Fast multi-touch sensor with user identification techniques

• US 10,261,646 B2
• Filed: 11/15/2017
• Issued: 04/16/2019
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Tactual Labs Co.
• Original Assignee: Tactual Labs Co.
• Inventors: Wigdor, Daniel
• Primary Examiner(s): Mandeville, Jason M
• Application Number:
  US15/813,297
• Publication Number:
  US 20180074618A1
• Time in Patent Office: 517 Days
• Field of Search: 345173, 345174
• CPC Class Codes: G06F 2203/0382 Plural input, i.e. interface arrangements in which a plurality of input device of the same type are in communication with a PC
• 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 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/03545 Pens or stylus
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• 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

A method and system for distinguishing between sources of simultaneous touch events on a touch sensitive device with row conductors and column conductors, the path of each of the row conductors crossing the path of each of the column conductors. Orthogonal signals are simultaneously transmitted on a respective one of the rows. Each column is processed to determine strength of each of the orthogonal signals present thereon. Simultaneous touch locations are associated with a discrete source based on the presence of body-transmitted cross-talk therebetween, as reflected by the determined signal strength corresponding to the touch locations. Alternatively or additionally, a user-coupled signal generator generating another orthogonal signal provides a user-unique signal to the receivers. The signal strength of the user-unique signal is used to associate one or more touch locations with the user coupled to the user-coupled signal generator.

Claims

1. A user-identifying touch sensitive system employing a plurality of unique frequency orthogonal signals having constant spacing (Δ

f) therebetween, and wherein a highest frequency of the plurality of unique frequency orthogonal signals is less than twice the lowest frequency in the plurality of unique frequency orthogonal signals, the system comprising;

user-coupled signal generator operatively connected to a user'"'"'s body, the user-coupled signal generator adapted to couple a unique signal to the user'"'"'s body, the unique signal being within the plurality of unique frequency orthogonal signals; and

touch sensitive device comprising a touch surface comprising a first plurality of signal channels and a second plurality of signal channels positioned in proximity to one another such that a touch event proximate to the touch sensitive device causes a change in coupling between at least one of the first plurality of signal channels and at least one of the second plurality of signal channels;

first signal generator operatively connected to each of the first plurality of signal channels, the first signal generator adapted to simultaneously transmit selected ones of frequencies within the plurality of unique frequency orthogonal signals on respective ones of the first plurality of signal channels, each of the selected ones of the plurality of unique frequency orthogonal signals being different than and orthogonal to each of the other ones of the plurality of unique frequency orthogonal signals and orthogonal to the unique signal;

receiver operatively connected to each of the second plurality of signal channels, the receiver adapted to receive signals from each of the second plurality of signal channels during a plurality of sequential measurement periods (τ

), the measurement periods (τ

) being equal to, or greater than, the reciprocal of the constant spacing (Δ

f) between the plurality of unique frequency orthogonal frequencies;

signal processor adapted to process the signals received during each measurement period (τ

) using a Fast Fourier Transform, thereby calculating at least one measurement for each of the plurality of unique frequency orthogonal signals in the signals received by the receiver during that measurement period; and

the signal processor being further adapted to use the measurements to identify touch location on the touch sensitive device and to associate one or more touch locations with the user'"'"'s body.

2. The system of claim 1, wherein the user-coupled signal generator is a handheld unit, and is operatively connected to a user'"'"'s body by hand holding the unit.

3. The system of claim 2, wherein the handheld unit is one selected from the group consisting of:

stylus;

pen; and

another hand-held object.

4. The system of claim 1, wherein the user-coupled signal generator is operatively connected to the user'"'"'s body through a chair pad.

5. The system of claim 1, wherein the touch sensitive device further comprises a body having an edge, the body supporting at least a portion of the touch surface.

6. The system of claim 5, wherein the user-coupled signal generator is operatively connected to the edge, and is operatively connected to the user when the user is in proximity to the edge.

7. The system of claim 6, wherein the touch sensitive device is a handheld device.

8. The system of claim 1, further comprising:

another user-coupled signal generator operatively connected to another user'"'"'s body, the another user-coupled signal generator adapted to couple another unique signal to the another user'"'"'s body, the another unique signal being within the plurality of unique frequency orthogonal signals;

the signal processor being further adapted to process the signals received during each measurement period (τ

) using a Fast Fourier Transform, thereby calculating a measurement of the another unique signal received during that measurement period;

the signal processor also being further adapted to process the another unique signal to associate one or more touch locations with the another user'"'"'s body.

9. The system of claim 1, further comprising:

second receiver operatively connected to each of the first plurality of signal channels, the second receiver adapted to receive signals from each of the first plurality of signal channels during a plurality of sequential measurement periods; and

wherein the signal processor is further adapted to process the signals from the first plurality of signal channels received during each measurement period (τ

) using a Fast Fourier Transform, thereby calculating at least one measurement for each of the plurality of unique frequency orthogonal signals in the first plurality of signal channels received by the second receiver during that measurement period; and

wherein the signal processor is also further adapted to use the measurements of an another unique signal in the signals from the first plurality of signal channels to associate one or more touch locations with the user'"'"'s body.

10. The system of claim 9, wherein a second signal generator is in the form of a handheld unit, and is operatively connected to a user'"'"'s body by hand holding the unit.

11. The system of claim 9, wherein the handheld unit is one selected from the group consisting of:

stylus;

pen; and

other hand-held object.

12. The system of claim 9, wherein a second signal generator is in the form of a pad under a chair seat.

13. The system of claim 9, wherein the touch sensitive device further comprises a body having an edge, the body supporting at least a portion of the touch surface.

14. The system of claim 13, wherein the user-coupled signal generator is operatively connected to the edge, and is operatively connected to the user when the user is in proximity to the edge.

15. The system of claim 14, wherein the touch sensitive device is a handheld device.