When an inventor applies for a patent with the patent office, the inventor files a patent application that decribes the invention, both in text and in drawings. During examination of the patent application, the patent examiner will usually object to parts of the application. For example, the patent examiner may feel the inventor’s claim is too close to the current state of the art. If so, the examiner rejects the claim as being too broad and gives the applicant a chance to narrow his claim. All of this correspondence is saved in what is called a “file history.”
Click here to see the file histories of some of America’s most famous patents.