Prohibition of Double Patenting: Assessment within the Framework of the Turkish Patent Office Practice
The prohibition of double patenting is a fundamental principle in patent law that aims to prevent obtaining multiple patent protection for the same invention. This prohibition is intended to prevent both the granting of a second patent for the same invention (narrow sense of double patenting) and the effective extension of the protection period through applications that are not substantially different from each other and contain the same invention idea in terms of technical contribution (broad sense of double patenting). The principle is based on the exceptional nature of the monopoly right granted by the patent system and the fact that its duration is limited by law; since the repeated protection of the same technical teaching through different applications or claims undermines the legal certainty of third parties, unnecessarily restricts free competition, and causes technical information that should become freely available to the public upon the expiration of the patent term to remain subject to private rights. Consequently, the prohibition of double patenting is a structural limitation that balances the scope and duration of patent protection and ensures proportionality between the public interest and the interests of the rights holder.
According to Article 145(2) of the Industrial Property Law (“IPL”), “No more than one patent or utility model, or both of these documents, shall be granted to the same person or their successor, independently of each other, for the same invention and with the same scope of protection.” The prohibition of double patenting defined by these provisions is a principle of patent law that prevents the same invention from being protected by more than one patent in favor of the same person.
Similarly, according to Article 21 of the Regulation on the Application of the European Patent Convention Concerning the Granting of European Patents (“Regulation”), "If the same person or their successor in title has requested the same priority date, on the same filing date or, if a priority date is claimed, on the same priority date, for the same subject matter, both a European patent for which Turkey is designated and a national patent or utility model certificate, the European patent shall continue unchanged following the opposition proceedings or, if no opposition is filed during the opposition proceedings, the national patent or utility model certificate shall expire at the end of the opposition period." This article states that when both a European patent for which Turkey has been selected and a national patent certificate are granted for the same subject matter, and if it is decided that the European patent shall continue unchanged as a result of the opposition proceedings or if no opposition is filed during the opposition proceedings, the national patent shall expire at the end of the opposition proceedings.
To the view, neither the SMK nor the Regulation requires claims to be word-for-word identical for double patenting to be considered. What matters is that the subject matter of the claims is the same and that the technical solution and technical effect provided by the patent overlap. This prohibition aims to prevent the circumvention of the limited patent protection period, ensure legal certainty, and prevent the excessive expansion of the property rights protected by the patent. Although there is no established practice example of the Turkish Patent and Trademark Office (“TÜRKPATENT”) conducting ex officio double patenting monitoring and examining patent applications in terms of the double patenting prohibition, it has been observed that it conducts evaluations within the framework of the double patenting prohibition in examinations conducted upon objection.
In the case that serves as an example for the assessment in question, a national application was filed with TÜRKPATENT, followed by an international PCT application with priority claimed, and this application was filed with the European Patent Office (“EPO”) by selecting the EPO. Following the examination conducted at the EPO, a patent with the same subject matter and set of claims was registered. No opposition was filed during the opposition period against this patent registered at the EPO, and after the opposition period ended and the patent became final, the patent was validated in Turkey and became valid in Turkey with a new number at TÜRKPATENT. Consequently, as a result of all these procedures, there are two registered patents on the same subject matter granted to the same person at TÜRKPATENT.
Upon learning of the second registration, which violated the prohibition on double patenting, an application was made to the TÜRKPATENT Patent Department requesting that the first registered patent be removed from the register, as its validity had expired in accordance with Regulation Article 21. However, TÜRKPATENT evaluated the patents in question by considering only the wording of their independent claims No. 1 and disregarding the differences arising from the translation. It stated that the newly registered patent offered a “different approach” with a different definition and decided to reject the request. The abstract expression “a more different approach” used in the decision was not justified technically or scientifically.
In the aforementioned rejection decision, Regulation Article 21 was misinterpreted. Despite the extremely clear wording of the Regulation provision, instead of assessing whether the two patents were on the same subject matter, an erroneous decision was made by comparing the words in the claims of both patents one-to-one and conducting a photographic assessment. An appeal was filed against this decision before the Re-examination and Evaluation Board (“Board”) pursuant to Article 100 of the IPL. In its evaluation, the Board decided to accept the appeal. The Board decision highlighted four criteria:
For two patents to cause double protection under the IPL, both patents must:
- Belong to the same person or their successor.
- Have the same application date (or the same priority date if priority rights are claimed).
- Be on the same subject matter.
- The European patent must be maintained unchanged following the opposition proceedings, or no opposition must be filed during the opposition proceedings.
In the Board decision, each criterion was evaluated individually, taking both patents into account and while it is permissible to pursue two applications simultaneously that have the same specification but do not claim the same subject matter in their claims (the decision also refers to EPO Board of Appeal decision T 2461/10 in this regard), it is stated that the basis for the “same subject matter” assessment should be the claims, not the specification. In this context, after the comparison based on the claims, it was concluded that the patents were “on the same subject matter,” even though the wording of the claims was not identical and/or the location of the elements was not exactly the same. The objection was accepted, and since the first registered patent had expired, it was decided to remove it from the register.
With this decision, TÜRKPATENT correctly pointed out that it is incorrect to take a photographic approach, such as considering whether the claims of the patents in question are identical or very similar, when assessing whether there is a violation of the “double patent” prohibition, and that the decision should be made by determining whether the subject matter of the invention is the same within the scope of protection of the claims.