Figure 1.

A schematic representation of the typical actions taken during the examination process of a patent application before (a) the US Patent and Trademark Office and (b) the European Patent Office. Dashed lines indicate alternative actions that are possible at each stage; solid lines indicate that the indicated action necessarily follows the previous one. It can be seen that two steps are available in Europe but not in the US: an optional oral hearing before the patent is allowed, in which applicants may argue orally for the patentability of their inventions before a panel of examiners, and an opposition period after the application is allowed, in which the public may oppose the patent. 'Restriction' and 'Lack of unity' are equivalent procedures through which the patent offices require an applicant to divide a single application into two separate patent applications (an 'original' and a 'divisional'), on the basis of a conclusion that the single original application disclosed and claimed two distinct inventions. An 'office action' is a written report issued by the examiner regarding the patentability of the claimed invention. Upon concluding that an application is patentable, the examiner will 'allow' the application. In the US, the issuing of the patent typically follows allowance after completion of certain simple formalities, whereas in Europe the issuing of a patent does not occur for several months; during this time, members of the public may oppose the patent and the patent applicant must substantively defend the patentability of the invention.