As an optimist, for me there are no problems but tasks to be solved. And puzzling over the best solution is for me like being a researcher uncovering a secret.

Jürgen Feldmeier

Dipl.-Ing. (Univ.) Mechanical Engineering, Master of Laws
Patent Attorney, European Patent Attorney,
European Trademark & Design Attorney
Registered Representative before the Unified Patent Court

+49 89 69 39 21-0feldmeier@pruefer.eu

Professional career

Jürgen Feldmeier has been a patent attorney since 1992 and has been the managing partner of Prüfer & Partner since 2001.
Prior to his training as a patent attorney, he gained practical experience at BMW Technik GmbH, Hurth and Convotherm.
He studied mechanical engineering with a focus on design and development at the TU Munich. He also acquired the Master of Laws (LL.M. European Intellectual Property).

German (mother tongue), English (business fluent), French (basic knowledge)

Specialist areas of activity


  • application procedures for patents, trademarks, designs
  • litigation in patent, trademark and design issues
  • prosecution procedures at GPTO, EPO, FPC, EUIPO
  • participation in more than 100 litigation proceedings (infringement proceedings, nullity and opposition proceedings) before the patent offices and the courts of Munich, Düsseldorf, Mannheim and Hamburg, as well as the Higher Regional Court of Karlsruhe, the Higher Regional Court of Düsseldorf and the Federal Court of Justice

Technical knowledge and experience in the fields of:

  • automotive technology
  • machine tools and components
  • precision engineering
  • mechanical components of all kinds
  • medical technology
  • sports equipment
  • mechatronic components, control and regulation technology
  • process engineering, especially in the food industry

Publications and memberships


“Protection and allowance for (industrial) intellectual property in European Community Law]


epi – European Patent Institute
Chamber of Patent Attorneys
AIPPI – International Association for the Protection of Intellectual Property
FICPI – International Federation of Intellectual Property Attorneys
INTA – International Trademark Association
EPLIT – European Patent Litigators Association

Ideas thrive better under professional protection.

Dr. Andreas Oser

Dr. rer. nat., Dipl.-Chem., Master of Laws
German Patent Attorney, European Patent Attorney,
European Trademark and Design Attorney
Registered Representative before the Unified Patent Court

+49 89 69 39 21-0oser@pruefer.eu

Professional career

Andreas Oser has been working in the IP field since 1991, became a German and European patent attorney in 1995 and has been managing partner at Prüfer & Partner since 2002.
In addition he holds an LL.M. degree in International Intellectual Property Laws (University of Hagen).
Prior to working in the IP field, he studied chemistry at the University of Freiburg i. Brsg., and then completed his Ph.D. and postdoctorate scientific work at the Max Planck Institute for Biochemistry in Munich.

German, English, French

Specialist areas of activity


  • Patent prosecution (drafting, examination)
  • High number of opposition and appeal proceedings at the European Patent Office
  • Patent litigation:
    • Patent infringement proceedings before German courts
    • nullity proceedings up to the highest instance, the Federal Supreme Court; also covering coordinated and complex EU-wide litigation activities
  • Infringement and validity opinions, freedom-to-operate (FTO) analyses, due diligence

Andreas Oser was and is currently involved in many litigation cases, among others related to medical devices and important drug products.


chemistry, pharmaceuticals, life science and biotechnology, in particular:

  • medicaments and drugs (active substances, formulations), biopharmaceuticals
  • biological materials, DNA-related inventions and vaccines
  • therapeutic and diagnostic methods
  • medical products and devices and targeted drug delivery
  • polymers, fibre materials, composites
  • semiconductors, LEDs, OLEDs and other optical materials and optoelectronic devices,
  • batteries and their components

Publications and memberships:


Oser A. and Sonnenhauser S., JUVE Handbuch Wirtschaftskanzleien 2022/2023, 773-774: “Plausibilität – ein ungelöstes Problem bei der Patenterteilung”

Schmidt T. and Oser A., GRUR Int 2019, 737: “New medical uses of known medical devices – A new perspective on purpose-limited product protection for medical devices in Europe”

Oser A. in GRUR Int 1998, 648 (=IIC 30, 1-18, 1999): “Patenting (Partial-)Gene Sequences”

Oser A., PATENTS & LICENSING 1998, 30: “EU Directive on Legal Protection of Biotech Inventions”

Oser A. and Bavec S., AIPPI Japan 2004 (Vol. 49 No. 7), 503: “Biotech Inventions in Europe”

Oser A. in GRUR Int 2006, 539 (=IIC 37, 520-550, 2006): “European Patent Litigation Agreement – Admissibility and Future of a Patent Dispute Regulation in Europe”

Thieme R„ Lay H., Oser A., Lehmann J., Wrissenberg S. and Boos W., Eur, J.Biochem. 160, 83-91 (1986)

Oser A., Roth W.K. and Valet G., Nucl. Acids Res. 16, 1181-1196 (1988)

Oser A. and Valet G., Nucl. Acids Res. 16, 8178 (1988)

Rothe G., Oser A. and Valet G., Naturwissenschaften 75, 354-355 (1988)

Oser A., Collasius M. and Valet G., Anal.Biochem. 191(2), 295-301 (1990)

Oser A. and Valet G., Angewandte Chemie International Edition 29(10), 1167-1169 (1990)

Rothe G., Banati R., Oser A., Assfalg-Machleidt I., Mangel W.F., Machleidt W., Kreutzberg G.W. and Valet G., Journal Immunol. Methods. 138(1), 133-135 (1991)

Oser A. and Valet G. (1988), Patent Applications WO8907606A, DE3804243A


Chamber of Patent Attorneys
epi – European Patent Institute
Member of the Biotech Committee of the epi
AIPPI – International Association for the Protection of Intellectual Property
FICPI – International Federation of Intellectual Property Attorneys
LES – Licensing Executives Society
GDCh – Gesellschaft Deutscher Chemiker

Even the longest way begins with the first step.

Christoph Jaeckel

(Cooperation Partner)

+49 89 69 39 21-0jaeckel@pruefer.eu

Professional career path

Christoph Jaeckel has been working as a freelance lawyer since March 2021 and supports Prüfer & Partner as a cooperation partner, in particular for intellectual property rights related to China . Before that, he first worked for a law firm specialized in trademark law in Berlin and later worked for six years in the area of trademark law and patent law in Shanghai, China. He studied law at the Free University of Berlin and completed his legal traineeship at Kammergericht Berlin.

German, English, Chinese

Specialst areas of activity


  • Filing and enforcement of trademarks
  • Advising on IP strategy (filing and enforcement) in China
  • Managing the enforcement of IP cases for German clients in China
  • Advising Chinese companies on all IP matters when entering the German market and when it comes to enforcing their IP in Germany.


  • Trademark law
  • Patent law

Publications and memberships

Publications and memberships

“Modeschutz – Gewerbliche Schutzrechte für Modeneuheiten und Modeunternehmen” Christoph Jaeckel, presentation, 13 October 2010, Hamburg,

“Strategie-Frage, Schutz des Designs vor Nachahmungen”, Christoph Jaeckel, China Contact 2009, p. 43-44,

“Rechtsschutz gegen unberechtigte Schutzrechtsverwarnungen”, Christoph Jaeckel (co-author), MarkenR 2008, p. 365-378,

“Die bösgläubige Markenanmeldung”, Christoph Jaeckel (co-author), MarkenR 2008, p. 296-309.

“Schutz geistigen Eigentums, geheim halten oder aktiv patentieren?” Christoph Jaeckel, ChinaContact 09/10 2019 S. 22-23

“Schneller Schutz mit Gebrauchsmustern” Christoph Jaeckel ChinaContact 11/12 2019 S. 44-46


DAV – German Bar Association
DCJV – German Chinese Lawyers Association
ECTA – European Communities Trade Mark Association
GRUR – German Association for the Protection of Intellectual Property
Chamber of Attorneys-at-Law Munich