Legal Definitions - judgment book

Judgment by Comparison

In patent law, "judgment by comparison" refers to the practice where a patent examiner approves a new patent application claim because a very similar claim has already been approved in a previous patent. While patent law does not strictly adhere to the legal principle of stare decisis (meaning "to stand by things decided," where past rulings are binding), patent examiners often use previously allowed similar claims as a helpful guide or benchmark when deciding whether to approve a new, comparable claim. This approach helps to promote consistency in patent examination decisions.

• Example 1: Software Algorithm

  A software development company applies for a patent on a novel algorithm designed to improve the efficiency of data encryption. The patent examiner initially expresses concerns that the algorithm's underlying mathematical principles are too generic to be patentable. However, the company's patent attorney points to a patent granted last year for a different encryption algorithm that utilized a very similar mathematical approach and was allowed despite initial concerns. The examiner, reviewing the details of the previously allowed patent, uses that decision as a reference point and subsequently approves the new algorithm's claim, finding it sufficiently distinct based on the established precedent.

  Explanation: This illustrates judgment by comparison because the examiner's decision to allow the new patent claim was significantly influenced by the fact that a similar claim had already been approved in a previous patent, even though there was no strict legal obligation to follow that prior decision.

• Example 2: Renewable Energy Device

  An inventor seeks a patent for a unique design feature in a small-scale wind turbine intended for residential use. The patent examiner questions the originality of the turbine's blade attachment mechanism, citing several existing patents for different types of wind turbines. The inventor's representative then highlights a recently granted patent for a water turbine that incorporates a blade attachment mechanism with a highly analogous structural design and functional purpose. Recognizing the strong similarity and the prior allowance, the examiner uses this comparison to conclude that the new wind turbine's attachment mechanism also meets the criteria for patentability.

  Explanation: Here, the allowance of the new patent claim for the wind turbine's design is a "judgment by comparison" because the examiner looked to a previously approved, similar design in a related field as a guide to determine the patentability of the current application.

• Example 3: Food Preservation Method

  A food science company files a patent application for a new method of preserving fresh produce using a specific combination of inert gases. The examiner initially believes the method might be too obvious given existing preservation techniques. The company's legal team then presents evidence of a patent granted five years prior for a similar gas-based preservation method applied to cut flowers, which involved a comparable mixture of gases and a similar application process. The examiner, seeing that a method with analogous principles and components has already been deemed patentable, uses this prior allowance to inform their decision and ultimately approves the claim for the new produce preservation method.

  Explanation: This example demonstrates judgment by comparison as the patent examiner's decision to allow the new food preservation method's claim was based on the fact that a highly similar method had already been granted a patent, serving as a comparative standard for patentability.