Legal Definitions - substantial equivalent

In patent law, the term substantial equivalent refers to an invention, product, or process that, despite having some differences in its appearance, name, or specific construction, performs essentially the same job, in fundamentally the same manner, to achieve the identical outcome as a patented invention.

This concept is crucial for determining patent infringement. It prevents someone from making minor, cosmetic changes to a patented invention and claiming it is a new, non-infringing product, when in reality, it operates in fundamentally the same way to achieve the same result.

• Example 1: A Retractable Dog Leash

  Imagine a patented retractable dog leash that uses a spring-loaded reel and a thumb-activated button to lock the leash at a desired length. A new company then introduces a leash that also features a spring-loaded reel but uses a slide-switch mechanism instead of a button for locking, and has a slightly different ergonomic grip.

  How it illustrates the term: Even though the new leash has a different locking mechanism (slide-switch vs. button) and a redesigned grip, it performs substantially the same function (controlling leash length), in substantially the same way (using a spring-loaded reel and a user-activated lock), to achieve the same result (safe and adjustable dog walking). A court might find this new leash to be a substantial equivalent of the patented invention, leading to a finding of infringement.

• Example 2: A Coffee Brewing Method

  Consider a patented method for brewing coffee that specifies pre-wetting the coffee grounds for 30 seconds before the main brewing cycle to enhance flavor extraction. A competitor then releases a new coffee maker that includes a "bloom" setting, which pre-wets the grounds for 25 seconds using a slightly different water dispersion pattern before initiating the full brew.

  How it illustrates the term: The competitor's "bloom" setting performs substantially the same function (pre-wetting grounds for flavor enhancement), in substantially the same way (brief initial water application before the main brew), to achieve the same result (improved coffee flavor). The minor differences in pre-wetting time or water dispersion might not be enough to avoid being considered a substantial equivalent of the patented method.

• Example 3: An Automatic Headlight Dimming System

  Suppose a car manufacturer holds a patent for an automatic headlight dimming system that uses a specific type of light sensor and a unique algorithm to detect oncoming vehicle lights and adjust the car's high beams accordingly. Another manufacturer develops a similar system for their new car model, employing a different brand of light sensor and a slightly modified algorithm, but it still detects oncoming lights and automatically dims the headlights.

  How it illustrates the term: The new system performs substantially the same function (automatic headlight dimming), in substantially the same way (sensing oncoming lights and adjusting brightness via an algorithm), to achieve the same result (improving night driving safety without blinding other drivers). Despite using different components or a slightly altered algorithm, it could be deemed a substantial equivalent to the patented system.