As per Indian Patent Law, one patent application shall relate to a single invention. However, if more than one inventions are to be claimed in single application, it is necessary to establish that the inventions so claimed have unity and they form a single inventive concept. The golden rule is that the claim (s) of a complete specification shall relate to a single invention, i.e. the concept of unity of invention shall be there.
According to Section 10 of the Patents Act 1970, if claims refer to a group of inventions, such inventions shall form a single inventive concept. The claims shall be clear and succinct and shall be fairly based on the matter disclosed in the specification and moreover, a single inventive concept may be recognized between independent claims of different categories.
The invention comprising of a polymer, process to prepare polymer and commercial utility of polymer can be claimed in the single patent application because even though the invention has three main components, all of them relate to a single invention and have unity. On the other hand, the invention relating to two independent formulations used to treat cancer and HIV/AIDS shall not be claimed in a single patent application as both formulations are independent of each other and hence lack unity of invention.
The purpose of this requirement of unity of invention is administrative, as well as financial. That is, the requirement serves to prevent the option of filing one patent application for several inventions, while paying only one set of fees, such as, fee for filing application, examination, early publication or annual renewal etc. Moreover, the concept of unity of invention also makes the technical classification easier.
Under section 16 of the Indian Patents Act, 1970, if a single patent application has been filed with more than one invention and invention so claimed lacks unity, the applicant may divide main application into divisional application. However, the further application (divisional application) and the complete specification accompanying it shall be deemed to have been filed on the date on which the first mentioned application had been filed, and the further application shall be proceeded with as a substantive application and be examined when the request for examination is filed within the prescribed period.
"According to Section 10 of the Patents Act 1970, if claims refer to a group of inventions, such inventions shall form a single inventive concept. The claims shall be clear and succinct and shall be fairly based on the matter disclosed in the specification and moreover, a single inventive concept may be recognized between independent claims of different categories."
However, during the process of examination of the patent application, the examiner may also ask the applicant to divide the application into two or more applications and file divisional application. It is interesting to note that both parent application and divisional application will have the same priority date though divisional application is often filed later than parent application. For example:
Date of filing provisional application and priority date: 15th November 2006
Date of filing complete specification: 13th November 2007
Publication and examination of the patent application takes place and the Controller raises the objection that the invention lacks unity of invention and hence the application shall be split into two applications i.e., main parent application and divisional application. Here, the date of filing divisional application will be 10th Jan 2009.
In such a case, both parent application and divisional application will have priority date of 15th November 2006 even though the divisional application was filed 10th Jan 2009, which also mean that both parent application and divisional application expire on the same date irrespective of the date of filing.
A specification in respect of a divisional application under section 16 shall contain specific reference to the number of the original application from which the divisional application is made. The request for examination in case of divisional application shall be filed within 48 months from the date of filing or priority of the parent application or within six months from the date of filing the divisional application, whichever expires later. Request for divisional application shall be filed only after filing request for the parent application to ensure the requirement of section 16(3).
Moreover, the complete Specification of a divisional application should not include any matter not in substance disclosed in the complete specification of the first application. The reference of parent application should be made in the body of the specification. A divisional application has to be filed before the grant for a parent application.
Though it sounds economical to club multiple inventions together and file for a single application, it is logical to follow the concept of unity of the invention and ensure that separate applications are filed for each invention.