Under the patent system, technical disclosure is traded for protection. The two fundamental objectives of the Patent Law – namely, the protection of patentees' personal interests and the promotion of the public interest in scientific and technological progress – hinge on the balance of patent protection and disclosure.

Legal framework

Article 26, Paragraph 4 of the Patent Law provides that "the claims shall be based on the description". Such 'claims' mainly define the scope sought to be protected by the patent, whereas the 'description' embodies more the patentee's technical contribution that is disclosed to the public. This is therefore a key mechanism devised to balance protection and disclosure under the Patent Law.

Further, the Patent Examination Guidelines specify that the technical solution for which patent claims can request protection must be a solution that a person skilled in the art can obtain directly or generalise from the patent's description. The scope of the claims cannot exceed the description.

Case law

In addition to the Patent Law and the Patent Examination Guidelines, the Supreme Court has rendered judgments regarding a patent description's support of the claims in a number of typical cases. These judgments are of guiding significance in the application of Article 26, Paragraph 4 of the Patent Law in practice.

Xu Wenqing In the 2005 case Xu Wenqing, the Supreme Court referenced the Patent Examination Guidelines in ascertaining the judicial adjudication rules, which are identical to those of the examination guidelines regarding the matter of support.

Eli Lilly In the 2010 case Eli Lilly, the Supreme Court further elaborated that the following generalisation will exceed the scope disclosed in the description:

If the generalization of the claims would cause a person skilled in the art to have reason to doubt that one or more subordinate concept(s) or option(s) contained in the superordinate generalization or parallel generalization cannot resolve the technical issue which the invention proposes to resolve and achieve an identical technical effect.

One of the claims of the patent in question involved the delimitation and protection of a method of preparing a pharmaceutical by using such factors as the raw materials, quantities, reaction temperature and solvent.

The Supreme Court held that the generalisation of the claim in question contained numerous other solutions that could not resolve the technical issue that the invention proposed to resolve, such that a person skilled in the art could not easily deduce – from the permutation and combination of various reaction conditions – the solution that could resolve the technical issue by way of conventional experimentation or reasonable inference. Instead, the court held that a great deal of repeated experimentation or excessive labour would be required to determine the claim's scope. Therefore, the scope of the claim's generalisation was overly broad and thus not supported by the description.

Sensormatic Electronics In 2017, on the basis of the criteria established in Eli Lilly, the Supreme Court clarified in Sensormatic Electronics the means for determining the "technical issue that the patent proposes to resolve". The Supreme Court held that:

  • the provision "the claims shall be based on the description" addresses the correlation between the claims and the description; and
  • the relevant content recorded in the description should be taken as the fundamental basis in determining the technical issue that the patent in question proposes to resolve and the technical effect that it aims to achieve, which the court can determine by considering:
    • the background technology recorded in the description and the defects existing therein;
    • the invention's objective;
    • the technical issue to be resolved by the invention;
    • the beneficial effect recorded in the summary of invention; and
    • the content relating to the technical issue and the beneficial effect in the specific embodiments.

However, the "technical issue actually resolved" referred to in the determination of a patent's inventive step is determined anew based on the technical features that enable the claims to be distinguished from the closest prior art and cannot directly serve as the basis for determining whether the claims are based on the description. The provision that a patent's inventive step and claims must be based on its description stipulate and regulate the legitimacy of the claims from different perspectives. Even if the claims involve inventive step, whether the various technical features – including the distinguishing technical features – recorded therein are properly generalised and whether the technical solution delimited by the claims as a whole is properly generalised still require determination based on Article 26, Paragraph 4 of the Patent Law.

In Sensormatic Electronics, the patent in question concerned a marker used in magnetomechanical electronic article surveillance systems. The Supreme Court held – after comprehensively considering such content in the patent's description as the background technology, the invention's objective, the beneficial effects and the specific embodiments – that the improvements made by the patent in question to the background technology mainly lay in using a specific material to fabricate the bias element in the marker, such that the marker could be deactivated more easily and would not be accidentally deactivated in a conventional operating environment.

The great majority of the claims for the patent in question were not delimited by the specific material of the bias element, but rather by the properties or parameter range of the materials or marker. The Supreme Court held that claims so delimited included numerous other bias elements made from known and unknown substances and that a person skilled in the art would have to go through a great deal of selection and experimental verification to confirm which specific materials could resolve the technical issue that the patent in question proposed to resolve and achieve the technical effect that it proposed to achieve. Accordingly, the court held that the claims' scope of protection exceeded the extent fully disclosed in the patent's description and the extent of the patent's technical contribution and therefore failed to take the description as their basis.

For further information on this topic please contact Johnson Li at Wanhuida Peksung by telephone (+86 10 6892 1000) or email ([email protected]). The Wanhuida Peksung website can be accessed at www.wanhuida.com and www.peksung.com.

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