Martial Art Carpet
Fujian Weizhixing Sports Goods Co., Ltd. v. Taishan Sports Industry Group Co., Ltd. et. al. - The Role of the “Purpose of Invention” Plays in Claim Construction (Civil Judgment (2012) Min Ti Zi No.4 by the Supreme People’s Court on June 26, 2012)
According to the legislative intent, the scope of protection of a patent should comply with the contribution that the invention made to the prior art. The claim in which the technical solution is defined is disclosed to enable the public to understand the scope of protection and avoid the risk of infringement. However, due to the limitation of language itself and drafting manners of claims, sometimes it is hard to understand the technical solutions defined in the claims properly without claim construction. Therefore, as the first thing to be done when determining patent infringement, claim construction plays an important role in infringement lawsuits. The judge proposed an important principle for claim construction in the following case, holding that the claim construction should comply with the purpose of invention described in the detailed description of the patent application.
The patentees, Taishan Sports Industry Group Co., Ltd. et. al., own a utility model patent No.ZL200420028451.8 titled “Martial Art Carpet”. The claim recites the technical solution as follow:
“A martial art carpet consists of an elastic layer arranged at the bottom, a multi-plate layer with supporting function arranged on the elastic layer, a cushioning layer adhered on the multi-plate layer, and a carpet layer adhered on the cushioning layer.”(as illustrated below)
Click here to view image.
The alleged product comprised of a first elastic sponge layer arranged at the bottom, a seven-plate laminate layer adhered to the first elastic sponge layer, a second elastic sponge layer adhered to the seven-plate laminate layer, a sponge layer adhered to the second elastic sponge layer, and a carpet layer laid on top of the sponge layer (as illustrated below).
Click here to view image.
In both of the first instance and the second instance courts, the judges held that, all of the features recited in the asserted claim are the same as or equivalent to the corresponding features of the alleged product. The judges reasoned that although in the alleged product, the carpet layer is simply laid on instead of being adhered to the sponge layer, there exists a significant friction force between the carpet layer and the sponge layer due to the considerable large area of the martial art carpet. It is obvious to a person skilled in the art that, because of this large friction force, it is almost impossible for the carpet layer to have a substantial lateral displacement when the martial art carpet is in use. Therefore, the judges held that the feature “a carpet layer laid on the sponge layer” of the alleged product is equivalent to the feature “a carpet layer adhered to the cushioning layer” recited in the asserted claim.
The alleged infringer, Fujian Weizhixing Sports Goods Co., Ltd. (the “FWSG” hereinafter), appealed to the Supreme People’s Court for retrial of the case, and the Supreme People’s Court granted the retrial. During the retrial hearing, the FWSG argued that, among all the layers of martial art carpet that are adhered to each other, “a carpet layer adhered to the sponge layer” is expressly recited in the asserted claim. The FWSG further argued that, the term “adhere” recited in the claim should be interpreted as “two layers are firmly bonded together by using chemical methods, e.g., adhesive.” The carpet layer of alleged product is simply laid on the sponge layer, rather than being adhered to the sponge layer. Therefore, the alleged product and the technical solution defined in the asserted claim use different ways and realize different results. Consequently, these features are not equivalent to each other.
Therefore, the question presented in this case during the retrial proceeding before the Supreme People’s Court is how to interpret the feature of “a carpet layer adhered to the sponge layer” recited in the asserted claim.
The judge pointed out particularly that the claim construction should be conducted by thoroughly considering the purpose of the invention. The claimed technical solution requires all of the layers adhere to each other, to prevent the layers of the martial art carpet from laterally displacing to each other when the martial art carpet is in use. From the viewpoint of a person skill in art of sports equipment, the term “adhere” should be interpreted to mean that surfaces of the layers opposite to each other are firmly bonded together; and the bonded portions can transfer the force. The judge further held that the scope of “adhere” shall be interpreted to cover technical solution in which chemical methods, physical methods, and/or their combination are taken with the bonded portions between two opposite layers transferring the force to prevent the layers of martial art carpet from displacing laterally when the martial art carpet is in use.
Furthermore, the FWSG’s argument that the term “adhere” should be interpreted as bonding the two layers together by chemical methods was not supported by the judge, who believed that such interpretation excessively limits the meaning of “adhere”. The judge reasoned that, if there exists no bonded portions between opposite surfaces of the layers, or if the bonded portions cannot endure the lateral force, it is difficult to prevent the layers from displacing relative to each other. Thus the problem in prior art cannot be solved and the purpose of invention cannot be realized. Therefore, the feature of “a carpet layer adhered to the sponge layer” should be interpreted to mean that the sponge layer and the carpet layer are bonded securely by using chemical methods, physical methods, and/or their combination and the bonded portions are able to endure the lateral force.
The alleged product cannot obtain the anti-skidding effect for lack of the feature of “a carpet layer adhered to the sponge layer”. The judge of the Supreme People’s Court finally concluded that the alleged product does not infringe the asserted claim, reversing the judgments of both the first and second instances.
In patent infringement lawsuits, the scope of claim may be delimited by the purpose of invention in the step of claim construction. To avoid the court applying Principle of Interpretation or Doctrine of Equivalents to improperly extend the scope of protection in infringement lawsuits and thus reduce the uncertainty of patent enforcement, in some necessary circumstances, especially in China, the purpose of invention should be described in the application documents as clearly, reasonably as possible.
First, the draftsman should make the literal meaning of the claims as clearly as possible to successfully determine the scope of protection in the step of claim construction. It is important to describe or amend the technical solution using terms according to the common understanding of a person skilled in the art during application drafting procedure and examination procedure, in order to realize that the scope of protection of claims is clear and reasonable and can eventually obtain stable patent right.
Second, for the infringers, the principle that claim construction should comply with the purpose of invention can be used to organize the arguments against infringement. In patent-infringement lawsuit, the patentee may improperly extend the scope of claim by means of excessive interpretation. As a defensive strategy, the infringer can use the principle proposed in this case to exclude the solutions which are unable to realize the purpose of invention from the scope of claim.
Like the understanding of “adhere” in this case, the purpose of invention, bonding the carpet layer and the sponge layer together with “adhering” is intend to prevent the layers from laterally displacing from each other when the martial art carpet is in use. However, the alleged product obviously cannot realize the purpose of invention obviously because the carpet layer is only laid on, not adhered to, the sponge layer. Therefore, the meaning of the term “adhere” should not include the situation of the alleged product in this case.
Additionally, the judicial policy issued by the Supreme People’s Court in 2011 also emphasizes that the purpose of invention is critical to determining the scope of protection of a patent, that is, “the protection scope of a patent should not include the solutions having defects or problems in prior art which intended to be solved by the patent.”
However, the principle of interpretation proposed in this case is not suitable for all instances. The claim construction should balance the public and the patentee’s interest. If a drafting mistake in a claim makes the scope of protection mismatches the real concept of the inventor and the claim has been open to the public, anyone should not substantially change the scope of protection in a manner of simply applying the principle mentioned above. The result of substantially changing the scope of protection is liable to damage the public reliance interest.
Finally, in this case, the reason that the asserted claim doesn’t cover the alleged product is the serious drafting defection in the independent claim. If a person takes into sufficient considerations the structure features of martial art carpet before starting to draft the claim, it is likely to avoid the problem arised in this case. For example, the independent claim can be drafted as “a martial art carpet, consisting of an elastic layer arranged at the bottom, a multi-plate layer with supporting function adhered to the elastic layer, a cushioning layer adhered to the multi-plate layer and a carpet layer bonded to the cushioning layer.” The manner of “bonded” recited in the claim can be further defined as adhering or laying in dependent claims.