Display device, driving method thereof, and electronic device
A display device including: first sensors; second sensors forming a capacitance with the first sensors; a sensor transmitter connected to the first sensors and configured to supply driving signals to the first sensors; and a sensor receiver connected to the second sensors and configured to receive sensing signals from the second sensors, wherein the sensor receiver includes an analog front-end connected to a (2-1)-th sensor and a (2-2)-th sensor of the second sensors, and the analog front-end is configured to output a differential signal of a (2-1)-th sensing signal from the (2-1)-th sensor and a (2-2)-th sensing signal from the (2-2)-th sensor in a first sensing mode, and output each of the (2-1)-th sensing signal and the (2-2)-th sensing signal in a time division manner in a second sensing mode.
1 . A display device comprising:
first sensors;
second sensors forming a capacitance with the first sensors;
a sensor transmitter connected to the first sensors and configured to supply driving signals to the first sensors; and
a sensor receiver connected to the second sensors and configured to receive sensing signals from the second sensors,
wherein the sensor receiver includes an analog front-end connected to a (2-1)-th sensor and a (2-2)-th sensor of the second sensors, and
the analog front-end is configured to output a differential signal of a (2-1)-th sensing signal from the (2-1)-th sensor and a (2-2)-th sensing signal from the (2-2)-th sensor in a first sensing mode, and output each of the (2-1)-th sensing signal and the (2-2)-th sensing signal in a time division manner in a second sensing mode.
2 . The display device of claim 1 , wherein
the differential signal outputted in the first sensing mode is used to determine a touch position, and
the (2-1)-th sensing signal outputted in the second sensing mode is set as a baseline of the (2-1)-th sensor, and the (2-2)-th sensing signal outputted in the second sensing mode is set as a baseline of the (2-2)-th sensor.
3 . The display device of claim 2 , wherein
when the display device operates in the first display mode, the analog front-end operates only in the first sensing mode, and
when the display device operates in the second display mode, the analog front-end alternates between the first sensing mode and the second sensing mode.
4 . The display device of claim 3 , wherein
when the display device operates in a third display mode, the analog front-end operates only in the second sensing mode.
5 . The display device of claim 4 , wherein
the first display mode is a normal display mode in which an image is displayed,
the second display mode is an idle display mode in which an image is displayed, but no user input is detected for a certain period of time, and
the third display mode is a low-power display mode in which no image is displayed, or only minimal information is displayed.
6 . The display device of claim 1 , wherein
the analog front-end includes a first charge amplifier and a second charge amplifier,
in the first sensing mode, the (2-1)-th sensor and the (2-2)-th sensor are connected to a first input terminal and a second input terminal of the first charge amplifier, and
in the second sensing mode, the (2-1)-th sensor is connected to the first input terminal of the first charge amplifier, and the (2-2)-th sensor is connected to a first input terminal of the second charge amplifier.
7 . The display device of claim 6 , wherein
the first charge amplifier is a fully differential amplifier, and
the second charge amplifier is a differential amplifier with a single-ended output.
8 . The display device of claim 6 , wherein
in the second sensing mode, the second input terminal of the first charge amplifier is connected to a reference node.
9 . The display device of claim 6 , wherein
the analog front-end further includes:
a first filter circuit connected to output terminals of the first charge amplifier;
a second filter circuit connected to an output terminal of the second charge amplifier; and
an analog-to-digital converter.
10 . The display device of claim 9 , wherein
in the first sensing mode, output terminals of the first filter circuit are connected to the analog-to-digital converter, and
in the second sensing mode, a first output terminal of the first filter circuit and an output terminal of the second filter circuit are alternately connected to the analog-to-digital converter.
11 . A driving method of a display device, comprising:
supplying, by a sensor transmitter, driving signals to first sensors; and
receiving, by a sensor receiver, sensing signals from second sensors that form a capacitance with the first sensors,
wherein the sensor receiver includes an analog front-end connected to a (2-1)-th sensor and a (2-2)-th sensor of the second sensors, and
the analog front-end outputs a differential signal of a (2-1)-th sensing signal from the (2-1)-th sensor and a (2-2)-th sensing signal from the (2-2)-th sensor in a first sensing mode, and outputs the (2-1)-th sensing signal and the (2-2)-th sensing signal in a time division manner in a second sensing mode.
12 . The driving method of the display device of claim 11 , wherein
the differential signal outputted in the first sensing mode is used to determine a touch position, and
the (2-1)-th sensing signal outputted in a second sensing mode is set as a base line of the (2-1)-th sensor, and the (2-2)-th sensing signal outputted in the second sensing mode is set as a base line of the (2-2)-th sensor.
13 . The driving method of the display device of claim 12 , wherein
when the display device operates in the first display mode, the analog front-end operates only in the first sensing mode, and
when the display device operates in the second display mode, the analog front-end alternates between the first sensing mode and the second sensing mode.
14 . The driving method of the display device of claim 13 , wherein
when the display device operates in a third display mode, the analog front-end operates only in the second sensing mode.
15 . The driving method of the display device of claim 14 , wherein
the first display mode is a normal display mode in which an image is displayed,
the second display mode is an idle display mode in which an image is displayed, but no user input is detected for a certain period of time, and
the third display mode is a low-power display mode in which no image is displayed, or only minimal information is displayed.
16 . The driving method of the display device of claim 11 , wherein
the analog front-end includes a first charge amplifier and a second charge amplifier,
in the first sensing mode, the (2-1)-th sensor and the (2-2)-th sensor are connected to a first input terminal and a second input terminal of the first charge amplifier, and
in the second sensing mode, the (2-1)-th sensor is connected to the first input terminal of the first charge amplifier, and the (2-2)-th sensor is connected to a first input terminal of the second charge amplifier.
17 . The driving method of the display device of claim 16 , wherein
the first charge amplifier is a fully differential amplifier, and
the second charge amplifier is a differential amplifier with a single-ended output.
18 . The driving method of the display device of claim 16 , wherein
in the second sensing mode, the second input terminal of the first charge amplifier is connected to a reference node.
19 . The driving method of the display device of claim 16 , wherein
the analog front-end further includes:
a first filter circuit connected to output terminals of the first charge amplifier;
a second filter circuit connected to an output terminal of the second charge amplifier; and
an analog-to-digital converter.
20 . The driving method of the display device of claim 19 , wherein
in the first sensing mode, output terminals of the first filter circuit are connected to the analog-to-digital converter, and
in the second sensing mode, a first output terminal of the first filter circuit and an output terminal of the second filter circuit are alternately connected to the analog-to-digital converter.
21 . An electronic device comprising:
a processor to provide input image data; and
a display device to display an image based on the input image data, the display device comprising:
first sensors;
second sensors forming a capacitance with the first sensors;
a sensor transmitter connected to the first sensors and configured to supply driving signals to the first sensors; and
a sensor receiver connected to the second sensors and configured to receive sensing signals from the second sensors,
wherein the sensor receiver includes an analog front-end connected to a (2-1)-th sensor and a (2-2)-th sensor of the second sensors, and
the analog front-end is configured to output a differential signal of a (2-1)-th sensing signal from the (2-1)-th sensor and a (2-2)-th sensing signal from the (2-2)-th sensor in a first sensing mode, and output each of the (2-1)-th sensing signal and the (2-2)-th sensing signal in a time division manner in a second sensing mode.