US-12622635-B2 - Display device and method of measuring skin moisture using the same

US12622635B2US 12622635 B2US12622635 B2US 12622635B2US-12622635-B2

Abstract

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.

Inventors

KYOUNGHUN BEEN
Jinwoo Kim
Byeongkyu JEON

Assignees

SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20220508
Priority Date: 20210805

Claims (13)

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0102965, filed Aug. 5, 2021, which is hereby incorporated by reference for all purposes as if fully set forth herein. BACKGROUND Field One or more embodiments generally relate to a display device and a method for measuring skin moisture using the same. Discussion A display device provides information to a user by displaying various images on a display screen. In general, the display device may display information within an allocated screen. As the display device is applied to various electronic devices, there is a need for display devices having various functions. For example, a skin moisture meter capable of measuring human skin moisture is of interest. However, because a touch sensor has a measurement area larger than a skin moisture meter, a mutual capacitance value of a center portion of a touch area is lowered in a low ground mass (LGM) state, and thus, the accuracy of skin moisture level measurement may also be reduced. The above information disclosed in this section is only for understanding the background of the inventive concepts, and, therefore, may contain information that does not form prior art. SUMMARY One or more embodiments provide a display device capable of measuring a skin moisture level regardless of an LGM state. One or more embodiments provide a method of measuring a skin moisture level regardless of an LGM state via a display device. One or more embodiments provide an apparatus capable of measuring a skin moisture level regardless of an LGM state. Additional aspects will be set forth in the detailed description which follows, and, in part, will be apparent from the disclosure, or may be learned by practice of the inventive concepts. According to an embodiment, 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 a first electrode and a second electrode of the touch panel in a mutual sensing mode; measuring, in response to the touch on the touch panel, a second capacitance for the touch area in association with 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. According to an embodiment, a display device includes a display panel, a touch panel, a control module, a comparison part, a computation part, and a moisture calculation part. The touch panel is disposed on the display panel. The control module is configured to: drive the touch panel in each of a mutual sensing mode and a self-sensing mode; measure a first capacitance of a touch area of the touch panel in the mutual sensing mode; and measure a second capacitance of the touch area in the self-sensing mode. The comparison part is configured to: receive the first capacitance and the second capacitance; and compare the first capacitance and the second capacitance with a first reference capacitance and a second reference capacitance, respectively. The computation part is configured to compensate for the first capacitance in response to the first capacitance being less than the first reference capacitance and the second capacitance being greater than the second reference capacitance. The moisture calculation part is configured to determine a skin moisture level using the compensated first capacitance. The computation part is configured to compensate for a value of the first capacitance using a value of the second capacitance. The foregoing general description and the following detailed description are illustrative and explanatory and are intended to provide further explanation of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the inventive concepts, and are incorporated in and constitute a part of this specification, illustrate embodiments of the inventive concepts, and, together with the description, serve to explain principles of the inventive concepts. FIG. 1 is a perspective view of a display device according to an embodiment. FIG. 2 is a diagram illustrating a cross-section of the display device shown in FIG. 1 according to an embodiment. FIG. 3 is a cross-sectional view of the display panel shown in FIG. 2 according to an embodiment. FIG. 4 is a plan view of the display panel shown in FIG. 2 according