In patent law, a patent watch is a process for monitoring newly issued patents, as well as possibly pending patent applications, to assess whether any of these patent rights might be of interest or might be annoying.
A newly issued patent may be of interest if it appears to cover one or more products or processes sold by a given company. That company then runs the risk of being sued for patent infringement. In this case, it is prudent for said company to commission a clearance opinion to at least show that they were diligent in making sure that they did not infringe the issued patent.
If the opinion finds that the company is indeed infringing the patent, then the company can:
A company might carry out a prior art search to determine if there is any prior art that would invalidate the patent that the patent office had not previously considered. If said prior art is discovered, the company may bring an opposition proceeding, or request a reexamination to have the patent declared invalid. Opposition proceedings are available in Europe and Japan. Reexaminations are available in the U.S. In the US, a company may also bring a lawsuit in Federal Court to have the patent declared invalid.