TOUCH OBJECT DETECTION FOR TOUCH SENSORS

• US 20170228062A1
• Filed: 02/10/2016
• Published: 08/10/2017
• Est. Priority Date: 02/10/2016
• Status: Active Application

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Brunet, Samuel, Hristov, Luben, Collins, Richard, Thaler, Stephan
• Application Number:
  US15/040,889
• Publication Number:
  US 20170228062A1
• Time in Patent Office: Days
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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

In one embodiment, a system includes one or more processors and one or more memory units storing logic. The logic is configured to, when executed by the processors, cause the processors to perform operations including detecting a position of a touch object within an area of a touch sensor during a period of time when an injected signal is present on one or more of the plurality of electrodes of the touch sensor. The injected signal is generated by a signal source and electrically coupled to the touch sensor through a source electrode distinct from the plurality of electrodes of the touch sensor. The operations further include identifying a source of the touch object based at least in part on a proximity of the injected signal present on one or more of the plurality of electrodes to the detected position of the touch object.

Claims

1. A system comprising:

a touch sensor comprising a plurality of electrodes distributed across an area of the touch sensor;

a source electrode embedded in a chair, the source electrode connectable to a signal source, the source electrode positioned to inject one or more signals generated by the signal source through an occupant of the chair to one or more of the electrodes of the touch sensor when the occupant of the chair is electrically coupled to the area of the touch sensor; and

a touch controller configured to;

detect a position of a touch object within the area of the touch sensor during a period of time when an injected signal generated by the signal source is present on one or more of the plurality of electrodes; and

determine whether the touch object is associated with the occupant of the chair based at least in part on a proximity of the injected signal present on one or more of the plurality of electrodes to the detected position of the touch object.

2. The system of claim 1 wherein the electrical coupling of the occupant of the chair to the area of the touch sensor comprises a capacitive coupling.

3. The system of claim 1 wherein the electrical coupling of the occupant of the chair to the area of the touch sensor comprises a galvanic coupling.

4. An apparatus comprising:

one or more processors; and

one or more memory units coupled to the one or more processors, the one or more memory units collectively storing logic configured to, when executed by the one or more processors, cause the one or more processors to perform operations comprising;

detecting a position of a touch object within an area of a touch sensor during a period of time when an injected signal is present on one or more of a plurality of electrodes of the touch sensor, the injected signal generated by a signal source and electrically coupled to the touch sensor through a source electrode distinct from the plurality of electrodes of the touch sensor; and

identifying a source of the touch object based at least in part on a proximity of the injected signal present on one or more of the plurality of electrodes to the detected position of the touch object.

5. The apparatus of claim 4 wherein the logic is further configured to, when executed by the one or more processors, cause the one or more processors to detect the position of the touch object by performing operations comprising:

acquiring, from a first electrode of the plurality of electrodes, a first signal and a second signal; and

processing the first and second signals to suppress the injected signal.

6. The apparatus of claim 5 wherein the second signal is acquired within a predetermined time from the acquisition of the first signal and has a polarity that is an inverse of a polarity of the first signal.

7. The apparatus of claim 4 wherein:

the injected signal has a dominant frequency; and

the logic is further configured to, when executed by the one or more processors, cause the one or more processors to perform operations comprising detecting the presence of the dominant frequency on one or more of the plurality of electrodes to determine the proximity of the injected signal present on one or more of the plurality of electrodes to the detected position of the touch object.

8. The apparatus of claim 7 wherein the logic is further configured to, when executed by the one or more processors, cause the one or more processors to perform operations comprising processing a signal acquired from one or more of the plurality of electrodes using a frequency sensitive algorithm to detect the presence of the dominant frequency on one or more of the plurality of electrodes.

9. The apparatus of claim 4 wherein:

the source electrode is embedded in a chair; and

the logic is further configured to, when executed by the processor, perform operations comprising identifying the source of the touch object by determining whether the touch object is associated with an occupant of the chair.

10. The apparatus of claim 4 wherein the electrical coupling of the injected signal to the touch sensor comprises a galvanic coupling.

11. The apparatus of claim 4 wherein the electrical coupling of the injected signal to the touch sensor comprises a capacitive coupling.

12. A method comprising:

detecting a position of a touch object within an area of a touch sensor during a period of time when an injected signal is present on one or more of the plurality of electrodes of the touch sensor, the injected signal generated by a signal source and electrically coupled to the touch sensor through a source electrode distinct from the plurality of electrodes of the touch sensor; and

selecting, after detecting the position of the touch object, an action from a predetermined set of actions based at least in part on the presence of the injected signal during the period of time.

13. The method of claim 12 wherein the selected action comprises disregarding a detected touch.

14. The method of claim 12 wherein the selection of the action from the predetermined set of actions is further based at least in part on proximity of the injected signal to the detected position of the touch object.

15. The method of claim 12 wherein detecting the position of the touch object comprises:

acquiring, from a first electrode of the plurality of electrodes, a first signal and a second signal from a first electrode of the plurality of electrodes; and

processing the first and second signals to suppress the injected signal.

16. The method of claim 15 wherein the second signal is acquired within a predetermined time from the acquisition of the first signal and has a polarity that is an inverse of a polarity of the first signal.

17. The method of claim 14 wherein the injected signal has a dominant frequency, and further comprising determining the proximity of an injected signal present on one or more of the plurality of electrodes to the detected position of the touch object by detecting the presence of the dominant frequency on one or more of the plurality of electrodes.

18. The method of claim 17 wherein detecting the presence of the dominant frequency on one or more of the plurality of electrodes comprises processing a signal acquired from one or more of the plurality of electrodes using a frequency sensitive algorithm.

19. The method of claim 12 wherein the source electrode is embedded in a chair, and further comprising identifying the source of the touch object by determining whether the touch object is associated with an occupant of the chair.