Active stylus and capacitive position detection system

Patent metadata

Field	Value
Publication number	US-11397477-B2
Application number	US-202117164676-A
Country	US
Kind code	B2
Filing date	Feb 1, 2021
Priority date	Jul 27, 2011
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

An elongated stylus is configured to be capacitively coupled with a sensor array providing a plurality of electrodes to indicate a position on the sensor array. The stylus includes a housing having an end in an elongated direction of the housing, a conductive tip disposed at least partially extended from the end of the housing, an electrode disposed around the conductive tip and configured to at least partially expose the conductive tip, and a signal transmit drive circuit configured to provide a signal. Control is performed to form an electrical connection between the electrode and a ground and an electrical connection between the electrode and the signal transmit drive circuit when the elongated stylus is activated for capacitive coupling with the sensor array.

First claim

The invention claimed is:

1. An elongated stylus configured to be capacitively coupled with a sensor array in an electronic device, wherein the sensor array provides a plurality of electrodes and is controlled by a sensor controller, to indicate a position on the sensor array, the stylus comprising:
a housing having an end in an elongated direction of the housing;
a first electrode disposed to at least partially extend from the end of the housing;
a second electrode disposed around the first electrode;
a signal transmit drive circuit configured to transmit a stylus signal to the sensor array; and
a stylus controller configured to control transmission of the stylus signal to the sensor array via at least one of the first electrode and the second electrode;
wherein the stylus controller is configured to transmit the stylus signal to the sensor array via the first electrode in response to a sensor signal transmitted from the sensor controller wirelessly and configured to electrically control the second electrode disposed around the first electrode to transmit the stylus signal to the sensor array via the second electrode;
wherein the stylus signal is modulated and distinguishable from the sensor signal that is modulated; and
wherein when the stylus signal is transmitted to the sensor array via the second electrode, the stylus signal is not transmitted to the sensor array via the first electrode.

2. The elongated stylus of claim 1 , wherein the sensor signal is code modulated.

3. The elongated stylus of claim 1 , wherein the stylus controller is configured to synchronize the transmission of the stylus signal to the sensor array with the sensor signal, using a synchronization signal transmitted from the electronic device.

4. The elongated stylus of claim 1 , wherein the stylus controller is configured to synchronize the transmission of the stylus signal with a synchronization signal transmitted using the sensor controller.

5. The elongated stylus of claim 1 , wherein the stylus controller is configured to synchronize the transmission of the stylus signal with a timing data signal transmitted from the electronic device.

6. The elongated stylus of claim 1 , wherein the stylus signal is phase modulated, frequency modulated, amplitude modulated, or code modulated.

7. The elongated stylus of claim 1 , wherein the stylus controller is configured to control the second electrode disposed around the first electrode to selectively transmit the stylus signal via the second electrode and the first electrode.

8. The elongated stylus of claim 7 , wherein the stylus controller is configured to control the second electrode disposed around the first electrode to selectively transmit the stylus signal via the second electrode and the first electrode in synchronization with the sensor signal transmitted from the sensor controller.

9. A capacitive position detection system comprising:
(i) an active stylus configured to be capacitively coupled with a sensor array to indicate a position on the sensor array, the active stylus comprising:
a housing having an end in an elongated direction of the housing;
a first electrode disposed to at least partially extend from the end of the housing;
a second electrode disposed around the first electrode;
a signal transmit drive circuit configured to transmit a stylus signal to the sensor array; and
a stylus controller configured to control transmission of the stylus signal to the sensor array via at least the first electrode and configured to electrically control the second electrode disposed around the first electrode to transmit the stylus signal to the sensor array via the second electrode while the transmission of the stylus signal to the sensor array via the first electrode is not performed; and
(ii) the sensor array in an electronic device, the sensor array including a first set of conductors disposed in a first direction and a second set of conductors disposed in a second direction different from the first direction, controlled by a sensor controller, wherein a finger and the active stylus are detectable on the sensor array based on transmission signals supplied to the first set of conductors and reception signals received in the second set of conductors and based on stylus signals transmitted from the active stylus and received in the first and second sets of conductors,
wherein the sensor controller is configured to transmit a sensor signal to the active stylus wirelessly to enable the stylus controller to transmit the stylus signal via the first electrode of the active stylus to the sensor array in response to the sensor signal, and
wherein the stylus signal is modulated and distinguishable from the sensor signal that is modulated.

10. The capacitive position detection system of claim 9 , wherein the sensor signal is code modulated.

11. The capacitive position detection system of claim 9 , wherein the stylus controller is configured to synchronize the transmission of the stylus signal to the sensor array with the sensor signal, using a synchronization signal transmitted from the electronic device.

12. The capacitive position detection system of claim 9 , wherein the stylus signal is modulated and differentiated from the sensor signal that is code modulated.

13. The capacitive position detection system of claim 9 , wherein the sensor controller is configured to transmit the sensor signal by supplying the transmission signals to the first set of conductors.

14. The capacitive position detection system of claim 9 , wherein the stylus signal is phase modulated, frequency modulated, amplitude modulated, or code modulated.

15. The capacitive position detection system of claim 9 , wherein the stylus controller is configured to control the second electrode disposed around the first electrode to transmit the stylus signal to the sensor array.

16. The capacitive position detection system of claim 10 , wherein the stylus controller is configured to control the second electrode disposed around the first electrode to selectively transmit the stylus signal via the second electrode and the first electrode.

Assignees

• Wacom Co Ltd

Inventors

• Kremin Viktor
• Ryshtun Andriy
• Wright David G

Classifications

• G06F3/0442

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

• G06F3/0383

  Signal control means within the pointing device · CPC title

• G06F3/041

  Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means · CPC title

• G06F2203/04107

  Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds · CPC title

• G06F2203/04106

  Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection · CPC title