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:
Jul. 10, 2001
Filed:
Aug. 31, 1999
Stanley E. Woodard, Hampton, VA (US);
Richard F. Hellbaum, Hampton, VA (US);
Robert H. Daugherty, Yorktown, VA (US);
Raymond C. Scholz, Gloucester, VA (US);
Bruce D. Little, Yorktown, VA (US);
Robert L. Fox, Gloucester, VA (US);
Gerald A. Denhardt, Dayton, OH (US);
SeGon Jang, Dayton, OH (US);
Rizza Balein, Dayton, OH (US);
Projects Unlimited, Inc., Dayton, OH (US);
Abstract
An alert apparatus for a personal communication device includes a mechanically prestressed piezoelectric wafer positioned within the personal communication device and an alternating voltage input line coupled at two points of the wafer where polarity is recognized. The alert apparatus also includes a variable frequency device coupled to the alternating voltage input line, operative to switch the alternating voltage on the alternating voltage input line at least between an alternating voltage having a first frequency and an alternating voltage having a second frequency. The first frequency is preferably sufficiently high so as to cause the wafer to vibrate at a resulting frequency that produces a sound perceptible by a human ear, and the second frequency is preferably sufficiently low so as to cause the wafer to vibrate at a resulting frequency that produces a vibration readily felt by a holder of the personal communication device.