Systems and methods for determining the location and pressure of a touchload applied to a touchpad
A computing device with a multi-touch touch interface having a plurality of rows of contact points and a plurality of columns of contact points. For each other row of contact points, every contact point in the row is connected to form a row sensor. For each other column of contact points, every contact point in the column that is not part of a row sensor is connected to form a column sensor. The contact points that are not part of a row sensor and not part of a column sensor are connected together to form at least one shape sensor. A computing device with a multi-touch touch interface having a plurality of contact points has at least one layer of piezoresistive material, an insulating structure disposed between the plurality of contact points and the piezoresistive material, and a gap between the plurality of contact points and piezoresistive material. A method of providing multi-layered password recognition for a computing device having a touch interface first provides a passcode associated with an alphanumeric symbol to the computing device. The alphanumeric symbol is associated with a passcode pressure level. A touch load is applied to the touch interface and a measured pressure level associated with the applied touch load is determined. Then it is determined whether the measured pressure level corresponds to the passcode pressure level associated with the alphanumeric symbol of the passcode.
1. A multi-touch interface comprising:
a two-dimensional array of contact points, wherein the contact points are substantially uniformly distributed within the array such that each contact point is substantially equidistant from neighboring contact points located in vertical and horizontal directions;
wherein a first subset of contact points are electrically connected to form at least one first type of sensor, each first type of sensor comprising contact points electrically connected in a first direction;
wherein a second subset of contact points are electrically connected to form at least one second type of sensor, each second type of sensor comprising contact points electrically connected in a second direction, wherein the second subset of contact points comprise contact points other than the first subset of contact points, and wherein the second direction is orthogonal to the first direction; and
wherein a third subset of contact points is divided into clusters of substantially locally distributed contact points, each of the clusters comprising contact points electrically connected to form a third type of sensor;
wherein the third subset of contact points comprises contact points other than the first and second subset of contact points; and
wherein each of the clusters is formed to provide an absolute location of one or more touch loads applied to the multi-touch interface.
2. The multi-touch interface of claim 1 , wherein the first direction is a horizontal direction and the second direction is a vertical direction.
3. The multi-touch interface of claim 1 , wherein each first type of sensor comprises adjoining contact points electrically connected in the first direction, and wherein each second type of sensor comprises adjoining contact points electrically connected in the second direction.
4. The multi-touch interface of claim 1 , wherein each of the clusters' contact points forms a geometric shape.
5. The multi-touch interface of claim 1 , wherein all the clusters are of equal size.
6. A method of determining characteristics of one or more touch loads applied to the multi-touch interface of claim 1 , wherein the touch load is associated with a contact point in the two-dimensional array of contact points, the method comprising:
activating a plurality of contact points in response to the touch load, wherein the plurality of contact points comprise contact points that are part of the at least one first type of sensor, the at least one second type of sensor and the at least one third type of sensor;
associating a sensor location index with each first type of sensor, a second type of sensor, and a third type of sensor activated by the touch load; and
determining a location for the contact point associated with the touch load based on the sensor location index.
7. The method of claim 6 , further comprising associating a sensor magnitude index with each first type of sensor, second type of sensor and third type of sensor activated by the touch load, and determining a magnitude for the contact point associated with the touch load based on the sensor magnitude index.
8. A multi-touch sensor mechanism comprising:
a two-dimensional array of contact points, wherein the contact points are substantially uniformly distributed within the array such that each contact point is substantially equidistant from neighboring contact points located in vertical and horizontal directions;
at least one conductive electrode pad corresponding to each contact point in the array;
a reference connection for providing connection to a reference signal; and
at least one circuit configured to provide an electrical measurement between each conductive electrode pad and the at least one reference connection when a touch event occurs;
wherein a first subset of contact points are electrically connected to form at least one first type of sensor, each first type of sensor comprising contact points electrically connected in a first direction;
wherein a second subset of contact points are electrically connected to form at least one second type of sensor, each second type of sensor comprising contact points electrically connected in a second direction, wherein the second subset of contact points comprise contact points other than the first subset of contact points, and wherein the second direction is orthogonal to the first direction; and
wherein a third subset of contact points is divided into clusters of substantially locally distributed contact points, each of the clusters comprising contact points electrically connected to form a third type of sensor;
wherein the third subset of contact points comprises contact points other than the first and second subset of contact points; and
wherein each of the clusters is formed to provide an absolute location of one or more touch loads applied to the multi-touch interface.
9. The multi-touch sensor mechanism of claim 8 , further comprising at least one layer of piezoresistive material, wherein the at least one circuit is configured to measure resistance between each conductive electrode pad and the reference connection.
10. The multi-touch sensor mechanism of claim 9 , wherein the reference connection is provided by an electrical connection to at least one location on the at least one layer of piezoresistive material.
11. The multi-touch sensor mechanism of claim 9 , wherein an insulating structure is used to form a gap between each conductive electrode pad and the at least one layer of piezoresistive material.
12. The multi-touch sensor mechanism of claim 11 , wherein the at least one conductive electrode pad is constructed by a multi-layer printed circuit board.
13. The multi-touch sensor mechanism of claim 12 , wherein the insulating structure is formed by an insulating layer on the multi-layer printed circuit board.
14. The multi-touch sensor mechanism of claim 11 , wherein the gap comprises an air gap.
15. The multi-touch sensor mechanism of claim 8 , wherein the at least one circuit is configured to measure capacitance between each conductive electrode pad and the reference connection.
16. The multi-touch sensor mechanism of claim 8 , wherein the reference connection is provided by a layer of highly conductive material.
17. A method of constructing a layout of contact points for a multi-touch interface, the method comprising:
providing a two-dimensional array of plurality of rows of contact points, wherein the contact points are substantially uniformly distributed within the array such that each contact point is substantially equidistant from neighboring contact points in vertical and horizontal directions;
electrically connecting a first subset of contact points to form at least one first type of sensor, each first type of sensor comprising contact points electrically connected in a first direction;
electrically connecting a second subset of contact points to form at least one second type of sensor, each second type of sensor comprising contact points electrically connected in a second direction;
wherein the second subset of contact points comprise contact points other than the first subset of contact points; and
wherein the second direction is orthogonal to the first direction;
dividing a third subset of contact points, the third subset comprising contact points other than the first and second subset of contact points, into clusters of substantially locally distributed contact points; and
electrically connecting contact points within each of the clusters to form a third type of sensor, wherein each cluster is formed to provide an absolute location of one or more touch loads applied to the multi-touch interface.
18. The method of claim 17 , wherein the first direction is a horizontal direction and the second direction is a vertical direction.
19. The method of claim 17 , wherein each first type of sensor comprises adjoining contact points electrically connected in the first direction, and wherein each second type of sensor comprises adjoining contact points electrically connected in the second direction.