Touchpad computer input system and method

• US 6,292,173 B1
• Filed: 09/11/1998
• Issued: 09/18/2001
• Est. Priority Date: 09/11/1998
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Manaresi, Nicoloʼ, Kovaks-Vajna, Zsolt Miklos, Tartagni, Marco, Rambaldi, Roberto
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Osorio, Ricardo
• Application Number:
  US09/151,558
• Time in Patent Office: 1,103 Days
• Field of Search: 345/157, 345/173, 345/163, 382/288, 382/107, 382/294, 382/130
• US Class Current: 345/157
• 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 of and system for providing user input to a computer captures a first finger position image at a first time and a second finger position image at a second time. The first and second finger position images each comprise a plurality of numerical gray scale values equal to or greater than zero. The system then subtracts the first finger position image from the second finger position image to obtain a composite image. The composite image has a first region comprising numerical values less than zero and a second region comprising numerical values greater than zero. The system provides X-Y input to the computer based upon the relative positions of first and second regions. The system further provides Z input to the computer based upon the relative sizes of said first and second regions.

Claims

1. A method of providing user input to a computer, which comprises the computer implemented steps of:

capturing a first finger position image at a first time with an array of electric field sensors, said first finger position image being a first data array comprising a numerical value equal to or greater than zero for each sensor of said array of sensors;

capturing a second finger position image at a second time with said array of electric field sensors, said second finger position image being a second data array comprising a numerical value equal to or greater than zero for each sensor of said array of sensors;

subtracting said first finger position image from said second finger position image to obtain a composite image, said composite image having a first region comprising gray scale, numerical values less than zero and a second region comprising gray scale numerical values greater than zero; and

providing input to said computer based upon said first and second regions.

2. The method as claimed in claim 1, further comprising the computer implemented step of:

moving a pointer according to displacement of said second region with respect to said first region.

3. The method as claimed in claim 2, further comprising the computer implemented step of:

computing a displacement vector based upon said displacement.

4. The method as claimed in claim 3, wherein said step of computing a displacement vector includes the computer implemented steps of:

computing a centroid for said first region;

computing a centroid for said second region; and

subtracting said centroid for said first region from said centroid for said second region to obtain said displacement vector.

5. The method as claimed in claim 1, further comprising the computer implemented steps of:

computing a centroid for said first region;

computing a centroid for said second region;

subtracting said centroid for said first region from said centroid for said second region to obtain a displacement vector; and

moving a computer pointer according to said displacement vector.

6. The method as claimed in claim 1, further comprising the computer implemented step of:

inputting a mouse button signal to said computer based upon the respective areas of said first and second regions.

7. The method as claimed in claim 6, further comprising the computer implemented steps of:

comparing the area of said first region to the area of said second region;

interpreting user input as a mouse button down if the area of said first region is less than the area of said second region; and

interpreting user input as a mouse button up if the area of said first region is greater than the area of said second region.

8. The method as claimed in claim 6, further comprising the computer implemented steps of:

(a) subtracting the area of said first region from the area of said second region;

(b) dividing the result of step (a) by the sum of the areas said first and second regions;

(c) interpreting user input as a mouse button down if the result of step (b) is greater than zero; and

(d) interpreting user input as a mouse button up if the result of step (b) is less than zero.

9. The method as claimed in claim 1, wherein a finger is in contact with said array of sensors during said capturing a first finger position image and during said capturing second finger position.

10. A method of providing user input to a computer, which comprises the computer implemented steps of:

capturing a first finger position image at a first time, said first finger position image comprising a plurality of numerical values equal to or greater than zero;

capturing a second finger position image at a second time, said second finger position image comprising a plurality of numerical values equal to or greater than zero;

subtracting said first finger position image from said second finger position image to obtain a composite image, said composite image having a first region comprising numerical values less than zero and a second region comprising numerical values greater than zero; and

providing input to said computer based upon said first and second regions,

wherein said step of providing input to said computer includes the computer implemented step of inputting a mouse button signal to said computer based upon the respective areas of said first and second regions,

wherein said step of inputting a mouse button signal includes the computer implemented steps of;

(a) subtracting the area of said first region from the area of said second region;

(b) dividing the result of step (a) by the sum of the areas of said first and second regions;

(c) interpreting user input as a mouse button down if the result of step (b) is greater than zero; and

(d) interpreting user input as a mouse button up if the result of step (b) is less than zero.

11. A method of providing user input to a computer, which comprises the computer implemented steps of:

capturing a first finger position image at a first time with an array of electric field sensors, said first finger position image being a first data array comprising a numerical value equal to or greater than zero for each sensor of said array of sensors;

capturing a second finger position image at a second time with said array of electric field sensors, said second finger position image being a second data array comprising a numerical value equal to or greater than zero for each sensor of said array of sensors;

subtracting said first finger position image from said second finger position image to obtain a composite image, said composite image having a first region comprising gray scale numerical values less than zero and a second region comprising gray scale numerical values greater than zero;

providing X-Y input to said computer based upon the relative positions of first and second regions; and

providing Z input to said computer based upon the relative sizes of said first and second regions.

12. The method as claimed in claim 11, further comprising the computer implemented step of:

moving a pointer according to displacement of said second region with respect to said first region.

13. The method as claimed in claim 12, further comprising the computer implemented step of:

computing a displacement vector based upon said displacement.

14. The method as claimed in claim 13, wherein said step of computing a displacement vector includes the computer implemented steps of:

computing a centroid for said first region;

computing a centroid for said second region; and

subtracting said centroid for said first region from said centroid for said second region to obtain said displacement vector.

15. The method as claimed in claim 11, further comprising the computer implemented steps of:

computing a centroid for said first region;

computing a centroid for said second region;

subtracting said centroid for said first region from said centroid for said second region to obtain a displacement vector; and

moving a computer pointer according to said displacement vector.

16. The method as claimed in claim 11, further comprising the computer implemented steps of:

comparing the area of said first region to the area of said second region;

inputting positive Z input if the area of said first region is less than the area of said second region; and

,

inputting negative Z input if the area of said first region is greater than the area of said second region.

17. The method as claimed in claim 11, further comprising the computer implemented steps of:

(a) subtracting the area of said first region from the area of said second region;

(b) dividing the result of step (a) by the sum of the areas said first and second regions;

(c) inputting positive Z input if the result of step (b) is greater than zero; and

(d) inputting negative Z input if the result of step (b) is less than zero.

18. The method as claimed in claim 17, wherein said positive Z input is interpreted as a mouse button down input and said negative Z input is interpreted as a mouse button up input.

19. A method of providing user input to a computer, which comprises the computer implemented steps of:

capturing a first finger position image at a first time, said first finger position image comprising a plurality of numerical values equal to or greater than zero;

capturing a second finger position image at a second time, said second finger position image comprising a plurality of numerical values equal to or greater than zero;

subtracting said first finger position image from said second finger position image to obtain a composite image said composite image, having a first region comprising numerical values less than zero and a second region comprising numerical values greater than zero;

providing X-Y input to said computer based upon the relative positions of first and second regions; and

providing Z input to said computer based upon the relative sizes of said first and second regions, wherein said step of providing Z input to said computer includes the computer implemented steps of;

(a) subtracting the area of said first region from the area of said second region;

(b) dividing the result of step (a) by the sum of the areas of said first and second regions;

(c) inputting positive Z input if the result of step (b) is greater than zero; and

(d) inputting negative Z input if the result of step (b) is less than zero.

20. The method as claimed in claim 19, wherein said positive Z input is interpreted as a mouse button down input and said negative Z input is interpreted as a mouse button up input.