The Incandescent Lamp Patent case in 1895 was a significant patent dispute involving Thomas Edison and the United States Electric Lighting Company. The issue at hand was whether Edison's patent for an incandescent lamp, which he had been granted in 1880, was valid or not. The US Supreme Court ruled that it indeed was. They found that while others may have previously invented similar lamps, none of them were practical or efficient enough to be considered as prior art against Edison's invention. This ruling established the principle that even if an invention is not entirely new, its improved functionality can make it eligible for a patent if it offers distinct advantages over previous versions of the same product.

In the dissenting opinion for The Incandescent Lamp Patent case, it was argued that Edison's patent should be upheld. It was contended that his invention of a practical incandescent lamp represented a significant advancement in technology and thus deserved protection under patent law. The dissenting justices believed that while others may have conceived similar ideas before Edison, he was the first to successfully implement them into a functional product. They also disagreed with the majority's interpretation of "prior art," arguing instead that previous attempts at creating an incandescent lamp were not sufficiently similar to invalidate Edison’s claim to originality. Furthermore, they asserted that even if some elements of his design had been previously known or used, this did not diminish from the novelty and utility of his overall invention which combined these elements in an innovative way.