navigating the patent maze

The US Patent and Trademark Office (USPTO) now has an on-line searchable database of assignments for U.S. patents and published patent applications. Assignment data for pending (and unpublished) and abandoned applications are not available.

A tour of the search page (found here) shows the typical bare-bones style as their search page for patents. Searchable terms include:
Reel/Frame Number: (location of data on tape; casual users aren’t likely to know this)
Patent Number: (e.g. 6345127)
Publication Number: (refers to patent applications e.g. 200300012456 — must contain 11 digits)
Assignor Name: (usually the inventor name)
Assignor Index: (same as above — see below for difference between index and name)
Assignee Name: (usually a company or university)
Assignee Index: (same as above)
Assignor/Assignee Name: (this means the name could be either assignor or assignee)

Do not be fooled (like I was) by the underlining of the input terms, thinking that means they link to help. The help file, such as it is, is found by clicking on the identically underlined “online help”, which is at the top of the page. “Help” failed to help me understand the difference between ‘name’ and ‘index’.

After some trial and error, I deduced that ‘name’ means just that; the results contain all entries with the inputted name or begin with the inputted name. (Example: ‘camb’ will return ‘cambia’, ‘cambridge’, etc.) ‘Index’ returns an alphabetical list of names contained in the entire dataset, with the inputted name at the top of the list. (Example: ‘cambia’ returns ‘cambia’ ‘cambber’ ‘camden’ etc.) Clear as mud yet?

Remember that the assignee of the patent rights is only the owner of the rights. The assignee may license away, give away, or sell any or all of the rights it owns. If you want to know who actually controls the patent rights, this database will not inform you. While ownership is public knowledge, the transaction between the owner and the recipient of the rights is often held in secret. When the transfer of rights is done by contract, the privacy of the contract is respected by law.

Sometimes it is possible though to find out who has control of the patent rights by searching news articles, press releases, or by asking the owner (assignee). Good luck.