I'm trying to do my own patentable idea search but noticed that an idea might appear in the USPTO granted/assigned patent database as well as their patent application database.
How can I perform a comprehensive search; must I search both, which will return mostly duplicates?
No - Unlike other organizations with patent databases, the USPTO maintains these as two different databases. Published applications - appft and issued patents - patft.
This is due to historic reasons. Patents have been issued for hundreds of years but applications have only been published for decades. At the USPTO you will need to run any prior art search separately on each of these sites.
The same application can cause a hit on both databases if an application is published and granted.
They are likely to not be identical since claims are often amended during prosecution. Also not all applications are published and it is rare but possible for a patent to be granted before it’s application is published. And not all applications generate issued patents.
Applications are automatically published at the 18 month point unless a non publication request was filed by the applicant. In that case there will not be a publication of the application. On the other hand it is possible that there are two publications of the application at the applicants request after an amendment is made.
If a patent is granted the patent is “published”, of course. In the event the patent is granted in less than 18 months it will be out before the date of publication of the application, if any.
Non publication requests require the applicant not to do any filing outside the U.S.
Google patents, Espacenet, The Lens, PatentScope and all other databases, both free and commercial, that I'm familiar with do not separate these categories.
