Searching prior art with the help of Inventor, assignee and Classification

Searching through the relevant keywords is safest approach for locating relevant prior art as there is a very high chance of finding prior art, but it is not the best approach. There are chances that some of the prior art may have been missed because of the different patent language or short description.

There are some other strategies that a good patent searcher should work out on. some of them are to use Inventors, assignees and Classifications, first of all shortlist all the closest patents you have found till date and then find their inventors, assignees and classifications (IPC, US, F terms etc). You can add some of the assignees by simply searching for the companies which are active in that field. 

Use this search engine for searching relevant US classes and use TACSY for searching relevant IPC classes. Once you have the list of Inventors, Assignees and Classifications you are ready to search.

PS: Make at-least one query which is only based on classification, and don't forget to check for the NPL that those inventors have published. You might find something interesting.