抄録
The purpose of this paper is to examine the development of optical design technology of Japanese photographic lenses by analyzing some historical documents of optical designs, patent specifications and the correspondence between Ryozo Furukawa (an engineer of Nippon Kogaku K.K.) and Tatsuhiko Arakawa (an employee of Nippon Kogaku K.K.). The first Japanese photographic lens "Hexar " was developed by Hiroo Mouri of Rokuoh-sha with the assistance of Kogoro Yamada (an engineering officer of the Imperial Japanese Navy) in 1931. It was manufactured making use of Seidel's formulae and ray-tracing. Kakuya Sunayama (a designing manager of Nippon Kogaku K.K.) directed photographic lens technology in Nippon Kogaku K.K. from 1928 to 1937. Photographic lens technology is dual-use technology. In both cases, the demand by the military that needed aerial cameras advanced photographic lens technology. Later this outcome was transferred to civilian use. The military demanded high quality photographic lenses which met the high cost. Up until about 1935, private companies had sophisticated optical design technology and mass production facilities for photographic lenses. They also owned the data of the photographic lens designs and the technological accumulation of optical designing. It has become clear that the Japanese "original optical designs of photographic lenses " were established around 1938.
