Touch panel sensor with optimal electrode separation for improved performance
A touch panel display includes a display panel having a plurality of pixel regions that emit light, and a touch sensor having an electrode configuration that overlays the display panel. The electrode configuration includes a first electrode and a second electrode that are separated by an insulating region. The electrode separation distance between the first and second electrodes is in a range whereby (1) with increasing electrode separation distance a first rate of proportional decrease in mutual capacitance between the first and second electrodes is greater than a second rate of proportional decrease in signal magnitude of an output signal, and (2) a ratio (R) of the first rate to the second rate satisfies the relationship 1.0<R<2.5. With such parameters, the electrode separation distance may be from 30 μm to 50 μm, and/or from 0.5 to 0.75 times a pixel pitch of the pixel regions.
1. A touch panel display comprising:
a display panel comprising a plurality of pixel regions that emit light; and
a touch sensor comprising an electrode configuration that is configured as an opaque metal mesh that overlays the display panel with the opaque metal mesh being positioned outside of the pixel regions;
the electrode configuration comprising a first electrode and a second electrode that are separated by an insulating region, an electrode separation distance being a distance between the first electrode and the second electrode across the insulating region in a direction perpendicular to opposing faces of the first and second electrodes; and
wherein the electrode separation distance is in a range whereby (1) with increasing electrode separation distance a first rate of proportional decrease in mutual capacitance between the first and second electrodes is greater than a second rate of proportional decrease in signal magnitude of an output signal, and (2) a ratio (R) of the first rate to the second rate satisfies the relationship 1.0<R<2.5.
2. The touch panel display of claim 1 , wherein the electrode separation distance is from 30 μm to 50 μm.
3. The touch panel display of claim 1 , wherein the electrode separation distance is from 35 μm to 45 μm.
4. The touch panel display of claim 1 , wherein the electrode separation distance is from 0.5 to 0.75 times a pixel pitch of the pixel regions.
5. The touch panel display of claim 1 , wherein the electrode separation distance is constant between a first electrode face of the first electrode and a second electrode face of the second electrode.
6. The touch panel display of claim 1 , wherein the first electrode is a drive electrode to which an electrical signal is inputted, and the second electrode is a sense electrode from which the output signal is measured.
7. The touch panel display of claim 1 , wherein the pixel regions are arranged in rows and columns, and the first electrode is a row electrode and the second electrode is a column electrode.
8. The touch panel display of claim 1 , wherein the insulating region is a non-straight insulating region.
9. The touch panel display of claim 1 , wherein the electrode configuration is made of a bulk metal material and the insulating region is made of an inorganic insulating material or an organic polymer.
10. The touch panel display of claim 1 , further comprising one or more inactive electrodes positioned within the insulating region between the first electrode and the second electrode.
11. The touch panel display of claim 1 , wherein the electrode configuration has a fishbone configuration in which the first electrode and the second electrode are interlaced.
12. A touch panel display comprising:
a display panel comprising a plurality of pixel regions that emit light; and
a touch sensor comprising an electrode configuration that overlays the pixel regions of the display panel;
the electrode configuration comprising a first transparent electrode and a second transparent electrode that are separated by an insulating region, an electrode separation distance being a distance between the first transparent electrode and the second transparent electrode across the insulating region in a direction perpendicular to opposing faces of the first and second transparent electrodes; and
wherein the electrode separation distance is in a range whereby (1) with increasing electrode separation distance a first rate of proportional decrease in mutual capacitance between the first and second transparent electrodes is greater than a second rate of proportional decrease in signal magnitude of an output signal, and (2) a ratio (R) of the first rate to the second rate satisfies the relationship 1.0<R<2.5.
13. The touch panel display of claim 12 , wherein the electrode separation distance is from 30 μm to 50 μm.
14. The touch panel display of claim 12 , wherein the electrode separation distance is from 35 μm to 45 μm.
15. The touch panel display of claim 12 , wherein the electrode separation distance is from 0.5 to 0.75 times a pixel pitch of the pixel regions.
16. The touch panel display of claim 12 , wherein the first transparent electrode is a drive electrode to which an electrical signal is inputted, and the second transparent electrode is a sense electrode from which the output signal is measured.
17. The touch panel display of claim 12 , wherein the pixel regions are arranged in rows and columns, and the first transparent electrode is a row electrode and the second transparent electrode is a column electrode.
18. The touch panel display of claim 12 , wherein the insulating region is made of an inorganic insulating material or an organic polymer.
19. The touch panel display of claim 12 , further comprising one or more inactive electrodes positioned within the insulating region between the first transparent electrode and the second transparent electrode.