A very early Olympus "kangaroo" Style Box https://patents.google.com/patent/US4064374A/en?oq=US4064374A
Olympus Microcassette with a radio similar to the one I posted in the show your microcassette player thread. https://patents.google.com/patent/US4233686A/en?oq=US4064374A
Olympus was really working the add-on radio in the 70's, truly a pioneer in personal cassette players although they were microcassettes. https://patents.google.com/patent/US4119813A/en?oq=US4064374A
Panasonic Headphones with radio from late 60's https://patents.google.com/patent/US3906160A/en?oq=US4064374A
I know mono microcassettes don't get much love anywhere but some of the units are really cool and I know everyone thinks...why...oh why aren't they in stereo... Here's a General Electric Patent, I always thought they subcontracted out these electronics but they had a few patents. https://patents.google.com/patent/USD264332S/en?oq=USD264332S
Can anyone guess what model Olympus this is? https://patents.google.com/patent/US3521010A/en?oq=US3521010A
It looks like Olympus was looking into the auto market for the microcassettes. https://patents.google.com/patent/US4434444A/en?q=recorder&assignee=Olympus+Corp&page=2
For those wondering about a microcassette/minicassette deck, here it is. https://patents.google.com/patent/US4216509A/en?oq=US4216509A
Some more proof that Olympus was looking to get into automotive tape decks with microcassette. https://patents.google.com/patent/US3768814A/en?oq=US3768814A
The Apollo 12 Walkman https://airandspace.si.edu/collection-objects/recorder-audio-cassette-apollo-12
Pioneer Headphones for portable cassette player https://patents.google.com/patent/US4597469A/en?oq=US4597469A