What do you mean the patent is invalid? How to understand invalid patent?

What does the so-called invalid patent mean? He is an extremely important information resource. There is a common misunderstanding that invalid patents have no use value since they have expired, so they are put aside and cause serious waste of resources. Therefore, it is necessary to improve the understanding of invalid patent as an important information resource, find out its formation reasons and application value, and clarify the ways and methods of its development and utilization. What does invalid patent mean? If the patent application documents do not meet the requirements of preliminary examination and the applicant fails to make corrections within the time limit, his application shall be deemed to have been withdrawn. If it still does not meet the requirements of the patent law after correction, it shall be rejected. An applied patent, whether regarded as withdrawn or rejected, is invalid. The disqualification is mainly due to the fact that one of several items, such as the description format and the identity of the applicant, may not meet the requirements. The preliminary examination does not involve the application content, so most of these invalid patents can be used for reference and have certain application value. If the patent applicant withdraws after the publication of the application or refuses to submit the foreign application materials without justifiable reasons, it shall be deemed to have withdrawn. If the applicant refuses to submit the foreign application materials without justifiable reasons, the application shall be deemed to have been withdrawn and the patent application shall be invalid for China. Patent applications that violate the application procedures, the technology itself does not meet the authorization conditions, and fail to pass the substantive examination are not used as much as possible, while patent applications that lose their patent rights due to technical problems in writing application documents have high technical content and application value, and should be developed and utilized more. To revoke the patent right and grant an invalid patent right within a certain period of time, China National Intellectual Property Administration shall revoke the patent right according to law at the request of the applicant.