Dynabook Inc. (Dynabook株式会社, Dainabukku Kabushiki-gaisha), formerly Toshiba Client Solutions Co., Ltd., is a Japanese personal computer manufacturer owned by Sharp Corporation; it was owned by, and branded as, Toshiba from 1958 to 2018. It claims its Toshiba T1100, launched in 1985, as the first mass-market laptop PC. Toshiba had used the brand name "DynaBook" or "dynabook" since 1989, but Dynabook became the worldwide brand in 2019.