Touchscreen controller with pen and/or finger inputs

• US 5,956,020 A
• Filed: 07/27/1995
• Issued: 09/21/1999
• Est. Priority Date: 07/27/1995
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: MicroTouch Systems, Inc. (3M Company)
• Inventors: Robsky, Steven R., Gehrig, Jay J., Surprenant, Joseph E., D'Amico, Vincent E.
• Primary Examiner(s): Luu, Matthew
• Application Number:
  US08/508,343
• Time in Patent Office: 1,517 Days
• Field of Search: 345/173, 345/174, 345/175, 345/176, 345/177, 345/178, 178/18, 178/19
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment

Abstract

A host computer system employs a touch sensitive display screen (touchscreen) as an input device. A controller receives positional signals from the touchscreen and transmits positional digital values indicative of (X, Y) coordinates of the point of contact of a touch device upon the touchscreen. The touch device may take the form of a touch pen which is electrically coupled to the controller or a human finger. The controller responds to different commands from the host computer to transmit inputs entered only by finger, only by pen, or by both finger and pen. Additional commands from the computer cause the controller to take a variety of different actions, including resizing the active area on the touchscreen which may be touched by the touch device.

Claims

1. A touchscreen controller for controlling operation of a touch sensitive screen in response to commands from an application program executing on a data processor that is electrically coupled to the controller, the controller comprising, in combination:

means, responsive to a plurality of analog signals indicative of a position on said screen of a touch device touching said screen, for generating positional digital values indicative of two-dimensional coordinates of the position of said touch device on said screen;

means, responsive to a touch pen, electrically coupled to said controller, for determining if the touch device contacting the screen is a pen or a finger;

means, responsive to a pen only signal produced by said data processor in response to a pen only command of said commands, for transmitting said positional digital values to said data processor only if said touch device contacting said screen is said touch pen;

means, responsive to a finger only signal produced by said data processor in response to a finger only command of said commands, for transmitting said positional digital values to said data processor only if said touch device contacting said screen is said finger; and

means, responsive to a pen and finger signal produced by said data processor in response to a pen and finger command of said commands, for transmitting said positional digital values to said data processor if said touch device contacting said screen is said pen or said finger.

2. A touchscreen controller as set forth in claim 1 wherein the means for transmitting said positional digital values to said data processor if said touch device contacting said screen is said pen or said finger comprises means, responsive to concurrent contact of said finger and said pen, for transmitting positional digital values indicative of the position of said pen.

3. A touchscreen controller as set forth in claim 2 wherein the means for transmitting said positional digital values to said data processor if said touch device contacting said screen is said pen or said finger further comprises means, responsive to termination of contact of said pen with said touchscreen, for ignoring contact of said finger for a calibratable period of time.

4. A touchscreen controller as set forth in claim 3 wherein the means for ignoring contact of said finger for a calibratable period of time, comprises override means, responsive to lift-off and subsequent contact of said finger, for transmitting positional digital values indicative of the position of said finger.

5. A touchscreen controller as set forth in claim 4 wherein the means for transmitting said positional digital values to said data processor if said touch device contacting said screen is said pen or said finger further comprises means, responsive to contact of said finger with said touchscreen and subsequent contact of said pen with said touchscreen during said contact of said finger, for transmitting positional digital values indicative of the position of said pen.

6. A touchscreen controller as set forth in claim 5 further comprising means for defining a rectangular active area on said touchscreen, wherein said controller transmits positional digital values indicative of the position of a touch device only upon contact of said touch device within said active area, said means for defining an active area responding to contact of said touch device at a first point and at a second point by defining boundaries of said rectangular active area such that said first point and said second point are at diagonally opposite corners thereof.

7. A touchscreen controller as set forth in claim 6 wherein said controller transmits along with said positional values, touch device contact values which indicate if said positional values correspond to continued contact of said touch device with said touchscreen, initial contact of said touch device with said touchscreen, or termination of contact of said touch device with said touchscreen.

8. A touchscreen controller as set forth in claim 7 further comprising means for applying an electrical signal to a contact surface of said touchscreen, and wherein the means for determining if the touch device contacting the screen is a pen or a finger comprises means is responsive to a phase shift in said electrical signal.

9. A touchscreen controller as set forth in claim 4 further comprising means, responsive to a stream command, for continuously transmitting said positional digital values for the duration of contact of said touch device with said touchscreen, irrespective of movement of said touch device.

10. A touchscreen controller as set forth in claim 1 wherein the means for transmitting said positional digital values to said data processor if said touch device contacting said screen is said pen or said finger further comprises means, responsive to contact of said finger with said touchscreen and subsequent contact of said pen with said touchscreen during said contact of said finger, for transmitting positional digital values indicative of the position of said pen.

11. A touchscreen controller as set forth in claim 1 further comprising means for defining a rectangular active area on said touchscreen, wherein said controller transmits positional digital values indicative of the position of a touch device only upon contact of said touch device within said active area, said means for defining an active area responding to contact of said touch device at a first point and at a second point by defining boundaries of said rectangular active area such that said first point and said second point are at diagonally opposite corners thereof.

12. A touchscreen controller as set forth in claim 1 wherein said controller transmits along with said positional values, touch device contact values which indicate if said positional values correspond to continued contact of said touch device with said touchscreen, initial contact of said touch device with said touchscreen, or termination of contact of said touch device with said touchscreen.

13. A touchscreen controller as set forth in claim 1 further comprising means for applying an electrical signal to a contact surface of said touchscreen, and wherein the means for determining if the touch device contacting the screen is a pen or a finger comprises means is responsive to a phase shift in said electrical signal.

14. A touchscreen controller as set forth in claim 1 further comprising means, responsive to a stream command, for continuously transmitting said positional digital values for the duration of contact of said touch device with said touchscreen, irrespective of movement of said touch device.

15. In a computer system which executes computer programs including an application program, the computer system including a storage unit, a central processing unit, input means for providing input data to the storage unit and central processing unit said input means including a touch sensitive display screen, and output means for providing discernible indications of actions performed by the central processing unit, said output means including said touch sensitive display screen, said storage unit containing one or more further programs which when executed in the computer system comprise:

means, responsive to a first command from the application program, for transmitting a pen only command to a controller which controls said display screen to cause said controller to transmit only data indicative of inputs entered via said touchscreen by a pen electrically coupled to said touchscreen;

means, responsive to a second command from the application program, for transmitting a finger only command to said controller to cause said controller to transmit only data indicative of inputs entered via said touchscreen by a user finger; and

means, responsive to a third command from the application program, for transmitting a pen and finger command to said controller to cause said controller to transmit data indicative of inputs entered via said touchscreen by said pen or said finger.

16. A computer system as set forth in claim 15 wherein said one or more programs, when executed in the computer system, further comprise:

means, responsive to a fourth command, for transmitting an active area command defining a rectangular active area on said touchscreen by touching said touchscreen at two points, each of which defines a diagonally opposite corner of said rectangular active area.

17. A computer system as set forth in claim 15 wherein said means responsive to said third command causes said controller to transmit data indicative of inputs entered via said touchscreen by said pen upon concurrent contact of said touchscreen by said pen and said finger.

18. A computer system as set forth in claim 17 wherein said means responsive to said third command causes said controller to ignore contact of said finger for a calibratable period of time upon termination of contact of said pen with said touchscreen.

19. A computer system as set forth in claim 18 wherein said means responsive to said third command causes said controller to override said calibratable period of time upon contact, lift-off and subsequent contact of said finger with said touchscreen.

20. A computer-readable storage apparatus for use in a data processor which is coupled to a touch sensitive input screen which accepts input from a pen electrically coupled to said screen and from touching of a human finger to said screen, said data processor being coupled to said screen by a controller which accepts positional signals from the screen and which receives commands from the data processor and transmits digital data indicative of the position of an input to the screen, the storage apparatus containing one or more programs which, when executed in said data processor, comprise in combination:

means, responsive to a first command from an application program being executed by said data processor, for causing said data processor to transmit a pen only command to said controller to cause said controller to transmit only data which is indicative of inputs entered via said pen;

means, responsive to a second command from the application program, for transmitting a finger only command to said controller to cause said controller to transmit only data indicative of inputs entered via said touchscreen by said human finger; and

means, responsive to a third command from the application program, for transmitting a pen and finger command to said controller to cause said controller to transmit data indicative of inputs entered via said touchscreen by said pen or said by said finger.

21. An improved controller for controlling a touch-sensitive panel which receives touch inputs from more than one type of touch device and has a first output which indicates a position in the touch panel and a second output which indicates the type of the touch device that is currently providing the touch inputs, the controller responding to the first and second outputs and to commands from an application program executing on a host processor and the controller having the improvement comprising:

a processor which responds to a command from the application program that specifies a type of touch device and to the second output from the touch sensitive panel by providing digital coordinates corresponding to the position specified by the first output to the host only if the type of touch device indicated by the second output agrees with the type of touch device specified by the command.

22. The controller set forth in claim 21, wherein:

the command specifies only one touch device type.

23. The controller set forth in claim 21 wherein:

the command specifies more than one touch device type.

24. The controller set forth in claim 23 wherein:

when the command specifies more than one touch device type and there are simultaneous touches from touch devices having different types, the processor outputs digital coordinates from only one of the touch devices.

25. The controller set forth in claim 24 wherein:

output of the digital coordinates with simultaneous touches is determined by a priority among the touch devices.

26. The controller set forth in claim 25 wherein:

the processor ignores cessation of touches from the touch device having priority for a predetermined period of time.

27. The controller set forth in claim 26 wherein:

the processor sets the predetermined period of time in response to a command specifying the period of time from the application program.

28. The controller set forth in claim 21 wherein:

a touch device belonging to at least one of the types generates a signal; and

the touchscreen produces the second output in response to the signal.

29. The controller set forth in claim 28 wherein:

a touch device belonging to another of the types does not generate the signal; and

the touchscreen produces the second output in response to the lack of the signal.

30. A computer-readable storage device, the storage device being characterized in that:

the storage device contains code which, when executed, implements the processor of claim 21.