This fact is in neuroscience and psychology text books. It has been well known for quite a while. That said, it&#x27;s true that others haven&#x27;t done this prior to f.lux coming out. From a business model perspective, they are making a utility that could have been bundled into the OS. It&#x27;s a small feature, not a whole business, unless they can gain exclusive use of their invention.<p>Whether this patent protection incentive was necessary for them to try to get their product out there in the marketplace is a harder question to answer. Certainly, they have chosen a business model that relies on getting the public familiar with the technology and then licensing it to manufacturers. It does seem to me that many fewer people would know about flux if they were charging for it initially, but it also doesn&#x27;t seem like a huge leap forward tech wise, though it may provide a lot of value. I&#x27;m kind of on the fence.<p>EDIT: I did a little digging. While I happened to have known about this fact for a long time, and am pretty sure it was in my textbooks as of around 2005 or 2006, it seems this may have been discovered around 2001. <a href="https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;11487664" rel="nofollow">https:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;11487664</a>