To be patentable, an invention claimed in a Canadian patent application must be new. Being “new” requires that the invention must not have been made available to the public, in Canada or elsewhere, in an enabling manner by a single prior disclosure. Such a prior disclosure, if found, is said to have anticipated the invention, and can be used to invalidate the patent issued for the invention.
Generally, anticipation is assessed based on what was known prior to the claim date of the invention. The claim date is either the filing date of the Canadian application, or the filing date of an earlier application disclosing the same invention. As an exception in Canada, any inventor-originated disclosure of the invention occurred within one year before the Canadian filing date cannot be cited against the claimed invention.
A prior disclosure can be a patent document, a publication, a known product, a communication of information, or the inventor’s prior public use or sale of the invention. It is worth noting that a third party’s Canadian patent application having an earlier claim date than the claimed invention may be citable against the claimed invention for anticipation, regardless of the publication date of the third party application.
A disclosure would be considered as made to the public if at least one member of the public had an opportunity to access the information that is the invention without any restriction to the use of the disclosed information.
To establish anticipation, a single prior disclosure must include all essential elements of the claimed invention, and must provide sufficient information so that a person skilled in the field of the invention can perform the invention without undue effort.
Anticipation can be difficult to establish. In the words approved by the Supreme Court of Canada:
A signpost, however clear, upon the road to the patentee’s invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee.
To avoid losing patent rights, the most prudent practice for the inventor is to never publicly disclose the details of his or her invention before filing a patent application for the invention.