Fujitsu FES-300
Contents
Overview
FES-300 is, or was, Fujitsu’s short-travel leaf spring switch type. Its production status is unclear, because the datasheet for FKB3000 keypads gives FES-301S as the switch, putting at least some if not all current short-travel switches under FES-301.
FES-300 switches provide high force and low travel, and are designed to be placed under a membrane cover bearing the key legends, referred to as a “sheet keyboard” (シートーキーボード). Between the contact assembly (which is soldered to a printed circuit board) and the membrane cover, is a metal plate that holds all of the switch plungers.
Design
Switch contacts can be either gold or silver. In 1980, the contact points were said to be plated with a 1 µm layer of gold.
The structure of a FES-300–based keyboard is as follows:
Documentation
The material from the Fujitsu Scientific & Technical Journal and the Fujitsu journal is presented here by kind permission of Fujitsu. The Japanese material was originally obtained by 聖人 (Kiyoto) with whom this research was conducted.
- シートキーボード (Sheet Keyboard): 木下良平, 石沢正美, 佐々木哲治, 田島修太郎, 田中敏明 and 安達昌彦 (Ryohei Kinoshita, Masami Ishizawa, Tetsuji Sasaki, Syutaro Tajima, Toshiaki Tanaka and Masahiko Adachi), Fujitsu, vol. 30 no. 6 pp. 91–100, November 1979
- Development and Application of Mechanical Switches: Masami Ishizawa, Hideo Nabetami and Ryohei Kinoshita, Fujitsu Scientific & Technical Journal, vol. 16 no. 3 pp. 47–63, September 1980
- 富士通における部品とその技術一歴史と展望ー (Fujitsu Electric Components and Related Technology): 高橋 節 (Misao Takahashi), Fujitsu, vol. 36 no. 4 pp. 424–433, June 1985