WO2000001131A2

WO2000001131A2 - Piezoelectric vibrational and acoustic personal communication device

Info

Publication number: WO2000001131A2
Application number: PCT/US1999/014469
Authority: WO
Inventors: Gerald A. Denhardt; Segon Jang; Rizza Balein
Original assignee: Projects Unlimited, Inc.
Priority date: 1998-06-26
Filing date: 1999-06-25
Publication date: 2000-01-06
Also published as: WO2000001131A3; WO2000001131A9; AU5206299A

Abstract

An alert apparatus for a personal communication device that includes a piezoelectric wafer (28) positioned within the personal communication device; an alternating current input line (42) coupled at the two sides of the wafer (28) where polarity is recognized; and a switch (40) coupled to the alternating current input line (42), operative to switch the alternating current on the alternating current input line (42) at least between an alternating current having a first frequency and an alternating current having a second frequency. The first frequency is sufficiently high so as to cause the wafer (28) to vibrate at a resulting frequency that produces a sound perceptible by a human ear, and the second frequency is sufficiently low so as to cause the wafer (28) to vibrate at a resulting frequency that produces a vibration readily felt by a holder of the personal communication device.

Description

PIEZOELECTRIC VIBRATIONAL AND ACOUSTIC ALERT FOR A PERSONAL COMMUNICATION DEVICE

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 from Provisional Application Ser. No. 60/090,881 filed June 26, 1998, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

The present invention relates to personal communication devices, and more particularly, to a vibrational and/or acoustic transducer for use with personal communication devices.

Vibrating alarms for use with personal communication devices are well known in the art. Many of these alarms comprise conventional motors having an eccentric weight attached to the rotor shaft. Accordingly, when the motor is activated, the rotation of the rotor shaft and corresponding rotation of the eccentric weight causes vibration within the personal communication device that is detected by the holder of the device. Typically, such vibrating alarms are not capable of also producing an acoustic alert signal; or if the vibrating alarm is capable of producing an acoustic alert signal, the design of the combination vibrating/acoustic alarm is complicated — rendering it not feasible for inexpensive mass production.

Accordingly, a need exists for a combination vibrating and acoustical alarm mechanism that has a relatively uncomplicated design, is relatively inexpensive to produce, that is substantially durable and is suited (relatively light-weight and small) to be incorporated into a hand-held communication device. SUMMARY

One aspect of the present invention is to provide an alert apparatus for a personal communication device that includes: a piezoelectric wafer positioned within the personal communication device; an alternating current input line coupled at the two sides of the wafer where polarity is recognized; and a switch coupled to the alternating current input line, operative to switch the alternating current on the alternating current input line at least between an alternating current having a first frequency and an alternating current having a second frequency. Where the first frequency is sufficiently high so as to cause the wafer to vibrate at a resulting frequency that produces a sound perceptible by a human ear, and where the second frequency is 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.

It is another aspect of the present invention to provide a personal communication device (such as a wireless telephone or pager) that includes: a housing; a receiver component, mounted within the housing, for receiving messages transmitted to the communications device; a processor, mounted within the housing, operatively coupled to the receiver component for processing messages received by the receiver component; and an alarm apparatus operatively coupled to the processor; where the alarm includes: a high frequency current supply; a low frequency current supply; a piezoelectric wafer positioned within the personal communication device, an alternating current input line coupled at the two sides of the wafer where polarity is recognized; and a switch coupled between the high frequency current supply, the low frequency current supply and the alternating current input line, operative to selectively couple the alternating current input line to at least the high frequency current supply or to the low frequency current supply. The frequency of the high frequency current supply is 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 frequency of the low frequency current supply is 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. Preferably, the frequency of the high frequency current supply is approximately 1200 to 6000 Hz and the frequency of the low frequency current supply is less than approximately 300 Hz. It is also preferred that the personal communication device also includes a voltage amplifier operatively coupled to the alternating current input line to amplify the alternating current input to the wafer, producing an amplified voltage signal, where the amplified voltage signal is approximately 1.5 Volts to approximately 10 Volts.

It is also preferred that the wafer be clamped to the housing of the personal communication device at one or both ends of the wafer or the that the wafer be held within a guid mounted within the housing, where the wafer is not attached to the guide or to the housing.

Accordingly, it is an object of the present invention to provide a combination vibrating and acoustical alarm mechanism that has a relatively uncomplicated design, is relatively inexpensive to produce, that is substantially durable and is suited (relatively lightweight and small) to be incorporated into a hand-held communication device. These and other objects and advantages of the present invention will be apparent from the following description, the appended claims and the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic, block diagram representation of a personal communication device incorporating the transducer of the present invention;

Fig. 2 is a schematic, elevational view of a first embodiment of the transducer device of the present invention;

Fig. 3 is a elevational view of a second embodiment of a transducer of the present invention; and

Fig. 4 is a elevational, cross sectional view of a third embodiment of a transducer of the present invention.

DETAILED DESCRIPTION

As shown in Fig. 1 , a cellular telephone, pager or other typical personal communication device typically includes a central processor 10 such as a micro-processor, micro-controller or other similar processing device; a receiver 22 such as an RF antenna, a infra-red sensor or other related reception device; an output device 24 such as an LCD or LED display component and/or an ear-piece component; and a power supply 26, such as a battery, a solar cell, or any other known means for providing power to the various components of the personal communication device. Such components are known to those of ordinary skill in the art and will therefore not be discussed in significant detail herein. Generally, the processor tends to receive information transmitted to the personal communication device from the receiver 22 and relays that information to the user of the personal communication device by controlling the output device 24. The personal communication device will also include a transducer 28 of the present invention for alerting a user of the device of an incoming message, for example. As will be described in detail below, the transducer is preferably adapted to provide both vibrational and/or acoustic alerts to the user. Accordingly, the processor includes an acoustic signal output 30 and a vibrational signal output 32. The acoustic signal output transmits an alternating voltage signal at a frequency of approximately 1200 to approximately 6000 Hz; while the vibrational signal output 32 transmits an alternating voltage signal at approximately 300 Hz or less.

The transducer 28 is preferably a piezoelectric wafer 44 (see Figs. 2-4) formed substantially according to the process described in U.S. Patent 5,632,841 to Hellbaum, et al., the disclosure of which is incorporated herein by reference. It has been found that upon applying an alternating input voltage having a frequency of approximately 1200 to 6000 Hz to the wafer 44, at two sides of the wafer where polarity is recognized, causes the wafer to vibrate at a resulting frequency to produce a sound which is perceptible by the human ear. It has also been found that upon applying an alternating voltage at a low frequency of approximately 300 Hz or less, to the wafer 44 produces a readily perceptible vibration for the transducer 28 which will be perceived by the holder of the personal communication device. The voltage level needed for such a device depends upon the thickness of the ceramic material and preferably ranges from VA to 10 volts, although voltages of up to approximately 300 volts may be used.

Accordingly, the personal communication device also includes a voltage amplifier 34 for amplifying the voltage from the power supply 26 into an amplified voltage signal 36. These amplified voltage signals 36 are provided to signal combiners 38 which respectively combine the amplified voltage signals 36 with the acoustic output signal 30 or the vibrational output signal 32. The personal communication device also includes a switch which may be controlled mechanically or electronically by the user. This switch switches the input 42 into the transducer 28 between the amplified acoustic output voltage 44 or the amplified vibrational output signal 46. The switch 40 can be controlled manually by a user or may be controlled by the processor 10.

As shown in Fig. 2, a first embodiment of the transducer 28 includes the piezoelectric wafer 44 retained on or to the housing 46 of the personal communication device by a single clamp 48 which is positioned at a far end of the wafer 44. Preferably the wafer is a planar wafer being substantially rectangularly shaped. However, as will be appreciated by those of ordinary skill in the art, the wafer can take many shapes such as a circular shape.

As shown in Fig. 3, a second embodiment of the transducer 28' includes the piezoelectric wafer retained to the housing 46 of the personal communication device by a pair of clamps 50, positioned on opposite ends of the wafer 44. While the embodiment shown in Fig. 3 will be retained to the housing 46 of the personal communication device more securely than the embodiment shown in Fig. 2, the deflection caused by the reception of the input signal 42 will be much greater than in the embodiment in Fig. 2 as opposed to the embodiment as shown in Fig. 3.

As shown in Fig. 4, a second embodiment of the transducer 28" includes a guide or box 52 mounted to the housing 46 of the personal communication device. The wafer 44 resides within the guide 52, but is not attached to the guide 52 or the housing 46. Accordingly, when power is applied to the wafer 44, it will vibrate freely within the guide 52.

Based upon the above, it will be apparent to those of ordinary skill in the art that many different means for mounting the wafer 44 within the personal communication device are available. The more securely the wafer is mounted, the lower the deflection of the wafer will occur when power is provided by the input signal 42. It is also within the scope of the invention to attach a diaphragm to the wafer 44 so as to provide a more distinct acoustic signal. Likewise, it is within the scope of the invention to attach a weight to the wafer 44 to obtain a more readily perceived vibrational signal from the transducer.

Following from the above description, it should be apparent to those of ordinary skill in the art that, while the designs and operations herein described constitutes several embodiments of the present invention, it is to be understood that the invention is not limited to these precise designs and operations, and that changes may be made therein without departing from the scope of the invention. What is claimed is:

Claims

1. An alert apparatus for a personal communication device comprising: a piezoelectric wafer adapted to be positioned within the personal communication device, the wafer having two sides where polarity is recognized; an alternating current input line coupled at the two sides of the wafer where polarity is recognized; and a switch coupled to the alternating current input line, operative to switch the alternating current on the alternating current input line at least between an alternating current having a first frequency and an alternating current having a second frequency; wherein the first frequency is 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 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.

2. The alert apparatus of claim 1, wherein the first frequency is approximately 1200 to 6000 Hz and the second frequency is less than approximately 300 Hz.

3. The alert apparatus of claim 1, further comprising a voltage amplifier operatively coupled to the alternating current input line to amplify the alternating current input to the wafer to produce an amplified voltage signal.

4. The alert apparatus of claim 3, wherein the amplified voltage signal is approximately 1.5 Volts to approximately 10 Volts.

5. The alert apparatus of claim 1 further comprising a clamp, positioned at an end of the wafer, adapted to couple the wafer to a housing of the personal communication device.

6. The alert apparatus of claim 5 further comprising a second clamp position at an opposite end of the wafer, adapted to further couple the wafer to the housing of the personal communication device.

7. The alert apparatus of claim 5 further comprising a weight attached to the wafer.

8. The alert apparatus of claim 5 further comprising a diaphragm attached to the wafer.

9. The alert apparatus of claim 1 further comprising a guide adapted to be mounted within a housing of the personal communication device, wherein the guide is adapted to retain the wafer to a particular area of the personal communication device, and wherein the wafer is not coupled to the guide or to the housing of the personal communication device.

10. A personal communication device comprising: a housing; a receiver component, mounted within the housing, for receiving messages transmitted to the communications device; a processor, mounted within the housing, operatively coupled to the receiver component for processing messages received by the receiver component; and an alarm apparatus operatively coupled to the processor, the alarm including: a high frequency current supply; a low frequency current supply; a piezoelectric wafer positioned within the personal communication device, the wafer having two sides where polarity is recognized; an alternating current input line coupled at the two sides of the wafer where polarity is recognized; and a switch coupled between the high frequency current supply, the low frequency current supply and the alternating current input line, operative to selectively couple the alternating current input line to at least the high frequency current supply or to the low frequency current supply; wherein the frequency of the high frequency current supply is 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 frequency of the low frequency current supply is 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.

11. The personal communication device of claim 10, wherein the frequency of the high frequency current supply is approximately 1200 to 6000 Hz and the frequency of the low frequency current supply is less than approximately 300 Hz.

12. The personal communication device of claim 10, further comprising a voltage amplifier operatively coupled to the alternating current input line to amplify the alternating current input to the wafer, producing an amplified voltage signal.

13. The personal communication device of claim 12, wherein the amplified voltage signal is approximately 1.5 Volts to approximately 10 Volts.

14. The personal communication device of claim 10 further comprising a clamp, positioned at an end of the wafer, coupling the wafer within the housing of the personal communication device.

15. The personal communication device of claim 14 further comprising a second clamp positioned at an opposite end of the wafer, further coupling the wafer to the housing of the personal communication device.

16. The personal communication device of claim 14 further comprising a weight attached to the wafer.

17. The personal communication device of claim 14 further comprising a diaphragm attached to the wafer.

18. The personal communication device of claim 10 further comprising a guide mounted within the housing of the personal communication device and enclosing the wafer and retaining the wafer to a particular area within the housing of the personal communication device, wherein the wafer is not coupled to the guide or to the housing of the personal communication device.

19. The personal communication device of claim 10, wherein the switch is manually operated.

20. The personal communication device of claim 10, wherein the switch is operated by the processor.

21. The personal communication device of claim 10, wherein both the high frequency current supply and the low frequency current supply are respective output lines from the processor.