Patents are generally documents issued by government agencies or regional organizations representing several countries according to their applications. This kind of document records the contents of the invention and creation, and in a certain period of time, it has produced such a legal state that the patented invention and creation can only be implemented by others with the permission of the patentee. In China, there are three kinds of patents: inventions, utility models and designs.
As the most effective carrier of technical information, patent literature contains more than 90% of the latest technical information in the world, which is 5-6 years earlier than the information provided by general technical publications. Moreover, 70%-80% of inventions are only disclosed through patent documents, which are not found in other scientific and technological documents. Compared with other literary forms, patents are more novel and practical. It can be seen that patent literature is the largest technical information source in the world. According to empirical statistical analysis, patent literature contains 90% ~ 95% of the global scientific and technological information.