United states patent dating
One of the principal ways of overcoming the presumption of validity is to attempt to find prior art which is more relevant to patentability of the claims than the prior art which was cited by the Patent and Trademark Office examiner. patent (issued more than a year before the filing date of the patent being evaluated) is the date the prior-art patent was issued.
Such prior art may, for example, take the form of prior patents or publications. If the prior-art patent was issued within one year prior to the application filing date which eventually became the patent being evaluated, the effective prior-art date of the patent is the filing date of the application which became the prior-art patent.
In order to obtain a patent, the invention must be useful, novel and unobvious.
Another approach to invalidating a patent is to prove that the invention was in public use or on sale in the U. more than a year prior to the date of the application.
Silverman In considering whether a specific product, apparatus, method or composition of matter may violate a United States patent, primary attention is directed toward the issues of infringement and validity.
Infringement in this context means that the particular technology falls within the patent claims.