For the legal status of U.S. patents, you need to check the website of the United States Patent and Trademark Office (http://www.uspto.gov/). The general steps are as follows: Enter the public query database (Public pair) through the USPTO website; enter the verification code to verify; enter the patent number to query; obtain the basic information of the patent you are querying; you can then see the status of the patent you are querying. (status), you can also query the patent review process information through the "Image File Wrapper" tab, and query the patent fee information through the "Fees" tab.