Legal analysis: First of all, we should make clear the purpose of purchasing patents, because according to different purposes, the types of patents purchased will be very different, and they must be announced patents, that is, patents that can be purchased. Specific methods can be found through announcements on the website of the Intellectual Property Office, patent transfer network and other news.
Legal basis: Article 70 of the Patent Law of People's Republic of China (PRC) uses, promises to sell or sells an unknown patent infringing product that is manufactured and sold without the permission of the patentee, and can prove the legal source of the product, and shall not be liable for compensation.