On 7 May 1946, after the end of World War II, Masaru Ibuka started a radio repair shop in a bomb-damaged Shirokiya department store building in the Nihonbashi district of Tokyo. The next year, he was joined by his colleague, Akio Morita, and they founded a company called Tokyo Tsushin Kogyo[1] (Tokyo Telecommunications Engineering Corporation). The company built Japan's first tape recorder, called the Type-G.[1] In the early 1950s, Ibuka traveled in the United States and heard about Bell Labs' invention of the transistor.[1] He convinced Bell to license the transistor technology to his Japanese company. While most American companies were researching the transistor for its military applications, Ibuka and Morita looked to apply it to communications. Although the American companies Regency Electronics and Texas Instruments built the first transistor radio as joint venture, it was Ibuka's company that made them commercially successful for the first time.

In August 1955, Tokyo Tsushin Kogyo released the Sony MK-55, Japan's first commercially produced transistor radio.[3] They followed up in December of the same year by releasing the Sony TR-72, a product that won favor both within Japan and in export markets, including Canada, Australia, the Netherlands and Germany. Featuring six transistors, push-pull output and greatly improved sound quality, the TR-72 continued to be a popular seller into the early sixties.

In May 1956, the company released the TR-6, which featured an innovative slim design and sound quality capable of rivaling portable tube radios. The following year, 1957, Tokyo Tsushin Kogyo came out with the TR-63 model, then the smallest (112 × 71 × 32 mm) transistor radio in commercial production. It was a worldwide commercial success.[1]

University of Arizona professor Michael Brian Schiffer, PhD, says, "Sony was not first, but its transistor radio was