Article 59 of the Patent Law of the People's Republic of China ("Chinese Patent Law") provides that: The protection scope of a patent right for 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 content of the claims. It is known that the interpretation of claims determines the protection scope of a patent. In this article, we reviewed the laws, regulations, and judicial interpretations and selected some typical cases aiming to provide a comprehensive and easy-understanding outline about the Chinese practice regarding the interpretation of the patent claims.

I. The Objects of an Interpretation and the Entity to Interpret

Rule 7 of the Interpretation by Supreme Peoples' Court (hereinafter "SPC") on Some Issues Concerning the Application of laws to the Trial of Patent Infringement Disputes (promulgated in 2009, hereinafter "the SPC Infringement Interpretation I") provides that:

When determining whether the technical solution alleged for infringement falls into the protection scope of the patent right, the courts shall examine all the technical features recited in the claim claimed by the patentee.

In 2014, the SPC promulgated the follow-up draft of the SPC Infringement Interpretation I for public comments (hereinafter "the SPC Infringement Interpretation II (draft for public comments)"), where Rule 7 further provides that:

The people's courts shall disassemble the technical solutions of the claim(s) and the technical solutions alleged for infringement into technical features and comparing the corresponding technical features on such basis.

Technical features are the minimum technical unit that can perform technical function in relatively independent manner and produce relatively independent technical effect.

From the above, we know the technical features are the object of interpretation. According to Section 3, Chapter 2, Part II of the Chinese Patent Examination Guidelines (hereinafter "the PEG"), technical features may be either component elements that constitute the technical solution of the invention or utility model or the interrelations between the elements.

Rule 2 of the SPC Infringement Interpretation I provides that:

The courts shall determine the content of a claim as provided in Article 59.1 of the Patent Law based on the recitations of the claim in combination with the understanding by a person of ordinary skill in the art after reading the description and the appended drawings.

According to an article written by the drafters of the SPC Infringement Interpretation I, the concept of "a person of ordinary skill in the art" is introduced pursuant to Article 26.3 of the Chinese Patent Law, which requires the description shall specify the invention or utility model in a clear and complete manner so as to enable a person skilled in the relevant field of technology to carry it out.1 "A person of ordinary skill in the art" has the average knowledge existing at the time when the infringement occurred in the technical field to which the invention pertains and is neither an expert nor a person who cannot understand the technology.2

However, according to the PEG, the entity judging inventiveness of a patent is "a person skilled in the art" who is presumed to be aware of all the common technical knowledge and have access to all the technologies existing before the filing date or the priority date in the technical field to which the invention pertains.

In view of the above, the knowledge scope of "a person of ordinary skill in the art" in the SPC Interpretation I is larger than that of "a person skilled in the art" prescribed in the PEG. The time point for their knowledge is different. The former is "at the time when the infringement occurred," while the latter is "before the filing date or the priority date." The duration of a patent right may be as long as twenty years for an invention patent and 10 years for a utility model patent. With the technology development, the technical solution not available before the filing date of the patent may be included into the protection scope of the patent right, as understood by "a person of ordinary skill in the art."

A problem derived thus is how to interpret a created term. In Shanghai Gujian v. Shanghai Mo Di Lu Ke,3 the SPC set forth its opinions regarding a created term "adjustable linkage device" in claim 1 that: In view of the practical needs to describe a new technical solution, the patent applicant shall be allowed to use created terms when drafting the application documents. On the other side, since the created term was not known for a person of ordinary sill in the art, the patent applicant is obliged to define, explain, and specify the term clearly and accurately in the description.

II. The Scope of the Objects of Interpretation

Rule 7 of the SPC Infringement Interpretation I above sets forth the All-Features-Covered Doctrine. This doctrine means that each technical features of a claim shall be taken into account when making a comparison between a claim and the technical solution alleged in an infringement. When applying the All-Features-Covered Doctrine, two opposite situations should be noticed, one is "Discretionary Inessential Features" and "Inferior Invention."

In Dalian Ren Da v. Dalian Xin Yi,4 the SPC set forth its opinions for the first time that the Inessential Features under Discretion shall not be applied in the patent infringement case. Such opinions have great impact on the theoretical research and the practice of the Chinese Patent Law.5 One of the technical features in the case was that the patented pipe shall comprise at least two layers of glass fiber cloth. The corresponding feature of the pipe alleged for infringement had only one layer of such cloth. The SPC held that: All the technical features in the independent claim shall be deemed essential and be taken into consideration for infringement comparison. The SPC did not agree to apply the "Discretionary Inessential Features," because only when respecting each technical features in a claim can the public have a consistent expectation on the scope of protection of a patent right, where a patent right can be affirmed and the patent system and its values be ensured.

Regarding whether an inferior invention infringes a patent, the SPC delivered its opinions in Shenyang Zhilian v. ZHANG Jianhua.6 The involved patent was directed to a venting and cut-off device of heating system for high rising building. The product alleged for infringement did not have the technical features of "surrounded and threaded guide plate," "rotation-stopping plate," etc. The courts of the first and the second instance decided the product alleged for infringement was an inferior invention and the infringement established. In the retrial, the SPC indicated that: The courts shall compare all the technical features of the technical solution alleged for infringement with all the technical features of the claim when establishing the infringement. It shall not be taken into account that whether the technical solution alleged for infringement was inferior in terms of technical function or technical effect due to lack of certain technical features or not. The SPC thus decided the patent infringement could not be established.

III. Evidence for Claim Interpretation

1. Intrinsic and Extrinsic Evidence

Rule 3 of the SPC Infringement Interpretation I provides that:

The courts may interpret a claim referring to the description and the appended drawings, relevant claim in the claims set, and patent prosecution history. Where the description has specifically defined an expression in the claim, such specific definition shall be adhered to.

If using the above-mentioned method still fails to clarify the meaning of the claim, interpretation maybe made in combination with publicly known documents such as reference books, textbooks, and common understanding of the meaning by a person of ordinary skill in the art.

In the invalidation case Seiko Epson v. the Patent Review Board7 the SPC held that: In either administrative patent right affirmation procedure cases or civil infringement cases, the general principles and doctrines for claim interpretation shall be followed. For example, intrinsic evidence such as the description, the appended drawings and prosecution history shall have more weight, and the applicant's own explanation shall have more weight.

Regarding whether to admit the extrinsic evidence with a date after the patent filing date, the SPC held that: When an extrinsic evidence was used to interpret a term in the patent application documents, the principle was only to accept evidence prior to the filing date of the patent. However, a meaning of a word could be adopted through a continuous use by the public. Unless this meaning was adopted much later in time or for some other specific reasons, a meaning adopted after the filing date could be admitted to help understanding the meaning prior to the filing date.

However, under some circumstances, if the extrinsic evidence contradicts with the general understanding of a person skilled in the art, the court may probably not accept the interpretation based on such extrinsic evidence. In another invalidation case TDK Corp. v. the Patent Review Board,8 the patentee, TDK Corp., submitted the content of Chemistry Dictionary as common knowledge (Counter Evidence No.5) to prove the silicon in the patent documents shall be deemed as metal, and supplemented around 30 pieces of evidence of other patent references, manuals, dictionaries of Chinese and foreign languages, etc. during the first instance trial. The court of the second instance held that: Silicon was commonly known as semi-conductor material. A person skilled in the art would not deem silicon as metallic element. The No. 5 Counter Evidence submitted by TDK Corp. divided materials into metals and non-metals and the materials with properties between metals and non-metals were classified as metals. Under such classification, silicon was deemed as metal. However, as generally required, the description of the patent shall describe the claims in a clear and complete manner. Since the applicant did not clarify that the silicon should be deemed as metallic element in the patent application document, the court would not accept the patentee's argument.

2. Embodiments

Section 2.2.6, Chapter 2, Part II of the PEG provides that:

The preferred mode for carrying out the invention or utility model is an important part of the description, which is extremely important for sufficiently disclosing, understanding, and carrying out the invention or utility model, as well as for supporting and interpreting the claims. Therefore, the description shall describe in detail the preferred mode contemplated by the applicant for carrying out the invention or utility model. Embodiments are exemplification of the preferred modes for carrying out the invention or utility model.

First, technical features not recited in the claim shall not be taken into account based on its appearance in the embodiments to limit the protection scope of a patent. In XU Yongwei v. Ningbo Huatuo Solar Energy,9 the SPC held that embodiments were only exemplification of the invention and such exemplary description shall not be used to limit the protection scope of a patent. For the "end cover" of the flashlight, it was not recited in the patent claims but only mentioned in the embodiments and the appended drawings of the description. Thus, "end cover" shall not be used to define the protection scope of the patent.

Second, for the technical features recited in the claims, the embodiments can help to understand the protection scope of a patent right. In FU Zhihong and Guangzhou Xin Lv Huan v. Taishan XianQu,10 one of the technical features in claim 1 is "cemented composite fiber layer of bamboo, wood, and plant." Regarding the relationship between "bamboo, wood, plant," the SPC held that: Merely based on the words of claim 1, it was difficult, indeed, to decide whether the three kinds of fiber were of an "and" relationship or "or" relationship. According to the description, the composite is "a mixture made of magnesium chloride, magnesia and bamboo fiber or wood dust or plant fiber." Thus, it is not necessary that all the three kinds of fibers have to be contained.

3. The Purpose of the Patent

Rule 6 of the SPC Infringement Interpretation II (draft for public comments) provides that:

The courts shall interpret the claims in accordance with the purpose of the patent. The courts shall determine that an allegedly infringing technical solution does not fall into the protection scope of a patent, if there is a defect that the patent intends to overcome in the allegedly infringing technical solution.

The provision above comes from JIANG Guo You v. Anshan Greatwall Plastics.11 In this case, the patent was directed to a safe electric blanket. One of the technical features was "heat-transfer liquid." However, the claims did not define the "heat-transfer liquid" further. In the description, it specified that: The heat-transfer liquid contained antifreeze. Antifreeze was used as heat transferring materials and it overcame the defect that water would be iced under subzero temperature so that the hose would likely be broken off. The product alleged for infringement was a water-heating electric blanket. The first instance court entrusted a technical appraisal institute to ascertain the liquid composition in the hose of the product alleged for infringement, but the technical appraisal institute could not conduct the appraisal because the antifreeze composition was unknown and the amount of liquid in the infringing samples were not enough. Meanwhile, the defendant stated that its antifreeze was water.

During the trial, the defendant filed invalidation request with the Patent Reexamination Board ("PRB") against the patent in dispute. The PRB's decision stated that: The heat-transfer liquid in the concerned patent contained antifreeze and thus excluded water as heat-transfer liquid. The court held that: The plaintiff did not provide evidence regarding defendant's addition of antifreeze into the heat-transfer liquid in the product. Thus, the defendant's statement that its product used water as heat-transfer liquid is accepted. Prior to the filing date of the concerned patent, use of water as heat-transfer liquid had been disclosed by the prior art. Therefore, the heat-transfer liquid of the product alleged for infringement was different from that of the claims. What's more, the patentee had excluded the water as heat-transfer liquid from the protection scope of its patent right. Thus, neither equivalence nor infringement could be established.

IV. Doctrines of Interpretation – the Equivalence Doctrine and its Limitations

Rule 17 of the Several Provisions of the SPC on Issues Relating to Application of Law to Adjudication of Cases of Patent Disputes (promulgated in 2001, amended 2015, hereinafter "2015 SPC Adjudication Provision") provides that:

The protection scope of the patent right shall be determined by the essential technical features expressly recited in the claims, including that as determined by the features equivalent to the essential technical features.

The equivalent features refer to the features which use substantially the same means, perform substantially the same function and achieve substantially the same effect and which can be contemplated by a person of ordinary skill in the art at the time when the infringement occurred without inventive labor.

When the 2015 SPC Adjudication Provision is amended, the "time" for the person of ordinary skill in the art to contemplate is defined as "the time when the infringement occurred." That means, those technical features not deemed as equivalent at the time of grant may possibly be deemed as equivalent during determination of infringement.

Equivalent infringement is supplementary to literal infringement. Due to this article's limited length, we will only introduce the judicial practice of the two limitations of the Equivalence Doctrine below – the Donation Doctrine and the Estoppel Doctrine.

1. The Donation Doctrine

Rule 5 of the SPC Infringement Interpretation I provides that:

For a technical solution which is only depicted in the description or the appended drawings but not recited in the claims, the incorporation of such technical solution by the right holder in a patent infringement lawsuit into the protection scope of the patent right shall not be supported by the courts.

In CHEN Shundi v. Zhejiang Le XueEr, et al.,12 the patent was consisted of twelve steps. The focus in dispute was whether the exchange of Steps 10 and 11 constituted as equivalence. The SPC held that: The exchange of Step 10 and Step 11, as said by the defendant, reduced the production steps, saved time and improved effectiveness. Therefore, the technical effect resulted from such exchange is substantial, and the steps after exchange does not constitute as equivalence with Steps 10 and 11 in claim 1. Regarding Rule 5 above, the SPC indicated that: If a person skilled in the art can understand the technical solution disclosed in the description but not recited in the claim was an alternative choice raised by the patentee, the solution shall be deemed as donated to the society. The description disclosed Steps 10 and 11 can be exchanged but such exchanged steps were not recited in the claims. Thus, the steps after exchange could not be included into the protection scope of the patent right.

2. The Estoppel Doctrine

Rule 6 of the SPC Infringement Interpretation I provides that:

In the grant or invalidation procedure of a patent right, where the patent applicant or the patentee abandons a technical solution by amendments to the claims, the description, or through observations, the incorporation of the abandoned technical solution into the protection scope of the patent right by the right holder in a patent infringement lawsuit shall not be supported by the courts.

In Aonuo (China) Pharmaceuticals v. Hubei Wu Shi Pharmaceuticals, et al.,13 one of the technical features in claim 1 was "active calcium." But in the published version of the patent application, it was "soluble calcium" (soluble calcium includes calcium gluconate, active calcium, etc.) The reason was that when responding to the first office action to support the description, the applicant amended the "soluble calcium" into "active calcium." The component in the product alleged for infringement was calcium gluconate. Regarding whether calcium gluconate constituted equivalence to active calcium, the SPC held that: The technical solutions containing calcium gluconate was abandoned by the patentee's amendments to claim 1 during the procedure of grant, thus these solutions could not be included in the protection scope of the patent.

However, not all the abandonment will trigger Estoppel Doctrine. Rule 16 of the SPC Infringement Interpretation II (draft for public comments) provides that:

Where the patent applicant or the patentee amended the claims or the description or stated the observations in the course of patent grant and affirmation procedure, the alleged infringer argues that the technical solutions abandoned in above circumstances does not fall within the protection scope of the patent right, and the right holder provides evidence to support that the amendment or the observation is not accepted by the examiner or has no causal relationship with the validity of patent right, the courts shall consider that the amendment or the observation does not lead to abandonment of the technical solution.

In Zhong Yu Electronics (Shanghai) v. Shanghai Jiu Ying Electronics,14 the patent was directed to a steering engine for model. After the invalidation procedure, claims 1-2 and 4-6 were invalidated and the patent was sustained on the basis of claim 3. One of the technical features of claim 3 is: on the circuit board for driving, a strip of carbon film and a strip of silver film are printed. Correspondingly on the product alleged for infringement, a strip of carbon film and a golden-plated copper bar were printed. The SPC held that: The abandonment of the Estoppel Doctrine was usually done by the patentee's amendments or observations. When deciding whether it is an abandonment of the Estoppel Doctrine, the situations where the patentee did not proactively abandon should be noticed. If the additional technical feature in a dependent claim was not generalized previously in the independent claim,15 the technical solutions without the said additional technical feature shall not be deemed as abandoned. In this case, the patentee did not amend the claims and the description during the invalidation procedure, so the patentee did not abandon the technical solutions with other conducting materials as electricity strip. Thus, it was wrong to decide the Equivalence Doctrine cannot be applied to the "silver film" based on the invalidation of claims 1-2.

V. New Trend – The patent cannot be protected if the claims cannot be clearly interpreted

Rule 5 of the SPC Infringement Interpretation II (draft for public comments) provides that:

When the literal meaning of a claim is clear but is in fundamental conflict with corresponding part in the description, which does not belong to the circumstances as prescribed by Rule 4, the people's court shall determine the patent protection scope based on the literal meaning of the claim.

If the meaning of a claim is unclear and the patent protection scope claimed by such a claim cannot be determined by any statutory manner of interpretation, which does not belong to the circumstances as prescribed by Rule 4, the courts may dismiss the lawsuit.

This provision indicates that, when the claims are contradictory to the description, if it is because of errors of grammar, letters, punctuation, signals, drawings, etc., and a person of ordinary skill can conclude the sole understanding after reading the claims, the description and the appended drawings, the claims shall be interpreted as such sole understanding. Otherwise, the protection scope of the patent shall be determined by the claims. In Xi'an Qin Bang v. Wuxi LongSheng, et al., the SPC indicated that: When a person of ordinary skill in the art could determine the meaning of the expression in the claim (the terms of the expression were not specified in the description), the claim shall be interpreted by the understanding of a person of ordinary skills. What was depicted in the description should not overturn the claims so that the claims would actually be amended and, in this manner, the infringement procedure would be served as additional opportunity for the patentee to amend the claims. The publication and boundary of a patent would be harmed and the patentee would be entitled unjustified protection that should not be given.

The second paragraph of Rule 5 further makes it clear that: the courts could dismiss the lawsuit if the claims cannot be clearly interpreted. The provision comes from BAI Wanqing v. Shanghai Tianxiang.16 In the case, regarding the "high permeability" in claim 1, there was no specific definition, numerical range, and the calculation methods in the description. A person of ordinary skill in the art could not determine the meaning of "high permeability" merely based on the description. The evidence submitted by the patentee could not prove that a person of ordinary skill in the art has consistent understanding regarding "high permeability." At the same time, the patentee argued that a person of ordinary skill could determine the lower limit based on the environment wherein the product was used. However, the SPC believed such argument actually had all the circumstances included into the protection scope of the patent right, which was too large and lacked basis. Thus, "high permeability" and the protection scope of the patent could not be determined. The infringement was not established.

Footnotes

1 KONG Xiangjun, WANG Yongchang, LI Jian, The understanding and application of the Interpretation by SPC on Some Issues Concerning the Application of laws to the Trial of Patent Infringement Disputes, People's Judiciary, Vol.3, 2010, Page 27-33.

2 See supra.

3 Shanghai Gujian v. Shanghai Mo Di Lu Ke, (2013) Ming Ti Zi No. 113, Civil Judgment by the SPC

4 Dalian Ren Da v. Dalian Xin Yi, (2005) Ming Ti Zi No.1, Civil Judgment by the SPC

5 http://www.chinacourt.org/article/detail/2008/11/id/332072.shtml

6 Shenyang Zhilian v. ZHANG Jianhua,(2009)Ming Ti Zi No.83, Civil Judgment by the SPC

7 Seiko Epson v. the PRB,(2013) Zhi Xing Zi No.53-1, Administrative Ruling by the SPC

8 TDK Corp. v. PRB,(2013) Gao Xing Zhong Zi No.1682, Administrative Judgment by Beijing Higher People's Court

9 XU Yongwei v. Ningbo Huatuo Solar Energy, (2011) Ming Ti Zi No. 64, Civil Judgment by the SPC

10 FU Zhihong and Guangzhou XinLvHuan v. Taishan Xian Qu,(2010) Ming Shen Zi No. 871, Civil Ruling by the SPC

11 JIANG Guo You v. Anshan Greatwall Plastics, (1999) Shen Jing Chu Zi No. 617, Civil Judgment by Shenyang Intermediate People's Court

12 CHEN Shundi v. Zhejiang Le XueEr, et al, (2013)Ming Ti Zi No. 225, Civil Judgment by the SPC

13 Aonuo (China) Pharmaceuticals v. Hubei Wu Shi Pharmaceuticals, et al., (2009) Ming Ti Zi No. 20, Civil Judgment by the SPC

14 Zhong Yu Electronics (Shanghai) v. Shanghai Jiu Ying Electronics, (2011) Ming Ti Zi No. 306, Civil Judgment by the SPC

15 There is no detailed definition or specification regarding circuit board for driving of the steering engine in claim 1.

16 BAI Wanqing v. Shanghai Tianxiang, (2012) Ming Shen Zi No. 1544, Civil Ruling by the SPC

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