Elan Microelectronics Corporation

Hsin-Shieh Tsai

Yi-Hsin Tao

Chia-Hsing Lin

Jung-Shou Huang

Tse-Lun Hung

Hung Nien

Chun-Chung Huang

Hsuan-Wen Tseng

Po-Hao Kuo

Brian Sung

Min-Jhih Lin

Chih-Hsien Teng

Methods are proposed for object positioning for an X-Y projected capacitive touch panel. In an embodiment, capacitance sensing under inphase excitation of traces is applied to set a base value when the capacitive touch panel is not touched and to obtain capacitances at intersections when the capacitive touch panel is touched, and the base value is compared with the measured capacitances to identify touch points. In other embodiments, X-Y projected sensing and all-point sensing are combined to reduce the amount of calculation and achieve the same positioning effect as an all-point capacitive touch panel.

Object positioning for an X-Y projected capacitive touch panel

A capacitive touch system uses two or more integrated circuits to simultaneously scan a touch panel in such a manner that each of the integrated circuits scans only a portion of the touch panel to retrieve a respective detected data by itself. All the detected data are used for computation by one of the integrated circuits or one other than the integrated circuits to determine a touch information. This approach enables axis intersect projected capacitance touch integrated circuits applicable to a large scale touch panel, without degrading the frame rate of a capacitive touch system.

Capacitive touch system and control method for a capacitive touch system

Ghost resolution sensing methods are provided for capacitive touch panels. When ghost is detected involving two points on a capacitive touch panel, for each of the two points, the intersected traces at that one are concurrently charged to sense the capacitance value from either one of the intersected traces, and according thereto, a real point and a ghost point can be distinguished from each other. Alternatively, the intersected traces are crisscross driven by two synchronous and in phase signals or synchronous but out of phase signals, to sense the capacitance values at the two points. Preferably, intersectional calibration is performed in conjunction therewith, to recognize the real points.

Ghost resolution for a capacitive touch panel

A capacitive touch panel has a plurality of traces including a boundary trace, and a virtual trace is defined outward of the boundary trace and assigned with a virtual coordinate and a virtual capacitance for interpolation to position a touch point around the boundary of the capacitive touch panel, thereby eliminating the non-addressable region of the capacitive touch panel.

Boundary resolution improvement for a capacitive touch panel

A capacitive touch system includes a touch panel and two touch integrated circuits connected to the touch panel to scan thereto. The touch panel has a boundary trace connected to both of the two touch integrated circuits. When one of the two touch integrated circuits charges/discharges the boundary trace, the other touch integrated circuit does not charges/discharges the boundary trace.

Capacitive touch system and sensing method for a capacitive touch system

A capacitive touch system uses at least two touch integrated circuits to simultaneously scan a touch panel, each of the touch integrated circuits only for scanning a portion of the traces of the touch panel. Therefore, the capacitive touch system can maintain a good frame rate, even the touch panel is a large scale touch panel. Sensing methods are provided to determine a sensed value for a boundary trace which is the last one of the traces connected to a first touch integrated circuit and prior to the first one of the traces connected to a second touch integrated circuit.

Growing community of inventors

Changhua County, Taiwan

Hsin-Shieh Tsai