Daiwa Kogyo Ltd.
Suwa, Nagano (1942)

Shinshu Seiki Co. (subsidiary, 1961)

Epson Corporation (1982)

Seiko Epson Corporation (1985)

Excerpts from Wikipedia:

The roots of Seiko Epson Corporation go back to a company called Daiwa Kogyo, Ltd. which was founded in May 1942 by Hisao Yamazaki, a local clock shop owner and former employee of K. Hattori, in Suwa, Nagano, Japan. Daiwa Kogyo was supported by an investment from the Hattori family (founder of the Seiko Group) and began as a manufacturer of watch parts for Daini Seikosha (currently Seiko Instruments). The company started operation in a 2,500-square-foot (230 sqm) renovated miso storehouse with 22 employees.

In 1943, Daini Seikosha established a factory in Suwa for manufacturing Seiko watches with Daiwa Kogyo. In 1959, the Suwa Factory of Daini Seikosha was split up and merged into Daiwa Kogyo to form Suwa Seikosha Co., Ltd., the forerunner of the Seiko Epson Corporation.

In 1961, Suwa Seikosha established a company called Shinshu Seiki Co. as a subsidiary to supply precision parts for Seiko watches. When the Seiko Group was selected to be the official time keeper for the 1964 Summer Olympics in Tokyo, a printing timer was required to time events, and Shinshu Seiki started developing an electronic printer.

In September 1968, Shinshu Seiki launched the world's first mini-printer, the EP-101 ("EP" for Electronic Printer), which was soon incorporated into many calculators. In June 1975, the name Epson was coined for the next generation of printers based on the EP-101 which was released to the public.

In July 1982, Shinshu Seiki officially named itself the Epson Corporation and launched the world's first handheld computer, HX-20 (HC-20), and in May 1983 the world's first portable color LCD TV was developed and launched by the company.

In November 1985, Suwa Seikosha Co., Ltd. and the Epson Corporation merged to form Seiko Epson Corporation.