Browse Prior Art Database

Improved Track Point Recalibration Method

IP.com Disclosure Number: IPCOM000113585D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Barker, JH: AUTHOR [+3]

Abstract

Described is a method whereby a Track Point* device, as used with in keyboards of laptop type of Personal Computers (PCs), is improved in the area of recalibration.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 61% of the total text.

Improved Track Point Recalibration Method

      Described is a method whereby a Track Point* device, as used
with in keyboards of laptop type of Personal Computers (PCs), is
improved in the area of recalibration.

      In prior art, the Track Point device is calibrated frequently
to compensate for temperature induced drifting.  However, errors can
occur if the recalibration does not take into account for the
possibility that the track point device can be exposed to external
pressure.  The concept described herein provides a means of
integrating pressure sensing capabilities so as to eliminate
unnecessary recalibration, as well as drifting.

      Typically, the track point device is located between the G, H
and B keys of the keyboard.  The track point buttons, at the lower
border of the keyboard, function like mouse buttons.  When the track
point device is subject to the calibration process, it is assumed
that no external force is applied in the area of the track point
device.  As a result, if an external force is present at the time of
calibration, the calibration will be invalid.  For example, if a
stack of paper is placed on top of the track point device, the
pointer will move a certain distance and stop.  The pointer will move
again for a distance when the weight is removed.

      The concept described herein is designed to improve on the
calibration of the track point by incorporating pressure sensing
capabilities into the track point device. ...