NOS 4" b&w from Ali Express

[jhalphen]

Hi to all,

The Chinese 4" flat CRT type 04MC has a TOSHO "made in China" label, see photo.
The Sony 4" WatchMan model FD-40A has a 4" CRT designated as 04JM, see extract from schematic.

Questions:
- does TOSHO manufacture in China using a Sony licence?
- unlicenced clone?

Unless the Sony patents have already run out, i don't see Sony sitting back doing nothing if someone stole their design.
From memory, WatchMans appeared circa 1983, so +20 years forward the patents have indeed expired.

Best Regards
jhalphen
Paris/France