According to Article 33 of the Patent Law, invention patent applications shall be filed on a case-to-case basis; where two or more inventions are so linked as to form a single general inventive concept, they may be claimed in a single application. To put it another way, a single application can cover two or more inventions only when the claimed inventions are in possession of a common feature being novel or non-obvious over the prior art.
As there are some grey areas in the Criteria for determining whether an invention patent application meets the "unity-of-invention" requirement set out in Article 33 of the Patent Law, recently, Taiwan’s IP Office, after seeking opinions from practitioners, has introduced amendments to the new criteria implemented as of January 1, 2019. The following are several main amendments which merit the applicant's attention:
1. An Examiner should have completed examination of a set of claims as to "novelty" and "inventive step" of the claimed invention when he/she raises the "unity of-invention" issue. In other words, it is not admitted for an Examiner to issue an Official Letter/Office Action merely based on the "unity-of-invention" issue. In principle, the Examiner should elect Claim 1 and its dependent claims as the basis for preliminary examination.
2. If an applicant fails to overcome the "lack-of-unity” rejection after filing an amendment or argument against an Official Letter in which the Examiner has raised not only the “novelty" and/or "inventive step" issue but also the "unity-of-invention" issue, the Examiner may formally reject the application. At that time, it is a must for the applicant who wishes to further prosecute the application to file a request for re-examination.
3. If an Examiner has rejected all the claims for being destitute of "novelty" or "inventive step", basically, he/she no longer can raise a “lack-of-unity” rejection afterward. The underlying rationale is that the applicant should be given full opportunity to file amendments or argument in a less favorable situation.
In view of the above amendments, the applicant is advised to: (1) define the most essential feature of an invention in Claim 1 and its dependent claims; (2) file a set of revised claims to meet the Examiner's requirement, if acceptable, and to, in turn, obviate the "unity-of-invention" rejection; and (3) pay special attention to the respective deadlines for filing divisional applications at different stages and file divisional applications at appropriate times.