converter 308, and thus further adjust the amplitude of its output waveform. This makes the output waveforms of the two electrodes relatively consistent, which helps to avoid excessive differences between the signal amounts received by the capacitive touch screen 104 from the tip and tail. Furthermore, the tail electrode is generally larger and can radiate a stronger downlink signal; therefore, power consumption can be reduced by independently lowering the transmission voltage of the tail electrode.

[0029] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and improvements, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A capacitive stylus device, characterized in that: The capacitive stylus device (101) includes a drive receiving circuit (102), and a pen tip conductive structure (103) and a pen tail conductive structure (106) connected to the drive receiving circuit. The driving receiving circuit (102) outputs downlink signals (105) to the pen tip conductive structure (103) and the pen tail conductive structure (106). These downlink signals (105) are received by the capacitive touch screen (104). The capacitive touch screen (104) detects and calculates the writing position of the capacitive stylus device (101) by sensing the position of the downlink signals (105). The driving receiving circuit (102) includes two independent receiving units (301) and transmitting units (302) and a processor (306). One receiving unit (301) and transmitting unit (302) are connected to the pen tip conductive structure (103), and the other receiving unit (301) and transmitting unit (302) are connected to the pen tail conductive structure (106). Both sets of receiving units (301) and transmitting units (302) are connected to the processor (306). The uplink signal (201) sent by the capacitive touch screen (104) enters the pen tip conductive structure (103) and the pen tail conductive structure (106), and is then amplified, converted from analog to digital and decoded by the receiving unit (301) before being sent to the processor (306). The transmitting unit (302) converts the uplink signal from digital to analog and generates the reference voltage required for the digital-to-analog conversion. Based on the digital value output by the processor (306), it generates the waveform required by the protocol and transmits it to the pen tip conductive structure (103) and the pen tail conductive structure (106) to form the downlink signal (105). The transmitting unit (302) includes a digital-to-analog converter (308) and a boost unit (309) connected thereto; the boost unit (309) generates a high voltage as a reference voltage for the digital-to-analog converter (308), and generates the waveform required by the protocol according to the digital value output by the processor (306) and transmits it to the pen tip conductive structure (103) and the pen tail conductive structure (106) to form a downlink signal (105), wherein the high voltage is a voltage of 10V-80V; The processor (306) adjusts the boost voltage of the boost unit (309) in the two-way transmission unit (302), thereby adjusting the reference voltage of the digital-to-analog converter (308) and adjusting the amplitude of its output waveform, so that the output waveforms of the pen tip conductive structure (103) and the pen tail conductive structure (106) are consistent, so as to avoid large differences in the signal amount of the downlink signal (105) received by the capacitive touch screen (104).

2. The capacitive stylus device according to claim 1, characterized in that: The capacitive stylus device (101) operates in a time-division multiplexing mode, receiving mode and transmitting mode. During writing, the capacitive touch screen (104) sends an uplink signal (201) into space. The capacitive stylus device (101) first operates in receiving mode to receive the uplink signal (201) and then switches to transmitting mode to send a downlink signal (105), so that the capacitive touch screen (104) can detect and identify the signal position of the capacitive stylus device (101) to complete bidirectional interaction.

3. The capacitive stylus device according to claim 1, characterized in that: The receiving unit (301) includes a DC blocking capacitor (307), a variable gain amplifier (303), an analog-to-digital converter (304), and a decoder (305) connected in sequence. The uplink signal (201) emitted by the capacitive touch screen (104) enters the pen tip conductive structure (103) and the pen tail conductive structure (106) and then enters the variable gain amplifier (303) through the DC blocking capacitor (307). The variable gain amplifier (303) controls the amplification factor of the signal. After the signal is amplified, it enters the analog-to-digital converter (304) to convert the analog signal into a digital signal. The digital signal enters the decoder (305) to obtain the decoding result of the uplink signal (201) and sends it to the processor (306).

4. A capacitive stylus device according to claim 1, characterized in that: The processor (306) compares the decoding results of the two uplink signals (201) and compares which uplink signal (201) is stronger. The processor (306) is connected to the transmitting unit (302) corresponding to the one with stronger uplink signal (201). When the capacitive stylus device (101) sends downlink signal (105), whichever of the two receiving units (301) receives the downlink signal first, its corresponding pen tip conductive structure (103) or pen tail conductive structure (106) will transmit the downlink signal (105).

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