What is the exception to the general rule for foreign patent reference dates?
While the general rule is that a foreign patent becomes available as a reference on the date it becomes enforceable, there is an important exception. The MPEP states:
“There is an exception to this rule when the patent is secret as of the date the rights are awarded.” (MPEP 2126.01)
This exception, based on the case In re Ekenstam, means that if a patent is kept secret even after the rights are formally awarded, its effective date as a reference may be delayed until it becomes publicly available.
To learn more:
Topics:
MPEP 2100 - Patentability,
MPEP 2126.01 - Date Of Availability Of A Patent As A Reference,
Patent Law,
Patent Procedure