Challenge from the previous edition

According to legal event information in Espacenet, the applicant applied for an extension of the patent term for this Korean patent


Can you find out more about this request for extension?

  • Was it granted?
  • If so, for how long?
  • What is the new expiry date for this patent?

The type of term extension in this example is a "term adjustment". Term adjustments are granted to compensate for delays in the grant procedure. For the solution to this challenge, see this issue's article on patent term adjustments, which includes the above-mentioned document as a search example.

New challenge

Test your knowledge and search skills with our quiz about the patent history of additive manufacturing (AM), or 3D printing as it is also known. All the answers are in alphabetical order and there may be multiple correct answers.

Patent information tools such as Espacenet might be helpful, along with the report published on the EPO's Chief Economist's webpage or at


1. Which AM technology did Charles Hull, a 3D printing pioneer and the winner of the European Inventor Award 2014, apply back in 1984 when he first applied for a patent?
(a) Electron beam melting
(b) Selective laser melting
(c) Stereolithography

2. Which CPC classification codes best describe the AM technology domain?
(a) B22F10
(b) B29C
(c) B33Y
(d) B64G

3. What is the AM application field that currently attracts most patent filings at the EPO?
(a) Food
(b) Health and medical
(c) Tooling

4. Which of the following countries were the top three filers for EP patents between 2010 and 2018?
(a) Brazil
(b) China
(c) Germany
(d) Japan
(e) United States of America

5. Which applicant was not among the top four applicants at the EPO in AM technology between 2010 and 2018?
(a) 3M
(b) HP
(c) Siemens
(d) United Technologies

6. Looking at the main areas of AM materials and processes shows that United Technologies is a very active player in the field. With which other company do they often collaborate?
(a) HP
(b) Raytheon
(c) Siemens
(d) Xerox

7. When did machine learning/artificial intelligence start playing a role in AM technologies?
(a) 2000
(b) 2010
(c) 2014
(d) 2018

8. For which AM material were most patent applications filed at the EPO before 2014?
(a) Ceramics
(b) High-temperature superconductors
(c) Metals and alloys
(d) Polymers

9. By how much did annual applications at the EPO for the AM material with the most patent applications increase between 2011 and 2018?
(a) they increased twofold
(b) they increased threefold
(c) they increased fourfold
(d) they increased tenfold

10. How many other documents or patent families cite Charles Hull's 1984 EP application from question 1?
(a) 15 patent families
(b) 49 patent families
(c) 98 patent families
(d) 98 publications
(e) more than 500 patent families

11. An opposition was filed against Charles Hull's EP application mentioned above. Who was the opponent and what was the outcome of the proceedings?
(a) Elix – opposition withdrawn/patent maintained as granted
(b) Elix – opposition successful/patent revoked
(c) EOS – opposition withdrawn/patent maintained as granted
(d) EOS – opposition rejected for formal reasons/patent maintained as amended
(e) Evonik– opposition partly successful/patent maintained as amended
(f) Evonik – opposition rejected for formal reasons/patent maintained as granted

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