The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 1989
Filed:
Feb. 13, 1987
Harry W Kompanek, Santa Barbara, CA (US);
Rickey H Ming, Ventura, CA (US);
KDC Corporation, Carpinteria, CA (US);
Abstract
A housing is constructed to define individual areas for depression to identify individual indicia such as numbers or the letters of the alphabet. A hard, electrically insulating material is attached to the housing to transmit strains produced in the housing by the depression of the individual areas on the housing. A plurality of thin sheets of an electrically insulating material are provided, each being attached to the insulating material at positions corresponding to the individual areas in the housing. A plurality of thin sheets of an electrically conductive material are also provided, each attached to an associated one of the thin sheets of insulating material. A plurality of ceramic crystals are also included, each attached to an individual one of the electrically conductive sheets. The electrically conductive sheets may be attached to the housing, which is preferably made from an electrically conductive material. This causes one surface of each ceramic crystal to be common to the adjacent area. Each crystal becomes stressed when the keyboard is depressed in the adjacent area on the keyboard. When the crystal becomes stressed, it causes an electrical signal to be generated on the ungrounded surface of the crystal.