Detection device having peripheral detection electrodes
A detection device includes a plurality of first detection electrodes disposed in a matrix of rows and columns in a detection region of a substrate, at least one second detection electrode disposed in a peripheral region outside the detection region, positioned adjacent to some of the plurality of the first detection electrodes, and provided along a side of the detection region, and a coordinate calculation circuit configured to calculate a detection position of a detection target body.
1. A detection device comprising:
a plurality of first detection electrodes disposed in a matrix of rows and columns in a detection region of a substrate;
at least one second detection electrode disposed in a peripheral region outside the detection region, positioned adjacent to some of the plurality of the first detection electrodes, and provided along a side of the detection region; and
a coordinate calculation circuit configured to calculate a detection position of a detection target body, wherein
when any of the first detection electrodes is disposed between a first detection electrode indicating a maximum detection value among the first detection electrodes and a side closest to the first detection electrode indicating the maximum detection value among sides of the detection region, the coordinate calculation circuit calculates the detection position of the detection target body based on the detection value of the first detection electrode indicating the maximum detection value and detection values of some first detection electrodes adjacent to the first detection electrode indicating the maximum detection value, among the plurality of first detection electrodes, and
when the first detection electrode indicating the maximum detection value is disposed on an outer edge side of the detection region, the coordinate calculation circuit calculates the detection position of the detection target body based on the detection value of the first detection electrode indicating the maximum detection value, a detection value of the at least one second detection electrode adjacent to the first detection electrode indicating the maximum detection value, and detection values of some first detection electrodes adjacent to the first detection electrode indicating the maximum detection value, among the plurality of first detection electrodes.
2. The detection device according to claim 1 , wherein the plurality of first detection electrodes and the at least one second detection electrode each output a detection signal in accordance with change in self-capacitance of the detection electrode.
3. The detection device according to claim 1 , wherein a width of the second detection electrode is shorter than a width of each of the first detection electrodes in a direction intersecting an extension direction of the second detection electrode.
4. The detection device according to claim 1 , wherein a time constant of the at least one second detection electrode is equivalent to a time constant of each of the plurality of first detection electrodes in effect.
5. The detection device according to claim 1 , further comprising a shield electrode provided in the peripheral region and surrounding outside of the plurality of first detection electrodes and the at least one second detection electrode.
6. The detection device according to claim 5 , wherein the shield electrode is supplied with a signal having the same phase as signals to the plurality of first detection electrodes and the at least one second detection electrode.
7. The detection device according to claim 5 , wherein the shield electrode is supplied with a signal having the same amplitude as signals to the plurality of first detection electrodes and the at least one second detection electrode.
8. The detection device according to claim 1 , further comprising a storage circuit configured to store a first correction value in accordance with sensitivity of the at least one second detection electrode, wherein the coordinate calculation circuit calculates the detection position of the detection target body based on a value obtained by multiplying the detection value of the at least one second detection electrode by the first correction value.
9. The detection device according to claim 8 , wherein the first correction value is determined based on an average value of a first correction amount of the detection value of the second detection electrode when the detection target body is positioned at a central part of a first detection electrode adjacent to the second detection electrode among the first detection electrodes and a second correction amount of the detection value of the second detection electrode when the detection target body is positioned in a region between the second detection electrode and the first detection electrode.
10. The detection device according to claim 8 , wherein
the first correction value is different for each height of the detection target body, and
the storage circuit stores, as a correction table of the second detection electrode, the relation between the height of the detection target body and the first correction value.
11. The detection device according to claim 8 , wherein
the at least one second detection electrode extends along the side of the detection region, and
the storage circuit stores a second correction value of the detection value of the second detection electrode in accordance with the position of the detection target body in an extension direction of the second detection electrode.
12. The detection device according to claim 11 , wherein
the second correction value is different for each height of the detection target body, and
the storage circuit stores, as a correction table of the second detection electrode, the relation between the height of the detection target body and the second correction value.
13. The detection device according to claim 1 , further comprising a determination circuit configured to determine whether the detection target body is in contact or nearby based on the detection values of the plurality of first detection electrodes and the at least one second detection electrode, wherein the determination circuit determines that the detection target body is in the peripheral region when the detection value of the second detection electrode is maximum among the detection values of the plurality of first detection electrodes and the at least one second detection electrode.
14. A detection device comprising:
a plurality of first detection electrodes disposed in a matrix of rows and columns in a detection region of a substrate; and
at least one second detection electrode disposed in a peripheral region outside the detection region, positioned adjacent to some of the plurality of first detection electrodes, and provided along a side of the detection region,
wherein when a first detection electrode indicating a maximum detection value among the plurality of first detection electrodes is disposed on an outer edge side of the detection region, a detection position of the detection target body is calculated based on the detection value of the first detection electrode indicating the maximum detection value, a detection value of the at least one second detection electrode adjacent to the first detection electrode indicating the maximum detection value, and detection values of some first detection electrodes adjacent to the first detection electrode indicating the maximum detection value, among the plurality of first detection electrodes.
15. The detection device according to claim 14 , wherein a width of the second detection electrode is shorter than a width of each of the first detection electrodes in a direction intersecting an extension direction of the second detection electrode.