|Company name||OHYO KOKEN KOGYO Co., Ltd.|
|Number of employees||66(as of November 2017)|
|*Head office (Factory)||1642- 26 Kumagawa Fussa-city Tokyo 197-0003 Japan|
|*Higashimatuyama Factory||88-77 Shingo Higashimatsuyama-city Saitama 355-0071 Japan|
|*Osaka sales office||4-4-63 Miyahara Yodogawa-ku Osaka-city 532-0003 Japan|
|*Kyushu works||293 Hondosumachi Tosu-city Saga 841-0026 Japan|
| * September 1963
|| Established OHYO KOKEN KOGYO Co., Ltd.
It was established at Shinjuku-ku Tokyo, succeeding the
production of optical materials and radiation detecting
materials, which were developed by optical laboratory of
Tokyo University of Education.
|| Established manufacturing know-how of large-scale radiation
|| Merged radiation instruments division of Tokyo Genshi Kogyo Co.,Ltd.
Started to supply radiation measuring instruments
|| Moved crystal manufacturing division to Higashimatuyama
city in Saitama-pref.
|| Moved head office and radiation instruments division
to Fussa city in Tokyo
|| Enlarged Higashimatuyama Factory
|| Opened Osaka sales office near Shin-Osaka Station
|| Opened Kyushu Works at Tosu-city in Saga-pref.
|| Rebuilt Head office
|| Built second crystal factory at Kodama in Saitama-pref.
|| Expanded crystal manufacturing line at Higashimatuyama factory
|| Constructed new Kyusyu works
|| 50th anniversary of company foundation
Annual sales JPY1,540,000,000