What is the limitation of action after the expiration of patent protection?

After the expiration of patent protection, it becomes an open technology, which has no legal effect and can be implemented by anyone for free, so there is no statute of limitations. According to national laws, after the expiration of patent protection, it is impossible to continue to apply. Invention patents are valid for 20 years from the date of filing, and utility models and designs are valid for 10 years from the date of filing. In the meantime, an annual fee will be paid to maintain the patent. When it expires, it will become an open technology, which has no legal effect and can be realized by anyone for free.