U.S. patent application number 13/018498 was filed with the patent office on 2011-05-26 for distributed mode speaker for mobile devices.
This patent application is currently assigned to Sony Ericsson Mobile Communications AB. Invention is credited to William Chris Eaton.
Application Number | 20110123051 13/018498 |
Document ID | / |
Family ID | 39828055 |
Filed Date | 2011-05-26 |
United States Patent
Application |
20110123051 |
Kind Code |
A1 |
Eaton; William Chris |
May 26, 2011 |
Distributed Mode Speaker for Mobile Devices
Abstract
A mobile communication device includes first and second housing
sections movably connected so as to move relative to one another
between open and closed positions. The first and second housing
sections each include protected surfaces that overlap when the
first and second housing sections are in the open position. A
distributed mode speaker is disposed on one of the protected
surfaces to protect the distributed mode speaker from damage.
Inventors: |
Eaton; William Chris; (Cary,
NC) |
Assignee: |
Sony Ericsson Mobile Communications
AB
Lund
SE
|
Family ID: |
39828055 |
Appl. No.: |
13/018498 |
Filed: |
February 1, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11774103 |
Jul 6, 2007 |
|
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13018498 |
|
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Current U.S.
Class: |
381/162 |
Current CPC
Class: |
H04M 1/03 20130101; H04R
7/045 20130101; H04M 1/0237 20130101; H04M 1/0227 20130101 |
Class at
Publication: |
381/162 |
International
Class: |
H04R 25/00 20060101
H04R025/00 |
Claims
1. A mobile communication device comprising: a housing; and a
distributed mode speaker disposed on said housing, said distributed
mode speaker including a speaker panel, a mode transducer to
generate bending waves in said speaker panel to generate audible
sounds, and a vibration transducer to vibrate said speaker panel to
generate a tactile alarm.
2. The mobile communication device of claim 1 wherein the vibration
transducer is further actuated at low frequencies to reproduce low
frequency sounds.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of patent application Ser.
No. 11/774,103 filed Jul. 6, 2007, which is incorporated herein by
reference.
BACKGROUND
[0002] The present invention relates generally to speakers for
mobile communication devices, and more particularly to distributed
mode speakers for mobile communication devices.
[0003] Distributed-mode loudspeakers (DMLs) are a type of
loudspeaker known in the art, and were developed by New Transducers
Limited (NXT.RTM.). DMLs comprise a thin but stiff speaker panel
excited by a transducer. Like conventional pistonic loudspeakers,
DMLs convert electrical audio signals to audible sounds that can be
heard by a user. However, a fundamental difference between pistonic
speakers and DMLs is in the way that DMLs generate and radiate
sound energy. In DMLs, audio signals drive the transducer to excite
the natural resonant modal structure of the panel. This excitation
vibrates the panel in a pseudo-random manner such that different
areas of the panel are independently excited with different
amplitudes and phases. In other words, the DML panel actually
"bends" according to the various frequencies of the vibration.
These "bending waves" produce wideband acoustical output over a
wide range of frequencies. DMLs eliminate the need for bulky
enclosures, multiple drivers, crossovers, and other parts that are
necessary in conventional pistonic speaker designs. These
attributes make DMLs an attractive choice for use as a speaker in
many consumer electronics devices.
[0004] Despite their advantages, DMLs have not gained widespread
acceptance for use in mobile devices. One drawback is the DML's
lack of robustness. DMLs require a relatively large area that makes
them more susceptible to damage than other speaker designs.
Speakers for mobile devices should be expected to withstand a
certain amount of impact or shock when the mobile devices are
dropped or hit against another object. Accordingly, there is a need
for a more robust design for distributed mode speakers for use in
mobile devices.
SUMMARY
[0005] The present invention comprises a mobile communication
device including a distributed mode speaker. In one exemplary
embodiment, the mobile communication device comprises first and
second housing sections that move (e.g. slide or pivot) relative to
one another between open and closed positions. In the open
position, the first and second housing sections partially overlap
to form protected surfaces that are not exposed in the open
position. One of the protected surfaces is on the obverse side of
the first housing section and one protected surface is on the
reverse side of the second housing section. A distributed mode
speaker is located on the protected surface of one of the first and
second housing sections.
[0006] In another exemplary embodiment, a distributed mode speaker
for a mobile communication device functions as both a speaker and a
vibratory alarm. The distributed mode speaker includes a speaker
panel, a mode transducer to generate bending waves in the speaker
panel to generate audible sounds and a vibration transducer to
vibrate said speaker panel to generate a tactile alarm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a plan view of an exemplary mobile communication
device in a closed position.
[0008] FIG. 2 is a plan view of a mobile communication device in an
open position.
[0009] FIG. 3 is a section view of an exemplary mobile
communication device in an open position.
[0010] FIG. 4 is a section view of another exemplary mobile
communication device in an open position.
[0011] FIG. 5 illustrates the structure of an exemplary distributed
mode speaker.
[0012] FIG. 6 illustrates the main functional components of a
mobile communication device.
DETAILED DESCRIPTION
[0013] Referring now to the drawings, a mobile communication device
according to one exemplary embodiment of the present invention is
shown therein and indicated generally by numeral 100. Mobile
communication device 100 includes a housing comprising a first
housing section 130 and a second housing section 132. A swivel or
slide mechanism 160, shown schematically in FIGS. 3 and 4, joins
the first and second housing sections 130, 132 so as to move
between open and closed positions. The first and second housing
sections 130, 132 may be configured to slide between the open and
closed positions or to rotate between the open and closed
positions. Because swivel and slide mechanisms are well-known in
the art, the details of such mechanisms are omitted.
[0014] The first housing section 130 includes an obverse surface
134 that is covered in the closed position and partially exposed in
the open position. Similarly, the second housing section 132
includes a reverse surface 136 (FIG. 3) that is covered in the
closed position and partially exposed in the open position. In the
open position, the first and second housing sections 130, 132
partially overlap so that a portion of the obverse surface 134 and
a portion of the reverse surface 136 are concealed in the open
position. The portions of the obverse surface 134 and reverse
surface 136 that are concealed in the open position are referred to
herein as protected surfaces.
[0015] In the embodiment illustrated in FIGS. 1 and 2, the first
housing section 130 includes a conventional numeric keypad 114 and
microphone 122. The keypad 114 and microphone 122 are disposed on a
portion of the obverse surface 134 that is exposed in the open
position. The second housing section 132 includes a display 112,
navigation control 116, and conventional piston-type speaker 124.
The keypad 114, navigation control 116, and display 112 form part
of the user interface 110 (FIG. 6) for interaction with the user.
The display 112 displays information for viewing by the user, while
the keypad 114 and navigation control 116 receive user input. The
mobile communication device 100 may include other input devices 118
(FIG. 6) in addition to keypad 114 and navigation control 116. For
example, the display 112 may be a touch sensitive display that is
capable of receiving user input. The microphone 122 and speaker 124
enable voice communication. The second housing section 132 may
include a second microphone 122' for use when the housing sections
130, 132 are in the closed position.
[0016] According to one exemplary embodiment, the mobile
communication device 100 further includes a distributed mode
speaker 140 (FIGS. 3 and 4). The distributed mode speaker 140 is
used for playing music and other audio files, and may be used for
voice communications in speakerphone mode. In one embodiment, the
distributed mode speaker 140 is disposed on the obverse surface 134
of the first housing section 130 (FIG. 3). More particularly, the
distributed mode speaker 140 is disposed on the portion of the
obverse surface 134 that is overlapped by the second housing
section 132 in the open position. Thus, the second housing section
132 protects the distributed mode speaker 140 from being damaged.
One or more acoustic ports 138 may be formed in the portion of the
second housing section 132 that overlaps the first housing section
130. The acoustic ports 138 project sound generated by the
distributed mode speaker 140. Alternatively, sound may exit from
the gap between the housing sections 130, 132. Sound channels (not
shown) can also be formed in the surfaces of the first and second
housing sections 130, 132 to channel sound out.
[0017] FIG. 4 illustrates an alternate embodiment wherein the
distributed mode speaker 140 is disposed on the reverse surface 136
of the second housing section 132. In this embodiment, the
distributed mode speaker 140 is disposed on the portion of the
reverse surface 136 that is overlapped by the first housing section
130 in the open position. Thus, the first housing section 130
protects the distributed mode speaker 140 in the open position. The
acoustic ports 138 pass through the first housing section 130 to
project sounds generated by the distributed mode speaker 140.
[0018] FIG. 5 illustrates the structural elements of an exemplary
distributed mode speaker 140. The distributed mode speaker 140
comprises a speaker panel 142, and a mode transducer 144 to excite
the speaker panel 142 and generate bending waves. As is known in
the art, the bending waves transmitted through the speaker panel
142 produce audible sounds that can be heard by the user. Speaker
panel 142 is typically a thin but stiff panel that can be
constructed from a wide variety of materials. For example, speaker
panel 142 may be constructed from plastics, glass fiber, carbon
fiber composites, or paper. The properties of the specific material
used to construct speaker panel 142, along with its dimensions,
dictate the acoustical properties of speaker panel 142. For
example, a certain material may be selected for speaker panel 142
to ensure audio above a given frequency. As seen in the figures,
speaker panel 142 is typically flat, however, those skilled in the
art will readily appreciate that panel 142 may also be curved or
bent.
[0019] Mode transducer 144 excites the natural resonance of the
speaker panel 142 according to an applied audio signal to produce
bending waves in the speaker panel 142. Mode transducer 144 causes
the speaker panel 142 to vibrate in a pseudo-random manner such
that different areas of the panel 142 bend as they are
independently excited with different amplitudes and phases. A wide
variety of transducers may be used in the distributed mode
speakers. These include, but are not limited to, piezoelectric
transducers and dynamic coil transducers. Piezoelectric transducers
have a thin profile that is desirable for mobile devices. However,
piezoelectric transducers are delicate, and thus, may break easily
if device 100 is dropped. Dynamic-coil transducers are more robust
and may provide greater protection from drop damage. However,
dynamic-coil transducers also have a larger profile than do
piezoelectric transducers.
[0020] Mode transducer 144 may be positioned anywhere on panel 142,
but is preferably positioned off-center of the panel 142. For
example, mode transducer 144 may be positioned on speaker panel 142
according to NXT's "Gold" and "Silver" ratios. These ratios define
the optimum distances from the edges of the speaker panel 142 to a
mounting point of mode transducer 144. Symmetrical mounting of mode
transducer 144 (e.g., centered on panel 142) tends to negatively
affect modal excitement of the speaker panel 142, and degrades the
audible output.
[0021] In some exemplary embodiments, the distributed mode speaker
140 may also function as a vibrator to generate a tactile alarm
that can be felt by a user. A vibration transducer 146, such as a
magnetic coil, may be mounted near the center of the speaker panel
142 to vibrate the entire speaker panel 142 at a low frequency.
Those skilled in the art will appreciate that the vibration
generated by the vibration transducer 146 is different in character
from the vibrations produced by the mode transducer 144. More
specifically, the vibration transducer 146 moves the speaker panel
142 in the same manner as a diaphragm in a conventional speaker.
The bodily movement of the panel 142 produces a vibration that can
be felt by the user.
[0022] The speaker panel 142 is mounted in a frame 150. The edges
of the speaker panel 142 are inserted into a channel in the frame
150 and held between elastomeric damping members 152. The damping
members 152 may be, for example, natural or synthetic rubber or
other resilient material that allows some displacement of the
speaker panel 142 when the speaker panel 142 is vibrated by the
vibration transducer 146.
[0023] The frequency range of the distributed mode speaker 140 is
affected by the size of the speaker panel 142. A large speaker
panel 142 is capable of produced a wide frequency range. However,
decreasing the size of the speaker panel 142 limits the ability of
the speaker 140 to reproduce low frequencies. The distributed mode
speaker 140 may be used in conjunction with a conventional woofer
or sub-woofer to provide a full range of sound.
[0024] Alternatively, the speaker panel 142 of the present
invention may operate as a conventional pistonic speaker at low
frequencies, and as a distributed mode speaker at higher
frequencies. The vibration transducer 146 may be actuated to
reproduce low frequency sounds (e.g., below 100 kHz) and the mode
transducer 144 may be actuated to reproduce high frequency sounds
(e.g., 100 kHz or above).
[0025] FIG. 6 illustrates the main components of an exemplary
mobile device 100. The mobile device 100 comprises a main control
unit 102, memory 104, a transceiver 106 connected to an antenna
108, user interface 110, and audio processing circuit 120. The main
control unit 102 is responsible for overall operational control of
the mobile device 100. The main control unit 102 may comprise one
or more processors, microcontrollers, and/or hardware circuits.
Memory 104 stores data and programs needed for operation. The
memory 104 may comprise one or more discrete memory devices,
including read-only memory, random access memory, flash memory,
etc.
[0026] Transceiver 106 may comprises a conventional cellular
transceiver for communicating with a mobile communication network
(not shown), or may comprise a conventional WiFI transceiver. The
transceiver 106 may operate according to known standards, such as
GSM, WCDMA, UMTS, and OFDM.
[0027] The audio processing circuits 120 process audio signals
input by microphone 122 or output to speakers 124, 140. Microphone
122 converts audible sounds into audible signals for input to the
main control unit 102. Speakers 124, 140 converts audio signals
into audible sounds that can be heard by the user.
[0028] User interface 110 comprises a display 112, keypad 114,
navigation control 116 and possibly other input devices 118. The
main control unit 102 outputs information in visual form to display
112 for viewing by the user. Keypad 114, navigation control 116,
and other input devices 118 provide user input to the main control
unit 102.
[0029] The present invention may, of course, be carried out in
other specific ways than those herein set forth without departing
from the scope and essential characteristics of the invention. The
present embodiments are, therefore, to be considered in all
respects as illustrative and not restrictive, and all changes
coming within the meaning and equivalency range of the appended
claims are intended to be embraced therein.
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