05212473 is referenced by 339 patents and cites 9 patents.

A membrane keyboard producing audible and tactile responses when individual character keys are depressed. To facilitate typing efficiency, the keyboard has membrane characters keys with different transverse heights and adjustable sensory responses.

Title
Membrane keyboard and method of using same
Application Number
7/658541
Publication Number
5212473
Application Date
February 21, 1991
Publication Date
May 18, 1993
Inventor
William M Louis
Encinitas
CA, US
Agent
William Patrict Waters
Jerry R Potts
Bernard L Kleinke
Assignee
TypeRight Keyboard
CA, US
IPC
G09G 3/02
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