Display device and input device
A sensing unit performs a first sensing process of sensing an approach or a contact of an object to a display panel by collectively sensing electrostatic capacitance of each of a plurality of sensing electrodes provided in a matrix pattern. Further, in a case where the approach or the contact of the object has not been sensed in the first sensing process, the sensing unit repeats the first sensing process, and in a case where the approach or the contact of the object has been sensed in the first sensing process, the sensing unit performs a second sensing process of sensing a position of the object by individually sensing the electrostatic capacitance of each of the plurality of sensing electrodes.
1. A display device comprising:
a display panel having a display surface on which images are displayed;
a plurality of first electrodes provided in a matrix pattern in the display panel when seen in a plan view;
a sensing unit which senses electrostatic capacitance of each of the plurality of first electrodes; and
a plurality of second electrode groups arranged in a fifth direction when seen in a plan view,
wherein the sensing unit performs a first sensing process of selecting all or part of the plurality of first electrodes as a plurality of sensing process electrodes and collectively sensing electrostatic capacitance of each of the plurality of selected sensing process electrodes, thereby sensing an approach or a contact of an object to the display panel,
in a case where the approach or the contact of the object has not been sensed in the first sensing process, the sensing unit repeats the first sensing process, and
in a case where the approach or the contact of the object has been sensed in the first sensing process, the sensing unit performs a second sensing process of sensing a position of the object by individually sensing the electrostatic capacitance of each of the plurality of first electrodes,
wherein the sensing unit includes:
a sensing circuit which senses electrostatic capacitance of each of the plurality of first electrodes; and
a connection circuit which connects each of the plurality of first electrodes to the sensing circuit;
in the first sensing process, the sensing unit collectively senses the electrostatic capacitance of each of the plurality of sensing process electrodes by connecting each of the plurality of selected sensing process electrodes to the sensing circuit via the connection circuit, and
in the second sensing process, the sensing unit individually senses the electrostatic capacitance of each of the plurality of first electrodes by sequentially switching and connecting the plurality of first electrodes one by one or in units of several first electrodes to the sensing circuit via the connection circuit, and
wherein each of the plurality of second electrode groups includes the plurality of first electrodes arranged in a sixth direction crossing the fifth direction when seen in a plan view,
the connection circuit includes a plurality of transistor groups which connect each of the plurality of second electrode groups to the sensing circuit,
each of the plurality of transistor groups includes a plurality of first field effect transistors,
each of the plurality of first field effect transistors includes a first gate electrode,
in each pair of the second electrode groups and the transistor groups, the plurality of first field effect transistors included in the transistor group connect each of the plurality of first electrodes included in the second electrode group to the sensing circuit,
the connection circuit further includes:
a plurality of unit register circuits which supply a first gate voltage of the first field effect transistor to each of the plurality of transistor groups;
a voltage supply circuit which supplies a second gate voltage of the first field effect transistor to each of the plurality of transistor groups; and
a plurality of OR circuits which calculate an OR of an output of the voltage supply circuit and an output of each of the plurality of unit register circuits,
the plurality of unit register circuits form a shift register circuit,
in each set of the transistor groups, the unit register circuits and the OR circuits, an output of the OR circuit is input to the first gate electrode of each of the plurality of first field effect transistors included in the transistor group,
the first field effect transistor is in an on state even when any of the first gate voltage and the second gate voltage is input to the first gate electrode, and
in the first sensing process, the sensing unit selects the plurality of first electrodes included in each of the plurality of second electrode groups as the plurality of sensing process electrodes by supplying the second gate voltage from the voltage supply circuit.
2. The display device according to claim 1 , further comprising:
a plurality of first electrode groups arranged in a first direction when seen in a plan view,
wherein each of the plurality of first electrode groups includes the plurality of first electrodes arranged in a second direction crossing the first direction when seen in a plan view, and
in the first sensing process, the sensing unit selects part of the plurality of first electrode groups as a plurality of sensing process electrode groups, and selects the plurality of first electrodes included in each of the plurality of selected sensing process electrode groups as the plurality of sensing process electrodes.
3. The display device according to claim 2 ,
wherein, in the first sensing process, the sensing unit selects the plurality of first electrode groups which are not adjacent to each other as the plurality of sensing process electrode groups.
4. The display device according to claim 1 ,
wherein the plurality of first electrodes are arranged in a matrix pattern in a third direction and a fourth direction which cross each other when seen in a plan view, and
in the first sensing process, the sensing unit selects some of the plurality of first electrodes which are not adjacent to each other in the third direction as the plurality of sensing process electrodes.
5. The display device according to claim 4 ,
wherein, in the first sensing process, the sensing unit selects some of the plurality of first electrodes which are not adjacent to each other in any of the third direction and the fourth direction as the plurality of sensing process electrodes.
6. The display device according to claim 1 , further comprising:
a plurality of scanning lines which overlap the plurality of first electrodes when seen in a plan view,
wherein the sensing unit performs the first sensing process in a state where each of the plurality of scanning lines is electrically floating.
7. The display device according to claim 1 , further comprising:
a plurality of scanning lines which overlap the plurality of second electrode groups when seen in a plan view;
a scanning signal output circuit which outputs a scanning signal input to the plurality of scanning lines; and
a switching unit which switches a connection state of the scanning signal output circuit and the plurality of scanning lines,
wherein the switching unit includes a plurality of second field effect transistors which connect each of the plurality of scanning lines and the scanning signal output circuit,
each of the plurality of second field effect transistors includes a second gate electrode,
an output of the voltage supply circuit is input to the second gate electrode of each of the plurality of second field effect transistors,
the second field effect transistor is in an off state when the second gate voltage is input to the second gate electrode, and
the sensing unit supplies the second voltage from the voltage supply circuit to the second gate electrode of each of the plurality of second field effect transistors and performs the first sensing process in a state where each of the plurality of scanning lines is electrically floating.
8. An input device comprising:
a substrate;
a plurality of first electrodes provided in a matrix pattern on the substrate when seen in a plan view; and
a sensing unit which senses electrostatic capacitance of each of the plurality of first electrodes; and
a plurality of second electrode groups arranged in a fifth direction when seen in a plan view,
wherein the sensing unit performs a first sensing process of selecting all or part of the plurality of first electrodes as a plurality of sensing process electrodes and collectively sensing electrostatic capacitance of each of the plurality of selected sensing process electrodes, thereby sensing an approach or a contact of an object to the substrate,
in a case where the approach or the contact of the object has not been sensed in the first sensing process, the sensing unit repeats the first sensing process, and
in a case where the approach or the contact of the object has been sensed in the first sensing process, the sensing unit performs a second sensing process of sensing a position of the object by individually sensing the electrostatic capacitance of each of the plurality of first electrodes,
wherein the sensing unit includes:
a sensing circuit which senses electrostatic capacitance of each of the plurality of first electrodes; and
a connection circuit which connects each of the plurality of first electrodes to the sensing circuit,
in the first sensing process, the sensing unit
collectively senses the electrostatic capacitance of each of the plurality of sensing process electrodes by connecting each of the plurality of selected sensing process electrodes to the sensing circuit via the connection circuit, and
in the second sensing process, the sensing unit individually senses the electrostatic capacitance of each of the plurality of first electrodes by sequentially switching and connecting the plurality of first electrodes one by one or in units of several first electrodes to the sensing circuit via the connection circuit, and
wherein each of the plurality of second electrode groups includes the plurality of first electrodes arranged in a sixth direction crossing the fifth direction when seen in a plan view, the connection circuit includes a plurality of transistor
groups which connect each of the plurality of second electrode groups to the sensing circuit,
each of the plurality of transistor groups includes a plurality of first field effect transistors,
each of the plurality of first field effect transistors includes a first gate electrode,
in each pair of the second electrode groups and the
transistor groups, the plurality of first field effect transistors included in the transistor group connect each of the plurality of first electrodes included in the second electrode group to the sensing circuit,
the connection circuit further includes:
a plurality of unit register circuits which supply a first gate voltage of the first field effect transistor to each of the plurality of transistor groups;
a voltage supply circuit which supplies a second gate voltage of the first field effect transistor to each of the plurality of transistor groups; and
a plurality of OR circuits which calculate an OR of an output of the voltage supply circuit and an output of each of the plurality of unit register circuits,
the plurality of unit register circuits form a shift register circuit,
in each set of the transistor groups, the unit register circuits and the OR circuits, an output of the OR circuit is input to the first gate electrode of each of the plurality of first field effect transistors included in the transistor group,
the first field effect transistor is in an on state even when any of the first gate voltage and the second gate voltage is input to the first gate electrode, and
in the first sensing process, the sensing unit selects the plurality of first electrodes included in each of the plurality of second electrode groups as the plurality of sensing process electrodes by supplying the second gate voltage from the voltage supply circuit.
9. The input device according to claim 8 further comprising:
a plurality of first electrode groups arranged in a first direction when seen in a plan view,
wherein each of the plurality of first electrode groups includes the plurality of first electrodes arranged in a second direction crossing the first direction when seen in a plan view, and
in the first sensing process, the sensing unit selects part of the plurality of first electrode groups as a plurality of sensing process electrode groups, and selects the plurality of first electrodes included in each of the plurality of selected sensing process electrode groups as the plurality of sensing process electrodes.
10. The input device according to claim 9 ,
wherein, in the first sensing process, the sensing unit selects the plurality of first electrode groups which are not adjacent to each other as the plurality of sensing process electrode groups.
11. The input device according to claim 8 ,
wherein the plurality of first electrodes are arranged in a matrix pattern in a third direction and a fourth direction which cross each other when seen in a plan view, and
in the first sensing process, the sensing unit selects some of the plurality of first electrodes which are not adjacent to each other in the third direction as the plurality of sensing process electrodes.
12. The input device according to claim 11 ,
wherein, in the first sensing process, the sensing unit selects some of the plurality of first electrodes which are not adjacent to each other in any of the third direction and the fourth direction as the plurality of sensing process electrodes.