Patent protection for software

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In recent years China has seen rapid growth in the number of patent application filings for computer programs. While recent patent lawsuits involving well-known Chinese and overseas enterprises (eg, Nokia v Huaqin, Sogou v Baidu, Huawei v ZTE) have been noteworthy, computer program-related patents have always attracted significant attention due to their large volume, broad application scope, high value in disputes and far-reaching technical, commercial and social effects.

This chapter highlights the primary issues faced by enterprises when applying for computer program-related patents in China.

Patentable subject matter

A computer program is patentable in China if it is written in the form of a method or virtual apparatus (ie, an apparatus including modules in one-to-one correspondence with methodological steps). In recent years, claims with an apparatus including processors and memories as their subject matter have been increasingly accepted by examiners.

On April 1 2017 the latest version of the State Intellectual Property Office (SIPO) Guidelines for Patent Examination entered into force. Major amendments were made to the guidelines in respect of computer programs, including the following:

  • An apparatus as the subject matter may comprise not only hardware, but also computer programs.
  • ‘Virtual apparatus’ should be interpreted as a program module architecture that implements a solution mainly using a computer program that is disclosed in the specification. The modules constituting the virtual apparatus are program modules, which are different from the usual functional features.
  • The latest guidelines clarify that “a computer-readable storage medium defined solely by a computer program per se which the medium records” is non-patentable subject matter. Therefore, a computer program-related invention protectable under the Patent Law is distinguishable from computer programming codes that are protectable under the Copyright Law. In other words, in patent practice the claim of a computer program-related invention may now be written in the form of “medium + computer program flow”.

According to SIPO’s interpretation, the claim form “medium + program” – which is a permissible form for “a pure software solution” in the United States – will also be allowed in China. The fact that “the constituting parts of an apparatus include not only hardware but programs as well” means that for a solution combining software and hardware, a ‘program’ may constitute a claim element parallel to other hardware elements. This implies a reformed approach by the administrative authorities which may contribute to reinforced protection of software patents.

In brief, patentable subject matter in China encompasses methods, virtual apparatuses and apparatuses including the forms “processors + memories”, “medium + program” and “hardware + program”. Since there is little Chinese case law on computer program-related infringement suits, the criterion for determining the scope of protection of some subject matter (eg, virtual apparatuses) remains unclear. Patentees are therefore advised to claim all of the currently allowable subject matter in the application document. Doing so may provide greater flexibility when enforcing the relevant patent rights.

Business methods

Under Article 25 of the Patent Law, “rules and methods for mental activities” are not patentable subject matter. This includes business methods, which may be involved in computer program-related patent applications. In Chinese patent examination practice, a business method claim will be rejected for falling within the scope of “rules and methods for mental activities” if it includes only human-made business methods and no technical means. In line with this practice, the latest patent examination guidelines explicitly stipulate that “if a claim is defined by not only rules and methods for mental activities but also technical features, the claim, as a whole, is not one of the methods and rules for mental activities, so it should not be excluded from patentability in accordance with Article 25 of the Chinese Patent Law”. In other words, a claim is usually deemed to meet the subject-matter requirements if it contains technical features and is subject to patentability evaluation under other criteria (eg, inventive step).

According to the guidelines, examiners should consider the claim as a whole when evaluating whether it meets the inventive step requirement. However, in relation to a claim containing a business method and a technical feature, there is no explicit stipulation on whether examiners must consider the business method as a contributor to inventive step. That said, in practice examiners usually give little consideration to business methods’ contributions to inventive step.

For these reasons, in order for business method-related patent applications to meet the eligibility requirements and be given greater weighting in the inventive step evaluation, applicants should ensure that:

  • the claim contains technical features (eg, features performed by technical means such as a computer, the Internet or a communication apparatus); and
  • the specification describes the technical problem that is solved and the technical effect that is achieved by the solution, and stresses the technical contribution of the solution.

This approach is also advisable in view of current European and US practice.

Functional features

Functional features are practically inevitable in claims for computer program-related solutions. As such, the interpretation of functional features is crucial to successful enforcement of computer program-related patents.

Instigated in 2012, the patent infringement suit between Nokia and Huaqin is a typical case relating to functional features. The first and second-instance courts both held that it was impossible to determine the scope of protection of the apparatus claim in Nokia’s Patent ZL200480001590.4, because the apparatus was defined by purely functional features “configured to perform steps of…”. The courts’ decision provoked heated debate among software innovators, as it was unfavourable to patentees which take the common approach of defining an apparatus with methodological steps. Although Nokia asked for a retrial, the question of how the Supreme People’s Court would interpret a patent drafted in this way remains unanswered, because all of the claims of the patent were invalidated for lacking inventiveness.

Functional features in China may cover a wider range of claim language than the known means-plus-function language in the United States. In 2016 the Supreme People’s Court issued its Interpretation on Issues Concerning the Application of Laws in the Trial of Patent Infringement Dispute Cases (II). Article 8 of the interpretation, regarding functional features, stipulates: “A functional feature is such a technical feature that is defined by the function or effect achieved in the invention-creation for structures, components, steps, conditions or the relationship among them, except where specific embodiments to achieve the above function or effect can be determined directly and expressly by those skilled in the art after reading solely the claims. Where compared with the technical feature defined in the specification and drawings which is indispensable for achieving the asserted function or effect in the preceding paragraph, the corresponding technical feature in the alleged infringing technical solution uses substantially the same means to implement the same function and achieves the same effect, and can be conceived by those skilled in the art without inventive endeavour at the time of occurrence of the alleged infringing action, the People’s Court shall determine that the corresponding technical feature is identical with or equivalent to the functional feature.”

Debate over such functional features is ongoing and there is little case law in this area to serve as a guide; but based on the Supreme People’s Court interpretation, patentees are advised to define a claim using features that meet the above requirement (ie, using specific embodiments to achieve the function or effect which can be determined directly and expressly by those skilled in the art after reading solely the claims), so that the features are less likely to be interpreted as functional features. Where only functional language can be used to express a feature, patentees must present at least two exemplary embodiments of the feature in the specification.

Take Nokia’s abovementioned patent as an example. The claims included the feature “applying the data transfer method in a message editor used for entering messages”. It is questionable whether a person skilled in the art, after reading only the claims, would understand how to apply the new data transfer method to a message editor. Had the specification included detailed examples of application, the patentee would have been in a better position to enforce its rights.

Another example may clarify how the application document for a computer database invention can be drafted so that features in the claims are less susceptible to unfavourable interpretation under the rules on functional features. The invention in question relates to sorting. Independent claim 1, directed to a computer-implemented method, has the feature “applying a boundary condition to the data elements stored in the buffer after receiving each individual data element of the stream of data elements”. This covers a broad scope, but a person skilled in the art can directly and expressly determine how to implement it. Hence, from the perspective of the Supreme People’s Court interpretation, the feature may not be considered as a functional feature.

Moreover, the application document provides several embodiments of the feature as fall-back positions. For example, the dependent claims and the corresponding parts of the specification have the following support and explanations:

  • “applying a boundary condition to the data elements stored in the buffer includes: identifying a smallest data element from the data elements stored in the buffer, and determining whether a difference between the smallest data element and the received individual data element exceeds a threshold value”;
  • “applying a boundary condition to the data elements stored in the buffer includes determining whether a maximum size of the buffer is exceeded”; and
  • “applying a boundary condition to the data elements stored in the buffer includes determining whether a newly received data element exceeds a cut-off value”.

Even if the above feature in claim 1 is considered a functional feature in litigation, the various embodiments will play an adequate role in determining the scope of claim 1, especially under the doctrine of equivalents.

Claims favourable to enforcement

Difficulties in both determining the protection scope and collecting evidence frequently arise in the course of enforcing computer program-related patents. To facilitate the determination of protection scope, patentees are advised to describe the technical solution using methods with specific implementations that are directly and expressly ascertainable by a person skilled in the art, as the smallest units constituting the technical solution.

To make evidence collection easier, patentees are advised to use a single subject that is capable of performing the smallest functional unit (eg, either of two communication parties) as the subject matter, targeted at potentially directly infringing subjects. Patentees should also define a claim using explicit features that are perceivable by human beings or whose signal stream is readily interceptable by detection devices. For instance, take a feature that reads “calculating a distance between a terminal device and a specified location, wherein the distance is displayed when the distance is less than a threshold value”. In this case, “calculating a distance between a terminal device and a specified location” is not particularly perceivable and its signal stream is not readily interceptable. As long as the technical solution can be described clearly, such an inexplicit feature is best avoided. For example, the feature could be replaced with “displaying a distance value between a terminal device and a specified location, when the distance value is less than a threshold value”, which is significantly more explicit.

Balance between sufficient disclosure and technical trade secrets

Computer program-related solutions are unique in that applicants may want to avoid publicly disclosing how to implement some underlying solutions. Applicants may seek to guard these solutions as technical trade secrets. Other solutions may become public knowledge once the products are placed on the market (eg, interaction-based solutions). For budgetary considerations, applicants may consider applying for more patents for interaction-based solutions to cover current and future products (including those of competitors) and fewer patents for solutions involving, for example, underlying architecture, so as to avoid disclosing technical trade secrets. Where a patent application inevitably involves an underlying solution, alternative known means may be substituted for the underlying solution in order to strike a balance between meeting the sufficient disclosure requirement and protecting the technical trade secret.

Linda Liu & Partners, Linda Liu Group

F16 Tower C, Beijing Global Trade Centre

36 North Third Ring East Road, Dongcheng District

Beijing 100013


Tel +86 10 5825 6366

Fax +86 10 5957 5201


Lei Zhou

Vice manager of domestic department

[email protected]

Lei Zhou is the vice manager in Linda Liu & Partners’ domestic department. She graduated with an ME and BE in integrated circuits from Tsinghua University, Beijing, China. She deals with patent drafting, invalidation and infringement proceedings for leading domestic and international high-tech companies before the Patent Re-examination Board and the courts. Her areas of expertise include telecommunications, computer science and microelectronics. Before she headed the domestic department, she spent 10 years working for several major international companies, including Apple and IBM. Her work has been appraised as Best Drafted Case of the Year by IBM. She gained substantial experience with A-D converter design as a researcher at the Chinese Academy of Sciences.

Nancy (Xiaowen) Song

Group leader of electrical engineering department

[email protected]

Nancy (Xiaowen) Song is a group leader in Linda Liu & Partners’ electrical engineering department. She graduated with a BE from Tsinghua University and is admitted as an LLM candidate at Santa Clara University School of Law, Santa Clara, United States. She serves medium-sized and large consumer electronics companies from the United States, Japan and Europe. Her areas of expertise include computer databases, medical instruments and secured identification and authentication instruments. Her practice encompasses patent drafting, prosecution, invalidation, portfolio analysis and commercial advice in these areas. Before joining Linda Liu & Partners, she was senior patent counsel with a global leader in integrated circuit chip design.

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