Keyboard for portable microprocessor system

摘要

The keyboard has keys (16-18) in rows (13--15). The number of keys is smaller than the number of characters in a character set to be selected, especially alphabetic and/or numeric characters. The entire number of characters in the set can be selected by touching a single key or simultaneously touching a number of keys. All numbers and letters in the character set can be selected by touching an individual key or simultaneously touching two or three adjacent keys.