There are three main ways to conduct a patent search:
1. Online patent search: This involves using various online databases such as the USPTO (United States Patent and Trademark Office), the EPO (European Patent Office), and WIPO (World Intellectual Property Organization) to search for patents that have been granted in a particular field or industry.
2. Patent search service: This involves using a patent search service offered by a professional search firm, which specializes in conducting comprehensive patent searches. These firms often use proprietary search tools and have access to a wide range of databases and other resources.
3. Manual patent search: This involves physically visiting a patent library or office and manually searching through patent documents using various search tools such as indexes, classification systems, and keyword searches. This method can be time-consuming and expensive, but it may be necessary in some cases when a comprehensive patent search is required.