Similar to US patent law, Taiwan's patent system allows for the use of means-plus-function or step-plus-function language for claim limitations. Article 18(8) of the enforcement rules to the Patent Act (as amended and implemented on July 1 2004) stipulates that:

"For an invention characterised in combining a plurality of technical features, the claims may be presented in means-plus-function or step-plus-function language. Whenever an interpretation of claims is made, it shall contain the structure, material or acts or equivalent scope thereof corresponding to the functions disclosed in the description of an invention."

This is similar to the specification provision under US patent law (Section 112 of Title 35 of the United States Code (35 USC 112)), which provides that:

"An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof."

In lawsuits for infringement of a patent containing means-plus-function or step-plus-function claim limitations, accused infringers occasionally employ this principle (specifically, "whenever an interpretation of claims is made, it shall contain the structure, material or acts or equivalent scope thereof corresponding to the functions disclosed in the description of an invention") to argue that the patent should be invalidated for not conforming to the 'definiteness' requirement under Article 26(2) of the Patent Act. This article states that:

"The description of invention shall contain a sufficiently clear and complete disclosure of contents of the invention so as to enable persons skilled in the art to understand the contents thereof and to practice said invention."

This view prevailed in a January 2010 decision ,(1) in which the IP Court held that Claim 6 of the patent in question failed to meet the definiteness requirement.

In practice, it is common for patent applications for business method inventions or software-related inventions to employ the means-plus-function or step-plus-function format in the drafted claims. This is because technical features of such inventions are difficult to describe in terms of concrete structures or materials; therefore, functional language may serve as a more expedient way to limit the claims.

However, the above-mentioned principle in the enforcement rules still applies to these inventions, even though business methods and software are fundamentally different from mechanical inventions - the technical features of which normally involve specific physical structures, materials or acts.

Thus, from a technical perspective, careful deliberation is required as to what the "structure, materials or acts" of a business method or a software invention actually refer to. A court that simply employs the aforementioned standard and invalidates a patent due to a lack of definiteness on the grounds that "the specification fails to recite any structures, materials or acts corresponding to the means-plus-function limitations in the claim" without carefully probing into the criteria for definiteness set forth in Article 26(2) of the Patent Act (ie, "whether persons skilled in the art could understand the contents of and practice said invention") risks scrutiny of its credibility for applying unduly superficial standards of relevance, given the nature of the patent in question.

In the 2010 case the patent in question, NI-152547, was entitled 'System for automatically matching advertiser and advertising object and the matching method based on the same'. Its Claim 6 read:

"A storage medium facilitating subscribers to automatically configure a desired advertising mode and category, which comprises: a functional means for configuring the advertisement mode, whereby allowing the subscriber to receive the feedback; a functional means for configuring advertisement category, whereby allowing the subscriber to configure the advertisement category desired to receive; a functional means for generating matching information; and a functional means for matching alert system, whereby allowing mutual matches with an advertising matching system."

Although this claim refers to a 'storage medium', from a reading of the specification, the substantial technical core relates to a software invention, as asserted by the patentee during the trial procedure. The IP Court ruled against the patent's validity, following which the patentee appealed to the Supreme Court. The Supreme Court reversed and remanded the IP Court's judgment on March 31 2011.(2)

The Supreme Court opined that the IP Court should have investigated and clarified the type of claimed invention, and should not have directly held the patent to be 'lacking definiteness' merely because no structure and material corresponding to the means-plus-function limitations of Claim 6 could be found in the specification or drawings.

On remand, the IP Court rendered a judgment in October 2011(3) in which it maintained its original position that "since there is no corresponding structure or material specified in the specification, Claim 6, having means-plus-function limitations, failed to comply with the requirement of definiteness".

Moreover, the IP Court indicated that, since the claimed objective of Claim 6 had not been definitely specified, the court had no way to make a comparison between it and the prior art citations raised by the defendant in order to determine whether the claimed invention met the requirements of novelty and inventive step.

In order to support its view, the IP Court cited:

  • the US specification provision (35 USC 112);
  • the Supplementary Examination Guidelines for Determining Compliance with 35 USC 112 and for Treatment of Related Issues in Patent Applications which came into effect on February 9 2011; and
  • cases including In re Hayes Microcomputer Prods Inc Patent Litigation,(4) Aristocrat Techs Australia Pty Ltd v Int'l Game Tech(5) and Finisar Corp v DirecTV Group Inc.(6)

The court indicated that if the invention is software related and the claim drafted with means-plus-function language, the patent applicant must describe in detail the algorithm of the software in the specification, so as to serve as a basis for the court or the patent authority to determine whether it has met the definiteness requirement. The IP Court stated that a domestic court can take such US law and judgments as reference regarding legal principles.

It remains to be seen how this opinion will influence practice on examination of software-related patents. Thus far, the patent examination guidelines for software-related patents stipulate only that a flowchart or a function block diagram can be employed to illustrate the desired function of the software and, if necessary, data flow diagrams, pseudo codes and time charts can also be utilised to disclose technical features in order to enable persons skilled in the art to realise and implement the claimed invention accordingly.

Once this IP Court opinion based on US law regarding disclosure of the algorithm becomes a standard criterion for evaluating the definiteness of a means-plus-function claim of a software-related patent, further precedents will be needed to establish how the 'algorithm' and its scope are defined, as well as how to correlate it to the "structure, material and act" specified in the enforcement rules of the Patent Act.

This case has been appealed again to the Supreme Court and a decision is pending.

For further information on this topic please contact Hsiu-Ru Chien at Lee and Li Attorneys at Law by telephone (+886 2 2715 3300), fax (+886 2 2713 3966) or email ([email protected]).


(1) Judgment 2009-Min Juan Shan-19.

(2) Judgment 2011-Tai Shan-480.

(3) Judgment 2011-Min Juang Shan Geng (1)-5.

(4) 982 F2d 1527, 1534 (Fed Cir 1992).

(5) 521 F3d 1328, 1333 (Fed Cir 2008).

(6) 523 F3d 1323, 1340 (Fed Cir 2008).