Unity of invention
In most patent laws, unity of invention is a formal administrative requirement that must be met for a patent application to proceed to grant. An issued patent can claim only one invention or a group of closely related inventions. The purpose of this requirement is administrative as well as financial. The requirement serves to preclude the possibility of filing one patent application for several inventions, while paying only one set of fees. Unity of invention also makes the classification of patent documents easier.
The WIPO and the EPO determine the unity of claims in a patent based on the presence of a common "special technical feature", which is usually equated with inventive step. On the other hand, the USPTO uses for its domestic applications a very different approach, which is based on the fields of use for each claim, justifying this approach by a "burden on the examiner" to search different areas of technology. The patent offices in Japan and China, similarly to the USPTO, also demand splitting patent applications into multiple divisionals as a means of increasing the monetary revenue of the offices.
When a patent application is objected to on the ground of a lack of unity, it may be still considered for patent protection, unlike for example in the case where the invention is found to be lacking novelty. A divisional application can usually be filed for the second invention, and for the further inventions, if any. Alternatively, the applicant may counterargue that there is unity of invention.
Jurisdictions
European Patent Convention
Under European patent practice and case law, lack of unity can appear either "a priori", before the prior art was examined, or "a posteriori", after the prior art was examined. An a posteriori lack of unity usually results from a lack of novelty or inventive step of the subject-matter of one independent claim.Patent Cooperation Treaty
Under the Patent Cooperation Treaty, an international application, also called PCT application, "shall relate to one invention only or to a group of inventions so linked as to form a "single general inventive concept". If the requirement of unity of invention is not met, the International Searching Authority "is entitled to request the applicant to pay an additional search fee for each invention beyond the first which is to be searched".In reaction to such a request from the ISA, the applicant may pay all or some of the requested additional search fees, and the ISA then establishes the international search for all or some of the inventions or groups of inventions, respectively. The applicant may also decide not to pay any of the additional search fees, and, in such case, the ISA does not carry out a search for the inventions or groups of inventions for which no search fees have been paid. The international search report is then established only for the first claimed invention.
If the applicant disagrees with the ISA's finding of lack of unity of invention, the additional fees may be paid under protest. In the protest procedure, the applicant files a reasoned statement explaining why it considers that the requirement of unity of invention has been complied with, or that the number of additional fees required is excessive. After payment of the additional search fees and, if required, of a protest fee, the protest is examined by a review body. If the review body finds the protest justified, it orders the total or partial reimbursement of the additional search fees, and, if applicable, the protest fee, to the applicant. When, for instance, the European Patent Office acts as ISA, the review body in charge of examining the protest consists of three members: "the head of a directorate, normally the head of the directorate by which the invitation to pay additional fees was issued, an examiner with special expertise in unity of invention and, normally, the examiner who issued the invitation."
United States
Although U.S. patent law does not use the term "unity of invention", the relevant legislative act specifies the conditions under which the patent examiner may issue a "restriction requirement", i.e. requesting a split:
If two or more independent and distinct inventions are claimed in one application, the Director may require the application to be restricted to one of the inventions.
Applications that claim more than one distinct invention may be subject to restriction to a single invention, and the applicant may prosecute the remaining invention by filing divisional applications.
35 U.S.C. 121 Divisional applications.
If two or more independent and distinct inventions are claimed in one application, the Director may require the application to be restricted to one of the inventions. If the other invention is made the subject of a divisional application, which complies with the requirements of section 120, it shall be entitled to the benefit of the filing date of the original application. A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application. The validity of a patent shall not be questioned for failure of the Director to require the application to be restricted to one invention.
However, the Manual of Patent Examining Procedure, a document written by the USPTO itself, replaced 'independent and distinct' with 'independent or distinct'. The USPTO justified this "and for or" replacement, by stating
The terms "independent" and "distinct" have mutually exclusive meanings and thus are interpreted as alternative requirements. Only one these requirements must be met in order to support a restriction.
Thus, according to MPEP, the claims in a patent application may be properly restricted to two or more divisional patent applications, if the claims are either independent or distinct.
After this split of the independent and distinct requirements, the MPEP adds a new definition of independent and of distinct, which are based on the field of use – a criterion never mentioned in legislative documents:
Distinctness is proven if the claims to the intermediate and final products do not overlap in scope and are not obvious variants and it can be shown that the intermediate product is useful other than to make the final product.
There are two criteria for a proper restriction requirement in case of patentably distinct inventions:
The inventions must be independent or distinct as claimed ; and
There would be a serious search and/or examination burden on the examiner if restriction is not required
The USPTO provides several examples that explained in greater details its current restriction practice based on one-way and two-way distinctions.
Briefly, the two main substantial differences between EPO's/WIPO's unity of invention and the USPTO's restriction requirement is that:
' The USPTO's approach to "independent and distinct" inventions is different from the "unity of invention" of the EPO's and WIPO's approach. Whereas the EPO would consider claims as relating to the same invention, if the claims share a "special technical feature" over prior art, the USPTO can find the lack of unity in the same application, if the two alleged inventions can be used not only in combination with each other, or because of several fields of use of the invention.
This difference results in a multi-fold larger number of restriction requirements issued by the USPTO compared to the EPO, Intellectual Property Office, German Patent and Trade Mark Office, National Institute of Industrial Property, JPO and CNIPA, that originate from the same Paris Convention or Patent Cooperation Treaty priority application.
The US "independent and distinct" approach has an advantage, that it can be used before substantial examination, i.e. before an inventive step is identified.
' There is no judicial review of the restriction requirement in the US.
This is an unusual situation for a generally litigious US justice system. Many American patent practitioners believe, that the broad discretion given to the USPTO and the lack of judicial review on the issues of unity of invention, allow patent examiners to cynically "issue knee-jerk restriction requirements due to incentives at the USPTO to increase revenue or for examiners to perform less work for the same credit." This policy causes delays in examination and unfairly extends the patent monopoly due to multiple patents with different expiration dates.
On the other hand, the current restriction practice allows the USPTO to raise its revenue with only minuscule increase in its efforts: the patent applicant has to pay to filing, examination, issuance and maintenance of each divisional patent application separately, even though the patent examiner reads exactly the same text in each of the divisionals. In 2003 the Biotechnology Industry Organization urged the USPTO to change its restriction practice because some applicants were forced to spend $500,000 "to fully protect a single invention" due to numerous divisionals. Most of this money goes to lawyers for prosecuting multiple divisionals, and not to the USPTO. Also, in contrast to the USPTO fees, small businesses do not receive any discounts on lawyers' fees, and such excessive amounts prohibit small businesses from getting proper protection of their IP.