Portable electronic device including touch-sensitive display and method of controlling same
View Patent ↗A method includes detecting first and second touches on the touch-sensitive display and determining a location of each of the first and second touches, determining, by a plurality of force sensors, reaction forces, for the first and second touches, and determining a respective applied force for each of the first and second touches based on the reaction forces and the locations of the first and second touches.
1. A method comprising,
detecting first and second touches on the touch-sensitive display that overlap in time such that each touch applies a respective force at a same time on the touch-sensitive display; and determining a location of each of the first and second touches utilizing capacitive touch sensors of the touch-sensitive display;
determining, by a plurality of force sensors, reaction forces for the first and second touches; and
in response to detecting the first and second touches and determining the location of each of the first and second touches utilizing the capacitive touch sensors, determining a respective applied force for each of the first and second touches based on the determined reaction forces and the locations of the first and second touches determined utilizing the capacitive touch sensors,
wherein determining the respective applied force comprises determining a force distribution vector matrix and wherein determining the force distribution vector matrix comprises determining
DistMatrix
=
[
(
SSX
-
X
1
)
*
(
SSY
-
Y
1
)
(
SSX
-
X
2
)
*
(
SSY
-
Y
2
)
X
1
*
(
SSY
-
Y
1
)
X
2
*
(
SSY
-
Y
2
)
(
SSX
-
X
1
)
*
Y
1
(
SSX
-
X
2
)
*
Y
2
X
1
*
Y
1
X
2
*
Y
2
]
/
(
SSX
*
SSY
)
where:
DistMatrix is the force distribution vector matrix;
X 1 is the x component of distance between the first touch and force sensors;
X 2 is the x component of distance between the second touch and force sensors;
Y 1 is the y component of distance between the first touch and force sensors;
Y 2 is the y component of distance between the second touch and force sensors;
SSX is the spacing between the force sensors in an x direction; and
SSY is the spacing between the force sensors in a y direction.
2. The method according to claim 1 , wherein determining a respective applied force comprises performing a matrix inversion on the force distribution vector matrix to provide an inverse matrix.
3. The method according to claim 2 , wherein determining a respective applied force comprises multiplying the inverse matrix by each the reaction forces determined from signals from the four force sensors to provide the force at each of the touches.
4. A non-transitory computer-readable medium having computer-readable code executable by at least one processor of a portable electronic device to perform the method according to claim 1 .
5. An electronic device comprising:
a touch-sensitive display including capacitive touch-sensors disposed in a layer on a display of the touch-sensitive display and arranged and constructed to:
detect first and second touches on the touch-sensitive display that overlap in time such that each touch applies a respective force at a same time on the touch-sensitive display; and
determine a location of each of the first and second touches utilizing capacitive touch sensors of the touch-sensitive display;
a plurality of force sensors disposed below the touch-sensitive display, each configured to determine a reaction force for first and second touches on the touch-sensitive display;
a processor operably coupled to the force sensors and the touch-sensitive display to, in response to detecting the first and second touches and determining the location of each of the first and second touches utilizing the capacitive touch sensors, determine a respective applied force for each of the first and second touches, based on the determined reaction forces determined utilizing the force sensors, and the previously determined locations of the first and second touches determined utilizing the capacitive touch sensors,
wherein determining the respective applied force comprises determining a force distribution vector matrix and wherein determining the force distribution vector matrix comprises determining
DistMatrix
=
[
(
SSX
-
X
1
)
*
(
SSY
-
Y
1
)
(
SSX
-
X
2
)
*
(
SSY
-
Y
2
)
X
1
*
(
SSY
-
Y
1
)
X
2
*
(
SSY
-
Y
2
)
(
SSX
-
X
1
)
*
Y
1
(
SSX
-
X
2
)
*
Y
2
X
1
*
Y
1
X
2
*
Y
2
]
/
(
SSX
*
SSY
)
where:
DistMatrix is the force distribution vector matrix;
X 1 is the x component of distance between the first touch and force sensors;
X 2 is the x component of distance between the second touch and force sensors;
Y 1 is the y component of distance between the first touch and force sensors;
Y 2 is the y component of distance between the second touch and force sensors;
SSX is the spacing between the force sensors in an x direction; and
SSY is the spacing between the force sensors in a y direction.
6. The electronic device according to claim 5 , wherein the respective applied force is determined by performing a matrix inversion and multiplying the matrix inversion by the reaction force at each of the plurality of force sensors.