Patent Enforcement

• Jurisdiction: Maryland

IV. PATENT ENFORCEMENT

A. Introduction

A U.S. patent entitles the owner to exclude others from the unauthorized manufacture, use, sale, offer to sell, or importation of the patented invention in the United States during the patent term. In this regard, the key questions that may arise in confronting allegations of patent infringement include: was the defendant's otherwise infringing activity authorized (e.g., was the defendant acting within an express or implied license)?; did the alleged infringement occur within the United States (e.g., might some steps of a patented method have been performed abroad)?; and was the patent in force at the time of the alleged infringement (e.g., was the patent expired or might it have been abandoned for failure to pay maintenance fees)? But perhaps most important is the question of what precisely is the patented invention, which is the subject of claim interpretation.

B. Claim Interpretation

At the end of a U.S. patent is a section consisting of one or more numbered paragraphs that set forth the patent claim(s). Claim interpretation (or claim construction) involves ascertaining the meaning of the words used in a patent claim. This is the paramount consideration in defining the legal entitlement of patent protection. It is a bedrock principle of patent law that the claims of a patent define the invention to which the patentee is entitled the right to exclude. Therefore, what the title, abstract, or drawings and figures of a patent might convey is not definitive of the scope of the patent.

The complexity of patent law to lay persons often starts with the legal doctrines that underlie proper claim interpretation. First, a patent and its claim(s) are not written for the ordinary person, but rather "for one skilled in the art to which the invention pertains." Accordingly, it may take a rocket scientist to understand a patent to an aerospace invention, and a patent written in this jargon may be legally acceptable while being incomprehensible to the typical citizen.

Second, unlike a real property plat or deed, there is no established patent claim nomenclature (similar to the relative precision of longitude, latitude, distance, elevation, etc.) upon which the public may rely. Indeed, the inventor or patent applicant "may be her own lexicographer," and thus, may define her invention in the manner she sees fit. Because the words of a patent claim need not reflect the ordinary or customary meaning, a proper claim interpretation requires an examination of the public record beyond the information provided in the patent itself.

Third, because the true enforceable patent scope is determined by the language of the claims, the remainder of the patent document, and the entirety of the record of proceedings before the patent office (i.e., the prosecution history), one cannot properly conclude what the legal right of a U.S. patent is by reference to the patent alone. Just as one cannot be certain where a real property boundary may lie simply by looking at a fence, one cannot be certain of the scope of a U.S. patent simply by looking at the print copy of the granted patent alone. A patent does not tell the entire story because the courts will interpret a patent claim only after examining the publicly accessible, but often not readily available, prosecution history. Thus, even a thorough examination of the patent itself by a seasoned patent attorney is insufficient to provide a proper claim interpretation, and one proceeds with grave peril in conducting her business affairs based on such an incomplete analysis.

C. Infringement

The statutory basis for patent infringement may be found at 35 U.S.C. § 271. Section (a) defines direct infringement and...