Driving algorithm on projected capacitance touch

摘要

A projected capacitive touch panel comprises a touch control integrated circuit, sensing electrodes, driving electrodes, a MCU, a AC signal generator, a sensing bus, and a driving bus. The driving electrodes are made of high resistance material. One driving electrodes is selected by MCU based on firmware program as selected driving electrode. A low voltage AC signal is generated by the AC signal generator. The AC signal is transmitted to the selected driving electrode and its adjacent two driving electrodes via the driving bus. The rest of driving electrodes are connected to a fixed DC level. Providing the same AC signal to three driving electrodes simultaneously can induce higher sensing signal in the sensing electrodes.

主权项

1. A projected capacitive touch panel architecture, comprising
a sensor; a touch control integrated circuit; a sensing bus; a driving bus; said touch control integrated circuit comprising a sensing IC, a driving IC, and a micro-programmed control unit (MCU); said sensor comprising a plurality of sensing electrodes, and a plurality of driving electrodes; said driving electrodes comprises a selected driving electrode; said selected driving electrode being selected by said micro-programmed control unit (MCU) from said driving electrodes; two of said driving electrodes adjacent to said selected driving electrode being selected by said micro-programmed control unit (MCU) from said driving electrodes; said plurality of driving electrodes parallel to each other; said plurality of sensing electrodes parallel to each other; said plurality of driving electrodes and said plurality of sensing electrodes are vertical to each other; a quantity of said sensing electrodes being N; a quantity of said driving electrodes being M+2; said micro-programmed control unit (MCU) select said selected driving electrode from a second driving electrode to a second from the last driving electrode cyclically; said micro-programmed control unit (MCU) select M of said driving electrodes within one cycle as selected driving electrode; said driving IC comprising an AC signal generator, said AC signal generator inputs square waveform from said micro-programmed control unit (MCU), and said AC signal generator outputs voltage no greater than 5V; said sensing bus connecting said sensing IC to said sensing electrodes; said driving bus connecting said driving IC to said driving electrodes; said driving electrodes being high resistance conductive material; said selected driving electrode being connected to said AC signal generator by said driving bus; two driving electrodes adjacent to said selected driving electrode being connected to said AC signal generator by said driving bus; and driving electrodes not being connected to said AC signal generator being connected to a fixed DC level.