Display device and method of measuring skin moisture using the same
A method of measuring skin moisture includes: measuring, in response to a touch on a touch panel, a first capacitance for a touch area in association with driving first and second electrodes of the touch panel in a mutual sensing mode; measuring, in response to the touch, a second capacitance for the touch area in association with driving one electrode of the first and second electrodes in a self-sensing mode; comparing the first capacitance with a first reference capacitance; determining, in response to the first capacitance being greater than the first reference capacitance, a skin moisture level using the first capacitance and the second capacitance; comparing, in response to the first capacitance being less than the first reference capacitance, the second capacitance with a second reference capacitance; and compensating, in response to the second capacitance being greater than the second reference capacitance, the first capacitance using the second capacitance.
1 . A method of measuring skin moisture, the method comprising:
measuring, in response to a touch on a touch panel, a first capacitance of a touch area by driving a first electrode and a second electrode of the touch panel in a mutual sensing mode, the first electrode comprising a plurality of transmission sensor parts, the second electrode comprising a plurality of reception sensor parts, the transmission sensor parts and the reception sensor parts forming a mesh;
measuring, in response to the touch on the touch panel, a second capacitance of the touch area driving one electrode of the first electrode and the second electrode in a self-sensing mode;
comparing the first capacitance with a first reference capacitance;
determining, in response to the first capacitance being greater than the first reference capacitance, a skin moisture level using the first capacitance and the second capacitance;
comparing, in response to the first capacitance being less than the first reference capacitance, the second capacitance with a second reference capacitance;
compensating, in response to the second capacitance being greater than the second reference capacitance, the first capacitance using the second capacitance, and determining the skin moisture level using the compensated first capacitance;
determining, in response to the second capacitance being less than the second reference capacitance, the user's skin is not normally touched in the touch area,
wherein the compensating of the first capacitance with the second capacitance comprises:
setting the touch area to include a central area and a peripheral area around the central area, the central area being defined by a first group of the transmission sensor parts and the reception sensor parts and forming a first central capacitance and a second central capacitance, the peripheral area being defined by a second group of the transmission sensor parts and the reception sensor parts and forming a first peripheral capacitance and a second peripheral capacitance; and
compensating the first central capacitance with the second central capacitance.
2 . The method of claim 1 , wherein the determining of the skin moisture level using the first capacitance and the second capacitance comprises:
generating a third capacitance by determining an average value of the first capacitance of the touch area and the second capacitance of the touch area; and
determining the skin moisture level using the third capacitance.
3 . The method of claim 2 , wherein the determining of the skin moisture level using the first capacitance and the second capacitance further comprises:
determining a moisture value, which corresponds to the third capacitance, from among moisture values stored in a lookup table, the moisture value being the skin moisture level.
4 . The method of claim 1 , further comprising:
outputting an average value of the compensated first capacitance of the touch area and the second capacitance of the touch area as a fourth capacitance; and
determining a moisture value, which corresponds to the fourth capacitance, from among moisture values stored in a lookup table, the moisture value being the skin moisture level.
5 . The method of claim 1 , wherein:
the first capacitance of the touch area is less than the first reference capacitance; and
the first central capacitance is less than the first peripheral capacitance.
6 . The method of claim 5 , wherein, in a state where a user performing the touch is not grounded, the first central capacitance is determined to be less than the first peripheral capacitance.
7 . The method of claim 6 , wherein, in a state where the user performing the touch is grounded, the first reference capacitance is set to an average value of the touch area capacitances.
8 . The method of claim 1 , wherein, in response to the second capacitance of the touch area being less than the second reference capacitance, the second central capacitance is less than the second peripheral capacitance.
9 . The method of claim 8 , wherein, in response to the determining the user's skin is not normally touched in the touch area, the touch panel is in an abnormal touch state, and the second central capacitance in the abnormal touch state is less than a second central capacitance in a normal touch state.
10 . The method of claim 9 , wherein:
the second central capacitance is an average value of capacitances measured in cells in the central area; and
the second reference capacitance is set to 30% of an average value of the second peripheral capacitances.
11 . The method of claim 1 , further comprising:
requesting, in response to the second capacitance of the touch area being less than the second reference capacitance, another touch of the touch panel.
12 . The method of claim 1 , wherein, in the mutual sensing mode, a driving signal is applied to the first electrode and a sensing signal is output through the second electrode.
13 . The method of claim 1 , wherein, in the self-sensing mode, a driving signal is applied to the one electrode of the first electrode and the second electrode, and a sensing signal is output from the one electrode.