Taiwan’s patent regime has been adopting means (or step)-plus-function (“MPF” for short) language for more than 20 years. MPF language is known as a special way to describe an element in a claim for a combination, and more specifically, it enables the element to be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof. From the practical perspective, there are two important aspects which need to be considered regarding MPF language: one is how to recognize whether a claim uses MPF language, while the other is how to judge whether a claim using MPF language is definite. This article will draw your attention to the highlight that the Taiwan Intellectual Property Office (TIPO) and the jurisdictional courts have divergent opinions on the two aspects.

Inconsistency in recognizing whether a claim uses MPF language

Same as other patent regimes, the TIPO must follow the Patent Act, the Enforcement Rules of the Patent Act and the Examination Guidelines for Patents during the prosecution of a patent application. The Patent Act is actually silent about MPF language, and MPF language is primarily stipulated in the Enforcement Rules, Article 19, Paragraph 4, as follows:

An element of a claim, pertaining to an invention being a combination of a plurality of elements, may be expressed by means-plus-function language or step-plus-function language. Such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

This article makes a limitation to the usage of MPF language that the claimed invention must be a combination of a plurality of elements, which means that the claim including only one single element shall not use MPF language. The Enforcement Rules do not specify how to recognize whether an element of a claim is described in MPF language, whereas the Examination Guidelines provide a determination rule including three conditions as follows:

1. Whether an element of a claim uses the expression of “means for” or “step for”?
2. Whether the element includes a specific function?
3. Whether the element does not include structure, material, or acts in support of the specific function?

Under the determination rule, an element of a claim shall not be regarded as being described in MPF language unless the description form of the element meets all of the above three conditions. That is, as MPF language is successfully adopted to an element recited in a claim, the element shall basically be expressed as a “means for” or “step for” performing a specific function without the recital of structure, material, or acts in support thereof.

In practice, the TIPO tends to follow the applicant’s intention more than the description form of an element. The author’s experiences tell that the TIPO rarely concludes that an element is described in MPF language without the applicant’s confirmation or acquiescence, even if the TIPO feels or suspects that the description form of the element has met all of the three conditions.

In contrast, the jurisdictional courts (i.e., the Taiwan Supreme Administrative Court and the Taiwan Intellectual Property and Commercial Court) almost always focus on whether the description form of an element meets all of the three conditions, regardless of the applicant’s intention. In other words, the jurisdictional courts may conclude that an element is described in MPF language although the applicant had no such intention, and vice versa.

On the other hand, the TIPO strictly operates by the determination rule, whereas the jurisdictional courts uses the same rule in a looser way. Alternatively, we can say that the TIPO follows the form of the determination rule, while the jurisdictional courts follow the substance of the same. For example, as an element uses the expression of “unit for” instead of “means for”, the TIPO may not identify that the first condition is met, but the jurisdictional courts may.

Inconsistency in judging whether a claim using MPF language is definite

Under the Enforcement Rules, Article 19, Paragraph 4, a claim using MPF language shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof. Nevertheless, the Patent Act and the Enforcement Rules do not stipulate whether failure of describing the corresponding structure, material, or acts in the specification will make the claim indefinite. To some extent, this is why the TIPO and the jurisdictional courts have divergent opinions on determining whether a claim using MPF language is definite.

The definiteness requirement is necessary for both of the claim(s) and the specification and has been stipulated in the Patent Act, Article 26, the first and second paragraphs, as follows:

1. A specification shall provide a description [for the claimed invention] in a definite and sufficient manner for a person ordinarily skilled in the art to understood and carried out.
2. Claim(s) shall define the claimed invention, and more than one claim can be included therein. Each claim shall be described in a definite and concise manner and be supported by the specification.

The Examination Guidelines made by the TIPO further specify that if the specification does not describe the corresponding structure, material, or acts for the specific function described in MPF language, a person ordinarily skilled in the art is unable to determine the corresponding structure, material, or acts, and such a situation will make the concerned claim indefinite. Because the patent examiners of the TIPO must be constrained by the Examination Guidelines, from the perspective of the TIPO, failure of describing the corresponding structure, material, or acts in the specification indicates that the concerned claim is indefinite.

The jurisdictional courts, however, have different opinions. Firstly, the jurisdictional courts are not bound by the Examination Guidelines, which means that the jurisdictional courts can judge by themselves whether failure of describing the corresponding structure, material, or acts in the specification makes the concerned claim indefinite.

Further, the Taiwan Supreme Administrative Court has affirmed, in its judgments (e.g., No. 355 in 2013, and No. 149 in 2016), that the requirement of describing the corresponding structure, material, or acts in the specification is made only for the sake of claim construction, and failure of describing the corresponding structure, material, or acts in the specification does not necessarily make the concerned claim indefinite. The Taiwan Supreme Administrative Court also expressed that the definiteness of a claim only depends on whether a person ordinarily skilled in the art can clearly understand the claimed invention based on the whole description of the specification, and this rule is fixed no matter whether the concerned claim uses MPF language.

Thus, from the perspective of the jurisdictional courts, a claim using MPF language may still be deemed definite as long as a person ordinarily skilled in the art can clearly understand the claimed invention, even if the specification fails to describe the corresponding structure, material, or acts for the specific function recited in the claim.

Takeaways

1. The specification had better somehow and somewhat provide descriptions about structure, material, or acts of each element of a claim, no matter whether the applicant intends to use MPF language in the claim or not.

If intending to use MPF language in the claim, the applicant, of course, shall describe the corresponding structure, material, or acts for the specific function of each element as much as possible. In doing so, the claim may more easily pass the inspection of the definiteness requirement, as either the TIPO or the jurisdictional courts are in charge. In addition, the more description for the corresponding structure, material, or acts the specification provides, the broader scope the concerned element can covers, once the TIPO or the jurisdictional courts conclude that the concerned element is described in MPF language.

On the other hand, it would be better still to provide some descriptions in the specification about structure, material, or acts of each element of a claim, even if the applicant does not have any intention to use MPF language in the claim. Such descriptions leave the claim a better way out from being indefinite.

If an amendment is applicable, the descriptions will enable the applicant to add the appropriate structure, material, or acts into the claim to help the claim escape from MPF language. If an amendment is not applicable, the descriptions may enable the applicant to clearly prove that the specification has described the corresponding structure, material, or acts for the specific function recited in the claim. In either situation, the applicant may accordingly have a good basis to emphasize that the concerned claim is definite enough based on the descriptions.

2. The applicant needs to carefully weigh up the pros and cons of MPF language before using it.

MPF language is an inherently indefinite way to describe an element of a claim. As an element of a claim is described in MPF language, the only definite part is the function recited in the claim, which means that a person ordinarily skilled in the art can only understand what the element does, but cannot understand how the element performs it. That is why a claim using MPF language shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

In other words, the protection scope of a claim using MPF language is sensitive to the description of the specification. As a result, using MPF language will put a more burden on the applicant about describing the claimed invention in the specification.

In return, MPF language enables the applicant to claim an invention in a concise and simple manner, and this is useful for the applicant to claim a complicated or diverse invention. In addition, MPF language can keep a claim from including an element which is defined and limited to the specific structure, material, or acts. Instead, the element described in MPF language will be limited to the specific function recited in the claim, which means that the claim will not cover the functions similar to the specific function recited therein.

More specifically, if the claimed invention needs a specific function which can be performed by more than one feasible mechanism (i.e., structure, material, or acts), MPF language may be adopted to avoid that the claimed invention is limited to only one of the feasible mechanisms. The “specific” function will exclude other similar functions from the claim construction. For example, as the function recited in the claim is “detachable connection”, the claim will not be construed to cover other kinds of connection, such as “fixed connection”.

In contrast, if the claimed invention needs a specific mechanism (i.e., structure, material, or acts) which can perform more than one feasible function, MPF language may not be adopted to avoid that the claimed invention is limited to one of the feasible functions. The “specific” mechanism will exclude other similar mechanisms from the claim construction. For example, as the specific material recited in the claim is “Iron (Fe)”, the claim will not be construed to cover other kinds of materials, such as “Cobalt (Co)”.

In a word, MPF language is a double-edged sword, which may help or hurt the claims depending on how the applicant uses it. Accordingly, the applicant needs to carefully weigh up the pros and cons of MPF language before using it.

Conclusions

The inconsistency between the TIPO and the jurisdictional courts may create a loophole for opportunists, and appropriate harmonization is therefore necessary. Before that happens, though, the takeaways mentioned above may be helpful in reducing the possible negative effects caused by the inconsistency.