Color Television

100 Most television researchers respected the value of color image transmission, with an early patent application in Russia in 1889 for a mechanically-scanned color system showing how early the import of color was realized. John Logie Baird established the world's first color transmission on July 3, 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with filters of a different primary color; and three light sources at the receiving end, with a commentator to exchange their illumination.

Color television in the United States had a prolonged history due to incompatible technical systems vying for approval by the Federal Communications Commission for commercial use. Mechanically scanned color television was established by Bell Laboratories in June 1929 using three complete systems of photoelectric cells, amplifiers, glow-tubes, and color filters, with a series of mirrors to place over the red, green, and blue images into one full color image.

In the electronically scanned era, the first color television exhibition was on February 5, 1940, when RCA privately showed to members of the FCC at the RCA plant in Camden, New Jersey, a television receiver producing images in color by electronic and optical means without moving device. CBS began non-broadcast color experiments using film as early as August 28, 1940, and live cameras by November 12. The CBS "field sequential" color system was partly mechanical, with a disc made of red, blue, and green filters revolving inside the television camera at 1,200 rpm, and a similar disc spinning in synchronization in front of the cathode ray tube inside the receiver set. The RCA "dot sequential" color system had no moving parts, using a series of diachronic mirrors to separate and direct red, green, and blue light from the subject through three separate lenses into three scanning tubes, and electronic switching that allowed the tubes to send their signals in rotation, dot by dot. These signals were sorted by a second switching device in the receiver set and sent to red, green, and blue picture tubes, and combined by a second set of diachronic mirrors into a full color image.