The prior use in patent law governs in several Länderm, for example in Germany and Austria, a user's right to a technical invention , the unpublished prior application or the priority date of a patent or a utility model has already taken advantage of this. This prior user does not lose the right to manufacture, own or market the object through the patent. Prior use can be recorded in the patent register.
However, this right is not alienable, but inheritable. This is particularly problematic if several partners are involved in a distribution channel, only one of whom has the status of a previous user, since the transport, offering for sale and selling also encroach on an existing property right, although the current case law in individual countries is strong is different.
In practice, it is usually difficult to prove prior use, and changes to the object are only possible if they do not infringe the corresponding patent.
A prior public use is when a part of the public was informed by the prior use before registration or the priority date, so for example, a guide was organized by the company's premises at which the details were revealed. If these are only business partners or employees who are obliged to maintain secrecy, prior use is not obvious.
In most countries, obvious prior use, whether by the applicant himself or by a third party, means that the part that is obviously previously used belongs to the state of the art and is no longer patentable.