Coordinate input device and display-integrated type coordinate input device capable of directly detecting electrostatic coupling capacitance with high accuracy
August 7, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesTablet input device Position detecting apparatus Position detecting device Display-integrated tablet device providing coordinate detection Capacitance-based proximity with interference rejection apparatus and methods Coordinate input apparatus with pen and finger input detection Coordinate detection device capable of obviating the need of forming closed loop in electrodes thereof Proximity sensor Display-integrated type tablet device Coordinate input apparatus having orthogonal electrodes on opposite surfaces of a dielectric substrate and through-hole connections and manufacturing method thereof InventorsApplicationNo. 09/131394 filed on 08/07/1998US Classes:345/173, Touch panel178/18.03Writing digitizer padExaminersPrimary: Shalwala, BipinAssistant: Piziali, Jeff International ClassesG06F 3/033 (20060101)G09G 3/36 (20060101) Foreign Application Priority Data1997-08-08 JPAbstractIn a coordinate detection period, a first electrode drive circuit sequentially selects source electrodes Sn of the TFT LCD panel to connect the same to an x-signal current amplifying circuit, and to apply an AC voltage to the non-selected electrodes. The x-signal current amplifying circuit detects a detection current flowing through the selected electrode, the magnitude of which corresponds to a distance to a finger (or a conductor pen), to obtain an x-coordinate detection voltage. A second electrode drive circuit and a y-signal current amplifying circuit operate in similar fashion to obtain a y-coordinate detection voltage. A coordinate detection circuit then obtains the x- and y-coordinate values of the designated position based on the x-coordinate detection voltage and the y-coordinate detection voltage, thus enabling pointing by a codeless pen and a finger. | |
