EPO express
Consequently, any subsequent filing in any of the other countries of the Union before the expiration of the periods referred to above shall not be invalidated by reason of any acts accomplished in the interval, in particular, >another filing, the publication or exploitation of the invention, the putting on sale of copies of the design, or the use of the mark, and such acts cannot give rise to any third-party right or any right of personal possession. Rights acquired by third parties before the date of the first application that serves as the basis for the right of priority are reserved in accordance with the domestic legislation of each country of the Union
Emphasis added
The EPC has implemented Article 4 B Paris Convention in the following way:
The right of priority shall have the effect that the date of priority shall count as the date of filing of the European patent application for the purposes of Article 54, paragraphs 2 and 3, and Article 60, paragraph 2.
Article 54 paragraph 2 EPC relates to everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application.
That means that if between the priority date and the filing date of the European patent application either yourself or a third party published any information that discloses your invention, the legal effect of the priority right is that this disclosure does not destroy the novelty of your invention. If however, such information was disclosed by you or any other party, before the priority date of your first application, then the right of priority does not help you.
Article 54 paragraph 3 EPC relates to that the content of European patent applications as filed, the dates of filing of which are prior to the date referred to in paragraph 2 and which were published on or after that date, shall be considered as comprised in the state of the art.
In the meaning of Article 54 paragraph 2 EPC, when a European patent application has been filed for the same invention but is not published yet, this application would not be considered as prior art when the European Patent Office examines the patent application for novelty. For example, the content of a US patent application, independent of the filing date of the US application, which is published after the application date of a European patent application, would not count as prior art, and thus would not destroy the novelty of the European patent application in question.
For example party A files a US application and does not file a European Patent application. Party B files on a later day a European patent application for the same invention, but before the US applcation is published or the invention has been published in another way. Consequently to Article 54 paragraph 2 EPC party B may still be entitled to a European patent. The European patent application cannot be rejected on basis that it is not novel with respect ot the US application. Other reasons for rejections, such as lack of inventive step still may apply.
This does not harm party A, as party A obviously did not intend to protect her invention in Europe. Assumming party B gets a patent in Europe, party B can hinder party A to use the invention in Europe without the consent of party B. As party A did not file his own application in Europe, he practically abanddoned his rights in Europe. If however, party A filed a patent application in Europe and his priority right is older than than the filing date of B in Europe or the priority filing date of B, then Article 54 paragraph 3 would render the applicaiotn of party B as not novel and only party A is rewarded a patent.
It is not the intention of Europen Patent law to hinder an applicant to get a patent granted, when the applicant files a European patent for an invention he made independently of another party, even if the other party filed an application for the same invention in a non European country earlier than the European applicant (and lacks to file a European patent himself), as long as the invention was not in the public domain at the date of filing.
Article 60 paragraph 2 EPC further stipulates that if two or more persons have made an invention independently of each other, the right to a European patent shall belong to the person whose European patent application has the earliest date of filing, provided that this first application has been published.
As a consequence that in Europe only the earliest inventor of a same invention should be entitled to a patent, Article 60 paragraph 2 EPC denies the right to a patent to inventors that have filed later than the first inventor, but only if the invention of the first inventor was published.
As a general remark, if for example the first inventor did not pay the filing fee and for that reason his application was deemed withdrawn, his invention would not have been automatically published after 18 months. If the invention was not published in any other way before the filing date of the later inventor, then the later inventor is not hindered by Article 60 paragraph 2 EPC to proceed with his application.
The reference of Article 89 EPC to Article 60 paragraph 2 EPC however means that an applicant who files at a later date in Europe than a first applicant, gives the later applicant priority over the first applicant, provided that the first applicant himself cannot claim a priority date that is older than the later applicant's priority date.
(c) EPO express 2020
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