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,[1] TI Asahi for surveying instruments, and Seiko Optical Products for certain optical lenses.

The company was founded as Asahi Kogaku Goshi Kaisha in November 1919 by Kumao Kajiwara, at a shop in the Toshima suburb of Tokyo, and began producing spectacle lenses (which it still manufactures).