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.