Re: Stereolithography Patent Issues

Date: Tue Jan 30 1996 - 16:43:34 EET

At 03:40 1/30/96 EST, Hubert Aunkofer wrote:
>Yakov Horenstein wrote (18th January):
>>I think that this announcement means that 3D Systems have won one of their
>patent infringement suits against the Germany company (EOS).
>This is a completely false interpretation. 3D Systems has never won any patent
>infringement suit against EOS or any users of EOS technology, despite trying
>hard for over two years.
>In 1993 3D Systems started a legal challenge against EOS relating to alleged
>infringement of the European patent EP 0 171 069, which covers the so-called
>deep-dip method of recoating in stereolithography. This litigation is pending
>before the District Court Munich 1. According to European patent law, in order
>to win the case 3D Systems must prove that EOS machines used the deep-dip
>after the patent came into effect. 3D Systems has been unable to prove this so
>far because the STEREOS active recoating method (see below), which does not
>involve any deep-dip, was introduced and fitted into all installed machines
>before the patent was granted.
>3D Systems has also challenged EOS regarding alleged infringement of claims
>relating to the doctor blade of 3Ds German utility model G 89 16 116.5. EOS
>petitioned for cancellation of this utility model, whereupon the court
>proceedings were suspended pending a final decision on the legal validity
of the
>utility model. The German Patent Office examined the utility model and in the
>first instance cancelled it completely.
>In 1995 EOS received orders for 40 STEREOS and EOSINT machines and thereby
>substantially increased our market share. Sales of both STEREOS and EOSINT
>systems increased very significantly. Our experience is that customers base
>their purchasing decision on the relative technical and economical performance
>of the available systems, and after studying the patent issues consider
them not
>to be a significant problem. Our recent customers include a number of companies
>whose own patent and legal departments have studied the issues before
>EOS equipment.
>To date EOS has been granted 19 patents and 12 utility models relating to our
>own rapid prototyping inventions and holds exclusive licences to two other
>prototyping patents.
>E. Derek Smith wrote (18th January):
>>I believe the system in question had an active recoating system,
>incorporating technology that may have a profound impact on build cycle
time and
>trapped volume success. What have the development engineers and lawyers done
>with all this?
>Correct. All STEREOS stereolithography systems from EOS have been using active
>recoating since 1993. This means that the new resin is actively applied from
>above, so that the partly-built model only has to be lowered by exactly the
>required layer thickness into the vat, a single movement which eliminates the
>need for a deep-dip.
>STEREOS MAX 600 uses a computer-controlled pump to precisely regulate the
>and rate of applied resin, and also has adaptive recoating control which can
>vary the rate of resin application within each recoating cycle. This enables
>some of the problems commonly encountered with other recoating systems,
>particularly closed volume effects, to be greatly reduced or eliminated and
>leads to much improved process reliability. This in turn leads to shorter
>recoating times and therefore faster part building. The recoater is also
>bidirectional and can make a full recoating cycle in one single traverse of the
>vat, thereby effectively halving the recoating time.
>Mike Shellabear
>Pasinger Strasse 2
>D-82152 Planegg/Munchen, Germany
>Tel. +49 89 8991310
>Fax.: +49 89 8598402

Asst. Manager
Rapid Prototype Technology
Champion Machine Tools (S) Pte Ltd.

Email :
FAX : (65) 4818855
TEL : (65) 4817000

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