What is an invention disclosure form, why do attorneys need it and how to prepare one?

In the European patent law (EPC), it is a requirement that the application describes the invention thoroughly so that others can carry out the invention based on the description.* Therefore, you have to disclose your invention in the application, the details of your invention have to be made available to the public. Unfortunately, you cannot simultaneously obtain a patent and keep your invention secret.

What is an invention disclosure form and why do patent attorneys need it?

We, patent attorneys need to know as many details about your invention as possible. We have to understand the invention as well as you do in order to be able to prepare the specification properly. We will ask you a lot of questions that you will need to answer in an invention disclosure form, which is basically a document presenting your invention. A good patent attorney will make effort to include additional examples and define the claims as broadly as possible, but fundamentally, it is the inventor's task to invent and not the attorney's.

How to prepare your invention disclosure form?

To prepare your invention disclosure form, you should answer the questions below, writing a few sentences as an answer to each question:

• What is the invention? (Device, system, component, method, use...)

  It can be both a product and the manufacturing method of the same product.

• What problem(s) does the invention solve? 

• How does the invention work?

  Can you provide some drawings? If yes, please describe shortly what the drawing depicts.

• What are the core features of the invention?

• What are essential and non-essential features?

• What is the prior art known to the inventor? 

• What are the disadvantages of the prior art? 

• How does the invention overcome these disadvantages? 

• Does the invention have any other advantages? What are the disadvantages, if any?

• Are there several ways for carrying out the invention? What are they? 

• What is the best (or preferred) mode for carrying out the invention and why?

  Please write a concrete description how the invention is carried out.

TIP:

You have to describe your invention in a way that it is possible "to be carried out by a person skilled in the art", but in the European patent law you are not required to disclose the best possible version. (This is different in the US, where the best mode requirement still exists.**) So, you are allowed to keep the best version a secret as long as you describe at least one way of working the invention.

Let's see an example. You know that your method works best if a certain step is performed at 86°C. When filing a European Patent Application, you do not necessarily have to disclose 86°C. You are allowed to use a range of 70-95°C for instance (if this range is new, inventive, and the invention works in this range). In this case, the best method (86°C) will not be available to the public, but will be protected since it is covered by the claim. In this example, performing the certain step at 86°C is your know-how, that you can sell in addition to licensing rights.

The role of a prior art search

As you can see, there are some questions above referring to the prior art. Preparing your invention disclosure report is easier if you know the prior art and the disadvantages of the inventions in the prior art. For this reason, we recommend conducting a prior art search before filing a patent application, as we also mentioned in the article “What to do before filing?”.  Your invention does not necessarily has to be better than the prior art, but it must be new and inventive over the known inventions. A prior art search will help you evaluate the patentability of your invention, in particular novelty and inventiveness.

It is advantageous if the same patent attorney conducts the search who drafts the application, since he/she can familiarize himself/herself with the invention already during the search phase. However, if you have time and understand patent language, you might be able to do the search yourself, using the EPO's Espacenet database for instance.

It is not possible to add new subject-matter later

It is very important to note that it is not allowed to add any new subject-matter to the application after the date of filing.*** The EPO examines this rigorously. Therefore, you need to do some serious thinking about all the possible features so that you do not leave out any important details.

For example, if the originally filed version of your application discloses a part made of aluminium, you cannot later change it to metal, because that would be an unallowable amendment. "Metal" is newly added subject-matter, as with the word metal you are adding about hundred new materials not previously disclosed.

The requirement of sufficiently disclosing your invention (the requirement at the beginning of this article) must be complied with as from the date of filing. Consequently, any objections in this regard unfortunately can rarely be rectified, since new explanations should be added to the text about how to work the invention, but adding new information is not allowed, as explained above.

Therefore, you have to disclose all features, embodiments, etc. at the time of filing, and that is the reason why you have to prepare a detailed invention disclosure form for your patent attorney.

* This is described in Art. 83 EPC:
"The European patent application shall disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art."
See the full legal text here.

** See an article about this topic here.

*** This is described in Art.123(2) EPC:
"The European patent application or European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed."
See the full legal text here.

Author: Zsofia Pintz
Published: August 2020
Updated: July 2023