In 1946,Dunmore Dunk and Zed Atlee jointly founded Dunlee. The title Dunlee is a separation of the names of the two founders, along with their respective resources and advantages. They successfully developed and manufactured radiographic imaging tubes and successfully entered the high-end CT tube market, which remains to this day.

In 1994,Dunlee's headquarters moved from Bellwood, Illinois, USA to Aurora, another city in Illinois, where a 162,000-square-foot design and manufacturing center was built.

In 1998,Dunlee was the first to explore the CT tube replacement market and produced the industry's first 1.0 MHU CT exchange tube, which was also a CT replacement tube.

In the past, the CT replacement tubes for immediate consumption once covered the products of major manufacturers such as GE, Philips, Siemens and Canon.

In 2001,Dunlee was acquired by Philips. Philips Healthcare's CT replacement tubes are a leader in the field of medical imaging, especially in X-ray tube technology. As early as 1895, Philips produced the first commercial X-ray tube. Subsequently, Philips achieved many technological accomplishments in the field of X-ray tubes. For instance, the liquid metal bearing technology it created in 1990 made X-ray tubes used in the cardiovascular field and CT equipment almost noiseless and would not fail due to the wear of traditional ball bearings.

After acquiring Dunlee, Philips Healthcare consumes more than 12,000 tubes annually.