Identifying contacts on a touch surface

• US 7,619,618 B2
• Filed: 07/03/2006
• Issued: 11/17/2009
• Est. Priority Date: 01/26/1998
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Westerman, Wayne Carl, Elias, John G.
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Sheng; Tom V
• Application Number:
  US11/428,521
• Publication Number:
  US 20060238521A1
• Time in Patent Office: 1,233 Days
• Field of Search: 345156-184, 715/863
• US Class Current: 345/173
• CPC Class Codes: G06F 18/24137 Distances to cluster centroïds
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• 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 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/0235 using chord techniques G06F3/0234 takes precedence
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/04186 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 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G06F 3/04815 Interaction with a metaphor-based environment or interaction object displayed as three-dimensional, e.g. changing the user viewpoint with respect to the environment or object
• CPC Class Codes: G06F 3/04845 for image manipulation, e.g. dragging, rotation, expansion or change of colour
• CPC Class Codes: G06F 3/0485 Scrolling or panning
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus
• CPC Class Codes: G06V 30/19173 Classification techniques
• CPC Class Codes: G06V 30/1983 Syntactic or structural pattern recognition, e.g. symbolic string recognition
• CPC Class Codes: G06V 40/107 : Static hand or arm
• CPC Class Codes: H03K 17/9622 : using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/960725 : Charge-transfer

Abstract

Apparatus and methods are disclosed for simultaneously tracking multiple finger and palm contacts as hands approach, touch, and slide across a proximity-sensing, multi-touch surface. Identification and classification of intuitive hand configurations and motions enables unprecedented integration of typing, resting, pointing, scrolling, 3D manipulation, and handwriting into a versatile, ergonomic computer input device.

Claims

1. A method comprising:

obtaining a set of contacts detected on or near a sensing surface;

generating a plurality of partitions, each partition representing an assignment of the contacts to a plurality of groups, wherein each group corresponds to a plurality of touch devices;

determining, for each partition, a fit of the assignment of the contacts to one or more constraints of the plurality of touch devices of each group; and

assigning the contacts to the groups according to the partition with the best fit.

2. The method of claim 1, wherein the plurality of groups includes a left hand group and a right hand group, and the plurality of touch devices includes at least one of right-hand fingers corresponding to the right hand group, a right-hand thumb corresponding to the right hand group, and a right-hand palm heel corresponding to the right hand group.

3. The method of claim 1, wherein the plurality of touch devices of each group includes different types of touch devices.

4. The method of claim 1, wherein determining the fit includes calculating a distance metric between the contacts assigned to a group and a template of attractor points of the group.

5. The method of claim 4, wherein the distance metric includes a sum of differences between the attractor points and contacts for each group.

6. The method of claim 4, wherein determining the fit includes one of adjusting the template based on a predetermined translation of a default template, adjusting the template based on a predetermined rotation of a default template, and adjusting the attractor points based on predetermined offset values of a default template.

7. The method of claim 1, wherein determining the fit includes calculating a separation factor representing a separation distance between the groups.

8. The method of claim 7, wherein the separation distance is based on a distance between a first contact in a first group and a second contact in a second group.

9. The method of claim 8, wherein the first and second contacts are nearest contacts of the first and second groups.

10. The method of claim 8, wherein the plurality of touch devices of each group includes different types of touch devices, and the first and second contacts correspond to a same type of touch device.

11. The method of claim 1, wherein the one or more constraints includes at least one of a geometric constraint of the plurality of touch devices of a group and a biomechanical constraint of the plurality of touch devices of a group.

12. The method of claim 1, wherein the set of contacts includes only contacts that physically touch the surface.

13. The method of claim 1, wherein generating a plurality of partitions includes defining one or more contours for each partition.

14. The method of claim 13, wherein the contours include one of substantially linear contours and substantially vertical contours.

15. The method of claim 13, wherein the number of contours defined for each partition is the same.

16. The method of claim 13, wherein generating a plurality of partitions includes defining a contour between a distal end of the surface and a contact nearest to the distal end of the surface.

17. The method of claim 13, wherein generating a plurality of partitions includes discarding a partition in which a number of contacts assigned to a group exceed a maximum number of contacts of the group.

18. The method of claim 1, further comprising:

determining whether a new contact has been detected on or near the surface, wherein the obtaining a set of contacts, generating a plurality of partitions, determining a fit, and assigning the contacts are performed only when the new contact is detected.

19. A computer-readable storage medium storing computer-executable program instructions executable to perform a method comprising:

obtaining a set of contacts detected on or near a sensing surface;

generating a plurality of partitions, each partition representing an assignment of the contacts to a plurality of groups, wherein each group corresponds to a plurality of touch devices;

determining, for each partition, a fit of the assignment of the contacts to one or more constraints of the plurality of touch devices of each group; and

assigning the contacts to the groups according to the partition with the best fit.

20. The computer-readable storage medium of claim 19, wherein determining the fit includes calculating a distance metric between the contacts assigned to a group and a template of attractor points of the group.

21. The computer-readable storage medium of claim 20, wherein determining the fit includes one of adjusting the template based on a predetermined translation of a default template, adjusting the template based on a predetermined rotation of a default template, and adjusting the attractor points based on predetermined offset values of a default template.

22. The computer-readable storage medium of claim 19, wherein determining the fit includes calculating a separation factor representing a separation distance between the groups.

23. The computer-readable storage medium of claim 19, wherein the one or more constraints includes at least one of a geometric constraint of the plurality of touch devices of a group and a biomechanical constraint of the plurality of touch devices of a group.

24. The computer-readable storage medium of claim 19, wherein generating a plurality of partitions includes defining one or more contours for each partition.

25. A touch sensing apparatus comprising:

a sensing surface;

a scanner that detects a set of contacts on or near the sensing surface; and

an identification module that generates a plurality of partitions, each partition representing an assignment of the contacts to a plurality of groups, wherein each group corresponds to a plurality of touch devices, determines, for each partition, a fit of the assignment of the contacts to one or more constraints of the plurality of touch devices of each group, and assigns the contacts to the groups according to the partition with the best fit.

26. The touch sensing apparatus of claim 25, wherein determining the fit includes calculating a distance metric between the contacts assigned to a group and a template of attractor points of the group.

27. The touch sensing apparatus of claim 26, wherein determining the fit includes one of adjusting the template based on a predetermined translation of a default template, adjusting the template based on a predetermined rotation of a default template, and adjusting the attractor points based on predetermined offset values of a default template.

28. The touch sensing apparatus of claim 25, wherein determining the fit includes calculating a separation factor representing a separation distance between the groups.

29. The touch sensing apparatus of claim 25, wherein the one or more constraints includes at least one of a geometric constraint of the plurality of touch devices of a group and a biomechanical constraint of the plurality of touch devices of a group.

30. The touch sensing apparatus of claim 25, wherein generating a plurality of partitions includes defining one or more contours for each partition.