PROGRAMMABLE MULTIPLE OUTPUT FORCE-SENSING KEYBOARD
 Inventor: Charles A. Sellers, Houston, Tex.
 Assignee: Compaq Computer Corporation,
 Appl. No.: 08/955,334  Filed: Oct. 21, 1997
 Int. CI.6 H03K 17/94; H03M 11/00
 U.S. CI 341/34; 341/22; 345/168;
 Field of Search 341/22, 34; 345/168;
400/480, 481; 340/825.31, 825.34
 References Cited
U.S. PATENT DOCUMENTS
5,675,329 10/1997 Barker et al 341/22
5,832,214 11/1998 Kikinis 380/25
Primary Examiner—Michael Horabik
Assistant Examiner—-Timothy Edwards, Jr.
Attorney, Agent, or Firm—Konneker & Smith, P.C.
Representatively using force sensing resistors as key switch elements, keys on a computer keyboard are each provided with pluralities of different keystroke output function signals which may be selectively varied in response to simply altering the user keystroke force imposed on the key. In addition to being provided with a default key force range/ output signal correlation, the keyboard may be programmed by the user to customize the key depression force ranges associated with selected different keystroke output signals. Representatively illustrated additional uses of this key force/ output signal correlation capability include a key forcebased typing correction mode and a combination character and key force sequence-based user password access system. To further expand the individual key functionality of the keyboard, a combination of sensed key depression force and duration is used to generate an additional keystroke output function signal for a given key.
37 Claims, 6 Drawing Sheets