Pentax is a brand name used primarily by Ricoh Imaging Company for cameras, sport optics (including binoculars and rifle scopes), and CCTV optics. The brand is also used by Hoya Corporation for medical products & services.
"Pentax" was originally a registered trade-name of East German Zeiss - annulled with the defeat of Germany at the end of WWII and taken by the Asahi Optical company in 1957 for its first 35mm camera. The company was primarily known for its photographic products, distributed under the name "Asahi Pentax". Pentax merged with with Hoya Corporation to form "Hoya Pentax HD Corporation" in 2006. On 1 Oct 2011, Ricoh acquired all the shares and on August 1, 2013, the company name was changed to "Ricoh Imaging Company Ltd".