Piezoelectric vibrational and acoustic alert for a personal communication device

US6259188A · kind A · utility

Assignee

• Projects, Ltd. · IL

Inventors

• Stanley E. Woodard · Hampton, US
• Richard F. Hellbaum · Hampton, US
• Robert H. Daugherty · Yorktown, US
• Raymond Scholz · Gloucester Courthouse, US
• Bruce D. Little · Hampton, US
• Robert L. Fox · Hayes, US
• Gerald A. Denhardt · Dayton, US
• SeGon Jang · Dayton, US
• Rizza Balein · Dayton, US

Key dates

• Filing date: Aug 31, 1999
• Grant date: Jul 10, 2001
• Expiry date: Aug 31, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G08B6/00
• WIPO field: Control
• WIPO sector: Instruments

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.