If they are 6x15 Jupiter binoculars, they were introduced in 1948.
On returning to peacetime production Asahi Optical began to make lenses for many other Japanese camera manufacturers. At this time coating began to be applied to all lenses. In 1948 Asahi developed a range of miniature binoculars under the trade name ‘Jupiter’, these also incorporated coated optics which provide unparalleled clarity and contrast, putting them in the front line of technology at that time.
A Brief History of the Asahi Optical Co.