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Philo Farnsworth developed the flyback HV supply in the early 1930s and was issued a patent for it in 1936.
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Thank you for locating the specifics on the flyback supply. As I suspected, it was an American inventor who developed the system upon which circuit designs for television HV supplies are still based today. The fact that the 6L6-driven flyback HV supply of the Farnsworth (listed in the Sams index as Capehart) 610P, 651P & 661P was obviously a part of the original prewar schematic makes perfect sense given this information. The set's postwar modifications which were incorporated prior to its reaching the market in 1948 included a 13-channel tuner (suspiciously similar in its circuitry to that of RCA 630TS), replacement of the original AM sound channel with an FM circuit, horizontal AFC circuitry which was located on a separate chassis, and the aluminized-screen 10FP4 picture tube. Anyone who has access to Sams Set #95A will find the schematic for this model included in that packet. The almost-exclusive use of prewar octal tubes with the exceptions of the few miniature tubes in the tuner, video det, video amp, audio IF and horiz. AFC strongly suggest that set was a prewar prototype with some postwar modifications. It is also noteworthy that one of its two 8016 HV Rect. tubes appears to act as half of a doubler while also performing damping action in the output plate circuit. Although I am not certain of that, it does appear upon looking at the schematic that this is the case. I have not actually worked on this chassis and thus have not had the opportunity to analyze waveforms to confirm my suspicions. I suspect, however, that if a scope, a 100:1 HV probe and a 661P chassis were set up for analysis there would be some clipping of the plate pulse through the action of the 8016 diode which would tend to damp high-frequency oscillations during retrace, producing the smooth sawtooth current required for proper sweep. Having only an EE Tech degree, as opposed to a full EE degree, I can only speculate. Math studies for my degree ended with basic Calculus, so I lack in-depth understanding of Laplace (sp), Fourier (sp), or Differential Equations. Basically, I was trained to be an assistant to engineers.