What's the use of invalid patents?

Legal analysis: invalid patents can be used by any unit or individual for free, thus obtaining economic benefits. Any unit or individual can improve invalid patents and implement them free of charge. The similarity between the first utility model and the second utility model is that anyone can use invalid patents for free. Difference: the first utility, anyone directly implements invalid patents; The second utility is to improve invalid patents before implementation.

Legal basis: People's Republic of China (PRC) Patent Law.

Article 47 An invalid patent right shall be regarded as nonexistent from the beginning.

The decision to declare the patent right invalid has no retrospective effect on the patent infringement judgments and conciliation statements made and executed by the people's court before the patent right was declared invalid, the decisions on handling patent infringement disputes that have been performed or executed, and the patent licensing contracts and patent transfer contracts that have been performed. However, if the patentee's malice causes losses to others, it shall make compensation.

If the patent infringement compensation, patent exploitation fee and patent transfer fee are not returned in accordance with the provisions of the preceding paragraph, which obviously violates the principle of fairness, they shall be returned in whole or in part.