Capacitive Touch Screen with Noise Suppression
A capacitive touch sensor wherein the touch sensitive panel has drive electrodes arranged on the lower side of a substrate and sense electrodes arranged on the upper side. The drive electrodes are shaped and dimensioned to substantially entirely cover the touch sensitive area with individual drive electrodes being separated from each other by small gaps, the gaps being so small as to be practically invisible. The near blanket coverage by the drive electrodes also serves to screen out interference from noise sources below the drive electrode layer, such as drive signals for an underlying display, thereby suppressing noise pick-up by the sense electrodes that are positioned above the drive electrodes.
1 - 20 . (canceled)
21 . A sensor comprising:
a substrate; and
a sensing region configured to sense a position of an object within the sensing region, the sensing region comprising:
a plurality of drive electrodes disposed on a first side of the substrate in a first layer; and
a plurality of sense electrodes disposed on a second side of the substrate in a second layer so that the sense electrodes intersect the drive electrodes at a plurality of intersections offset by a thickness of the substrate,
wherein the sensing region further comprises a plurality of isolated conductive elements disposed on the second side of the substrate between the sense electrodes so that, together, the plurality of sense electrodes and the plurality of isolated conductive elements are substantially area filling within the sensing region.
22 . The sensor of claim 21 , wherein:
a first drive electrode is coupled to a first voltage source;
a second drive electrode is coupled to a second voltage source; and
a third drive electrode, disposed between the first drive electrode and the second drive electrode, is not coupled to the first or second voltage source.
23 . The sensor of claim 22 , wherein a fourth drive electrode, disposed between the first drive electrode and the second drive electrode, is not coupled to the first or second voltage source.
24 . The sensor of claim 22 , wherein:
the first voltage source provides a pulse signal; and
the second voltage source provides ground.
25 . The sensor of claim 21 , wherein each drive electrode is made of a mesh or filigree pattern of interconnected lines of highly conductive material which collectively define each electrode.
26 . The sensor of claim 21 , wherein each drive electrode is coupled to an adjacent drive electrode through a resistive element.
27 . The sensor of claim 21 , wherein each sense electrode is made of a mesh or filigree pattern of interconnected lines of highly conductive material which collectively define the sense electrode.
28 . The sensor of claim 21 , wherein:
the sense electrodes have a line width one quarter or less than a pitch of the drive electrodes, or
a gap between adjacent sense electrodes has a width that is at least three-fifths of a pitch of the sense electrodes
29 . The sensor of claim 28 , wherein the pitch of the sense electrodes is approximately 5 millimeters or less.
30 . The sensor or claim 28 , wherein the gap between adjacent sense electrodes is approximately 3.5 millimeters or more.
31 . The sensor of claim 28 , wherein the line width of the sense electrodes is between approximately 100 micrometers and approximately 250 micrometers.
32 . The sensor of claim 21 , wherein adjacent drive electrodes are separated by small gaps, wherein the gaps are less than around 100 micrometers.
33 . The sensor of claim 21 , wherein the second side of the substrate is coupled to a display module.
34 . The sensor of claim 21 , wherein an outermost drive electrode has a width that is approximately half of a width of an adjacent drive electrode, the outermost drive electrode being adjacent to only one drive electrode.
35 . The sensor of claim 21 , wherein the drive electrodes extend arcuately and the sense electrodes extend radially so that the plurality of intersections lie on one or more arcuate paths.
36 . A computer-readable non-transitory storage media embodying logic that is configured when executed to:
sense a position of an object within a sensing region, the sensing region comprising:
a plurality of drive electrodes disposed on a first side of a substrate in a first layer; and
a plurality of sense electrodes disposed on a second side of the substrate in a second layer so that the sense electrodes intersect the drive electrodes at a plurality of intersections offset by a thickness of the substrate; and
communicate a capacitance sensed by the drive and sense electrodes and indicative of the position of the object within the sensing region,
wherein the sensing region further comprises a plurality of isolated conductive elements disposed on the second side of the substrate between the sense electrodes so that, together, the plurality of sense electrodes and the plurality of isolated conductive elements are substantially area filling within the sensing region relative to the plurality of sense electrodes.
37 . The media of claim 36 , wherein:
each drive electrode is coupled to an adjacent drive electrode through a resistive element;
a first drive electrode is coupled to a first voltage source;
a second drive electrode is coupled to a second voltage source; and
a third drive electrode, disposed between the first drive electrode and the second drive electrode, is not coupled to the first or second voltage source.
38 . The media of claim 37 , wherein a fourth drive electrode, disposed between the first drive electrode and the second drive electrode, is not coupled to the first or second voltage source.
39 . The media of claim 36 , wherein:
the first voltage source provides a pulse signal; and
the second voltage source provides ground.
40 . The media of claim 36 , wherein the sensing region further comprises a plurality of isolated conductive elements disposed on the second side of the substrate between the sense electrodes so that, together, the plurality of sense electrodes and the plurality of isolated conductive elements are substantially area filling within the sensing region relative to the plurality of sense electrodes.
41 . The media of claim 36 , wherein each drive or sense electrode is made of a mesh or filigree pattern of interconnected lines of highly conductive material which collectively define each electrode.
42 . A method comprising:
sensing a position of an object within a sensing region, the sensing region comprising:
a plurality of drive electrodes disposed on a first side of a substrate in a first layer; and
a plurality of sense electrodes disposed on a second side of the substrate in a second layer so that the sense electrodes intersect the drive electrodes at a plurality of intersections offset by a thickness of the substrate; and
communicating a plurality of signals resulting from a capacitance sensed by the drive and sense electrodes and indicative of the position of the object within the sensing region,
wherein the sensing region further comprises a plurality of isolated conductive elements disposed on the second side of the substrate between the sense electrodes so that, together, the plurality of sense electrodes and the plurality of isolated conductive elements are substantially area filling within the sensing region relative to the plurality of sense electrodes.
43 . The method of claim 42 , wherein:
each drive electrode is coupled to an adjacent drive electrode through a resistive element;
a first drive electrode is coupled to a first voltage source;
a second drive electrode is coupled to a second voltage source; and
a third drive electrode, disposed between the first drive electrode and the second drive electrode, is not coupled to the first or second voltage source.
44 . The method of claim 43 , wherein a fourth drive electrode, disposed between the first drive electrode and the second drive electrode, is not coupled to the first or second voltage source.
45 . The method of claim 43 , wherein:
the first voltage source provides a pulse signal; and
the second voltage source provides ground.
46 . The method of claim 42 , wherein the sensing region further comprises a plurality of isolated conductive elements disposed on the second side of the substrate between the sense electrodes so that, together, the plurality of sense electrodes and the plurality of isolated conductive elements are substantially area filling within the sensing region relative to the plurality of sense electrodes.
47 . The method of claim 42 , wherein the drive electrodes extend arcuately and the sense electrodes extend radially so that the plurality of intersections lie on one or more arcuate paths.