Limiting by publication country (patent office) can be useful to narrow your search results.
You may search by:
•2 Letter Country Code: EP, US, WO, or any other from the list of ISO 3166 country codes, etc.
•The 2 letter Country Code and Kind Code: EPA1, USB? (to find B2,B3,etc.), etc.
•The publication date in the format: YYYYMMDD, YYYYMM or YYYY
•To combine the Country Code and Date use the S operator (the terms are searched within the same phrase).
e.g. f you are looking for U.S. patents issued in 2005, the request will be: USB? S 2005.
You can also exclude types of publications.
Example: The query: CN? NOT CNU? will search for families that have a Chinese publication, but not families containing a Chinese Utility model.
If you have other search criteria, the publication country will be combined with the other criteria using the AND operatorNote: Uppercase and lowercase letters are treated the same.