TAKEAWAY: While the European Patent Office is a popular venue for patent filings of U.S.-based applicants, notable differences exist between Europe and the United States when it comes to patentability. Importantly, the EPO strictly prohibits the patenting of inventions made publicly available prior to filing a patent application. The EPO also has rigorous requirements for claim support, often requires a two-part claim structure identifying elements in the prior art, and lacks an analogous “means-plus-function” provision.

Along with the patent offices of the United States, Japan, South Korea, and China, the European Patent Office (EPO) is one of the top five patent filing offices in the world. It also remains a popular patent filing destination for U.S. residents, who constituted 26 percent of EPO’s applicants in 2014. Therefore, U.S. applicants and practitioners should become familiar with differences between Europe and the United States when it comes to the laws and rules for patentability. We review a few of them here.

Before filing a patent application in the EPO, it is important to confirm whether inventors or applicant made a public disclosure of the invention. Under the America Invents Act, the United States allows for public disclosure of an invention prior to filing, if the public disclosure occurs within a one year grace period from the effective filing date of a patent application, and if the public disclosure was made by the inventor or one who obtained the invention from the inventor. In contrast, Europe has a strict prohibition against patenting an invention if the invention was made publicly available before filing, even if the public disclosure was made by the inventors.

An applicant should also tailor the patent application to comply with the European patentability standards. For example, relative to the more liberal U.S. practice, the EPO has more stringent standards for written description support of claim elements. Under Article 123(2) of the European Patent Convention, the EPO prohibits claim amendments containing subject matter that extends beyond the contents of the application as filed. The subject matter must be directly and unambiguously derivable, by a person skilled in the art, from the disclosure of the invention as filed. However, the skilled person may be able to use common knowledge and implicit features in what is expressly mentioned in the document to derive the subject matter. Therefore, it is prudent to provide a more detailed explanation and terminology for any inventive aspects of the disclosure.

The EPO also commonly requests that European patent applications have a two-part claim structure, which is similar to a Jepson claim in the United States. The first part of such a European patent claim lists some features that describe the closest and/or most relevant prior art. After the first part, the claim may contain the phrase “characterized in that” or “with an improvement comprising,” followed by the second part, the novel elements of the claimed invention. It often is prudent to resist the EPO’s request for a two-part claim format and instead argue that it is not suitable for the application at hand. The Guidelines for Examination in the EPO lists a few examples of claims where the two-part claim structure may not be as suitable, including: the combination of known integers of equal status, the inventive step lying solely in the combination; the modification of, as distinct from addition to, a known chemical process e.g., by omitting one substance or substituting one substance for another; and a complex system of functionally inter-related parts, the inventive step concerning changes in several of these or in their inter-relationships.  The EPO states that for these claims, imposing a two-part claim structure would result in a distorted or misleading picture of the invention or prior art, or lead to an inordinately lengthy and involved claim.

In addition, it may be desirable to edit the U.S. claim language to preserve the intended claim scope. Claim construction differences in the United States and Europe may cause identical claims to have differing scopes. For example, the EPO lacks an analogous provision to 35 U.S.C. §112(f), which provides the USPTO with a method of construing “means-plus function” claims such that the means is determined from the “specification and equivalents thereof.” Instead, the EPO interprets a “means plus function” claim to encompass any means of performing the claimed function. Therefore, a European patent applicant may want to specify the structure of the means within the claim itself.