Himax Technologies, Inc.

Yi-Yang Tsai

Yaw-Guang Chang

Jia-Ming He

Zong-You Hou

Yu-Chun Lin

A touch detection circuit includes at least one driving signal generator. The least one driving signal generator receives a first power voltage and a second power voltage as operation powers. Each of the at least one driving signal generator generates at least one driving signal based on the first power voltage and a second power voltage and each of the at least one driving signal swings between a first voltage and a second voltage, wherein the first voltage is a positive voltage and the second voltage is a negative voltage.

Touch detection circuit

A circuit, for a touch panel, comprising N touch signal processing circuits; a backup processing circuit; and a controller, coupled to the N touch signal processing circuits and the backup processing circuit, configured to determine whether one of the N touch signal processing circuits is failed and generate a determining result, and control the N touch signal processing circuits and the backup processing circuit to process N touch signals received from the touch panel to obtain N digital signals according to the determining result.

Signal processing method and related circuit having backup processing circuit

A touch event processing circuit includes receiving circuits and an average circuit. Each of the receiving circuits includes an operation amplifier, a current processing circuit, and a touch event detection circuit. The operation amplifier receives an input signal from a touch panel, and outputs a first current signal and a second current signal. The current processing circuit processes the first current signal and the second current signal according to a first current average signal and a second current average signal, to generate a processed current signal. The touch event detection circuit detects a touch event according to the processed current signal. The average circuit receives first current signals and second current signals from the receiving circuits; performs an average operation upon the first current signals, to generate the first current average signal; and performs an average operation upon the second current signals, to generate the second current average signal.

Touch event processing circuit

A touch controller coupled to a touch sensor panel and arranged to detect touch events on the touch sensor panel includes a sensing circuit. The sensing circuit includes an integrator circuit and a reference voltage controlling circuit. The integrator circuit includes a first input node coupled to a sensing node for receiving a sensing signal, a second input node coupled to a guard trace disposed adjacent to the touch sensor panel and an output node outputting an integrated signal. The reference voltage controlling circuit includes a switch coupled between the second input node of the integrator circuit and a voltage source providing a reference voltage. The switch is closed during a pre-charge period to charge a voltage on the guard trace to the reference voltage in beginning of a sensing period and is opened after the pre-charge period.

Touch controllers capable of reducing noise interference

A touch event processing circuit includes a plurality of receiving circuits and an average circuit. Each of the plurality of receiving circuits includes a first integrator circuit, a resistor, and a touch event detection circuit. The first integrator circuit is arranged to receive an input signal that includes a voltage sensing signal from a touch panel, and output a first integrated voltage signal. The resistor has a first terminal coupled to an output terminal of the first integrator circuit and a second terminal. The touch event detection circuit is arranged to detect a touch event according to the output from the second terminal of the resistor and a voltage average signal. The average circuit is arranged to: receive a plurality of first integrated voltage signals from the plurality of receiving circuits; and perform an average operation upon the plurality of first integrated voltage signals, to generate the voltage average signal.

A touch sensing circuit for use in a touch sensitive device includes: an integrator, a first switching unit and a control signal generator. The integrator, coupled to at least one sensing electrode of a touch panel in the touch sensitive device, and arranged to collect charges on the at least one sensing electrode and accordingly generate an output sensed signal. The first switching unit is arranged to selectively couple a first end of the at least one sensing electrode to a reference voltage level according to a first mask signal. The control signal generator is arranged to generate the first mask signal according to a synchronization signal of a display panel in the touch sensitive device, wherein the first switching unit couples the first end of the at least one sensing electrode to the reference voltage level when the synchronization signal is asserted.

Touch sensing circuit that selectively couples a sensing electrode to a reference voltage in response to an assertion of a synchronization signal and touch sensitive device

Growing community of inventors

Tainan, Taiwan

Yi-Yang Tsai