Information and explanations about patent family

If an invention is made for which a patent application is to be filed, this may subsequently be done in several countries, depending on the countries in which market opportunities are expected for a product that is to be marketed in whole or in part with features protected by the patent. Since the patent right is a territorial right, it is necessary to apply for a patent in each country where the product is to be protected later. So these patent documents are somehow related to each other, since they are based in whole or in part on the same invention. This also applies if a utility model, which is subject to less stringent examination, is also filed from the patent application. One of the explanations of the European Patent Office on its website:

"A patent family is a group of patent applications covering the same or similar technical content."

Priorities

In this case, the documents are necessarily linked to each other via their priorities. This results as follows: First, a patent application is filed in a country. This is the so-called first application (priority application). If further applications are filed in other countries with reference to the so-called first application, these are referred to as subsequent applications. These subsequent applications formally claim the same seniority as the first application, the so-called priority application. This is only possible if the subsequently filed applications are identical or very similar in content to the first application.

Why is it done this way? If one wants to obtain a patent (not only to apply for it, but to obtain an actually granted property right and only this develops a protective effect), the Office will check whether there is not already prior art (so to speak published knowledge before the application) which contradicts the granting, because it would be assumed that the inventor was able to copy from the already existing knowledge and thus did not invent anything new at all. Information available up to the filing date of this first application is taken into account. A subsequent application which claims this priority application therefore refers to this filing date of the first application. Thus, only prior art that existed up to the filing date of the priority document can be invoked against this subsequent application. After the priority period has expired, an application can no longer claim this priority. On the contrary, the first application would even constitute prior art which could be held against this document to be filed subsequently as being detrimental to novelty.

Strict and extended patent family

The information shows that the patent family always refers to documents which refer to the same priority document, i.e. the first application. This forms the so-called strict patent family.

But now there are documents that want to protect further technology in addition to the technical content of the initial application. This can even happen in one and the same state. Thus, if a subsequent application refers to two priority documents or if the subsequent application itself is again a priority document, this results in an extended patent family whose technical content is no longer identical but at least very similar. Several priorities then form a so-called extended patent family.

In XPAT we work with the extended patent family. Often the term "patent family member" is used as something synonymous to the original document. But beware, it is always the claims of the documents to be protected or actually protected that are decisive. These may well be different within the same family.

The term patent line used in XPAT

In XPAT we also use the term patent line, which are marked in the family overview by color change. If we take as an example the document or the patent family to DE4342171:

The patent family is as follows:

• EP0660660 (A1)
• EP0660660 (B1)
• EP0660660 (B2)
• AT157840 (T)
• AU7493894 (A)
• DE4342171 (A1)
• DE4342171 (C2)
• DK0660660 (T3)
• DK0660660 (T4)
• US5754137 (A)
• WO9502318 (A2)
• WO9502318 (A3)

Now the following patent lines are represented in this family:

• EP0660660 (A1), EP0660660 (B1), EP0660660 (B2)
• DE4342171 (A1), DE4342171 (C2)
• WO9502318 (A2), WO9502318 (A3)
• DK0660660 (T3), DK0660660 (T4)
• The other documents, each represented only once, also represent patent lines but have only one document.
• US5754137 (A)
• AT157840 (T)
• AU7493894 (A)

The term patent family is not a binding term under patent law.

Attention: different databases may use different definitions of a patent family. The term "patent family" has no legal or legally binding meaning. Likewise, it is possible that there is more than one patent line in an extended patent family from one state.

Patent family oriented databases carry risks that should be known

The often observed attitude that all patent family members are somehow "the same" is very problematic from our point of view. As much as the merging of patent families in a data set in a database is seen with pleasure, it also involves dangers. These dangers arise from the fact that the patent claims of two patent family members need not be identical and often enough are not. If one searches for concrete facts and does not find a family, because e.g. the leading family document in this database does not show this concrete fact, one could be shipwrecked here with the search.

In XPAT, on the other hand, each document is stored individually in its own data record. If the user is bothered by the fact that he might receive several documents of a patent family as search results, he can reduce these families in the hit list to one document of his choice by pressing a button. If he then looks at this document, he can in turn look at each individual family member. This is a very good compromise and such research traps are thus excluded. There are also interesting visualizations of patent families.