- June 1951
Seiko Electric Industries Co., Ltd. (present Sekonic Co., Ltd.) is established. The first product of Sekonic-brand exposure meter, Sekonic P-1, is marketed.
- June 1959
- Tokyo Plant is completed for production of exposure meters for photographic use (site of present headquarters).
- December 1959
The Hachiyou optical industry Ikeda Factory Co., Ltd. (Ikeda, Ikeda-cho, kita-azumi-gun, Nagano prefecture) is opened for the manufacture of exposure meters.
- August 1960
- Company name is changed to Sekonic Co., Ltd.
- August 1961
Tokyo Plant is authorized as JIS Designated Factory for "electric exposure meters for photographic use".
- May 1963
- Sekonic stocks are listed on the Second Section of Tokyo Stock Exchange.
- November 1965
Current Ikeda Factory (Kaizome, Ikeda-cho, Nagano prefecture) opened as manufacturing factory for exposure meters, etc.
- May 1971
- Fukushima Sekonic Corporation established as subsidiary.
- May 1971
Consignment manufacture of Konica's copiers 「U-Bix」is begun.
- October 1974
- Manufacture and sales of Sekonic Industrial Recorders are begun.
- April 1976
Consignment manufacture is begun for the option units of Konica's dry type electronic copiers.
- April 1983
- Manufacture and sales of Optical Mark Readers (OMR) are begun.
- February 1984
Sekonic Digipro X-1, L-518, is taken into space on NASA Space Shuttle.
- October 1992
- Manufacture and sales of electronic hygrothermographs are begun.
- January 1993
Overall manufacture of the Tokyo Plant transferred to the Ikeda Factory.
- March 1993
- Consignment manufacture of strobe boards for films with lenses.
- April 1993
Manufacture and sales of Optical Character Readers (OCR) are begun.
- October 1998
- Consignment manufacture of Digital Automatic Processors.
- March 1999
Consignment manufacture of printing devices (ink-jet printers).
- April 2000
- Enforcing the business collaboration with Konica Corporation, complete consignment of national manufacture for copiers' bodies.
The Ikeda Factory name is changed to Azumino Factory.
The Hachioji Tokyo Business Office of Konica Corporation is inaugurated as our company's Hachioji Office for the manufacture line of copiers' bodies.