Why does it take so long to apply for an invention patent?

The invention patent processing cycle is about 1-2.5, including the substantive examination stage. Compared with the preliminary examination, it contains more content, stricter requirements, and longer time. Higher standards have been set in terms of novelty, inventiveness and practicality, the degree of disclosure of the description, and whether the claim drafting meets the requirements. If you need to shorten the time, you can choose the priority examination service.