Legal Definitions - blocking patent

A blocking patent refers to an existing patent that prevents another party from manufacturing, using, or selling a newer, related invention, even if that newer invention is also patented. This situation arises when the newer invention necessarily incorporates or relies upon technology or methods protected by the earlier, foundational patent. To legally implement the newer invention, a license from the holder of the blocking patent is typically required.

Here are some examples to illustrate this concept:

• Example 1: Software Algorithm

  Imagine Company A holds a patent for a groundbreaking algorithm that significantly improves the efficiency of data encryption. Later, Company B develops an innovative secure messaging application that uses Company A's patented encryption algorithm as a core component to ensure its high level of security. Company B also patents its new messaging application. In this scenario, Company A's patent on the encryption algorithm is a blocking patent. Even though Company B has its own patent on the messaging application, Company B cannot legally sell or distribute its application without obtaining a license from Company A, because the application relies directly on Company A's patented technology.

• Example 2: Pharmaceutical Compound

  Consider a pharmaceutical company, PharmaCorp, which holds a patent for a novel chemical compound that effectively targets a specific type of cancer cell. Years later, a research startup, BioInnovate, discovers a new method of delivering this exact compound to the cancer cells with fewer side effects, and patents their innovative delivery system. PharmaCorp's patent on the original chemical compound acts as a blocking patent. BioInnovate cannot produce or sell its improved drug delivery system, which incorporates PharmaCorp's patented compound, without first securing a license from PharmaCorp.

• Example 3: Advanced Material

  Suppose a materials science firm, DuraTech, patents a unique, super-strong, and lightweight alloy. Subsequently, an aerospace company, SkyWings, invents and patents a revolutionary aircraft wing design that specifically utilizes DuraTech's patented alloy to achieve unprecedented fuel efficiency and structural integrity. DuraTech's patent on the alloy is a blocking patent. SkyWings cannot manufacture or sell aircraft with its patented wing design using DuraTech's alloy without obtaining a license from DuraTech, as the core functionality of their invention depends on the use of the patented material.