Modulated back plate for capacitive sensing
First Claim
1. An input device comprising a display device having an integrated capacitive sensing device, the input device comprising;
- a system ground;
a conductive back plate configured to be coupled to an input object;
a plurality of display elements;
a plurality of sensor electrodes; and
a processing system coupled to the conductive back plate, to the plurality of display elements, and the plurality of sensor electrodes, the processing system configured to;
drive modulation signals onto the conductive back plate; and
receive resulting current signals with at least one of the plurality of sensor electrodes, the resulting current signals comprising effects corresponding to the modulation signals and induced in the at least one of the plurality of sensor electrodes from the conductive back plate;
wherein the modulation signals cause the conductive back plate and the input object to be modulated with respect to system ground;
wherein the resulting current signals are received while holding the at least one of the plurality of sensor electrodes with which resulting current signals are received at a constant voltage with respect to the system ground, while simultaneously driving a display element of the plurality of display elements for providing display image update information to the display element;
wherein the display element comprises a capacitor having as one plate, a portion of the at least one electrode of the plurality of sensor electrodes held at the constant voltage with respect to the system ground;
wherein the resulting current signals are required to hold the at least one electrode of the plurality of sensor electrodes at the constant voltage with respect to the system ground when the input object is modulated with respect to the at least one electrode of the plurality of sensor electrodes by the modulation signals; and
wherein the constant voltage is different from the system ground and an earth ground.
3 Assignments
0 Petitions
Accused Products
Abstract
Embodiments described herein include an input device comprising a display device having an integrated capacitive sensing device, a processing system, and a method for detecting presence of an input object. In each of these embodiments, a modulation source provides modulation signals between a back plate and a system ground of the input device. Other embodiments include a display device having a capacitive sensing device, a processing system and a method for detecting presence of an input object using a capacitive sensing device, wherein the capacitive sensing device includes a matrix of discrete sensor electrodes.
19 Citations
21 Claims
-
1. An input device comprising a display device having an integrated capacitive sensing device, the input device comprising;
-
a system ground; a conductive back plate configured to be coupled to an input object; a plurality of display elements; a plurality of sensor electrodes; and a processing system coupled to the conductive back plate, to the plurality of display elements, and the plurality of sensor electrodes, the processing system configured to; drive modulation signals onto the conductive back plate; and receive resulting current signals with at least one of the plurality of sensor electrodes, the resulting current signals comprising effects corresponding to the modulation signals and induced in the at least one of the plurality of sensor electrodes from the conductive back plate; wherein the modulation signals cause the conductive back plate and the input object to be modulated with respect to system ground; wherein the resulting current signals are received while holding the at least one of the plurality of sensor electrodes with which resulting current signals are received at a constant voltage with respect to the system ground, while simultaneously driving a display element of the plurality of display elements for providing display image update information to the display element; wherein the display element comprises a capacitor having as one plate, a portion of the at least one electrode of the plurality of sensor electrodes held at the constant voltage with respect to the system ground; wherein the resulting current signals are required to hold the at least one electrode of the plurality of sensor electrodes at the constant voltage with respect to the system ground when the input object is modulated with respect to the at least one electrode of the plurality of sensor electrodes by the modulation signals; and wherein the constant voltage is different from the system ground and an earth ground. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method for capacitive sensing, the method comprising:
-
driving modulation signals onto a conductive back plate that is proximate to a display device, the display device having a plurality of display elements and an integrated capacitive sensing device; and receiving resulting current signals from at least one of a plurality of sensor electrodes that are included in the display device having the integrated capacitive sensing device, the resulting current signals comprising effects corresponding to the modulation signals and induced in the at least one of the plurality of sensor electrodes from the conductive back plate; wherein the resulting current signals are received while holding the at least one of the plurality of sensor electrodes with which resulting current signals are received at a constant voltage with respect to the system ground, while simultaneously driving a display element of the plurality of display elements for providing display image update information to the display element; wherein the display element comprises a capacitor having as one plate, a portion of the at least one electrode of the plurality of sensor electrodes held at the constant voltage with respect to the system ground; wherein the resulting current signals are required to hold the at least one electrode of the plurality of sensor electrodes at the constant voltage with respect to the system ground when the input object is modulated with respect to the at least one electrode of the plurality of sensor electrodes by the modulation signals; and wherein the constant voltage is different from the system ground and an earth ground. - View Dependent Claims (14, 15, 16, 17)
-
-
18. A processing system for an input device, the processing system comprising:
-
a modulation source configured to drive modulation signals onto a conductive back plate that is proximate to a display device, the display device having a plurality of display elements and an integrated capacitive sensing device; and a sensor module having sensing circuitry configured to receive resulting current signals from at least one of a plurality of sensor electrodes that are included in the display device having the integrated capacitive sensing device, the resulting current signals comprising effects corresponding to the modulation signals and induced in the at least one of the plurality of sensor electrodes from the conductive back plate, wherein the resulting current signals are received while holding the at least one of the plurality of sensor electrodes with which resulting current signals are received at a constant voltage with respect to the system ground, while simultaneously driving a display element of the plurality of display elements for providing display image update information to the display element; wherein the modulation signals cause the conductive back plate and an input object proximate to the at least one sensor electrode to be modulated with respect to system ground; wherein the display element comprises a capacitor having as one plate, a portion of the at least one electrode of the plurality of sensor electrodes is held at the constant voltage with respect to the system ground; wherein the resulting current signals when received hold the at least one electrode of the plurality of sensor electrodes at the constant voltage with respect to the system ground when the input object is modulated with respect to the at least one electrode of the plurality of sensor electrodes by the modulation signals; and wherein the constant voltage is different from the system ground and an earth ground. - View Dependent Claims (19, 20, 21)
-
Specification