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 this ad for a SONY Schreibrekorder (a micro-cassette dictating/transcribing machine that could be operated with a foot pedal while the secretary typed) as advertised in an April 1982 edition of Der Speigel:
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.