Path: utzoo!attcan!uunet!fernwood!decwrl!ucbvax!hplabs!hp-pcd!hp-vcd!scottb
From: scottb@hp-vcd.HP.COM (Scott Bigelow)
Newsgroups: sci.electronics
Subject: Re: Pizo-electric Ink Jets
Message-ID: <2470002@hp-vcd.HP.COM>
Date: 17 Oct 90 15:50:42 GMT
References: <1990Oct16.142553.26623@batcomputer.tn.cornell.edu>
Organization: Hewlett Packard, Vancouver, WA
Lines: 28

Larry writes:

>	You might wish to look at the various ink jet product marking
>systems used to put lot number and date codes on cans, bottles and other
>packages.  Almost all of these devices utilize ink jet technology.

>	One particular model that I have extensively seen in my travels
>is called "Videojet" and is manufactured by A. B. Dick.  "Videojet" will
>label containers on a conveyor belt from at least one inch away.  I do
>not know what internal pumping mechanism is used for this product, however.

>Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
>VOICE: 716/688-1231   {boulder, rutgers, watmath}!ub!kitty!larry
>FAX:   716/741-9635                  {utzoo, uunet}!/      \aerion!larry
----------

The Videojet system uses a continuous ink jet technology.  The ink is pumped
through a nozzle (I believe with a pulsating pump).  As the stream of ink
travels through the air it breaks up into tiny droplets.  Just before the 
droplet separates from the stream it is electrically charged.  The charged
ink droplet then passes through two sets of charged plates (at 90 degrees
from each other).  One set to control vertical motion of the drop and the other
set to control horizontal.

Look for date codes on soda cans and bottles to see the results.  I think a 
typical system runs about $20k.

Scott