Early Color Television
The CFT Grid Type Color CRT
The following is from Jerome Halphen:
I found a copy of the May 1967 issue of the French
electronics magazine "Le Haut-Parleur" (the Loudspeaker)
which for 7 decades was the authoritative publication in
this field - sort of a French "Wireless World" (UK
I am sending you a scan of the article covering the description of the color grid tube developed by the CFT (Compagnie Française de Television) Henri de France's research lab. Actual manufacture was accomplished by Thomson.
This 19" tube had purity problems: the unsupported grid wires were not rigid enough and vibrated because of the deflection magnetic fields, thus degrading color purity. Lack of money and time prevented the CFT to perfect the design and industrial production never happened.
Apparently the patents were sold to Sony, and along with the other patents they purchased from Paramount - Chromatic Laboratories, formed the foundation upon which the Trinitron tube was developed.