Features a and b did not contribute to inventiveness, and the patentee did not obtain any benefit based on them. The narrowing statements made by the patentee regarding features a and b during the grant and validation stages do not constitute a disclaimer of the technical solution, and the "doctrine of estoppel" does not apply. For features that did not play a substantive inventive role during the grant and validation stages, and from which the patentee also did not obtain grant or any other benefit, the narrowing statements made regarding those features do not constitute a disclaimer of the technical solution, and the "doctrine of estoppel" does not apply.

Basic Case Information

Supreme People's Court Case No.: (2017) Zui Gao Fa Min Shen No. 1826

Retrial Applicant (Appellant for Retrial): Cao Guilan et al. (4 persons) (First-instance Plaintiff, Second-instance Appellee)

Respondent (Appellee for Retrial): Chongqing Lifan Automobile Sales Co., Ltd. (First-instance Defendant, Second-instance Appellant)

Respondent (Appellee for Retrial): Chongqing Lifan Passenger Vehicle Co., Ltd. (First-instance Defendant, Second-instance Appellant)

Respondent (Appellee for Retrial): Kunshan Huasheng Electronics Co., Ltd. (First-instance Defendant, Second-instance Appellant)

First-instance Defendant: Nanjing Jiuhuashan Automobile Sales Service Co., Ltd.

First-instance Defendant: Lifan Industry (Group) Co., Ltd.

First-instance Defendant: Hangzhou Yafan Automobile Co., Ltd.

The retrial applicants Cao Guilan et al. (4 persons), Hu Meiling, Jiang Li, and Jiang Haotian (hereinafter collectively referred to as "the retrial applicants or patentees") inherited the invention patent titled "Shark Fin Antenna" with patent number ZL200710019425.7.

Case Judgment Result Information

Cause of Action: Invention Patent Infringement Dispute

Judgments at Various Levels in First and Second Instances:

First Instance: Nanjing Intermediate People's Court Civil Judgment (2014) Ning Zhi Min Chu Zi No. 135: The first-instance judgment found infringement.

Second Instance: Jiangsu High People's Court Civil Judgment (2016) Su Min Zhong No. 161: The second-instance judgment found no infringement. The reasoning was that the retrial applicants' statement of opinions during the invalidation procedure for the patent in question constituted a disclaimer of the technical solution, and the doctrine of estoppel should apply. The alleged infringing product did not constitute equivalent infringement of the patent.

Retrial: The Supreme People's Court instructed the Jiangsu High People's Court to retry the case.

Controversial Issue

Whether the narrowing statements made by the patentee regarding "distinguishing technical features relative to the prior art" for the claims during the grant and validation procedures lead to the application of the doctrine of estoppel.

Relevant Laws and Judicial Interpretations

Article 6 of the "Interpretation of the Supreme People's Court on Several Issues concerning the Application of Law in the Trial of Patent Infringement Dispute Cases" effective January 1, 2010, clearly stipulates the application of the doctrine of estoppel: "Where the patent applicant or patentee, during the patent grant or patent invalidation procedure, has disclaimed a technical solution by amending the claims or the description or by making statements, and then seeks to include that technical solution within the scope of patent protection in a patent infringement dispute, the people's court shall not support such a claim."

Article 13 of the "Interpretation (II) of the Supreme People's Court on Several Issues concerning the Application of Law in the Trial of Patent Infringement Dispute Cases" (Fa Shi [2016] No. 1): Where the right holder proves that the narrowing amendments or statements made by the patent applicant or patentee to the claims, description, or drawings during the patent grant or validation procedure were explicitly rejected, the people's court shall determine that such amendments or statements did not lead to a disclaimer of the technical solution.

Official Determinations at Different Stages

Technical features of Claim 1 related to "estoppel":

Feature a: The antenna signal output terminal is connected to the antenna amplifier signal input terminal via an antenna connection element, or directly connected in a matched manner with a coaxial cable.

Feature b: The radio receiving antenna is injection-molded and embedded or fixedly snapped onto the upper inner side of the antenna housing.

Feature c: The radio receiving antenna is a shared AM/FM antenna.

1. Determination of Features a and b during the Grant Stage

Comparison Document 1 disclosed: "The antenna device has a shark fin-shaped cover 21, an AM antenna is disposed at the top inside the shark fin-shaped cover 21, said AM antenna is connected to an AM amplifying circuit 231, the connection point is necessarily the signal output terminal of the AM antenna and the signal input terminal of the amplifying circuit 231, the bottom of the shark fin-shaped cover 21 of the antenna is equipped with a metal base 25." Based on this, the examiner considered that Comparison Document 1 disclosed features a and b.

The patentee believed that Claim 1 of the invention limited the connection between the antenna and the antenna amplifier via an antenna connection element, and its connection method was different from that in Comparison Document 1. The patentee believed that Claim 1 of the invention limited the fixing method of the radio receiving antenna as injection-molding and embedding or fixedly snapping onto the upper inner side of the antenna housing. This could be understood as the patentee disclaiming other fixing methods, acknowledging only "injection-molding and embedding or fixedly snapping."

The examiner stated in both the first and second examination opinion notifications that using connection elements for impedance matching was a conventional technical means in the field, and "injection-molding embedding" and "fixed snapping" were also common fastening methods in the field, belonging to common general knowledge. The examiner explicitly rejected the patent applicant's opinion statement that features a and b made the patent inventive. Finally, the patent applicant responded to the second examination opinion by incorporating feature c into Claim 1, further narrowing the scope of protection, so that the patent in question could be granted.

2. Determination of Features a and b during the Validation Stage

Invalidation Decision No. 25637 explicitly determined that features a and b were disclosed by multiple comparison documents. Ultimately, it was based on feature c that Claim 1 was deemed inventive, and the validity of the invention patent in question was maintained.

3. Second-instance Judgment Determination

The invalidation decision did not explicitly reject the patentee's statements regarding features a and b in form, thus determining that the patent in question constituted a "disclaimer of the technical solution regarding features a and b" during the validation stage, and the doctrine of estoppel applied. The patentee limited the fixing method for connecting the antenna to the antenna amplifier in the invention to "antenna connection element" and the fixing method of the radio receiving antenna to "injection-molding and embedding or fixedly snapping" during the grant and validation stages.

The judicial interpretation of the Patent Law stipulates that narrowing interpretation is considered not to have led to a disclaimer of the technical solution only if it is explicitly rejected. The patentee's narrowing interpretation regarding features a and b was not explicitly evaluated by the Patent Reexamination Board regarding whether features a and b made the patent in question inventive. This did not meet the requirement of "explicit rejection," and the narrowing interpretation of the claims had already constituted a disclaimer of the technical solution.

Where the patentee makes narrowing interpretations of the claims during the grant and validation stages, and then seeks to include the disclaimed technical solution within the scope of patent protection by claiming equivalence in the infringement litigation stage, the court shall not support it. Therefore, during the infringement litigation stage, when the patentee claimed that the antenna lead of the alleged infringing product was equivalent to the connection element of this patent, and that the adhesive bonding of the alleged infringing product was equivalent to the injection-molding embedding or snapping of this patent, the second-instance court did not support it.

4. Retrial Ruling Determination

During the grant and validation procedures, whether a statement made by the right holder is "explicitly rejected" focuses on examining whether the narrowing statement made by the right holder regarding the technical solution is ultimately recognized by the adjudicator, and whether it leads to the grant of the patent application or the maintenance of the patent right. In this case, during the grant stage, the examiner did not accept the patentee's statement regarding features a and b, holding an explicit negative opinion. The grant of the patent in question was not based on the narrowing statements made regarding features a and b; in fact, it was granted based on feature c. In the subsequent invalidation stage, the Patent Reexamination Board did not overturn the negative opinion held during the grant stage and reach a contrary conclusion. Under such circumstances, it should be determined that the fact exists that the patentee's narrowing statements have been explicitly rejected. This is consistent with the fact that the narrowing statements made did not lead to the acquisition or maintenance of the patent right. Therefore, the narrowing statements made by the patentee regarding features a and b do not have the legal effect of disclaiming the technical solution. The doctrine of estoppel should not be applied in the infringement determination of this case. The second-instance court was instructed to retry the case.

Case Commentary

The purpose of establishing the doctrine of estoppel is to prevent patentees from employing "blowing hot and cold" tactics: first limiting the scope of protection during the patent grant stage, excluding content not within their patent protection scope (i.e., the "disclaimed technical solution") through amendments or statements during the patent grant or invalidation procedure, and then "burning the bridge after crossing the river" during infringement litigation by restoring the scope of protection, claiming equivalent infringement to bring the disclaimed technical solution back into the scope of patent protection, thereby gaining benefits from both ends. The so-called "disclaimed technical solution" should be a technical solution that could originally be included within the scope of protection but was excluded from the scope of protection due to the applicant's or patentee's amendments or statements. This principle restricts the unreasonable expansion of patent protection scope during the infringement stage. Its essence lies in restricting patentees from gaining benefits from both ends—during the grant/validation stage and the infringement stage. Although the original intent of "estoppel" is to prevent patentees from "gaining benefits from both ends," harming the interests of the public, patentees should not be allowed to "suffer losses from both ends" either. The conclusion of the second-instance judgment in this case clearly caused the patentee to "suffer losses from both ends," seriously damaging the legitimate interests of the patentee, which is not conducive to the current environment promoting patent innovation.

How to determine whether a technical solution surrounding the controversial issue constitutes a disclaimer: first, clarify whether the narrowing statements made by the patentee regarding "distinguishing features relative to the prior art" for the claims during the grant and validation stages constitute a disclaimer of the technical solution; if it is determined to constitute a disclaimer, whether it was explicitly rejected by the Patent Office/Patent Reexamination Board.

During the grant and validation stages, both the examiner and the Reexamination Board explicitly determined that features a and b did not contribute to inventiveness, while feature c did contribute to inventiveness. Specifically, during the grant stage, the examiner held a negative opinion regarding features a and b being distinguishing features relative to the prior art. The grant of the patent in question was not based on the narrowing statements made regarding features a and b; in fact, it was granted based on feature c. In the subsequent invalidation stage, the Patent Reexamination Board did not overturn the negative opinion held during the grant stage and reach a contrary conclusion. Instead, it held a consistent opinion with the grant stage, considering features a and b to be disclosed by the prior art. In fact, the patent right was maintained based on feature c.

In summary, during the grant and validation stages, features a and b did not play a substantive inventive role, and the patentee also did not obtain any benefit based on them. Therefore, the narrowing statements made regarding features a and b do not constitute a disclaimer of the technical solution, and the doctrine of estoppel does not apply.

In conclusion, for features that did not bring inventive contribution, and from which the patentee also did not gain any benefit, the narrowing statements made by the patentee regarding such features during the grant and validation stages do not constitute a disclaimer of the corresponding technical solution, and the doctrine of estoppel does not apply. The criterion for determining "explicit rejection" should not be understood mechanically from the literal surface. Instead, it should start from the substantive role played, objectively and comprehensively understanding the content of the examination notifications during the grant stage and the invalidation decisions during the validation stage to accurately determine whether the examiner or the Patent Reexamination Board held an explicit negative attitude. The original intent of "estoppel" is to prevent patentees from "gaining benefits from both ends," harming the interests of the public. The conclusion of the second-instance judgment in this case clearly caused the patentee to "suffer losses from both ends," seriously damaging the legitimate interests of the patentee, which is not conducive to the current environment promoting patent innovation.