In the 1944 case Precision Instrument Manufacturing Co. et al. v. Automotive Maintenance Machinery Co., the U.S Supreme Court ruled in favor of Automotive Maintenance Machinery Company (AMMCO). The case revolved around a patent dispute where Precision Instrument Manufacturing Company had obtained patents that AMMCO claimed were procured through fraudulent means, including perjury and suppression of evidence during Patent Office proceedings. The court held that those who have engaged in inequitable conduct or fraud cannot seek enforcement of their patent rights from courts as it would be contrary to public policy and principles of equity, even if they are technically within their legal rights under patent law. This ruling established an important precedent known as "the doctrine of unclean hands," which states that a party seeking relief in equity must come with clean hands i.e., not having acted deceitfully or unfairly themselves.

In the dissenting opinion for Precision Instrument Manufacturing Co. et al. v. Automotive Maintenance Machinery Co., Justice Robert H. Jackson argued that the majority's decision to void a patent due to misconduct during its procurement could potentially discourage inventors from seeking patents and stifle innovation in general, as they might fear losing their rights over minor infractions or honest mistakes made during the application process. He also disagreed with the majority's view that courts should be able to use their equitable powers to punish such misconduct, arguing instead that this was a matter best left up to Congress and administrative agencies like the Patent Office, which are better equipped than courts of law to handle complex technical matters related to patent applications.