Active pen, touch controller, and method of operating active pen

Patent metadata

Field	Value
Publication number	US-12487708-B2
Application number	US-202318357552-A
Country	US
Kind code	B2
Filing date	Jul 24, 2023
Priority date	Sep 7, 2022
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

An active pen adapted for use with a touch pad includes: a receiving circuit configured to generate an internal signal in response to modulating a received uplink signal, a first filter configured to generate a first sampling signal by sampling the internal signal at a first frequency, a second filter configured to generate a second sampling signal by sampling the internal signal at a second frequency unequal to the first frequency, and a timing information generating circuit configured to generate timing information associated with the uplink signal from the internal signal. The receiving circuit is also configured to receive the uplink signal at the first frequency in a first frame, and at the second frequency in a second frame. A noise power calculating circuit is also provided to calculate a noise power level of the uplink signal at each of the first and second frequencies, in response to the first and second sampling signals.

First claim

What is claimed is:

1 . An active pen adapted for use with a touch pad, said active pen comprising:
a receiving circuit configured to generate an internal signal in response to modulating a received uplink signal; a first filter configured to generate a first sampling signal by sampling the internal signal at a first frequency; a second filter configured to generate a second sampling signal by sampling the internal signal at a second frequency unequal to the first frequency; a noise power calculating circuit; a timing information generating circuit configured to generate timing information associated with the uplink signal from the internal signal; and a transmitting circuit configured to: (i) receive information associated with a noise power level at a specific frequency among the first and second frequencies, and (ii) transmit the information that was received as a downlink signal to a device external to the active pen, wherein the receiving circuit is configured to receive the uplink signal at the first frequency in a first frame, and at the second frequency in a second frame, wherein the uplink signal in the first frame and the uplink signal in the second frame include equivalent information for communication, and wherein the noise power calculating circuit is configured to calculate the noise power level of the uplink signal at each of the first and second frequencies, in response to the information within the uplink signal in the first frame, and the information within the uplink signal in the second frame.

2 . The active pen of claim 1 , wherein the active pen further comprises a third filter configured to generate a third sampling signal by sampling the internal signal at a third frequency, which is unequal to the first and second frequencies; wherein the receiving circuit is configured to receive the uplink signal at the third frequency in a third frame; and wherein the uplink signal in the first frame and the uplink signal in the third frame include equivalent information for communication.

3 . The active pen of claim 2 , wherein the noise power calculating circuit is configured to calculate the noise power level of the uplink signal at each of the first and second frequencies and a noise power level of the uplink signal at the third frequency, in response to the first, second and third sampling signals, respectively.

4 . The active pen of claim 3 ,
wherein the transmitting circuit is further configured to receive information associated with the noise power level at the third frequency frequencies, from the noise power calculating circuit.

5 . The active pen of claim 3 , wherein the noise power calculating circuit is configured to select a frequency associated with a relatively greater noise power level from the first, second and third frequencies, and output information associated with the selected frequency.

6 . The active pen of claim 2 , wherein the second frame is a frame following the first frame and the third frame is a frame following the second frame.

7 . The active pen of claim 2 , wherein, in a specific frame between the first frame and the second frame, the receiving circuit is configured to receive an uplink signal having the first frequency; and wherein the uplink signal in the first frame and the uplink signal in the specific frame include identical information that is out of phase relative to each other.

8 . The active pen of claim 2 , wherein the first, second and third filters each comprise a discrete Fourier transform (DFT) filter.

9 . The active pen of claim 1 , wherein the uplink signal includes a preamble code and a command identification (ID).

10 . A touch controller, comprising:
a transmitting circuit configured to transmit, to an active pen, an uplink signal having a first frequency in a first frame, and an uplink signal having a second frequency unequal to the first frequency in a second frame; a receiving circuit configured to receive a downlink signal provided by the active pen, said downlink signal including information on a noise power level associated with at least one of the uplink signal having the first frequency and the uplink signal having the second frequency; and a touch processor configured to control the transmitting circuit based on the information on a noise power level, such that an uplink signal having a frequency that is different from the first and second frequencies is transmitted in a frame after the first and second frames, wherein the uplink signal in the first frame and the uplink signal in the second frame include equivalent information for communication.

11 . The touch controller of claim 10 , wherein the transmitting circuit is further configured to transmit, to the active pen, an uplink signal having a third frequency in a third frame; and wherein the first, second and third frames are spaced apart in time relative to each other.

12 . The touch controller of claim 10 , wherein, in a specific frame between the first frame and the second frame, the transmitting circuit is configured to transmit an uplink signal having the first frequency; and wherein the uplink signal in the first frame and the uplink signal in the specific frame comprise equivalent information, but are out of phase with each other.

13 . The touch controller of claim 10 ,
wherein the transmitting circuit comprises a plurality of transmitters configured to provide a driving signal to driving electrodes within a touch panel; and wherein the receiving circuit comprises a plurality of receivers configured to receive a sensing signal from receiving electrodes within the touch panel.

14 . The touch controller of claim 11 , wherein, in the first, second, and third frames, the uplink signals comprise equivalent information, but have different frequencies.

15 . The touch controller of claim 10 , wherein each of the uplink signals includes a preamble code for synchronizing transmission timing with the active pen and a command identification (ID) for assigning an ID to the active pen.

16 . A method of operating an active pen adapted for use with a touch pad, the method comprising:
receiving a first uplink signal having a first frequency; calculating a power level of noise occurring in the first uplink signal; receiving a second uplink signal having a second frequency unequal to the first frequency; calculating a power level of noise occurring in the second uplink signal; receiving a third uplink signal having a third frequency unequal to the first and second frequencies; calculating a power level of noise occurring in the third uplink signal; and transmitting information associated with the power level of noise at a specific frequency among the first, second, and third frequencies as a downlink signal to a device external to the active pen, wherein the first uplink signal, the second uplink signal, and the third uplink signal include equivalent information for communication, which is used during said calculating the power level of noise occurring in the first, second and third uplink signals.

17 . The method of claim 16 , further comprising transmitting a downlink signal comprising information on the power levels of noise in the first, second, and third uplink signals.

18 . The method of claim 17 , wherein the downlink signal comprises information on a frequency having a greatest noise power level among the first, second, and third frequencies.

19 . The method of claim 16 , wherein the first uplink signal is received in a first frame, the second uplink signal

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Choonghoon
• Kim Kiup
• Baek Seunghoon
• Hwang Yoonion

Classifications

• G06F3/04162

  for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware · CPC title

• H04W4/80

  Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication · CPC title

• G06F3/046

  by electromagnetic means · CPC title

• G06F3/0441

  using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals · CPC title

• G06F3/0442

  using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser · CPC title