Capacitive stylus pen having a transformer for boosting a signal

Patent metadata

Field	Value
Publication number	US-9304615-B2
Application number	US-201414521247-A
Country	US
Kind code	B2
Filing date	Oct 22, 2014
Priority date	Nov 27, 2013
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A capacitive stylus pen is provided that inputs an indicated position to a tablet by capacitive coupling. The capacitive stylus pen includes a signal generating circuit that generates a signal having the same frequency as a frequency of a signal to be transmitted from an electrode, a transformer that boosts the generated signal and that includes a primary winding and a secondary winding, and an analog switch for controlling connection between a first end of the secondary winding and the electrode to an on-state or an off-state. The capacitive stylus pen further includes a power extracting circuit that extracts power to be supplied to the analog switch from an electromotive force induced in the secondary winding, and a capacitor coupled to a second end of the secondary winding to set the second end at a fixed potential in an alternating-current manner.

First claim

The invention claimed is:

1. A capacitive stylus pen, comprising:
an electrode configured to transmit a first signal, the electrode being positioned at a position indicating part of the capacitive stylus pen;
a signal generating circuit configured to generate a second signal, the second signal having a frequency that is substantially the same as a frequency of the first signal;
a transformer configured to boost the second signal, the transformer including a primary winding and…

Assignees

• Wacom Co Ltd

Inventors

• Katsurahira Yuji

Classifications

• G06F3/044

  Physics · mapped topic

• G06F3/03545 Primary

  Physics · mapped topic

• G06F3/0383 Primary

  Physics · mapped topic

• G06F3/0442

  Physics · mapped topic