Browse Prior Art Database

Scanner or Wand as Optical Communication Port

IP.com Disclosure Number: IPCOM000117104D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 191K

Publishing Venue

IBM

Related People

Cato, RT: AUTHOR

Abstract

Optical communication ports are becoming common and standardized (with the IRDA format) on today's Portable Terminals. Described is a way to use a scanner as an optical communication port to a Point-Of-Sale Terminal (POST) or personal computer. A portable terminal or personal digital assistant (PDA) could then use its infrared port to communicate with the store's computer.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 31% of the total text.

Scanner or Wand as Optical Communication Port

      Optical communication ports are becoming common and
standardized (with the IRDA format) on today's Portable Terminals.
Described is a way to use a scanner as an optical communication port
to a Point-Of-Sale Terminal (POST) or personal computer.  A portable
terminal or personal digital assistant (PDA) could then use its
infrared port to communicate with the store's computer.

      A scanner is a specialized electro-optical input device,
designed to collect laser light reflected off a bar code and convert
the signal into a meaningful datastream.  There is a well-defined
data path from the optics to the attached computer or POST.  Modern
scanners use solid state lasers that can be modulated to carry
information.  Present bar code scanners do not carry any information
on their laser beams.  Described is a way to utilize the scanner's
laser and photodectetor system to perform the function of an optical
communication port.  A scanner equipped Portable Terminal could also
use its scanner as an optical communication port.

      The brute force approach to the solution would be to simply
shine the IR data beam from the Portable Terminal into the scanner's
window.  The directed IR light would be much more powerful than the
weak light the scanner is designed to detect.  It is likely that the
scanner's detector would pick up the signal.

      The problem is getting information from the scanner to the
Portable Terminal.  If optimum communication performance is required,
then the scanner must stop scanning its laser spot.  This would
require time for the deflector to slow to a stop or be actively
braked.  In addition, the scanner's beam must be carefully aimed at
the Portable Terminal.

      A better solution would be to make a minor modification of the
scanner's design to provide an optical communication port.  The
"retro" mirror of a scanner is a small mirror mounted in front of the
collection lens.  Its small size allows it to fold the stationary
laser beam into the scanner's light collection path and towards the
scanner's moving deflector (see the illustration).

      The retro mirror could be a beam splitting type mirror that
would allow a fraction of the incident laser light to pass through.
This stationary laser light could then be directed to an optical
communication port.

      When the optical beam from a Portable Terminal travels into the
optical communication port and hits the back of the retro mirror, it
will be reflected towards the scanner's collection lens.  This light
is indicated by the "A" in the example below.  The scanner's
photodetector would then pick up the Portable Terminal's laser light
signal.

      The back side of the beam splitting retro mirror will be mostly
"silvered" and will reflect a large part of the incoming optical beam
from the Portable Terminal into the scanner's collection lens.
Alternatively, the back of the r...