Legal Definitions - nonliteral infringement

Nonliteral infringement occurs in patent law when an accused product or process does not precisely match every single word or element described in a patent claim, but is nevertheless considered to infringe because it is "equivalent" to the patented invention. This concept, often referred to as the Doctrine of Equivalents, prevents others from making minor, insubstantial changes to a patented invention to avoid infringement, while still capturing the essence and benefit of the original invention.

For an accused device or method to be found to infringe nonliterally, it must perform substantially the same function, in substantially the same way, to achieve substantially the same result as the patented invention.

• Example 1: Mechanical Design Variation

  Imagine a patent exists for a unique type of garden hose nozzle that uses a "lever-activated valve" to control water flow. A competitor then releases a very similar nozzle that uses a "push-button mechanism" to control the water flow. Both mechanisms achieve the same function (controlling water flow), in a substantially similar way (a user-operated mechanical interface), to achieve the same result (convenient water dispensing).

  Even though the competitor's nozzle does not literally use a "lever-activated valve," a court might find nonliteral infringement because the push-button mechanism is considered an equivalent means of achieving the same functional outcome, representing an insubstantial change from the patented invention.

• Example 2: Chemical Composition Substitute

  Consider a patent for a specialized adhesive that claims the use of "silicon dioxide particles" as a strengthening agent. A rival company develops an adhesive with an identical formula, but instead uses "titanium dioxide particles" as the strengthening agent. Both silicon dioxide and titanium dioxide are known in the industry to serve similar functions as strengthening fillers in adhesives, and the rival's product achieves the same adhesive strength and durability.

  Despite the literal difference in the specific chemical compound, a court could determine that the use of titanium dioxide particles constitutes nonliteral infringement because it performs substantially the same strengthening function, in substantially the same way, to achieve substantially the same result as the patented invention.

• Example 3: Software Method Adaptation

  Suppose a patent protects a method for organizing digital photos by automatically tagging them based on "facial recognition of individuals in the image." A competitor develops a photo organization software that uses an identical process but tags photos based on "object recognition of prominent landmarks or pets in the image." Both methods perform the function of automatically categorizing photos, in a substantially similar way (using AI to identify elements within the image), to achieve the same result (easier photo retrieval and organization).

  While the patent specifies "facial recognition," the competitor's use of "object recognition" for landmarks or pets could be deemed a nonliteral infringement. The core inventive concept of automatic AI-driven tagging is present, and the specific type of recognition is an equivalent variation that does not fundamentally alter the patented method.