Browse Prior Art Database

Automatic Switching Mechanism for Touch Screen Computers

IP.com Disclosure Number: IPCOM000111968D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 4 page(s) / 75K

Publishing Venue

IBM

Related People

Davis, JC: AUTHOR [+2]

Abstract

Described is an automatic switching mechanism for touch-screen computers that provides an automatic means of changing the touch screen from finger use to stylus use. A pressure-switching function is incorporated within the stylus so as to eliminate the need for a separate mechanical switch when changing from finger mode to stylus mode.

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This is the abbreviated version, containing approximately 52% of the total text.

Automatic Switching Mechanism for Touch Screen Computers

      Described is an automatic switching mechanism for touch-screen
computers that provides an automatic means of changing the touch
screen from finger use to stylus use.  A pressure-switching function
is incorporated within the stylus so as to eliminate the need for a
separate mechanical switch when changing from finger mode to stylus
mode.

      In prior art, many different stylus types were provided to
interact with the computer screen.  All of the stylus types required
a separate, mechanically operated switch to change from touch-screen
mode to pen mode and back to touch-screen mode.

      The concept described herein eliminates the need for a separate
mechanical switch to make the touch-screen change by incorporating a
Force-Sensing Resistor (FSR) as an integral part of the stylus.  The
FSR functions as a threshold switch to provide the switching
function.  Fig. 1a shows the typical stylus enclosure shaped like a
pen with wires extending from one end.  Fig. 1b shows the internal
items of the stylus with FSR 10 positioned at the lower core of the
stylus and wrapped with self-adhesive material 11.  Sleeve 12,
typically made of silicon rubber, is used to cover FSR 10.  Two wires
13 are fastened to contacts within FSR 10.

      Fig. 2 shows a schematic circuit of FSR 10 variable-force
threshold switch circuitry connected to the stylus.  When there is no
pressure on FSR 10, the circuit is considered OFF and the...