When analyzing design patent prosecutions with non-final rejections over the past four years (2021-2024), we uncovered interesting insights from the top 50 most cited cases. The chart and table (see below) highlight these cases and provide key takeaways about their influence.
Key Observations
1. Age of the Cases
One of the most striking observations is the average age of these cases—1970. This is surprising, given the perception that design patent law is evolving rapidly. It suggests that foundational principles established decades ago continue to dominate legal reasoning in design patent prosecutions, even though several key legal concepts and tests recently have been modified.
2. Dominance of Foundational Cases
Cases like International Seaway Trading Corp. v. Walgreens Co. (2009) and Gorham Co. v. White (1871) top the list with citation counts of 6,509 and 5,690, respectively. These cases reflect enduring principles such as the “ordinary observer” test for design patent infringement, which remains a cornerstone of design patent law.
Click here for a full case table containing 212 cases cited in design patent prosecution histories and/or Chapter 1500 of the MPEP.
3. Key Legal Principles
The most frequently cited cases focus on:
Anticipation and Infringement Tests: Gorham Co. v. White established the “ordinary observer” standard for infringement, while International Seaway clarified its role in anticipation analysis.
Prosecution Procedure: Ex Parte Quayle (1935) clarified the practice for handling formal matters in design applications when substantive issues are resolved, allowing for allowance pending formal corrections.
Broken Lines and Scope of Protection: In re Blum (1966) and similar cases underscore how procedural and technical aspects—like the use of broken lines to indicate unclaimed features—shape prosecution strategies.
Double Patenting: cases including In re Thorington (1969), In re Goodman (1993), and In re Longi (1985) explain principles involved in double patenting rejections.
Restriction Requirements: In re Platner (1967) clarifies that embodiments patentably distinct from one another do not constitute a single inventive concept and cannot be included in the same application
Written Description: cases such as In re Daniels (1998) and In re Rasmussen (1981) define the standards for the written description requirement and explain when there is proper support for amendments.
Obviousness: cases such as In re Frick (1960), In re Rosen (1982), and In re Glavas (1956) establish the framework for obviousness, primary references, and when secondary references can be combined. Many of these principles have recently been eliminated or modified by LKQ v. GM (2024).
Claiming: In re Zahn (1980) allowed portion claiming.
Evolving Standards: Cases like In re Maatita (2018) reveal how modern challenges are pushing the boundaries of written description and enablement in design patents.
4. Categories of Influence
Each case fits into one or more categories, such as anticipation, infringement, procedure, and patent scope. The wide distribution across categories illustrates how design patents intersect with a broad spectrum of legal doctrines.
What This Means for Practitioners
For design patent attorneys and agents, these cases provide essential guidance. They offer a roadmap for navigating common issues in non-final rejections and addressing examiner concerns effectively. Tools like ProSearch can help analyze prosecution histories and leverage these citations strategically by identifying arguments other practitioners have used successfully.
Insights for the Future
While older cases remain influential, recent decisions like LKQ v. GM (2024) (obviousness), Columbia Sportswear v. Seirus (2023) (scope of comparison prior art), In re SurgiSil (2021) (article of manufacture), and In re Maatita (2018) (definiteness) suggest that the legal framework for design patents is far from static. Practitioners interested in prosecuting effective and broadly enforceable design patents in an efficient manner should stay informed of new developments, as new precedents may redefine key aspects of the law.
