US Patent 10324547 Active stylus pen, touch sensing system and driving method thereof

An active stylus pen according to the present invention includes a first signal processor configured to generate a touch frame recognition signal for discriminating touch frames on the basis of sub-pulses corresponding to part of each touchscreen driving signal received from a touchscreen and a second signal processor configured to generate a pen driving signal synchronized with main pulses of each touchscreen driving signal other than the sub-pulses and to vary the pen driving signal in units of a touch frame according to the touch frame recognition signal such that additional pen information is reflected in the pen driving signal.