Sony’s interest in electronic office equipment seems to have extended only as far as Japanese word processors, plus an extensive range of cassette recorders for dictation/transcription. Hardly a surprise, when you consider their flagship product, for many years, was the Sony Walkman.

The closest I came to unearthing a SONY electronic typewriter was an ad for a SONY Schreibrekorder (Typecorder – a micro-cassette dictating/transcribing machine that could be operated with a foot pedal while the secretary typed) in an April 1982 edition of Der Speigel and other advertising in the USA and Canada in 1982 and 1983.

Dubbed a “keystroke capture device” the Typecorder unit was able to store text on a micro-cassette, or in its internal memory. For editing, the micro-cassette was inserted into a slot on the Series 35 keyboard and the recorded text then appeared on screen.
Text stored in the typewriter’s memory could be entered directly onto floppy disk.

National Post (Toronto, Ontario, Canada) · 16 July 1983

Sony co-founders Masura Ibuka (井深 大 ; 11 April 1908 – 19 December 1997) and Akio Morita (盛田 昭夫 , January 26, 1921 – October 3, 1999) built Japan’s first tape recorder after founding Tokyo Tsushin Kogyo K.K  (Tokyo Communications Industry Company) in 1946. They adopted the western sounding name Sony Corporation in 1958 following the international commercial success of their transistor radios.

Technologically, Sony had good ties with Sanyo.

Sanyo made the mistake of backing Sony’s Betamax video format during the 1980s, and then made the same mistake twice (in a way) by backing Toshiba’s HD DVD format rather than Sony’s ultimately victorious Blu-ray format.