The term «patent» contains the latin verb «patere», which means «to be open or visible or known». Thus, an invention described in a patent application becomes known to the public through publication (in German: Offenlegungsschrift) by the Patent Office. As a reward, the Patent Office may grant a patent, which defines a legal monopoly for your invention in a country for a maximum of 20 years. A patent can only be granted when strict formal and substantial patentability criteria are fulfilled. In particular, the patent claims, that define the scope of the monopoly, must be novel and inventive over all prior art, i.e. over all technical information that has been published in any manner in any country before the filing date of the patent application at the Patent Office.

Someone unfamiliar with patents may believe that owning a granted patent gives the right to market and sell a product that contains the patented invention. However, this is not the case. The reason is that the monopoly conferred by the patent claims after grant is not defined as a positive right for the patent owner to use the invention, but as a negative right to forbid third parties to use the invention in their products.

Making use of a patented invention encompasses manufacture, offer, sale or import of a product implementing the invention. Thus, in order to manufacture, offer, sell or import a product, the product shall be free of third party patents. For this purpose, own patents are legally not relevant. Rather, a freedom to operate patent search and analysis (FtO) may be made to identify critical third party patents. In case any part or aspect of the product would come into conflict with a valid and enforceable third party patent (patent infringement), a license of the third party patent would be needed, or the product should be modified to avoid the infringement. 

Example: The prior art is a car. The patented invention is a car with a radio with antenna (basic patent), and an embodiment with antenna embedded in a window glass also falls under the granted claims (even if not mentioned explicitly). The basic patent owner and producer wants to manufacture, offer, sell or import cars with such an antenna embedded in a window glass. However, if a third party owns a more specific, later filed patent on such an embodiment of a window-embedded antenna (dependent patent), the third party can file an infringement lawsuit with the aim to legally stop the basic patent owner and producer to manufacture, offer, sell or import such cars with window-embedded antenna. An infringement lawsuit may equally be based on any other third party patent that covers any other inventive feature used in the cars.

In conclusion:

• An invention to be patented will be published and thus can not be kept secret.
• A granted patent does not give the patent owner the positive right to use the invention, but the negative right to forbid third parties to use the invention.
• Before developing or launching a new product, a freedom to operate search and analysis (FtO) allows to assess and avoid infringement of third party patents.