Presumed valid but rebuttable All issued United States patents are presumed valid but this presumption is rebuttable with clear and convincing evidence. During prosecution of a patent application, the examiner looks for prior art references to see if the invention being claimed is novel and non obvious.  If no prior art reference is found that [...]

All issued United States patents are presumed valid but this presumption is rebuttable with clear and convincing evidence.  When submitting previously considered evidence, it is generally more difficult to overcome the presumption of validity. The following case explains and illustrates how to treat evidence that was previously considered by the Patent Office during prosecution of [...]

The evidence needed to invalidate a patent needs to be clear and convincing regardless of whether the information was before the Patent Office. This is a higher standard than the preponderance of the evidence standard. Hence, this case strengthens patents because it eliminates arguments that might have been used to invalidate patents.