Wacom Co., Ltd.

Wacom Corporation Limited

Tomohiro Kagami

Yasuo Oda

A pen detection system is provided that detects a pen signal transmitted from a pen to detect a position of the pen. The system includes a sensor pattern in which an electrode group including first and second partial electrode groups is disposed; a first integrated circuit that is connected to the first partial electrode group to acquire a level distribution of the pen signal in the first partial electrode group; and a second integrated circuit that is connected to the second partial electrode group to acquire a level distribution of the pen signal in the second partial electrode group. A predetermined number of boundary electrodes positioned near a boundary of the first partial electrode group and the second partial electrode group among a plurality of electrodes included in the electrode group are connected to both of the first and second integrated circuits, wherein the predetermined number is an even number.

Pen detection system

A pen detection system is provided which does not require an integrated circuit dedicated to a large display panel. A pen detection systemincludes an integrated circuitand an integrated circuit. The integrated circuitis connected to a first partial column electrode groupGa to acquire a first column level distribution indicating a level distribution of a pen signal in the first partial column electrode groupGa and is connected to a first partial row electrode groupGa to acquire a first row level distribution indicating a level distribution of the pen signal in the first partial row electrode groupGa. The integrated circuitis connected to a second partial column electrode groupGb to acquire a second column level distribution indicating a level distribution of the pen signal in the second partial column electrode groupGb and is connected to a second partial row electrode groupGb to acquire a second row level distribution indicating a level distribution of the pen signal in the second partial row electrode groupGb. The pen detection systemderives a column direction position of a pen based on the first and second column level distributions and derives a row direction position based on the first and second row level distributions.

A signal transmitting circuit prevents oscillation efficiency from dropping regardless of changes in transmission signal frequency. The signal transmitting circuit includes a switch circuit that enables a current to flow to a resonance circuit including a capacitor and a coil to provide energy that sustains resonance of the resonance circuit, and a control signal generating circuit that generates a control signal to control changeover of the switch circuit, thereby outputting a transmission signal having a resonance frequency of the resonance circuit. The control signal generating circuit includes a detection circuit that detects a cycle of the transmission signal, a timing generating circuit that generates a timing point at which the changeover control signal is generated based on a detection result of the detection circuit, and a drive circuit that generates the control signal at the timing point generated by the timing generating circuit to control changeover of the switch circuit.

Transmitting type electronic pen and signal transmitting circuit thereof

An electrostatic pen has a switch, control circuitry to control the switch and a pen point electrode. The switch has first, second and third terminals and a first diode having an anode coupled to the first terminal and a cathode coupled to the third terminal. The pen point electrode is coupled to the first terminal of the switch. The control circuitry, in operation, supplies respective potentials to the second terminal and the third terminal of the switch and switches between two or more states including a first state in which a potential of the second terminal is higher than a potential of the third terminal and a second state in which the potential of the second terminal is equal to or lower than the potential of the third terminal.

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Saitama, Japan

Tomohiro Kagami