IP Insights: File wrapper estoppel

09/27/23 • 4 min

For a deep dive into the Unified Patent Court, please visit: https://www.bardehle.com/en/upc-special

In the context of the UPC, the file wrapper estoppel will become highly relevant, because some UPC member states do recognize the file wrapper estoppel in their legal systems. However, other member states, such as Germany, do not. Before we go into detail, Julia, could you explain what “file wrapper estoppel” means?

Under the doctrine of the file wrapper estoppel, statements made by the patentee vis-á-vis the patent office during prosecution are binding. It is noteworthy that in the end we are talking about “clear statements”, as the prosecution history is often rather vague.

However, in some instances, the applicant concedes to a narrow claim interpretation during prosecution proceedings in order to overcome objections of lack of novelty or inventive step. The file wrapper estoppel in these cases prevents the patentee from arguing a broader claim interpretation in subsequent infringement proceedings.

The file wrapper estoppel is also very important for cases which are argued under the doctrine of equivalents. If the applicant does not claim protection for certain embodiments so that such embodiments are not covered by the literal sense of the granted claims, it might be difficult in the light of such prosecution history to claim protection for these embodiments under the doctrine of equivalents.

But some terms may have a very specific meaning in the patent description. And the prosecution history can help to understand what exactly the patentee wanted to protect.

In German patent litigation, statements made by the patentee during prosecution are not binding for claim construction. They can only serve as a mere indication of how the person skilled in the art would understand a certain claim feature.

But there is one exception: Statements limiting the claim scope made during pending invalidity proceedings. Such statements are considered binding and thus limiting the claim scope if the parties in the invalidity and the infringement proceedings are identical.

What is also relevant for claim construction in Germany is the prior art mentioned in the description. A skilled person understands that the patented invention must distinguish itself from such prior art, as it cannot be assumed that the patentee wanted to patent such prior art. Therefore, prior art appreciated in the description is the starting point and one of the most important means of claim construction.

For a deep dive into the Unified Patent Court, please visit: https://www.bardehle.com/en/upc-special

But some terms may have a very specific meaning in the patent description. And the prosecution history can help to understand what exactly the patentee wanted to protect.

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IP Quick Tip. How to choose the right countries for patent protection

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Patent rights are territorial, meaning that they only apply in the countries where you've obtained legal protection. This means, selecting the right countries to protect your invention can be crucial in ensuring that your intellectual property is protected where it matters most.

While there is no one-size-fits-all answer, there are several factors you can use as a checklist when considering where to file or validate your patent. First, what is your overall business strategy? If your business is already operating in a country, it may be necessary to seek patent protection to protect your market position.

This also includes countries where you have manufacturing units, suppliers, or existing customers; in the case of digital inventions, it could be the location of your server, for example. If you plan to expand your business into a particular country, it may make sense to seek patent protection there.

Second, what is the potential market for your invention? Is it a niche or a mass-market product? This can help you prioritize countries where your invention is likely in high demand.

Additionally, you may also consider the presence of competitors in those countries, as patent protection can help you prevent competitors from using your invention. Third, what are the intellectual property laws and enforcement mechanisms? Check if your invention is patentable, as some jurisdictions may have stricter requirements for granting a patent for certain technologies.

Can you make use of certain enforcement mechanisms? For instance, if your product is at risk from infringers importing them into your market, deciding to protect it in countries that act as an entry ports can allow you to use the customs enforcement mechanism to stop entry into a wider market.

Finally, what are the cost and complexity of obtaining and enforcing patents in different countries? Depending on your invention, you may decide based on the cost of obtaining a patent relative to the market size.

In summary, every business's needs are unique, but by considering these general factors, you can develop a strategy tailored to your individual circumstances, protecting the value of your intellectual property.

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IP Insights: What to bear in mind when making joint inventions

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While collaborations between different companies are more and more common, it is astonishing that jointly owned patents lead to legal issues and questions which are still unresolved and not taught in the textbooks. A playing field for us practitioners. Jan, you are one of these practitioners and regularly advise our clients in this field. Could you please give us a brief overview of such cases?

The good case is when both parties are aware of what they are doing: If they combine their knowledge and capacities on purpose and with a specific aim. For instance, we regularly advise clients on publicly funded R & D projects with clearly defined work packages, where it is known beforehand if and where joint inventions may be created. In these cases, the parties can define their future interests in the projected invention, predict potential conflicts and – finally – write this down in an agreement. Here, the parties can define their respective exploitation rights: Are they allowed to sell the invention? And if so: Can they even sell it to competitors? Who is allowed to use the invention? And does the active owner have to compensate the other co-owners? These are typical questions which arise during negotiations of R & D agreements. In most cases, they can be answered to the benefit of both parties in view of their respective market position and specific interests. A second group of cases are those in which the joint ownership occurs “unintentionally”. Be it among friends on the occasion of a different collaboration, be it that a part of the invention is stolen and then further developed.

In the past, an important example of this second group originated from the German Act of Employee Inventors. If the employer did not correctly transfer the invention from the inventor to the company, the inventor was still a co-owner, in many cases together with its employer – the origin of many disputes. Which cases do you like most, Jan?

I like the first group. When drafting the R & D contract, you create a small piece of law, you can weigh the different interests and literally bring the parties together. The second group, in contrast, can lead to awful conflicts.

Let's use the “classical” example of the automotive industry: Imagine a car maker and their supplier having invented a new product which then turns out to be successful on the market. Questions arise: “Is the car maker entitled to source the new devices from other suppliers? And vice versa: Is the supplier entitled to sell the device which it invented itself to other car makers? Even these fundamental questions are not clearly solved in our existing law.

I always find it astonishing that these very simple questions are not easy to answer.

The reason is that our patent law is silent in that regard. It simply reverts us to general civil law which does not differentiate between sailing boats, apple trees, and patents. What is appropriate for apple trees and sailing boats may not be appropriate for patents.

Right. In 2005, the Federal Court of Justice issued a very important decision that answered at least some of these questions. If only one (first) co-owner is practicing the invention, the other (second) co-owner does not automatically receive a remuneration. So, the second owner must engage with the first owner and request a broad exploitation agreement. As part of such an agreement, one could define that the second co-owner is not even allowed to use the invention – but in turn receives a compensation. In my understanding, this decision was received very well.

It was really a good decision. Unfortunately, it left many questions open and the disputes continued. For instance, it is still not clear if ...