SYSTEM AND METHOD FOR FINGER RESOLUTION IN TOUCH SCREENS

• US 20110310040A1
• Filed: 06/20/2011
• Published: 12/22/2011
• Est. Priority Date: 06/21/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: BEN-SHALOM, Itamar, Garfinkel, Gadi, Gershfeld, Arthur
• Granted Patent: US 8,913,018 B2
• 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 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

Abstract

System and methods for determining multiple interactions with a digitizer sensor are provided. Entries in a matrix may be provided based on measured and reference values associated with junctions in a digitizer sensor. An entry associated with at least two extreme values related to respective at least to dimensions of the digitizer sensor may be located. A junction associated with the located entry may be designated as an interaction point. In some embodiments, one or more interactions may be determined using a topographical-like evaluation of interactions.

Claims

1. A method for identifying a plurality of interactions with a digitizer sensor, the method comprising:

assigning a set of values to a respective a set of entries of a relative magnitude matrix according to a set of measured values, the set of values corresponding to a respective set of junctions in the digitizer sensor, wherein a value corresponding to a junction is calculated based on relating a measured value of the junction to a reference value associated with the junction;

determining an interaction threshold;

a. determining a set of entries in the relative magnitude matrix having values above the interaction threshold;

b. determining at least one subset of entries in the set, the subset associated with a continuous area of the digitizer sensor;

c. for each of the at least one subset of entries;

if the continuous area is associated with a predefined arrangement of junctions, indicating the continuous area as an interaction area; and

if the continuous area is larger than a predefined size, increasing the interaction threshold by an amount and repeating steps a, b and c.

2. The method of claim 1, comprising repeating steps a, b and c until a continuous area having a substantially predefined shape is identified.

3. The method of claim 1, comprising repeating steps a, b and c until a maximal number of iterations has been reached.

4. The method of claim 1, comprising determining the interaction threshold based on the set of values corresponding to the respective set of junctions, and repeating steps a, b and c.

5. The method of claim 1, comprising determining the continuous area is smaller than a predefined size and ignoring the continuous area in a determination of an interaction parameter.

6. The method of claim 1, comprising ignoring the continuous area based on at least one of:

values associated with junctions associated with the continuous area, a presence of larger continuous area, a presence of a number of continuous area within a predefined size area and a distance of the continuous area from an identified pattern.

7. A method for identifying a plurality of interactions with a digitizer sensor, the method comprising:

receiving a set of entries of a relative magnitude matrix according to a set of values, the set of values corresponding to a respective set of junctions in the digitizer sensor, wherein a value corresponding to a junction is calculated based on relating a measured value of the junction to a reference value associated with the junction;

determining an interaction threshold;

a. determining a set of entries in the relative magnitude matrix having values below the interaction threshold;

b. determining at least one subset of entries in the set, the subset associated with a continuous area of the digitizer sensor; and

c. for each of the at least one subset of entries;

if the continuous area is associated with a predefined arrangement of junctions, indicating the continuous area as an interaction area; and

if the continuous area is larger than a predefined size, decreasing the interaction threshold by an amount and repeating steps a, b and c.

8. The method of claim 7, comprising determining the interaction threshold based on the set of values corresponding to the respective set of junctions, and repeating steps a, b and c.

9. A method for identifying a plurality of interactions with a digitizer sensor, the method comprising:

providing a set of entries in a relative magnitude matrix according to a set of values, the set of values corresponding to a respective set of junctions in the digitizer sensor, wherein a value corresponding to a junction is based on relating a measured value of the junction to a reference value associated with the junction; and

identifying at least one junction as a location of a touch point based on locating an entry in the relative magnitude matrix associated with at least two extreme values related to at least two dimensions of the digitizer sensor.

10. The method of claim 9, comprising:

detecting a first pattern based on a first set of entries in the matrix, said entries associated with a respective set of values, wherein each one of said values is smaller than a first threshold value;

determining a second threshold value based on a parameter related to the first pattern; and

detecting a second pattern included in the first pattern based on the second threshold.

11. The method of claim 10, wherein if a second pattern can not be detected then identifying the first pattern as an interaction of a human palm.

12. The method of claim 9, further comprising determining a center of mass for an interaction based on values of entries with a predefined proximity to an entry associated with at least two extreme values related to at least two dimensions of the digitizer sensor.

13. The method of claim 9, wherein identifying a junction associated with at least two extreme values related to at least two dimensions of the digitizer sensor comprises:

identifying at least one group of entries in the relative magnitude matrix by detecting a subset of values associated with a contiguous subset of junctions on a conductive line in the digitizer sensor, wherein each of the values in the subset is below an interaction threshold value; and

for each of the at least one group;

setting an entry preceding the group and an entry following the group to a value exceeding or equal to the interaction threshold value;

determining an entry associated with a minimal value in the group;

locating an entry associated with a value that is higher than the minimal value by at least a first predefined threshold value, and setting the value of the entry to a value exceeding or equal to the interaction threshold value;

if a new group is created, scheduling to process the new group; and

deleting a false minimum created by setting the value of the entry.

14. The method of claim 13, wherein determining an entry associated with a minimal value comprises verifying that the minimal value is lower than the interaction threshold value by at least a second predefined threshold value.

15. The method of claim 9, wherein locating an entry associated with at least two extreme values related to at least two dimensions of the digitizer sensor comprises:

identifying at least one group of entries associated with a respective group of values and associated with a contiguous subset of junctions on a conductive line in the digitizer sensor, wherein each of the values in the group is above an interaction threshold value; and

for each of the at least one group;

setting an entry preceding the group and an entry following the group to a value below or equal to the interaction threshold value;

determining an entry associated with a maximal value in the group;

locating an entry associated with a value that is lower from the maximal value by at least a first predefined threshold value, and setting the value of the entry to a value below or equal to the interaction threshold value;

if a new group is created, scheduling to process the new group; and

deleting a false maximum created by setting the value of the entry.

16. The method of claim 15, wherein locating an entry associated with a maximal value comprises verifying that the maximal value is higher than the interaction threshold value by at least a second predefined threshold value.

17. The method of claim 9, wherein the plurality of interactions are interactions selected from the list consisting of:

a finger touch, a finger hover, an object touch, and an object hover.

18. An article comprising a non-transitory computer-readable storage medium, having stored thereon instructions, that when executed on a computer, cause the computer to:

provide a set of entries in a relative magnitude matrix according to a set of values, the set of values corresponding to a respective set of junctions in a digitizer sensor, wherein a value corresponding to a junction is based on relating a measured value of the junction to a reference value associated with the junction; and

identify at least one junction as a location of a touch point based on locating an entry in the relative magnitude matrix associated with at least two extreme values related to at least two dimensions of the digitizer sensor.

19. The article of claim 18, wherein the instructions when executed further result in:

detecting a first pattern based on a first set of entries in the matrix, said entries associated with a respective set of values, wherein each one of said values is smaller than a first threshold value;

determining a second threshold value based on a parameter related to the first pattern; and

detecting a second pattern included in the first pattern based on the second threshold.

20. The article of claim 19, wherein if a second pattern can not be detected then identifying the first pattern as an interaction of a human palm.

21. The article of claim 18, wherein the instructions when executed further result in:

determining a center of mass for an interaction based on values of entries with a predefined proximity to an entry associated with at least two extreme values related to at least two dimensions of the digitizer sensor.