invention, or so much thereof as has not expired, and shall remain in force during that term or until the previous cesser of the patent for the main invention and no longer:
Provided that if the patent for the main invention is revoked under this Act, the court, or, as the case may be, the Controller, on request made to him by the patentee in the prescribed manner, may order that the patent of addition shall become an independent patent for the remainder of the term for the patent for the main invention and thereupon the patent shall continue in force as an independent patent accordingly.
(2) No renewal fee shall be payable in respect of a patent of addition, but, if any such patent becomes an independent patent under sub-section (1), the same fee shall thereafter be payable, upon the same dates, as if the patent had been originally granted as an independent patent.
56. Validity of Patents of Addition
(1) The grant of a patent of addition shall not be refused, and a patent granted as a patent of addition shall not be revoked or invalidated, on the ground only that the invention claimed in the complete specification does not involve any inventive step having regard to any publication or use of -
- a. the main invention described in the complete specification relating thereto; or
- b. any improvement in or modification of the main invention described in the complete specification of a patent of addition to the patent for the main invention or of an application for such a patent of addition,
and the validity of a patent of addition shall not be questioned on the ground that the invention ought to have been the subject of an independent patent.
(2) For the removal of doubts it is hereby declared that in determining the novelty of the invention claimed in the complete specification filed in pursuance of an application for a patent of addition regard shall be had also to the complete specification in which the main invention is described.
CHAPTER X
AMENDMENT OF APPLICATIONS AND SPECIFICATIONS
57. Amendment of application and specification before Controller
(1) Subject to the provisions of section 59, the Controller may, upon application made under this section in the prescribed manner by an applicant for a patent or by a patentee, allow the application for the patent or the complete specification to be amended subject to such conditions, if any, as the Controller thinks fit:
Provided that the Controller shall not pass any order allowing or refusing an application to amend an application for a patent or a specification under this section while any suit before a court for the infringement of the patent or any proceeding before the High Court for the revocation of the patent is pending, whether the suit or proceeding commenced before or after the filing of the application to amend.
(2) Every application for leave to amend an application for a patent or a specification under
