Technology transformation of the optical industry in Japan : Research and development of Japanese rangefinders (1913-1927)

Abstract

The Japanese optical industry started with the outbreak of World War One when the import of the optical weapons was suspended. The Imperial Japanese Navy made a decision to produce them domestically. The optical factory of the Naval Arsenal in Tsukiji succeeded in making an original rangefinder for preproduction purposes. In this paper, I would like to discuss the technology transformation process of the Japanese optical industry by verifying the technological progress of Japanese rangefinders. The database of the Industrial Property Digital Library is used. The early composition of the Japanese optical industry was the Naval Arsenal factory and two private companies closely associated with the government (i.e. Nippon Kogaku K.K. and Tokyo Gasu Denki K.K.). The new optical design technology (ray tracing method) was introduced to the Naval Arsenal by Kogoro Yamada from England independently from the German engineers whom Nippon Kogaku K.K. invited. However, due to the disarmament by the Washington Naval Treaty, the Naval Arsenal was closed and the optical factory of Tokyo Gasu Denki K.K. was also shut down despite its high technological level. As a result rangefinder and optical glass manufacturing technology was transferred to Nippon Kogaku K.K. from the Naval Arsenal which became a single powerful optical company. It was made clear in this paper that the technological level of the Japanese optical industry was self-reliant by early the Showa era through close cooperation between military, industry and academic.