MULTI-PURPOSE STYLUS ANTENNA

• US 20130207925A1
• Filed: 03/16/2012
• Published: 08/15/2013
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Ryshtun, Andriy, Boschee, Jeffrey M.
• Granted Patent: US 8,922,527 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2200/1637 Sensing arrangement for detection of housing movement or orientation, e.g. for controlling scrolling or cursor movement on the display of an handheld computer
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

Methods and apparatuses of a multi-purpose stylus antenna are described. One device includes a processing device comprising a switch, an antenna circuit, and a capacitance sensor. The switch is configured to couple a conductive element between the antenna circuit and the capacitance sensor. The processing device is configured to communicate data to or from a stylus when the switch is coupled to the antenna circuit and to measure capacitance associated with the conductive element when the switch is coupled to the capacitance sensor.

Claims

1. An apparatus comprising:

a capacitive sense array comprising a plurality of sense elements, the plurality of sense elements configured to detect a conductive object proximate to the capacitive sense array; and

a conductive element disposed adjacent to the capacitive sense array, wherein the conductive element is configured to operate as an antenna in a first mode and as an additional capacitive sense element in a second mode.

2. The apparatus of claim 1, wherein the antenna is a stylus antenna in the first mode, and wherein the stylus antenna comprises a radiating element disposed around at least a portion of the capacitive sense array.

3. The apparatus of claim 2, wherein the radiating element comprises a coil disposed around the capacitive sense array.

4. The apparatus of claim 3, wherein the coil is a three-turn coil.

5. The apparatus of claim 2, wherein the radiating element comprises conductive traces disposed a common substrate as the plurality of sense elements of the capacitive sense array.

6. The apparatus of claim 5, wherein the conductive traces are 3-turn silver traces and the capacitive sense array comprises one or more Indium Tin Oxide (ITO) sensors.

7. The apparatus of claim 1, wherein the additional capacitive sense element is configured to operate as a proximity sensor in the second mode.

8. The apparatus of claim 7, further comprising a second proximity sensor.

9. The apparatus of claim 7, further comprising a processing device coupled to the capacitive sense array and the conductive element, wherein the processing device is configured to use the proximity sensor in the second mode to initiate a grip detection algorithm when the processing device detects the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed.

10. The apparatus of claim 7, further comprising a processing device coupled to the capacitive sense array and the conductive element, wherein the processing device is configured to use the proximity sensor in the second mode for edge protection to prevent reporting touch coordinates of the conductive object when the processing device detects the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed.

11. The apparatus of claim 7, further comprising:

a display;

a processing device coupled to the capacitive sense array, the conductive element, and the display; and

a second proximity sensor, wherein the processing device is configured to use the proximity sensor and the second proximity sensor in the second mode for face-down detection to turn off the display when the processing device determines that a mutual capacitance between the proximity sensor and the second proximity sensor is above a first threshold or below a second threshold.

12. The apparatus of claim 7, further comprising a processing device coupled to the capacitive sense array and the conductive element, wherein the processing device is configured to use the additional capacitive sense element in the second mode for edge correction when the processing device detects the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed.

13. The apparatus of claim 1, wherein the conductive object is at least one of an active stylus, a passive stylus, or a finger.

14. A method, comprising:

detecting a conductive object proximate to a capacitive sense array comprising a plurality of sense elements;

communicating data to or from another device using a conductive element disposed adjacent to the capacitive sense array in a first mode at a first time; and

detecting the conductive object proximate to the conductive element in a second mode at a second time.

15. The method of claim 14, wherein the conductive element is configured as a stylus antenna in the first mode and as a proximity sensor in the second mode, wherein the other device is a stylus, and wherein the method further comprises:

communicating data to or from the stylus via the stylus antenna in the first mode;

detecting the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed using the proximity sensor in the second mode; and

initiating a grip detection algorithm when the conductive object is detected proximate to the periphery area to determine whether to prevent reporting of touch coordinates of the conductive object.

16. The method of claim 14, wherein the conductive element is configured as a stylus antenna in the first mode and as a proximity sensor in the second mode, wherein the other device is a stylus, and wherein the method further comprises:

communicating data to or from the stylus via the stylus antenna in the first mode;

detecting the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed using the proximity sensor in the second mode; and

preventing reporting touch coordinates of the conductive object the conductive object is detected proximate to the periphery area.

17. The method of claim 14, wherein the conductive element is configured as a stylus antenna in the first mode and as a proximity sensor in the second mode, wherein the other device is a stylus, and wherein the method further comprises:

communicating data to or from the stylus via the stylus antenna in the first mode;

detecting the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed using the proximity sensor in the second mode;

measuring a mutual capacitance between the proximity sensor and a second proximity sensor for face-down detection; and

turning off a display when the mutual capacitance is above a first threshold or below a second threshold.

18. The method of claim 14, wherein the conductive element is configured as a stylus antenna in the first mode and as a proximity sensor in the second mode, wherein the other device is a stylus, and wherein the method further comprises:

communicating data to or from the stylus via the stylus antenna in the first mode;

detecting the conductive object proximate to a periphery area adjacent to the capacitive sense array in which the proximity sensor is disposed using the proximity sensor in the second mode; and

using a capacitance measured on the proximity sensor for edge correction when the conductive object is detected proximate to the periphery area.

19. A device, comprising

a processing device comprising a switch, an antenna circuit, and a capacitance sensor, wherein the switch is configured to couple a conductive element between the antenna circuit and the capacitance sensor, wherein the processing device is configured to communicate data to or from a stylus when the switch is coupled to the antenna circuit and to measure capacitance associated with the conductive element when the switch is coupled to the capacitance sensor.

20. The device of claim 19, wherein the device further comprises:

an Indium Tin Oxide (ITO) panel comprising ITO sensors coupled to the processing device, wherein the processing device is configured to detect a conductive object proximate to the ITO sensors; and

the conductive element disposed at least partially around the ITO sensors.