IDENTIFYING CONTACTS ON A TOUCH SURFACE

• US 20060238521A1
• Filed: 07/03/2006
• Published: 10/26/2006
• Est. Priority Date: 01/26/1998
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: FingerWorks Limited (Apple Inc.)
• Inventors: WESTERMAN, WAYNE, ELIAS, JOHN G.
• Granted Patent: US 7,619,618 B2
• Time in Patent Office: Days
• 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 for identifying contacts in a proximity image, the method comprising:

finding a shortest path connecting a plurality of contacts, said shortest path passing through each contact once to form an ordered loop; and

identifying and assigning an identity to an innermost contact in the ordered loop from contact and inter-contact features of the innermost contact.

2. The method of claim 1 further comprising identifying and assigning an identity to non-innermost contacts based upon one or more of:

features of the non-innermost contacts, identity of the innermost contact, vertical position relative to identified contacts, and loop ordering.

3. A method for determining which of a user'"'"'s hands causes each of a plurality of surface contacts detected on a multi-touch surface, the method comprising:

defining a template of hand part attractor points on the surface;

partitioning the plurality of surface contacts into at least one left hand cluster and at least one right hand cluster;

assigning identities to one or more contacts within each cluster;

computing for each partitioned cluster an assignment fitness measure; and

choosing the partitioned cluster that has the best assignment fitness measure.

4. The method of claim 3 wherein the attractor points for each hand approximately form a ring.

5. The method of claim 3, wherein each attractor point is placed at an expected position of a corresponding hand part.

6. The method of claim 3, wherein partitioning the plurality of surface contacts further comprises:

constructing approximately vertical contours between each pair of horizontally adjacent contacts; and

constructing a partitioned cluster from each contour by tentatively assigning contacts that are positioned left of the contour to the left hand cluster and contacts right of the contour to the right hand cluster.

7. The method of claim 6 further comprising locking one or more previously identified contacts to one of the left or right hand clusters so to not depend on which side of the contour the one or more previously identified contacts lie.

8. The method of claim 3, wherein each attractor ring is translated, scaled and/or rotated to match previous position estimates for the hand corresponding to the attractor ring.

9. The method of claim 3, wherein the attractor points within each ring are individually offset by previously estimated finger offsets.