Browse Prior Art Database

Dials With Antistatic Feature

IP.com Disclosure Number: IPCOM000100715D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 78K

Publishing Venue

IBM

Related People

Kesselman, JJ: AUTHOR [+4]

Abstract

The figure illustrates a device which permits a user to automatically discharge static when touching a dial device. The dials are made of conductive plastic and grounded to a frame.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Dials With Antistatic Feature

       The figure illustrates a device which permits a user to
automatically discharge static when touching a dial device. The dials
are made of conductive plastic and grounded to a frame.

      The figure shows a dial device 1 used for graphical input on a
computing system.  It has eight dials 2 which are molded from plastic
impregnated with carbon fibers.  This results in the dial itself form
ing a conductive path.  The upper surface which is handled by the
user is plated with a conductive metal to insure excellent electrical
contact between the user's fingers and the carbon fibers in the
plastic.

      Right dial 3 is shown disassembled.  The right quarter section
is shown cut out so that the inside geometry is visible.  The inner
hub is press fit onto an attached bushing 4.  This sandwiches dial
assembly 3 around a conductive bushing 5 on the frame.  Attached
bushing 4 is made of conductive metal which is electrically connected
to the carbon fibers in the dial.  The attached bushing is a close
fit to the conductive bushing on the frame.  This insures that the
dials turn freely but are maintained in position.  Since the two
bushing surfaces always touch in at least one position, an electrical
connection always exists between the dial and the frame.  The frame
is electrically attached to the frame of the using device through a
cable. This serves to discharge the user when touching any of the
dials.

      A bottom cover 6 fits over the bottom of dial device 1. Any
standard method is used to detect movement of the dials. One example
is that shown in the figure.  The device has a series of reflecti...