Research guides: Introduction to Patents and Patent Searching: Finding patents

Patent and Trademark Offices

Canadian Patents Database (CIPO)
Canadian patent records from 1869 and full-text documents from 1920 to the present.
United States Patent and Trademark Office (USPTO)
US patents from 1790, full-text available from 1976 to the present.
European Patent Office (EPO)
Espacenet: International patent database.
World Intellectual Property Office
WIPO is the global forum for intellectual property services, policy, information and cooperation.

To be most effective in your search for patents you must determine how your invention works, NOT how you will use your invention.

Start by making a list of words that describe your idea (including synonyms)
Record class/subclass of any related terms
Ask yourself:
- What does the invention do?
- What is the end result/anything unique/special/ unexpected?
- What is it made of/method or material of fabrication?
- What is it used for?
Keep track of useful and non-useful patents (by patent number) to avoid duplication of efforts

PatentScope (WIPO)
It includes over 73 million patent documents: PCT and national/regional collections, AI-based developed-in translation tool, chemical structure search and CLIR that finds synonyms search terms and translates everything into 13 languages.
The Lens
Australia, European, United States, and WIPO patent documents.
Google Patents
U.S. patents in pdf format from 1790 to the present.
EPO patents from 1978 to the present. Text only with links out to EPO and PDF download.

Patent Classification is a system of codes designed to organize and index the technical content of patents.

Cooperative Patent Classification (CPC)
The Cooperative Patent Classification (CPC) system, in force from 1 January 2013, is a bilateral system which has been jointly developed by the EPO and the USPTO. It combines the best classification practices of the two offices.

How to cite a patent
This site gives examples using multiple citation styles.
Citing Patents
This guide from the University of Kansas provides clear examples of patent citations in a variety of styles.