The claims of a patent define the scope of protection sought by the patent holder by specifying the technical solution to be protected. When the technical features in the claims have specific meanings or multiple interpretations, and when determining the literal scope of protection, it is necessary to further clarify the actual scope of protection. In such cases, the description must be used to interpret the scope of the claims. However, it is important to avoid narrowing or expanding the scope of protection through interpretation. Therefore, there are many points to note when using the description to interpret claims, which will be briefly discussed below.

I. Rules and Sequence for Interpreting Technical Features

1. Rules for Interpretation

① Legal Basis

Patent Law of the People’s Republic of China, Article 64:
"The protection scope of an invention or utility model patent shall be determined by the content of the claims. The specification and drawings may be used to interpret the claims.
The protection scope of a design patent shall be determined by the product’s design as shown in drawings or photographs, and the brief description may explain such design."

② Judicial Interpretation

Supreme People’s Court Interpretation on Patent Infringement Disputes, Article 3:
"When interpreting claims, courts may rely on the specification, drawings, related claims, and patent prosecution history. If the specification provides a specific definition for a term in the claims, that definition shall prevail. If ambiguity remains, publicly available literature (e.g., technical manuals, textbooks) and the common understanding of a person skilled in the art may be considered."

2. Sequence for Interpretation

① Primacy of the Claims

The claims form the foundation for determining protection scope. While the specification and drawings aid interpretation, they cannot override the claims’ central role.

② Priority to Internal Evidence

Technical terms in claims should first be interpreted using internal evidence (specification, drawings). Only when internal evidence is insufficient may external evidence (e.g., industry standards, technical literature) be introduced.

③ Alignment with Inventive Purpose

Interpretation must reflect the perspective of a person skilled in the art, considering the technical context, claim language, and the invention’s objectives to ensure a reasonable and implementable scope.

II. Key Considerations for Interpreting Claims via the Specification

1. Avoid Limiting Claims to Specific Embodiments

The specification describes embodiments but cannot exhaustively list all implementations. Using the specification to restrict claims to illustrated examples (e.g., specific operating conditions) improperly narrows protection.

2. Avoid Importing Parameters or Configurations

If a technical feature’s meaning is clear in the claims and the specification provides no special definition, the claim language governs. Importing parameters, positions, or configurations from the specification (e.g., dimensions in drawings) unduly limits scope.

3. Adhere to Special Definitions in the Specification

When a technical feature lacks clarity or a universally accepted definition, the specification’s explicit definitions must guide interpretation.

4. Contextual Interpretation of Terms

Terms with established meanings must be interpreted in light of the invention’s background, objectives, and technical problem. A generic interpretation divorced from the specification risks misalignment with the patent’s purpose.

Case Study: CN200780027217.X "Cleaning Device" Infringement Dispute

Key Issue: Interpretation of "power source" in Claim 1.

Claim 1 Excerpt:
"A handheld vacuum cleaner comprising:

• An elongated suction pipe with a longitudinal axis and an intake opening;

• A airflow generator;

• A cyclonic separation unit;

• A power source for the airflow generator;

• An elongated handle between the airflow generator and power source, angled 80°–90° relative to the suction pipe’s axis."

Specification [0027]:
"The handheld vacuum cleaner may use standard batteries, rechargeable batteries, or a power cord."

Analysis:
While the specification broadly defines "power source" to include batteries and cords, the technical solution using a power cord fails to achieve the invention’s purpose (portability). Thus, "power source" cannot be interpreted to include power cords, despite the general description. The claims’ scope remains limited to configurations aligned with the invention’s core objective.