Patent validity search is conducted after the patent application is granted, and the owner of the patent wants to file an infringement case against the potential infringer. All patent acts have a disclaimer disclaiming validating or guarantying of the search and examination by the examiner. Therefore, to recheck and confirm the grant is correct, patent validation search is conducted. It’s similar to patentability search but with restricting date to cite documents published before the date of filing.
This is done to double check and negate any possibility of revocation of the patent in future. Patent Invalidation search is conducted when an owner is about to file patent infringement case against the infringer and want to double check and negate any possibility of revocation of the patent. Also, invalidation search is conducted when you are a defending in an infringement case, and you need to invalidate the patent that is in issues to get off this case quickly.