Stylus pen control system and stylus pen control method using the same

Abstract

A preferred embodiment of the present invention relates to a stylus control system and a stylus control method thereon, for controlling a display device according to the operation of a stylus. The stylus control method includes: dividing the operation of the display device into an uplink transmission time, a downlink reception time, and a touch time; during the downlink reception time, the display device receives signals from a plurality of receivers and performs demodulation; when the digital data after demodulation of the received signal reaches a threshold value, a phase comparison is performed; and when the phase of the digital data differs from a preset phase value greater than a phase boundary value, the digital data is discarded.

Claims

1. A stylus control method for controlling a display device based on the operation of a stylus, the stylus control method comprising: The operation of the display device is divided into an uplink transmission time, a downlink reception time, and a touch time; During the downlink reception time, the display device receives the downlink signal from multiple receivers and performs demodulation. When the received downlink signal reaches a threshold value, a phase comparison is performed. And when the phase of the digital data differs from a preset phase value from a phase boundary value, the digital data is discarded.

2. The stylus control method according to claim 1 further includes: Record the number of consecutive times the phase of the digital data differs from the preset phase by more than the phase boundary value. And when the number of consecutive discards exceeds a preset threshold, during the uplink transmission time of the display device, the stylus is notified to change the downlink transmission frequency via an uplink transmission signal.

3. The stylus control method according to claim 1, wherein, When the received signal is demodulated and the resulting digital data reaches the threshold value, the phase comparison is performed, including: extracting the phase of the digital data to obtain a first phase; extracting the phase of the previous digital data to obtain a second phase; comparing the first phase and the second phase to obtain a phase difference; and determining whether the phase difference is greater than the preset phase difference.

4. The stylus control method according to claim 1, wherein, When the received signal is demodulated and the resulting digital data reaches the threshold value, the phase comparison is performed, including: extracting the phase of the digital data to obtain a first phase; extracting the phase of the synchronization signal of the digital data to obtain a second phase; comparing the first phase and the second phase to obtain a phase difference; and determining whether the phase difference is greater than the preset phase difference.

5. The stylus control method according to claim 4, wherein, The synchronization signal for this digital data is a preamble signal.

6. The stylus control method according to claim 1, wherein, When the display device receives the signal during the downlink reception time, the signal is received by multiple receivers of the display device and the demodulation is performed, including: performing an analog-to-digital conversion process on the received signal of each of the receivers to obtain a plurality of digital values; and performing a phase key shift demodulation on each of the digital values.

7. The stylus control method according to claim 6, wherein, The phase key shift demodulation of each of the digital values ​​includes: multiplying each of the digital values ​​by a cosine carrier and then performing a low-pass filter to obtain the in-phase component of the received signal of each of the receivers; and multiplying each of the digital values ​​by a sine carrier and then performing a low-pass filter to obtain the right-angle component of the received signal of each of the receivers.

8. A stylus control system, comprising: One stylus; A display device, wherein the operation of the display device is divided into an uplink transmission time, a downlink reception time and a touch time; During the downlink reception time, the display device receives the downlink signal through multiple receivers and demodulates the downlink signal through multiple digital decoding circuits. When the digital data of the demodulated signal reaches a threshold value, a phase comparison is performed. And when the phase of the digital data differs from a preset phase value by more than a phase boundary value, the digital data is discarded.

9. The stylus control system according to claim 8, wherein, The display device includes: a plurality of analog front-end receiving circuits, each preset time, for converting the received signal into a digital value; and digital decoding circuits, correspondingly coupled to each of the analog front-end receiving circuits, for performing a phase key shift demodulation on the received corresponding digital value.

10. The stylus control system according to claim 9, wherein, Each of the digital decoding circuits includes: a co-phase component acquisition circuit for multiplying the corresponding digital value by a digital cosine carrier and then performing low-pass filtering to obtain the in-phase component of the received signal of each of the receivers; and a right-angle component acquisition circuit for multiplying the corresponding digital value by a digital sine carrier and then performing low-pass filtering to obtain the right-angle component of the received signal of each of the receivers.

11. The stylus control system according to claim 9, wherein, The display device further includes: a stylus control circuit coupled to each of the digital decoding circuits, for acquiring coordinate data of a plurality of decoded values ​​in each of the digital decoding circuits that are greater than a threshold value; wherein, when at least one of the decoded values ​​is a first decoded value that is greater than the threshold value, the stylus control circuit compares whether the phase difference between the first decoded value and the preset phase is greater than a phase boundary value.

12. The stylus control system according to claim 11, wherein, The stylus control circuit is further used to record a number of consecutive discards where the phase difference between the first decoded value and the preset phase is greater than the phase boundary value. When the number of consecutive discards is greater than a preset number, the stylus control circuit notifies the stylus to change the downlink transmission frequency during the uplink transmission time of the display device via an uplink transmission signal.

Images