Taiwan: Construction Of Means-Plus-Function Claim By Taiwan IP Court

The Enforcement Rules of the Patent Law permit a combination of multiple technical features of an invention to be defined in "means-plus-function" or "step-plus-function" language.  In general, "means-plus-function" language shall be construed to cover "the structure, material or acts corresponding to the function" described in the specification and the equivalents thereof.

While it is worthwhile to have a close look at how the above-noted rules are applied to actual cases, the IP Court has recently expressed its opinion regarding how a means-plus-function claim ought to be construed.  This precedent case is summarized as follows:

Two invalidation actions against a patent were filed with the Taiwan Intellectual Property Office (hereinafter referred as the TIPO) in a row. In the first invalidation action, after the petitioner filed an appeal with the Board of Appeals and, in turn, an administrative litigation with the IP Court against the Decision rendered by the TIPO, the IP Court opined that as the element, "immediate stop unit," recited in the claims of the patent is defined by the function of "generating a control signal to make two ends of the magnetic poles of the stator have the same electric potential so as to immediately stop the fan system" without a structure to perform the function recited in the means-plus-function limitation, the "immediate stop unit" is apparently a means-plus-function language and should be construed based on the circuit of the unit as disclosed in the one and only embodiment of the specification.  Given that the evidence submitted to the IP Court to establish reasons for invalidity of the patent did not disclose an "immediate stop unit" capable of "making two ends of the magnetic poles of the stator have the same electric potential," as recited in the claims of the patent, the IP court affirmed the decision made by TIPO that the patent is valid.

A second invalidation action was then filed with the TIPO by another party.  While the patentee amended the claims during the invalidation proceedings, the definition for the "immediate stop unit" was left unchanged.  Therefore, the TIPO took a stance similar to the judge of IP Court hearing the first invalidation action, i.e. the "immediate stop unit," a means-plus-function language, should be construed based on the circuit of the unit recited in the one and only embodiment of the specification, including two switches, an energy storage and a resistor, where the energy storage and the resistor are electrically connected "in parallel" as disclosed in the specification.  As the submitted evidence disclosed an energy storage and resistor in "series connection" rather than in "parallel connection," the TIPO found the patent to be valid.

The second invalidation action petitioner was dissatisfied with the TIPO's decision and filed an appeal to the Board of Appeals and subsequently an administrative litigation with the IP Court.  Prior to the oral proceedings, the patentee amended the claims, this time, changing "the immediate stop unit" to include "two switches, an energy storage and a resistor, wherein the energy storage and the resistor are electrically connected," a move that incorporated into the claims the elements disclosed  in the embodiment of the specification.  The IP Court agreed to review the case based on the amended claims.

Therefore, the main issue that should be addressed was whether the claims of the patent, as the result of a post-grant amendment, are still the so-called "plus-means-function" claims.  In other words, consideration should be given to the fact that whether the energy storage and resistor that are electrically connected can be interpreted as being equivalent to "the energy storage and the resistor are electrically connected in parallel."

The IP Court expressed that means-plus-function language ought to be interpreted to cover the structure, material or acts described in the specification and equivalents thereof that "can perform the function recited in the means-plus-function limitation. Given that the invention embodied in the patent does need two switches and an energy storage to function, including a resistor in the circuit that does not perform the function defined by the means-plus-function language, and that a resistor allows an energy storage to rapidly discharge electricity, the IP court held that the interpretation rendered by the TIPO in the second invalidation action was improper.

Further, the IP Court opined that the amended claims, in which the complete structure of the immediate stop unit is recited, no longer falls under means-plus-function language.  Thus, the scope of the amended claims should be construed based on the literal meaning of the recitations in the claims, rather than the structure in the embodiment of the specification. As a result of this finding, the IP court held that the patent is invalid for lack of inventive step.  The Supreme Administrative Court affirmed the judgment of the IP court.

It can be learnt from this case that when drafting a means-plus-function claim, a practitioner should give elaborate care to the function of each separate element, and avoid incorporating into the claims all the elements of an invention without heeding function.  The rationale underlying this is that, as a more stringent criterion may be applied to construct means-plus-function claim, if the claims of a patent drafted in means-plus-function language, are revised to include the structure of the elements disclosed in the specification, the claims could be more strictly interpreted on the basis of the literal meaning of the recitations thereof.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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