Display with touchless indications and methods for use therewith
A capacitive touch screen display operates by: providing a display configured to render frames of data into visible images; providing a plurality of electrodes integrated into the display to facilitate touch sense functionality based on electrode signals having a drive signal component and a receive signal component; generating, via a plurality of drive-sense circuits coupled to at least some of the plurality of electrodes, a plurality of sensed signals; receiving the plurality of sensed signals; generating capacitance image data associated with the plurality of cross points that includes capacitance variation data corresponding to variations of the capacitance image data from a nominal value; and processing the capacitance image data to determine a touchless indication proximal to the touch screen display based on a touchless indication threshold.
1. A touch screen display comprises:
a display device configured to render data into visible images;
a plurality of electrodes configured to facilitate touch sense functionality of the display device based on electrode signals having a drive signal component and a receive signal component, wherein the plurality of electrodes includes electrodes in a first direction and electrodes in a second direction, wherein the electrodes in the first direction are separated from the electrodes in the second direction by a dielectric material and wherein the electrodes in the first direction and the electrodes in the second direction form a plurality of cross points;
a plurality of drive-sense circuits coupled to at least some of the plurality of electrodes to generate a plurality of sensed signals, wherein each the plurality of drive-sense circuits includes a first conversion circuit and a second conversion circuit, and wherein, when a drive-sense circuit of the plurality of drive-sense circuits is enabled to monitor a corresponding electrode of the plurality of electrodes, the first conversion circuit is configured to convert the receive signal component into a sensed signal of the plurality of sensed signals and the second conversion circuit is configured to generate the drive signal component from the sensed signal of the plurality of sensed signals;
a processing module that includes at least one memory that stores operational instructions and at least one processing circuit that executes the instructions to perform operations that include:
receiving the plurality of sensed signals, wherein the sensed signals indicate variations in capacitance associated with the plurality of cross points;
generating, based on the plurality of sensed signals, capacitance image data associated with the plurality of cross points that includes capacitance variation data corresponding to variations of the capacitance image data from a nominal value; and
processing the capacitance image data to determine a touchless indication proximal to the touch screen display based on a touchless indication threshold.
2. The touch screen display of claim 1 , wherein the variations in capacitance associated the plurality of cross points vary from a nominal capacitance.
3. The touch screen display of claim 1 , wherein the nominal capacitance corresponds to an average capacitance of the plurality of cross points in an absence of the touchless indication.
4. The touch screen display of claim 1 , wherein the sensed signals indicate an impedance of the plurality of cross points.
5. The touch screen display of claim 4 , wherein the nominal value is proportional to a nominal impedance corresponding to each of the cross points of the plurality of cross points in an absence of the touchless indication.
6. The touch screen display of claim 1 ,
wherein the first conversion circuit includes:
a comparator to compare the electrode signal to an analog reference signal to produce an analog comparison signal; and
an analog to digital converter operable to convert the analog comparison signal into the sensed signal;
wherein the second conversion circuit includes:
a digital to analog converter operable to convert the sensed signal into an analog feedback signal;
a signal source circuit operable to generate a regulated source signal based on the analog feedback signal; and
a driver operable to increase power of the regulated source signal to produce the drive signal component.
7. The touch screen display of claim 1 , wherein each of the electrodes comprise:
a transparent conductive trace placed in a layer of the touch screen display, wherein the transparent conduction trace is constructed of one or more of: Indium Tin Oxide (ITO), Graphene, Carbon Nanotubes, Thin Metal Films, Silver Nanowires Hybrid Materials, Aluminum-doped Zinc Oxide (AZO), Amorphous Indium-Zinc Oxide, Gallium-doped Zinc Oxide (GZO), or poly(3,4-ethylenedioxythiophene) (PEDOT).
8. The touch screen display of claim 1 , wherein the touchless indication proximal to the touch screen display is determined based on an area size in the capacitance image data where the capacitance variation data compares favorably to the touchless indication threshold.
9. The touch screen display of claim 8 , wherein the touchless indication proximal to the touch screen display is determined based a temporal stability of a parameter the area in the capacitance image data where the capacitance variation data compares favorably to the touchless indication threshold.
10. The touch screen display of claim 9 , wherein the parameter of the area includes at least one of: a centroid of the area or a boundary of the area.
11. The touch screen display of claim 8 , wherein the touchless indication proximal to the touch screen display is determined based a proximity of a parameter of the area in the capacitance image data where the capacitance variation data compares favorably to the touchless indication threshold to a selectable region on the touch screen display.
12. The touch screen display of claim 11 , wherein the parameter of the area indicates at least one of: a centroid of the area or a boundary of the area.
13. A method for use in a touch screen display comprises:
providing a display device configured to render data into visible images;
providing a plurality of electrodes configured to facilitate touch sense functionality of the display device based on electrode signals having a drive signal component and a receive signal component, wherein the plurality of electrodes includes electrodes in a first direction and electrodes in a second direction, wherein the electrodes in the first direction are separated from the electrodes in the second direction by a dielectric material and wherein the electrodes in the first direction and the electrodes in the second direction form a plurality of cross points;
generating, via a plurality of drive-sense circuits coupled to at least some of the plurality of electrodes, a plurality of sensed signals, wherein each the plurality of drive-sense circuits includes a first conversion circuit and a second conversion circuit, and wherein, when a drive-sense circuit of the plurality of drive-sense circuits is enabled to monitor a corresponding electrode of the plurality of electrodes, the first conversion circuit is configured to convert the receive signal component into a sensed signal of the plurality of sensed signals and the second conversion circuit is configured to generate the drive signal component from the sensed signal of the plurality of sensed signals;
receiving, at a processing module that includes at least one memory and at least one processing circuit, the plurality of sensed signals, wherein the sensed signals indicate variations in mutual capacitance associated with the plurality of cross points;
generating, via the processing module and based on the plurality of sensed signals, capacitance image data associated with the plurality of cross points that includes capacitance variation data corresponding to variations of the capacitance image data from a nominal value; and
processing, via the processing module, the capacitance image data to determine a touchless indication proximal to the touch screen display based on a touchless indication threshold.
14. The method of claim 13 , wherein the variations in capacitance associated the plurality of cross points vary from a nominal capacitance.
15. The method of claim 13 , wherein the sensed signals indicate an impedance of the plurality of cross points.
16. The method of claim 13 ,
wherein the first conversion circuit includes:
a comparator to compare the electrode signal to an analog reference signal to produce an analog comparison signal; and
an analog to digital converter operable to convert the analog comparison signal into the sensed signal;
wherein the second conversion circuit includes:
a digital to analog converter operable to convert the sensed signal into an analog feedback signal;
a signal source circuit operable to generate a regulated source signal based on the analog feedback signal; and
a driver operable to increase power of the regulated source signal to produce the drive signal component.
17. The method of claim 13 wherein the touchless indication proximal to the touch screen display is determined based on an area size in the capacitance image data where the capacitance variation data compares favorably to the touchless indication threshold.
18. The method of claim 17 , wherein the touchless indication proximal to the touch screen display is determined based a temporal stability of a parameter the area in the capacitance image data where the capacitance variation data compares favorably to the touchless indication threshold.
19. The method of claim 17 , wherein the touchless indication proximal to the touch screen display is determined based a proximity of a parameter of the area in the capacitance image data where the capacitance variation data compares favorably to the touchless indication threshold to a selectable region on the touch screen display.
20. The method of claim 19 , wherein the parameter of the area indicates at least one of: a centroid of the area or a boundary of the area.