1. Patent Application is published after 18 months of filing.  India requires a request of examination to be filed within 48 months of the priority date for the patent application to be taken up for examination.
  1. There are two kinds of opposition, viz. pre-grant opposition and post-grant opposition which are filed at the patent office.  Rectification of a patent is filed either before the civil court or before the Intellectual Property Appellate Board.

Pre-grant opposition:

  1. After publication of the patent application, it is open for pre-grant opposition.  A pre-grant opposition can be filed any time till the grant of the patent.  It can be filed by any person under Section 25 (1) of the Patents Act on the grounds stated in this section along with evidence.
  1. The Patent office will notify the patent applicant about the pre-grant opposition.  The applicant can file a response in support of the patent application.  The pre-grant opposition is taken up for hearing and a detailed order passed by the Controller of Patents.

Post-grant opposition:

  1. Another opposition is a post grant opposition which can be filed anytime from the date of grant until the expiry of one year of grant.  Unlike pre-grant opposition, a post-grant opposition can be filed only by an interested person.  The grounds for opposition are under Section 25 (2) of the Patents Act.
  1. The Patent office will notify the patent applicant about the post-grant opposition.  The applicant can file a response in support of the patent application along with evidence.  The post-grant opposition is taken up for hearing and a detailed order passed by the Controller of Patents.
  1. The proceedings before the Controller are like that of a civil court.  The parties are entitled to cross examine the deponent of the evidence affidavits; summon witnesses amongst others.  However, in practise, the statement made in the affidavits are accepted as true unless some contraction or error is apparent.
  1. A party is entitled to file additional evidence with the leave of the Controller of Patents.  It will have to be shown why the additional evidence was not filed at the first instance.
  1. An order passed in post-grant opposition is appellable.  On the other hand, an order passed in pre-grant opposition is appellable only in the even of rejection of the patent application.  Rejection of a pre-grant opposition is not appellable.  Whether a writ petition is maintainable against rejection of a pre-grant opposition is to be considered.
  1. An appeal against the order of Controller of Patents lies before the Intellectual Property Appellate Board (IPAB).  There is no further appeal against the order of IPAB but a writ petition would lie before the jurisdictional High Court.
  1. Considering the backlog at the Patent office, it takes couple of years for an opposition hearing even though the pleadings are complete and set for a hearing.  The Patent office has taken many steps to reduce the backlog like service of Opposition. 

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