What is the examination and approval procedure for American invention patents?

Application process application date: the date of submitting the application to the US Patent Office, which will be known within 2 weeks after submission; Application number; Examiners examine patents before granting them; After submitting the application, it shall provide the information of other prior approximate rights to the US Patent Office; After the application is submitted, the first official opinion is received about 18 months. Audit time: 2.5-3 years Protection period: 20 years from the date of application.