Touch input system and method for detecting touch using the same

摘要

A touch input system and a touch detection method using the same are disclosed. With the disclosed touch input system, the size and manufacturing costs of the stylus are reduced while finger touch and touch of stylus without a battery are distinguished and detected. The touch input system includes a sensor panel including a plurality of first channels and a plurality of second channels, crossing each other, a stylus including one or a plurality of primary coils connected in series to each other, a resonance capacitor connected in parallel to the primary coil, and a conductive tip connected to the primary coil, a ground connected to the stylus, an antenna loop formed outside an edge of the sensor panel, and a touch controller connected to the first channel, the second channel, and the antenna loop.

主权项

1. A touch input system comprising:
a sensor panel comprising a plurality of first channels and a plurality of second channels crossing each other; a stylus comprising one or a plurality of primary coils connected in series to each other, a resonance capacitor connected in parallel to the primary coil, and a conductive tip connected to the primary coil; a ground connected to the stylus; an antenna loop formed outside an edge of the sensor panel; and a touch controller directly connected to the plurality of first channels, the plurality of second channels, and the antenna loop, wherein a sensing capacitor is formed at a contact area between the conductive tip and the sensor panel, wherein a drive signal is applied to each channel of the sensor panel from a drive signal generator of the touch controller, and a resonance circuit including the primary coil and the resonance capacitor of the stylus electromagnetically resonates with a same resonant frequency of the applied drive signal input through the sensing capacitor, and wherein the resonance frequency satisfies the condition: f=1/[2π*(L1*C1)0.5], where L1 is an inductance of the primary coil and C1 is a capacitance of the resonance capacitor, and wherein the touch controller includes an amplifier for amplifying a voltage difference between two ends of the antenna loop, a filter unit connected to the amplifier to remove noise, a converter connected to the filter unit to convert an analog signal into a digital signal, a signal processor connected to the converter to collect digital signal to extract coordinates, and the drive signal generator.