OKI produced the first Japan-made telephone in 1881, and now specializes not only in developing and manufacturing telecommunications equipment but also in information products and mechatronics products, such as automated teller machine (ATMs) and printers. OKI had a semiconductor business, which it spun off and sold to Rohm Company, Limited on October 1, 2008.
OKI Data, a subsidiary, which markets its products under the OKI brand, is focused on creating professional printed communications products, applications and services. OKI Data provides a wide range of devices, from printers, faxes and multi-functional products to business applications and consultancy services. Through its American business arm, OKI Data America markets the OKI proColour Series, a line of digital production printers designed specifically for the graphic arts and production market in North America to offer print solutions for colour-critical applications.