According to the provisions of Article 45 of the Patent Law of People's Republic of China (PRC), any unit or individual may request the Patent Reexamination Board to declare the patent right invalid if it thinks that the grant of the patent right is not in conformity with the relevant provisions of this law since the date when the patent administration department of the State Council announced the grant of the patent right.
According to the provisions of Article 47 of the Patent Law of People's Republic of China (PRC), the patent right is deemed to have no effect.
It didn't exist from the beginning.
Patent invalidation generally exists in patent infringement litigation. When an enterprise becomes the defendant of patent infringement, it will generally study the other party's patent, hoping to find out the reason why the other party's patent is invalid. If the patent of the other party can be invalidated through the patent invalidation procedure, then the infringement fact does not exist.
Although the law stipulates that any unit or individual can file a patent invalidation, the person who files a patent invalidation is generally an interested party, such as the accused patent infringer mentioned above, or other interested parties.