In Taiwan patent litigation, a defendant can argue patent invalidity of the patent-in-suit, and the court has authority to determine this issue. In practice, the defendant often challenges the novelty or non-obviousness by presenting prior art, or questions whether the patent meets requirements for disclosure and enablement. This August, the Intellectual Property and Commercial Court (hereinafter referred to as "the IPC Court") came across an extremely rare patent infringement case (No. 2023 Civil Patent Suit 4, August 2023), where the court determined that the patent-in-suit was invalid on the ground that the plaintiff’s post-grant amendment approved by the Taiwan Intellectual Property Office (hereinafter referred to as "the TIPO") substantially altered the scope of the previously allowed and published claims.
The plaintiff's patent in this case relates to the technology of automatic laundry hanger. After the patent was granted by TIPO, the plaintiff applied for a post-grant amendment for claim scope, and TIPO approved said amendment. The plaintiff then sued the defendant based on the amended claims. To challenge the validity of plaintiff’s patent, the defendant presented prior art to question its non-obviousness, and also argued that the plaintiff’s post-grant amendment approved by TIPO substantially altered the scope of the claims as published and thus, the post-grant amendment should not have been approved.
Per Article 67 of Taiwan Patent Act, after a patent was granted, the patentee may file with TIPO a request for post-grant amendment; however, said amendment shall only be limited to deleting claim(s); narrowing down the scope of claim(s); correcting errors or translation errors; or clarifying ambiguous statement(s). In addition, the post-grant amendment shall not extend beyond the scope of content disclosed in the description, claim(s), or drawing(s) as filed and shall not substantially enlarge or alter the scope of the claim(s) as published (collectively referred to as "the requirements for amendment"). After approving the post-grant amendment, TIPO shall publish the approval decision, and such post-grant amendment shall take effect retroactively from the filing date. If TIPO rejects the post-grant amendment, the patentee still maintains the originally allowed patent content and may reserve the right to request a new post-grant amendment. As for the rejection decision, the patentee could appeal by filing administrative remedy actions including the administration suit.
It should be noted that Article 71(1) of Taiwan Patent Act, as amended in 2011 and enforced to date, stipulates the grounds for an invalidation action against invention patent, including whether the post-grant amendment violates Article 67 of the same. That said, any person can file the invalidation action to challenge whether a post-grant amendment approved by TIPO meets the requirements for amendment as stipulated in Article 67. If TIPO determines that a previously approved post-grant amendment does not meet the requirements for amendment (hereinafter referred to as the "erroneous approval for post-grant amendment"), TIPO will make an invalidation decision. However, according to Article 82(1) of the current Taiwan Patent Act, where an invalidation action against an invention patent is considered well grounded, the patent right shall be revoked, i.e., it is not only to withdraw the TIPO’s decision for erroneous approval for post-grant amendment to restore the claim scope before the amendment, but also to revoke the pre-amendment patent which has nothing to do with the subject matter of the invalidation action (namely, whether the post-grant amendment approved by TIPO meets the "requirements for amendment"). In other words, if TIPO did not approve the post-grant amendment at that time, the patentee would at least retain the original patent and have the opportunity to file another post-grant amendment application later. However, once TIPO approves the post-grant amendment first and then changes its position in the subsequent invalidation proceeding, determining said post-grant amendment does not meet the “requirements for amendment”, the patentee would lose the whole patent because of the previous erroneous approval which is attributed to TIPO. It is worth exploring whether the legal effect of such a legislative design in relation to the erroneous approval for post-grant amendment from TIPO is appropriate. In contrast, for a patent where the TIPO has granted a term extension, any person may file an invalidation action and challenge against the TIPO granting the patent term extension. However, per Article 57(2) of Taiwan Patent Act, if an invalidation decision revoking the patent term extension has become final and binding, the legal effect is that the granted patent term extension shall be deemed non-existent ab initio (i.e., the original patent term is reinstated), rather than the patent being revoked, which is a more delicate and appropriate legislation.
From the viewpoint of practices, if the patentee’s post-grant amendment is approved by the TIPO, it is difficult for an invalidation action petitioner to challenge whether said post-grant amendment meets the "requirements for amendment" and to urge the TIPO to change its opinion during the invalidation proceedings. Usually, the TIPO affirms the previous approval of post-amendment in this kind of cases. Even though the invalidation action petitioner subsequently initiates an administrative lawsuit, the IPC Court mostly affirms the approval of post-amendment from the TIPO (see No. 2017 Administration Patent Suit 12, IPC Court). However, in this civil litigation case, the IPC Court reversed the TIPO's original position of approving the post-grant amendment with the court’s discretion on the "requirements for amendment", holding that the post-grant amendment had substantially altered the scope of the claim(s) as published, and then dismissed the case on the ground that the patent was invalid, since the grounds for revocation of the patent include the post-grant amendment’s violation of Article 67 of Taiwan Patent Act.
Regardless of whether it is reasonable for the Patent Act to stipulate that the legal effect of an invalidation decision due to the TIPO’s erroneous approval for post-grant amendment is revocation of the patent (rather than the withdrawal of the post-amendment approved by the TIPO), under the existing legal framework, if the invalidation action petitioner or the patent litigation defendant argues in the invalidation proceedings or litigation, respectively, that the post-grant amendment should not have been approved by the TIPO, and there is any risk that the post-grant amendment does not meet the "requirements for amendment", the patentee and his/her patent attorney should take a conservative and prudent approach in assessing the situation and adopt further proactive countermeasures. For example, it may be necessary to file a request for new post-grant amendment at an appropriate time or to ask the TIPO or the IPC Court to disclose conviction in order to avoid the patent being deemed invalid because of erroneous approval for post-grant amendment from the TIPO.