# US 2009/0260900 A1 · Untethered electrostatic pen/stylus for use with capacitive touch sensor

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- Number: US 2009/0260900 A1
- Document ID: US20090260900A1
- Status: Published application
- Kind: A1
- Application number: 12/104,392
- Filed: 2008-04-16
- Published: 2009-10-22
- Earliest claimed: 2008-04-16
- Inventors: Michael J. Ure
- Web page: https://patentgrep.com/patent/US20090260900A1

## CPC

- G06F 3/03545: {Pens or stylus}
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

An untethered electrostatic pen/stylus for use with capacitive touch sensors, described herein, allows for a single device like the iPhone to receive input via both finger touches and a stylus. Stylus input is more precise for various uses including, for example, text input and drawing input.

## Claims

### Claim 1

A pen or stylus for interacting with a capacitive touch sensor, comprising:
an elongated housing having a grip area to be gripped in a writing grip; and
an electron beam source within the elongated housing.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the electron beam source comprises a field-emission electrode.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein the electron beam source comprises a field-emission array of micro-emitters.

### Claim 4 (depends on 1)

The apparatus of claim 1, comprising an electron beam lens for focusing an electron beam produced by the electron beam source.

### Claim 5 (depends on 1)

The apparatus of claim 1, comprising a rechargeable battery and a charging connector.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the charging connector is a USB connector.

### Claim 7 (depends on 1)

The apparatus of claim 1, comprising a contact switch responsive to contact of the pen/stylus for causing supply of a high voltage to the electron beam source to be interrupted during absence of contact.