One Case a Day | China: The Effect of Patentee's Narrowing Interpretation in Invalidation Proceedings on Civil Litigation - (2023) Supreme People's Court IP Civil Final No. 607

Case Introduction

Today's case involves the principle of prosecution history estoppel.

To obtain authorization or maintain the validity of a patent, applicants/patentees may make narrowing interpretations of the claims in the authorization or validity determination process to distinguish them from the prior art, thereby ensuring the patent's validity. In such cases, they cannot later assert protection for the scope they have already abandoned during enforcement.

In practice, such narrowing interpretations are sometimes necessary, but sometimes they result from unconscious erroneous actions, requiring special attention.

Case Information

• Patent Number: 201721717014.0
• Invention Title: A Mobile Phone Number Plate Mounting Stand
• Invalidation Decision Information: Nos. 55861, 562751
• First Instance Information: (2021) Guangdong 73 IP Civil Initial No. 885
• Second Instance Judgment Date: May 14, 2024
• Second Instance Judgment: (2023) Supreme People's Court IP Civil Final No. 607

Patent Information

The upheld Claim 2 of the involved patent protects a mobile phone number plate mounting stand, specifically including the following features:

It includes a base 30 and a seesaw plate 10 movably connected to each other. A groove is provided on the base 30, and the seesaw plate 10 is partially accommodated in the groove of the base 30 and can rotate within the groove. A number plate 20 is provided on one side of the seesaw plate 10, with mobile phone number information displayed on the outer surface of the number plate 20. The seesaw plate 10 is driven to rotate relative to the groove to hide the number plate 20 within the groove or protrude it from the groove, thereby displaying or hiding the mobile phone number information on the number plate 20. The seesaw plate 10 includes a pressure plate 11 and a protrusion 12, with the pressure plate 11 connected to the top of the protrusion 12. The diameter of the protrusion 12 is smaller than the aperture of the groove, the protrusion 12 is partially inserted into the groove, and it is rotationally connected to the opposite inner sidewalls of the groove via a rotating shaft 40.

Evidence 1 discloses a press-to-hide temporary parking sign, including a temporary parking sign body 15 and 3M adhesive 16. The temporary number parking sign body has a number display screen 14 inside; number blocks 17 are fixed on the number display screen. The number display screen and the temporary parking sign body are fixed by a pin method, with the number display screen connected to a spring. When the number display screen is pressed, the fixing buckle engages with the fixing groove, and the internal spring compresses. Pressing the number display screen again causes the fixing buckle to disengage from the fixing groove under external force, and the spring returns to its original shape when unrestricted, causing the number display screen to rotate upward.

The invalidation decision records: "The patentee submitted an opinion statement arguing that the involved patent uses a seesaw plate that rotates at both ends, requiring no spring, fixing buckle, or fixing groove combination, with the seesaw plate partially accommodated in the groove of the base." "From the known structure of the seesaw plate described above, it can be seen that in this patent, the middle part of the protrusion of the seesaw plate is pivotally connected to the rotating shaft, and the entire seesaw plate rotates around this shaft, causing both ends of the seesaw plate to rise and fall alternately. By partially inserting the protrusion into the groove, the seesaw plate and the groove cooperate. The upper parts of both ends of the seesaw plate are exposed outside the groove at the raised high position, while the lower parts of both ends are located inside the groove at the lowered low position, enabling the number plate provided on the side of the seesaw plate ends to be displayed or hidden by the groove. Relying on gravity, the seesaw plate can maintain stability in a state where one end is raised and the other end is lowered. In the stable state, one end of the seesaw plate must be at a high position exposed outside the groove, which is the seesaw plate being 'partially accommodated' in the groove." "This patent uses a seesaw plate structure, which by its own working principle can achieve rotation and maintain a stable state with one end raised and the other end lowered."

"Regarding essential technical features, the patentee believes that the seesaw plate of this patent can achieve display or hiding and maintain stability through gravity alone. Magnets or increased friction are technical means adopted for greater stability and are not essential technical features."

Controversial Focus

Whether the accused infringing product, which must rely on a positioning maintenance structure to keep the "seesaw plate" stably in a state with one end raised and the other lowered, falls within the protection scope of Claim 2.

First Instance Court's View

The accused infringing product contains all the technical features of Claim 2 of the involved patent and falls within the protection scope of the involved patent right. Firstly, Claim 2 of the involved patent does not limit the "protrusion" to a solid block structure; the accused infringing product contains the technical feature of "protrusion." Secondly, the accused infringing product has a "seesaw plate," which includes a "pressure plate" and a "protrusion." The relevant party's claim that the function of the "seesaw plate" in the accused infringing product differs from that in the involved patent is inconsistent with the facts.

Second Instance Court's View

Article 64, Paragraph 1 of the Patent Law of the People's Republic of China stipulates: "The scope of protection of the patent right for an invention or utility model shall be determined by the terms of the claims. The description and the appended drawings may be used to interpret the claims."

Article 3, Paragraph 1 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 stipulates: "The people's court may interpret the claims by using the description and appended drawings, the relevant claims in the claims, and the patent prosecution history. Where the description provides a special definition for a term used in the claims, such special definition shall prevail."

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 stipulates: "Where a patent applicant or patentee abandons a technical solution by amending the claims or description or by making a statement during patent prosecution or invalidation proceedings, and the patentee includes it in the scope of patent protection in a patent infringement dispute case, the people's court shall not support it."

Regarding the disputed issue of whether the technical solution of the accused infringing product falls within the protection scope defined by Claim 2 of the involved patent, the court analyzes and comments as follows:

Firstly, the scope of patent protection should correspond to its technical contribution and degree of innovation. The involved patent is a utility model patent. Based on all contents disclosed in the description and appended drawings of the involved patent, its structure is not complex (the patent drawings 1-3 are attached). Whether it is the basic principle of a "seesaw" or the statement in the description of the involved patent that "affected by gravity, unless acted upon by external force, the seesaw plate maintains a state with one end raised," these belong to common knowledge in daily life. Although Claim 2 is currently recognized as inventive by the China National Intellectual Property Administration in the relevant invalidation decision, its degree of innovation is obviously very limited, and its protection scope should not be excessively broad, leading to disproportionate protection.

Secondly, the patent prosecution history is an important basis for interpreting the claims, reasonably determining the scope of protection, and subsequently conducting infringement judgment. The specific reasons for which the China National Intellectual Property Administration recognized Claim 2 of the involved patent as inventive and maintained its validity in the relevant invalidation decision, as well as the patentee's relevant statements regarding Claim 2 during the patent invalidation administrative proceedings, all belong to the prosecution history of the involved patent. When determining whether the accused infringing product falls within the protection scope defined by Claim 2, these should be duly considered to prevent inconsistency between the determination for maintaining patent validity and the determination standard for infringement, resulting in the patentee benefiting from both ends.

According to the contents recorded in the description of the involved patent and the determinations in Decisions Nos. 55861 and 562751, the "seesaw plate" of the involved patent is a plate-like structure with alternating rotatable raised ends, with a pivot shaft set in the middle of the plate. Relying solely on the gravity of the "seesaw plate" itself, it can maintain stability in a state with one end raised and the other lowered. This is also an important reason why Claim 2 is still maintained as valid. In particular, a certain company emphasized during the invalidation administrative proceedings that this patent "does not require a spring" to "distinguish" it from the relevant prior art. In contrast, the accused infringing product must rely on a positioning maintenance structure to keep the "seesaw plate" stably in a state with one end raised and the other lowered. Therefore, compared to the "seesaw plate" in the involved patent, which can maintain stability "by relying on its own gravity," the accused infringing product does not have identical or equivalent technical features.

Finally, the exercise of rights by the right holder should follow the principle of good faith. Based on the patentee's statements during the patent invalidation administrative proceedings, such as "the involved patent uses a seesaw plate that rotates at both ends, requiring no spring, fixing buckle, or fixing groove combination," "by its own working principle, the seesaw plate can achieve rotation and maintain a stable state with one end raised and the other lowered," and "magnets or increased friction are technical means adopted for greater stability and are not essential technical features," the patentee, on one hand, emphasized during the invalidation administrative proceedings that this patent "does not require a spring, fixing buckle, or fixing groove combination" and that "by its own working principle, the seesaw plate can achieve rotation and maintain a stable state with one end raised and the other lowered" to "distinguish" it from the relevant prior art. On the other hand, in this case, they advocate applying the doctrine of equivalents, claiming that the accused infringing product, which can only maintain stability by relying on a positioning maintenance structure (including a spring), constitutes infringement. This clearly violates the principle of prosecution history estoppel.

In accordance with 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, the court does not support the patentee's claim that the accused infringing product constitutes infringement.