Keyboard Membrane Structure for Shift Keys
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
This article describes the keyboard membrane for typewriter and PC products modified to eliminate the "beat the shift" problem. In one aspect of this problem, the typing keys as well as the shift keys are tied into a matrix of drive lines and sense lines, and this matrix is periodically scanned to see which keys are activated, and at some time during the scan the shift key activation is scanned. This latter scanning may come before or after the scanning of the condition of the activation of the character key. In the case of a very rapid typist, this typist may have released the shift key after striking the character key, but before the condition of the shift key has been sensed. This will cause the wrong character mode (cap or non-cap) to be typed.