Crafting Effective Arguments Against an Examiner's Interpretation of a Claim Term: A Guide for Patent Professionals

In the world of patent prosecution, a critical battle can occur when an examiner interprets a claim term differently from how the applicant intended. This discrepancy in interpretation can have profound implications for the patent's scope and, ultimately, its enforceability. To effectively navigate this challenge, patent professionals can present well-reasoned arguments backed by solid evidence rather than relying solely on attorney argument. In this post, we will delve into the importance of a proper interpretation of claim terms, the significance of supporting arguments with evidence, and practical tips for patent professionals. We will also discuss a recent case from the Patent Trial and Appeal Board (PTAB) that highlights these crucial issues.

A fundamental concept in patent prosecution is that claim terms must be properly interpreted. When an examiner interprets a claim term differently from the applicant's intention, it can lead to significant consequences. A misinterpreted term can result in the examiner rejecting the claim based on prior art that should not be considered a block to patentability. To avoid this scenario, patent professionals should ensure that the claim terms are interpreted correctly.

To convince the examiner of the correct interpretation, the applicant should provide substantial supporting evidence. Mere attorney argument, no matter how well-crafted, often falls short in persuading the examiner. The following are some ways to support your argument with evidence:

  1. Declarations from Experts: One effective strategy is to obtain a declaration from an expert in the field. An expert's opinion can carry significant weight and provide a credible source to support your interpretation of the claim term.   

  2. Dictionary Definitions: If the term's meaning is ambiguous or subject to interpretation, referencing reputable relevant dictionaries can be persuasive. Dictionaries can provide an objective and widely-accepted understanding of the term, particularly if a technical dictionary is used from the same field as the invention.  

  3. Prior Art that Supports Your Interpretation: Identify prior art that uses the claim term in the same way as you propose. This demonstrates that your interpretation aligns with how the term is commonly understood and used in the relevant technical field.

  4. Specification Consistency: Highlight how your interpretation is consistent with the patent specification (including each and every instance in the specification). The specification can provide essential context for the examiner to understand the inventor's intended meaning, and the examiner’s interpretation must be consistent with the specification.

Let's take a closer look at a recent case from the PTAB that underscores the importance of proper interpretation and supporting arguments with evidence. In this case (Appeal 2022-004287,
Application 16/369,978). The invention pertains to computer graphics and in particular to texture mapping, which encodes surface properties of 3D geometry within a scene as bitmaps. As part of rendering a scene, a graphics processing unit (GPU) performs texture filtering. Texture filtering is typically necessary because the pixel centers in the rendered scene do not align with the texel centers in the texture (where a texture comprises an array of texels (i.e.[,] texture elements), such that texels in a texture are analogous to the pixels in an image) and in different situations, pixels can be larger or smaller than texels.

Claim 1 required, among other limitations, coefficients relating to a plurality of different texture filtering methods. There was a dispute between the applicant and the examiner as to whether the cited prior art disclosed texture filtering. The applicant argued that the prior art related to image filtering based on structural information, including filters in this spatial aspect, but that such features were not texture filtering methods within the meaning of the claim term. However, beyond these arguments, the applicant did not refer to the specification, provide a dictionary definition, or provide any other evidence in the record to support this argument. The PTAB was unconvinced:

Appellant provides insufficient evidence to persuade us of error in the Examiner’s interpretation of the disputed term “texture filtering.” Other than attorney argument, Appellant does not provide any basis for a narrower interpretation. See Johnston v. IVAC Corp., 885 F.2d 1574, 1581 (Fed. Cir. 1989) (“Attorneys’ argument is no substitute for evidence.”). For example, Appellant does not proffer a narrower interpretation of texture filtering needed for consistency with the Specification, does not provide an authoritative definition of the term such as may appear in a technical dictionary, or provide other evidence, such as an expert declaration,10supporting Appellant’s contention that an image filter, as disclosed by Jiang, does not encompass texture filtering. Therefore, as mere attorney argument, Appellant’s assertions have little probative value and are “not the kind of factual evidence that is required to rebut a prima facie case of obviousness.”

The battle over claim term interpretation is a common challenge in patent prosecution. Patent professionals should be diligent in presenting their arguments and use evidence to support their positions. A proper interpretation not only safeguards the patent's scope but also ensures that prior art is correctly considered.