For the Invalidation of a patent, dates play an important role. Every jurisdiction has different reforms regarding the date of the subject patent that is to be considered for invalidation. Here are the reforms of some major jurisdictions regarding the invalidation of a patent.
For performing a patent invalidation search in Indian jurisdiction, an analyst has to first find out the priority date of the claims of the subject patent or the patent which needs to be invalidated. Usually, any patent or non-patent literature that is available in public before the date of filing of the subject patent then that disclosure is marked as prior art. In some cases, if a relevant patent that is published after the filing date of the subject patent but the filing date or priority date of the relevant patent is before the filing or priority date of the subject patent then the relevant patent is considered as prior art for the subject patent and can invalidate the subject patent.
In Chinese jurisdiction, the filing date or priority date of a patent, whichever is earliest, is considered as the critical date for invalidating a patent. If the novel and inventive features of a patent are disclosed before the date of filing or priority date of the patent, then the patent can be invalidated. Moreover, China provides a legal grace period of 6 months that is a prescribed period after public disclosure of an invention to file a patent application within which the patent application can be filed without considering that the disclosure is destroying the novelty.
In Australia, an invention is marked as a novel only if the invention has not been sold, used in public, or described in a publication anywhere in the world before the patent’s priority date or the date when the first patent application for the invention was lodged. A patent in the Australian jurisdiction can be invalidated if any disclosure discloses the same thing before the priority date of the patent. Also, Australia provides a one-year grace period for public use or disclosure of the invention by the applicant. If an inventor has unintentionally published or publicly used the invention, then that publication or use will not invalidate the novelty of the subsequent patent application if the patent application is applied within twelve months of the initial publication or use.
In European jurisdiction, if a European application claims the right of priority of the date of filing of a previous application then the date of filing of the previous application becomes the effective date or priority date. On the other hand, if the application does not claim any right of a priority then the date of filing of the application is considered as the effective date. This effective date is interpreted as a critical date for the invalidation of a European patent. Moreover, the German Patent Law provides a 6-months grace period that applies to any publication that an applicant has published at some defined international trade fairs.
In Japan, the date of publication of prior art documents is especially important to mark it as the reason for the refusal. An examiner confirms the relationship between the date of publication of each of the prior art documents and filing date or the priority date of the subject patent in the examination for novelty and inventive step. However, if a secret prior art is considered for invalidation of a patent the examiner confirms the relationship between the filing date or priority date of the subject patent and the filing date or priority date of the secret prior art. Moreover, like China and Australia, Japan also provides a grace period of twelve months between the initial disclosure and the filing of a complete application. Recently, Japan has extended the grace period from six months to twelve months.
In Canada, the priority date is assessed on a claim-by-claim basis and it is called as claim date of each claim. Generally, the claim date of every claim in an application is the application’s Canadian filing date. In case if the application is a national phase entry of a PCT application then the international filing date is the claim date of every claim of the application. Moreover, if priority is claimed by the application then the claim date is the filing date of the earliest priority document disclosing the subject-matter defined by that claim. Further, Canada provides a grace period of 12 months for filing a patent application after disclosing the invention to some specific disclosure such as displays at officially recognized exhibitions, presentations at officially recognized academic or technical meetings, publications by officially recognized journals or experimental testing.
In the jurisdiction of Korea, the filing date or the priority date of a patent is considered as the critical date for invalidating the patent. If the features of the patent are disclosed or discussed in the public domain earlier than the filing date or the priority date of the patent, then the patent has a high chance to be invalidated. Additionally, Korea provides a grace period of 6 months for filing a patent after the disclosure of the novel and inventive features in public.
Under US jurisdiction, if an application is a divisional or continuation application of an earlier filed US application then the critical date is the filing date of the earliest US application. On the other hand, if claims of the application were not disclosed earlier in the parent US application then the critical date id the filing date of the divisional application. Moreover, for US patent/published application claiming priority from an application that subjects to pre-AIPA version (international application filed before November 29, 2000) then the filing date of the US patent/published application is considered as a critical date. Alternatively, for US applications that directly result from an international application that falls under the pre-AIPA version then the publication date of the US application is considered as the critical date. If the international application is filed on or after November 29, 2000, and the international application is published in English designating the US then the international filing date or earlier filing date is the critical date for such application, otherwise, the publication date of the international application is considered as the critical date of the application. Further, if the foreign patent/published application falls under pre-AIA then its publication date or grant date is considered a critical date, whichever is the earliest. If a US patent/published application claims priority from a pre-AIA foreign application, then the critical date will be the filing date of the US application. Optionally, if a foreign patent/published application falls under post-AIA then the filing date is considered as the critical date of the patent/published application. Furthermore, the USPTO provides a flowchart to simplify USC guidelines related to international applications. This chart helps to understand that in which category does the validating /invalidating patent belongs to and accordingly, the critical dates are established to uncover the potential prior art. The link for the flow chart is provided below:
Author: Subham Shaw, Sr. Patent Engineer, Neropat IP