IP Court's Decision on Inventive Step of “Wherein” Clauses
Date: 23 May 2024
【Volume 135】
Recently, the Taiwan Intellectual Property and Commercial Court (IP Court) revoked the Taiwan Ministry of Economic Affairs (MOEA)’ administrative appeal decision and Taiwan Intellectual Property Office (IPO)’s administrative act of rejecting the patent, affirming an inventive step of the disputed patent application (Taiwan Intellectual Property Court 2023 XingZhuanSuZi No. 30 Judgment). The IP Court clarified in this case that: when determining an inventive step of a claimed element further defined by a “wherein clause” with described function, even though the appearance, material and structure of the elements have been disclosed by the prior art, if the function of the element defined in the disputed patent is different from that of the exhibit, and if changing the element of the prior art would be detrimental to the function the element aimed to carry out in the prior art, then the wherein clause of the disputed patent should serve as the basis to determine inventive step.
Case Fact
Delta Electronics, Inc. (plaintiff, “Delta”) filed an invention patent application entitled “Wavelength Conversion Member and Light Source Module” with the IPO (defendant) in 2020 (Appl. No.: 109128366, hereinafter referred to as‘366 patent). After examination, the IPO determined that the ‘366 patent is unpatentable after examination. Dissatisfied with the IPO’s decision, the plaintiff filed a reexamination, which left the application rejected, and then the plaintiff filed an administrative appeal with MOEA, which was later dismissed. Therefore, the plaintiff filed an administrative lawsuit with the IP Court.
After examining the case, the IP Court held that the ‘366 patent involved an inventive step and overturned the IPO’s original administrative act and MOEA’s administrative appeal decision.
The Technical Features of Claim 1 of the ‘366 Patent
The Claim 1 of the ‘366 patent describes:
A wavelength conversion member, comprising:
a substrate configured to rotate based on an axis; a phosphor layer disposed on the substrate; and a ventilated blade disposed on the substrate and has a pore density between 10 ppi and 500 ppi or a volume porosity between 5% and 95%, wherein through holes of the ventilated blade are configured to allow airflow to pass through during rotation of the substrate to guide micro-vortexes.
The main point of this case is whether “heat dissipation layer” and “assembly hole” in Exhibit 1 correspond to “ventilated blade” in Claim 1 of the ‘366 patent. :
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Fig.3 of ’366 patent
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Fig.2 of Exhibit 1
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Opinion of the IPO
- The heat dissipation layer 3 of Exhibit 1 has disclosed the ventilated blade 123 of Claim 1 of ‘366 patent:
According to the wavelength conversion member (20) illustrated in FIG. 2 of Exhibit 1 and the cross-sectional view of the wavelength conversion member (FIG. 3) in ‘366 patent, it can be found that they are identical in appearance. In addition, paragraph [0024] of the specification of ‘366 patent describes that “the material of the ventilated blade 123 comprises one of metal, ceramic, and glass”, and Exhibit 1 also describes that the material of the heat dissipation layer is ceramic. Thus, the materials used in ‘366 patent and Exhibit 1 are identical as well . - The heat dissipation layer 3 of Exhibit 1 has disclosed the “blade” that generates airflow by means of “convection” in ‘366 patent, in terms of both appearance and function:
‘366 patent claims that the micro-vortex is generated by the “through holes”, and Exhibit 1 also discloses that the element 3 is an element with “through holes”. Moreover, “porosity” recorded in Exhibit 1 matches the “porosity” in Claim 1 of ‘366 patent, so that a person of ordinary skill in the art can reasonably infer that the element 3 would generate micro-vortexes when the wavelength conversion element is in operation.
In addition, Exhibit 1 has disclosed that the wavelength conversion mechanism converts the wavelength of the light source by means of a phosphor layer, so that a person of ordinary skill in the art would understand that this heat dissipation layer generates an airflow in the heat dissipation layer when the conversion mechanism is in operation with rotating. Therefore, it is expected that the through holes in the heat dissipation layer 3 of Exhibit 1 generate micro-vortexes when the wavelength conversion member is in operation.
Accordingly, the heat dissipation layer 3 of Exhibit 1 has disclosed, in terms of both appearance and function, the “blade” that generates airflow by means of “convection” claimed in ‘366 patent.
Opinions of the IP Court
However, the IP Court held that the “heat dissipation layer” of Exhibit 1 could not correspond to the “ventilated blade” in Claim 1 of ‘366 patent and Exhibit 1 did not disclose the technical feature of “allowing airflow to pass through during rotation of the substrate to guide micro-vortexes,” with the following reasons.
- According to the description on page 3 and page 11 of the specification of Exhibit 1, “As the heat dissipation layer 3, for example, a dense ceramic layer can be used. The porosity of the dense ceramic layer is less than 20% by volume, preferably less than 15% by volume, and especially less than 10% by volume. If the porosity of the dense ceramic layer is too high, the heat conductivity will be reduced and the heat dissipation will be easily reduced,” the heat dissipation layer adopted in Exhibit 1 is to enhance the efficiency of heat dissipation by means of “heat conduction”, and the porosity of the heat dissipation layer should be as low as possible.
- However, ‘366 patent adopts “heat convection” to enhance the efficiency of heat dissipation via micro-vortexes. Therefore, it is considered that the “holes” inherent in the “heat dissipation layer” of Exhibit 1 is different from the intended configuration of “through holes” in the “ventilated blade” to generate micro-vortexes in ‘366 patent, in terms of formation and purpose. Therefore, the “holes” in the heat dissipation layer of Exhibit 1 do not have the function of “ allowing airflow to pass through during rotation of the substrate to guide micro-vortexes”.
- Furthermore, referring to the disclosure of “the porosity of the dense ceramic layer is too high, the heat conductivity will be reduced” in Exhibit 1, in order to achieve the purpose of increasing the efficiency of heat dissipation, a person of ordinary skill in the art should adopt the dense ceramic layer or other materials with “low porosity” as the way of heat dissipation. The invention claimed in Claim 1 of ‘366 patent cannot be easily achieved by simply changing or modifying the “heat dissipation layer” with lower the porosity for better heat dissipation into the one which applies heat convection to enhance the efficiency of heat dissipation, i.e. adopting the “ventilated blade” with through holes for airflow to pass through.
- The IPO argued that the “porosity” disclosed in Exhibit 1 matches the “porosity” described in Claim 1 of 366 patent, and a person of ordinary skill in the art could reasonably expect that the “heat dissipation layer” would generate micro-vortexes when the wavelength conversion member is in operation. However, when the wavelength conversion member of Exhibit 1 is rotating, if the porosity is too low or insufficient, the “heat dissipation layer” disclosed therein does not necessarily allow airflow to pass through the holes to generate micro-vortexes. Thus, it is not implied that the “holes” of Exhibit 1 have the function of “allowing airflow to pass through during rotation of the substrate to guide micro-vortexes”.
Wisdom Suggested Strategies
According to our analysis, Claim 1 of ‘366 patent further defines the function of the ventilated blade after defining the configuration and material properties of the ventilated blade. Therefore, the function defining description is a “wherein clause” describing a function of an element in essence. Moreover, as to whether a wherein clause with described function in a patent claim is limitation, Taiwan Patent Examination Guidelines do not specifically regulate the determination of inventive step of wherein clause. Neither Taiwan Patent Infringement Assessment Guidelines (2016) nor Taiwan Patent Examination Guideline have specific stipulations regarding a wherein clause describing a function, which therefore often leads to disputes in practice.
In this case, the IPO considered that since the configuration and material of the ventilated blade described in Claims of ‘366 patent have been disclosed in the heat dissipation layer of the exhibit, it is obvious that the configuration of the element of Exhibit 1 can also achieve the function described in ‘366 patent. Therefore, the heat dissipation layer of Exhibit 1 has revealed the ventilated blade disclosed in ‘366 patent.
The IP Court, however, deemed that the wherein clause imposed a substantive limitation on the function defined in ‘366 patent. Since the exhibit has taught that high porosity will be detrimental to heat conduction, a person of ordinary skill in the art would not be motivated to increase the porosity of the heat dissipation layer in the exhibit and utilize it for a completely different type of heat transfer - heat convection. Therefore, the ventilated blade of ‘366 patent is not identical to the heat dissipation layer disclosed in the exhibit, and a person of ordinary skill in the art cannot obtain the ventilated blade of ‘366 patent by a simple change. Apparently, the IP Court held that the wherein clause with described function of ‘366 patent should be included to determine the element definition and inventive step. Thus, the IP Court issued a decision contrary to that of the IPO.
In addition, it is worth noting that since the function of the element taught in the exhibit is almost completely opposite to that of ‘366 patent, and fulfilling the function of “heat convection dissipation” of ‘366 patent would be detrimental to the function of “heat conduction dissipation” claimed in the exhibit, the wherein clause with described function in this case thus serves as the basis for determining inventiveness. However, in contrast, if the functions claimed in the exhibit and ‘366 patent are not mutually exclusive, i.e. they are concurrent functions that can co-exist, whether the wherein clause with described function can be included as a basis of inventive step may lead to a different conclusion. Patent applicants can also take advantage of this rationale in response.
