METHOD FOR IDENTIFYING PALM INPUT TO A DIGITIZER

• US 20130300696A1
• Filed: 05/13/2013
• Published: 11/14/2013
• Est. Priority Date: 05/14/2012
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: HARAN, On, PELEG, Sharon, ZYSKIND, Amir, GERSHFELD, Arthur, BOUMGARTEN, Eyal, LINENBERG, Nadav
• Application Number:
  US13/892,381
• Publication Number:
  US 20130300696A1
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 2203/04106 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 Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• 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
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

A method for classifying input provided to a digitizer sensor includes sampling output over one or more sampling periods, identifying a location of intentional input to the digitizer sensor from the output sampled over the one or more sampling periods, identifying an area of potential palm input based on the identified location of the intentional input, and classifying output detected in the area of the potential palm input as output potentially obtained from undesired input to the digitizer sensor. The area of potential palm input is defined to have a defined spatial relation to the location of the intentional input. The output classified is sampled over one or more sampling periods other than the one or more sampling periods from which the area of potential palm input is identified.

Claims

1. A method for classifying input provided to a digitizer sensor, the method comprising:

sampling output over one or more sampling periods;

identifying a location of intentional input to the digitizer sensor from the output sampled over the one or more sampling periods;

identifying an area of potential palm input based on the identified location of the intentional input, wherein the area of potential palm input is defined to have a defined spatial relation to the location of the intentional input; and

classifying output detected in the area of the potential palm input as output potentially obtained from undesired input to the digitizer sensor, wherein the output classified is sampled over one or more sampling periods other than the one or more sampling periods from which the area of potential palm input is identified.

2. The method of claim 1, wherein the area of potential palm input is updated over subsequent sampling periods responsive to changes in the location of the intentional input.

3. The method of claim 1, wherein the area of potential palm input is defined as a dynamic area that is updated as the location of the intentional input is updated.

4. The method of claim 1, wherein the intentional input to the digitizer sensor is input provided by a stylus.

5. The method of claim 4, comprising determining an orientation of the stylus and identifying the area of potential palm input in relation to the orientation of the stylus.

6. The method of claim 5, wherein determining an orientation of the stylus includes determining a three dimensional orientation of the stylus with respect to the digitizer sensor as identified.

7. The method of claim 4, wherein the area of potential palm input in relation to the orientation of the stylus is defined as an area on the digitizer sensor covered by the stylus and a hand holding the stylus.

8. The method of claim 4, comprising determining a moving direction of the intentional input and defining the area of potential palm input in relation to the moving direction.

9. The method of claim 1, wherein the intentional input is input provided by one or more fingertip touches.

10. The method of claim 9, comprising:

determining an angle of at least one fingertip touch with respect to an axis of the digitizer sensor; and

defining the area of potential palm input in relation to the angle of at least one fingertip touch.

11. The method of claim 9, comprising:

identifying one or more features of the at least one fingertip touch;

identifying a hand structure from the one or more features; and

determining the area of potential palm input responsive to the identified hand structure.

12. The method of claim 9, comprising:

determining the output using more than sensing configuration;

identifying an interaction area on the digitizer sensor that is larger than a threshold size area for identifying palm input; and

defining the area of potential palm input in the vicinity of the interaction area that is larger than a threshold area for identifying palm input.

13. The method of claim 9, comprising sampling output using a self-capacitance detection method and a mutual capacitance detection method, and determining the area of potential palm input responsive to output obtained from both the self-capacitance detection method and the mutual capacitance detection method.

14. The method of claim 9, comprising determining a size of an area over which the intentional input is provided over a plurality of sampling periods, and invalidating the input as intentional input responsive to the rate in the change of size being larger than a pre-defined rate.

15. The method of claim 1, wherein input detected within the area of potential palm input is refrained from being reported to the host.

16. The method of claim 1, wherein input detected within the area of potential palm input is reported to the host as undesired input.

17. The method of claim 1, wherein input detected within the area of potential palm input is associated with a reduced level of confidence that the input is an intentional input provided by fingertip touch.

18. The method of claim 1, wherein the intentional input to the digitizer sensor is one of touch input and hover input.

19. The method of claim 1, wherein a size of the area of potential palm input is a pre-defined.

20. The method of claim 19, wherein the pre-defined size is user specific.

21. A method for classifying input provided to a digitizer sensor, the method comprising:

sampling output over at least two sampling periods;

determining an area of input based on the sampled output;

determining a change in size of the area of input over the at least two sampling periods; and

invalidating the input as intentional input responsive to the change of size being larger than a pre-defined threshold.

22. A method for detecting finger touch to a digitizer sensor, the method comprising:

defining a threshold level of output for identifying a presence of a finger over the digitizer sensor;

determining a change in the digitizer sensor'"'"'s impedance to ground; and

adjusting the threshold level response to the change in the digitizer sensor'"'"'s impedance to ground.

23. The method of claim 22 comprising:

defining ratios between voltage level measured in association with each junction of the digitizer sensor when the junction is touched and a voltage level measured in association with each corresponding junction when the junction is untouched is used to detect touch; and

applying the threshold on the ratios to detect the presence of the finger over the digitizer sensor.