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"Display Device Including Integrated Touch Panel and Method of Driving the Same" in Patent Application Approval Process

June 5, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- A patent application by the inventors PYO, Seung-Eun (Gyeyang-gu, KR); LEE, Jeong-Seop (Gimje-si, KR), filed on April 2, 2013, was made available online on May 22, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.

This patent application is assigned to LG Display Co., Ltd.

The following quote was obtained by the news editors from the background information supplied by the inventors: "The following description relates to a display device, and more particularly, to a display device including an integrated touch panel.

"A touch panel is a kind of input device that is installed in an image display device, such as a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an electroluminescence device (EL), an eletrophoretic display (EPD), etc., to allow a user to input predetermined information by pressing (or touching) a touch sensor in the touch screen while viewing the image display device.

"Recently, in order to implement a slim mobile terminal, such as a smart phone, a tablet PC, or the like, demands on an in-cell type display device including an integrated touch panel where elements configuring the touch panel are installed are increasing.

"Hereinafter, an in-cell type display device including an integrated touch panel and a noise level according to application of a touch driving voltage will be described with reference to FIGS. 1, 2A, and 2B.

"FIG. 1 is a view showing a display device including an integrated touch panel according to the related art. Specifically, FIG. 1 shows an in-cell self-capacitive type display device including an integrated touch panel.

"In FIG. 1, an in-cell self-capacitive type display device including an integrated touch panel according to the related art includes a panel 10 where a plurality of electrodes 11 and a plurality of lines 12 connected to the plurality of electrodes 11, respectively, are formed, and a touch integrated circuit (IC) 20.

"For example, the touch IC 20 may sense a change in capacitance due to a touch input applied to the plurality of electrodes 11 through a touch sensing unit 21.

"FIGS. 2A and 2B are graphs showing a noise level according to application of a touch driving voltage in a display device including an integrated touch panel according to the related art.

"In FIG. 2A, when touch driving voltages VDDT of about 0.7V and about 0.85V are applied to a plurality of electrodes of a first display device including an integrated touch panel, touch sensing results of changes in capacitance have noise levels of about 25 F and about 30 F, respectively.

"In FIG. 2B, when touch driving voltages VDDT of about 0.7V and about 0.85V are applied to a plurality of electrodes of a second display device including an integrated touch panel, sensed signals of changes in capacitance have noise levels of about 60 F and about 30 F, respectively.

"Here, a touch sensitivity is proportional to a signal to noise ratio (SNR), which is an average value of a sensed signal with a touch input and an average value of a sensed signal without a touch input divided by a maximum value of a noise without a touch input. Accordingly, as the noise increases, the signal to noise ratio decreases and the touch sensitivity is reduced.

"The display device including an integrated touch panel has a deviation in noise level and the noise level of the display device including an integrated touch panel varies according to a driving circumstance. For example, the specific touch driving voltage may be an optimum value which minimizes the noise level in a display device including an integrated touch panel and may be a value which maximizes the noise level in another display device including an integrated touch panel. Thus, the noise level may vary across different display devices even when using the same touch driving voltage."

In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "Embodiments of the present invention relate to a display device including an integrated touch panel and a method of driving the same. Accordingly, embodiments of the present invention are directed to a display device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

"An object of embodiments is to provide a display device including an integrated touch panel where a touch driving voltage VDDT suitable for a touch driving circumstance is applied to the touch panel.

"Advantages, objects, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

"To achieve these objects and other advantages and in accordance with the purpose according to one aspect of the invention, there is provided a method of driving a display device including an integrated touch panel, the method comprising: applying a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel; determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages; comparing the plurality of noise levels to a threshold level; and selecting a sampling voltage from the plurality of sampling voltages to use as a touch driving voltage based on the comparison of the plurality of noise levels to the threshold level; and applying the selected sampling voltage as the touch driving voltage to the plurality of electrodes.

"In another aspect, there is provided a method of driving a display device including an integrated touch panel, the method comprising: applying a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel; determining a plurality of noise levels associated with the plurality of sampling voltages; determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages; comparing the plurality of noise levels to a threshold level; responsive to determining that all the plurality of noise levels are greater than the threshold level: determining a sampling voltage associated with a minimum noise level from amongst the plurality of noise levels; and selecting the determined sampling voltage associated with the minimum noise level as the touch driving voltage; responsive to determining a sampling voltage of the plurality of sampling voltages that is associated with a determined noise level that is less than the threshold level: selecting the determining sampling voltage as the touch driving voltage; and applying the selected sampling voltage as the touch driving voltage to the plurality of electrodes.

"In another aspect, there is provided a display device comprising: an integrated touch panel having a plurality of electrodes; and a touch integrated circuit (IC), comprising: a switching unit for applying a plurality of sampling voltages to the plurality of electrodes of the integrated touch panel; a comparing unit for: determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages; comparing the plurality of noise levels to a threshold level; and selecting a sampling voltage from the plurality of sampling voltages to use as a touch driving voltage based on the comparison of the plurality of noise levels to the threshold level; and a touch sensing unit for applying the touch driving voltage to the plurality of electrodes.

"It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

"The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate implementations of the invention and together with the description serve to explain the principles of the invention.

"FIG. 1 is a view showing a display device including an integrated touch panel according to the related art.

"FIGS. 2A and 2B are graphs showing a noise level according to application of a touch driving voltage in a display device including an integrated touch panel according to the related art.

"FIG. 3 is a view showing a display device including an integrated touch panel according to one embodiment.

"FIG. 4 is a view showing an operation of a display device including an integrated touch panel according to one embodiment."

URL and more information on this patent application, see: PYO, Seung-Eun; LEE, Jeong-Seop. Display Device Including Integrated Touch Panel and Method of Driving the Same. Filed April 2, 2013 and posted May 22, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4779&p=96&f=G&l=50&d=PG01&S1=20140515.PD.&OS=PD/20140515&RS=PD/20140515

Keywords for this news article include: LG Display Co. Ltd.

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Source: Politics & Government Week


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