The European Patent Convention is a regional international patent organization, which is only open to European countries. The European Patent Convention provides a unified legal system and a unified patent granting procedure for all member countries. The review procedure adopts the system of publicity in advance, delayed review and objection after authorization. When filing a European patent application, one, several or all member States may be designated. Once the patent right is granted in accordance with the convention, it can take effect in all designated member States and has the same effect as the patent granted by designated member States in accordance with their own laws. The European patent right is valid for 20 years from the date of application.