Prior invention can be prior art in one of two ways

Prior invention can be prior art in one of two ways.

 35 USC 102(f) states simply that you don’t get a patent if “he did not invent himself the subject matter sought to be patented” That seems self evident enough, but it was quickly interpreted to mean that any invention that you learned of before your invention was prior art to you. That seems a pretty strained interpretation, but courts can define laws as they want.

 Next, 35 USC 102(f) was decided by some court to be a section that defines prior art to be applied under 35 USC 103 – obviousness. Now, you are not only precluded from patenting an invention that is disclosed to you by another. You are also precluded from patenting an obvious variation of an invention disclosed to you by another.

 The other section of 35 USC 102 that pertains to prior invention is 35 USC 102(g). This was thought for a time to simply be the basis of interference practice, but some court soon decided that a prior invention under 35 USC 102(g) could be prior art to an applicant, provided that the invention was made in this country and it was not abandoned, suppressed or concealed.