Some people are natural born inventors and they invent stuff all the time. Then one day, they decide to file a patent application.... but they can't. What?
Yes, you heard me. You may be unable to file a patent application for an invention that you invented. 35 U.S.C. Section 102 states what you can and cannot patent.
Section 102(a) states:
A person shall be entitled to a patent unless--
(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention; or
(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
When I conduct patent searches, I can almost tell whether a patent application would be successful or not based on the search results. For instance, when I look for a certain type of a camera, many patents I come across are actually registered patents, so that tells me that my application claiming a camera can be registered. But when I look for a business method, many patents I come across are patent application publications, so that tells me that it would be difficult for me to register my application claiming a business method. This doesn't work a 100% of the times, but patent search results give me a good idea of whether an invention is registrable or not.
Preparing a patent application is no easy feat, especially for first time inventors/applicants. It can be overwhelming to put everything down on paper and answer questions about every aspect of your invention. Then you ready through a twenty-page document that your patent attorney hands you to make sure that your invention was described accurately, sign some forms, pay all the fees, and you’re good… for now. Then one day, someone asks you, “What did you patent?” or “What are you patenting?” and all of a sudden, you’re not really sure how to answer that question.