Chunghwa Picture Tubes, Ltd.

Chih-Chung Chen

Chia-Lin Liu

Ming-Ta Hsieh

Hsueh-Fang Yin

Chien-Ming Lin

Ke-Horng Chen

Chi-Neng Mo

Huai-An Li

Chi-Lin Chen

Shih-Wei Wang

Yi-Chun Chen

A touch input device includes a substrate, plural sensible conductive layers and plural first switch units. The substrate is provided with an upper surface, the sensible conductive layers are all configured on the upper surface and are arranged in columns and rows. The first switch units are configured on the substrate and are electrically connected with the sensible conductive layers. By the first switch units, same columns of the sensible conductive layers can conduct electrically with one another and same rows of the sensible conductive layers can conduct electrically with one another.

Touch input device

A capacitance sensing circuit for a touch panel includes an analog capacitance-detecting circuit, a PWM-to-digital circuit and a self-calibration circuit. The analog capacitance-detecting circuit detects the capacitance of the touch panel based on a charging current, and converts the detected capacitance into a PWM control signal. The PWM-to-digital circuit converts the PWM control signal into a sensing count value based on a clock signal. The self-calibration circuit adjusts the value of the charging current or the frequency of the clock signal according to the difference between the range of the sensing count value and a predetermined detecting range. The predetermined detecting range can thus be adjusted for matching the range of the sensing count value.

Capacitance sensing circuit

A sensor structure of a touch panel and a method of determining a touch signal generated by the same are disclosed. The sensor structure includes a plurality of sensor lines disposed on a surface of a substrate, and a control circuit electrically connected to the sensor lines. Each of the sensor lines has a plurality of conductive pads and a conductive line electrically connected the conductive pads. The control circuit receives a touch signal from one of the sensor lines. The touch signal is resulting from a touch capacitance generated between a touch and one of the conductive pads of the sensor line. The control circuit calculates the position of the touch based on the touch capacitance. In addition, the touch capacitance generated by a conductive pad close to the control circuit is larger than the touch capacitance generated by another conductive pad further away from the control circuit.

Method for determining touch signal generating by sensor structure of touch panel

In a capacitance sensing analog circuit of a touch panel sensing circuit, by raising a magnitude of a current flowing through a sensing capacitor to form an amplified sensing capacitance, while sensing the amplified sensing capacitance with the aid of pulse width modulation signals, higher resolution of the original sensing capacitance may thus be achieved. Besides, by using a self-calibrating capacitance sensing circuit on the touch panel sensing circuit, linear errors and DC errors of an output signal of the capacitance sensing analog circuit may be filtered off, and thereby resolution of a capacitance amplifying ratio may be effectively raised so as to relieve errors within the capacitance amplifying ratio caused by noises.

Touch panel sensing circuit

Sensor structure of touch panel and method for determining touch signal generating by sensor structure of touch panel

A method of positioning a coordinate suitable for a touch panel includes following steps. When a touch event occurs, the touch panel generates a corresponding detection coordinate periodically until the touch event ends. When the touch event occurs, the detection coordinate generated by the touch panel is sequentially stored. The touch event is ignored until the number of coordinates generated by the touch panel is greater than or equal to N, and N is a positive integer. When the number of coordinates generated by the touch panel is greater than or equal to N, a touch coordinate corresponding to the touch event is generated according to the last generated N detection coordinates. The above-mentioned step of generating the touch coordinate is repeated according to a cycle of generating the detection coordinate by the touch panel so as to renew the touch coordinate until the touch event ends.

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Taichung County, Taiwan

Chih-Chung Chen