Information
-
Patent Grant
-
6345102
-
Patent Number
6,345,102
-
Date Filed
Thursday, June 10, 199925 years ago
-
Date Issued
Tuesday, February 5, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Isen; Forester W.
- Pendleton; Brian Tyrone
Agents
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
A loudspeaker, for example, for an in-vehicle hands-free commnunication system or an in-vehicle entertainment system is provided as part of a vehicle sun visor (10), or as an attachment (24) to a vehicle sun visor so that the loudspeaker can be placed relatively close to the driver's ears and in front of the driver. Accordingly, there will not be any significant tendency for the driver to turn their head when listening to the loudspeaker. The loudspeaker comprises a flat panel (26) which is driven by a piezo-electric actuator (28), enabling an extremely thin construction to be realised and the loudspeaker to be conveniently integrated into the sun visor, or provided as an unobtrusive attachment for the sun visor.
Description
This invention relates to vehicle loudspeakers, which may be used, for example, in in-vehicle hands-free communication systems such as telephone systems, and which may also be used in in-vehicle entertainment systems.
One disadvantage of an in-vehicle hands-free telephone system which uses conventional loudspeakers is that the microphone and loudspeaker need to be, or are typically, widely separated. Typically, the microphone is attached to the windscreen pillar so as to be relatively close to the driver's mouth, whilst the loudspeaker is placed in the foot-well on the passenger side, i.e. on the other side of the driver to the microphone. This can cause an unwanted strain in a telephone conversation, because it is instinctive for the driver to turn towards the sound source, i.e. the foot-well loudspeaker, and away from the microphone. This therefore reduces the signal-to-noise ratio at the microphone and consequently reduces the conversation quality. Also, the driver may be distracted from looking straight forward, thus reducing the overall safety of the vehicle and its occupants.
In accordance with a first aspect of the present invention, there is provided an attachment for a vehicle sun visor, the attachment being characterised by: a panel which can be vibrated to generate sound; a piezo-electric actuator coupled to the panel and operable to vibrate the panel in response to a driving signal so as to act as a loudspeaker; and means for attaching the panel to the sun visor.
In accordance with a second aspect of the present invention, there is provided a sun visor for a vehicle, comprising: a panel; and means for attaching the panel to the vehicle adjacent an upper edge of a windscreen of the vehicle; characterized in that: the panel is vibratable to generate sound; and a piezo-electric actuator is coupled to the panel and is operable to vibrate the panel in response to a driving signal so as to act as a loudspeaker.
By providing the loudspeaker as part of a vehicle sun visor, or as an attachment to a vehicle sun visor, the loudspeaker can be placed relatively close to the driver's ears and in front of the driver. Accordingly, there will not be any significant tendency for the driver to turn their head when listening to the loudspeaker. Also, by using a panel, such as a flat panel, which is driven by a piezo-electric actuator, as the loudspeaker, an extremely thin construction can be realised, and the loudspeaker can conveniently be integrated into a sun visor, or be provided as an unobtrusive attachment for a sun visor, in such a way that there is little likelihood of the sun visor or attachment causing any greater injury to the driver in the event of an accident than a conventional sun visor.
In one embodiment of the first aspect of the invention, the attaching means is arranged to one side of the panel for attaching the panel to the vehicle sun visor with said one side of the panel facing the sun visor.
In another embodiment of the first aspect of the invention, the attaching means comprises: a second panel hinged to the first-mentioned panel; and means for biasing the panels towards each other so that they can grip the vehicle sun visor therebetween. In this case, the attachment may further include a second piezo-electric actuator coupled to the second panel and operable to vibrate the second panel in response to the, or a further, driving signal so as to act as a second loudspeaker.
The sun visor of the second aspect of the invention may further include a second panel generally parallel to the first-mentioned panel; the first-mentioned piezo-electric actuator, or a second piezo-electric actuator, being coupled to the second panel and operable to vibrate the second panel in response to the, or a further, driving signal so as to act as a second loudspeaker.
In the case where the attachment or the vehicle sun visor has two loudspeakers, the first-mentioned loudspeaker and the second loudspeaker may have substantially different frequency response characteristics. Accordingly, the two loudspeakers can be designed to provide a better overall frequency response.
The attachment or vehicle sun visor may further include a microphone.
In accordance with a third aspect of the present invention, there is provided a vehicle hands-free telephone system having a loudspeaker and a microphone, characterized in that the loudspeaker is provided by a vehicle sun visor attachment, or a vehicle sun visor, according to the first or second aspect of the invention.
The microphone of the telephone system is preferably provided by the mnicrophone of the attachment or sun visor.
In accordance with a fourth aspect of the present invention, there is provided a vehicle having at least one of: (a) a sun visor, and an attachment therefor according to the first aspect of the invention; (b) a sun visor according to the second aspect of the invention; and (c) a telephone system according to the third aspect of the invention.
Specific embodiments of the present invention will now be described, purely by way of example, with reference to the'accompanying drawings, in which:
FIG. 1
is an isometric view of a conventional vehicle sun visor;
FIG. 2
is an isometric view, on a larger scale and from one corner and behind, of a vehicle sun visor attachment of a first embodiment of the invention;
FIG. 3
is an isometric view, from one corner and behind, of a vehicle sun visor attachment of a second embodiment of the invention;
FIG. 4
is an isometric view, from one corner and behind, of a vehicle sun visor attachment of a third embodiment of the invention;
FIG. 5
is an isometric view, on a smaller scale and from one corner and in front, of the vehicle sun visor attachment of
FIG. 4
secured to a vehicle sun visor;
FIG. 6
is an isometric view of a vehicle sun visor attachment of a fourth embodiment of the invention;
FIG. 7
is a view of the cockpit of a motor vehicle, with the vehicle sun visor attachment of
FIG. 6
secured to a sun visor of the vehicle;
FIG. 8
is an end view of a vehicle sun visor of a fifth embodiment of the invention, cross-sectioned on a section plane
8
—
8
shown in
FIG. 9
;
FIG. 9
is a view on a smaller scale of the sun visor of
FIG. 8
, cross-sectioned on a section plane
9
—
9
shown in
FIG. 8
; and
FIG. 10
is a block diagram of an in-car hands-free telephone system which may employ a sun visor, or sun visor attachment, of any of the first to fifth embodiments of the invention.
Referring to
FIG. 1
, a conventional vehicle sun visor
10
comprises a rectangular panel
12
which is hinged adjacent and along one of its longer edges to an arm
14
of a crank
16
. The other arm
18
of the crank
16
can rotate relative to a mounting plate
20
, by which the sun visor
10
can be attached to a motor vehicle adjacent an upper edge of the vehicle windscreen. The attachments shown in
FIGS. 2
to
4
are intended to be secured to one side of the panel
12
of the sun visor
10
in the region denoted by the dot-dash line
22
in FIG.
1
.
Referring now to
FIG. 2
, the first embodiment of a loudspeaker attachment
24
for the sun visor
10
of
FIG. 1
comprises a rectangular panel
26
formed from a sheet of, for example, aluminium, hardboard or plastics material, or from a composite of two thin sheets of such material between which a honeycomb- or foam-like material is sandwiched. A piezo-electric actuator is mounted on the rear face of the panel
26
, and in the embodiment shown comprises two elements
28
, each comprising a layer of piezo-electric material sandwiched between a pair of electrode layers, which are adhered to the rear face of the panel
26
. The piezo-electric elements
28
are connected together, either in series or in parallel, by wires
30
. When a driving signal is applied to the wires
30
, the piezoelectric elements
28
cause the panel
26
to vibrate and thus to act as a loudspeaker.
Fixing material
32
is provided around the marginal edge of the rear face of the panel
26
, by which the loudspeaker attachment
24
can be attached to the sun visor
10
in the region
22
. The fixing material
32
may be, for example, double-sided releasable adhesive tape, hook-and-loop tape (such as Velcro®) or magnetic tape. In the latter two examples, complementary tape is applied to the sun visor
10
. The manner of fixing the loudspeaker attachment
24
to the sun visor
10
is preferably releasable, as in the examples given above, so that the loudspeaker attachment
24
can be removed from the vehicle if and when required.
It should be understood that the loudspeaker attachment
24
can be attached to either side of the sun visor
10
. It will be noted that the panel
26
is fixed to the sun visor
10
with the side of the panel
26
which bears the piezo-electric elements
28
facing the sun visor
10
. Accordingly, the piezo-electric elements
28
are hidden. This has aesthetic advantages, together with providing added protection against accidental electric shock from the relatively high voltages used to drive the piezo-electric elements
28
.
Referring now to
FIG. 3
, the second embodiment is similar to the first embodiment of
FIG. 2
, except that a layer
34
of acoustic absorbing material is applied to the front face of the panel
26
. Depending on the side by which the panel
26
is attached, the acoustic absorbing material could be provided by the sun visor itself. For certain applications, such as hands-free in-car telephone systems, the high frequency components which can be generated by the flat panel loudspeaker
24
are not desirable, and the acoustic absorbing layer
34
is used to absorb the high frequencies and therefore improve the perceived quality of sound generated by the loudspeaker
24
. Instead of, or in addition to, using such an acoustic absorbing layer
34
, electrical filtering may be employed.
Referring now to
FIG. 4
, the third embodiment is similar to the second embodiment of
FIG. 3
, except in the following respect. The covering layer
34
, which may or may not be of acoustic absorbing material, extends beyond the edges of the panel
26
, and the fixing material
32
is secured to the marginal edge of the rear surface of the covering layer
34
, with a gap
36
between the inner edge of the fixing material
32
and the outer edge of the panel
26
. The material of the covering layer
34
is slightly stretchable. Therefore, as shown in
FIG. 5
, when the loudspeaker attachment
24
is applied to the sun visor
10
, the marginal page of the covering layer
34
can be stretched so that the fixing material
32
can be secured to the panel
12
of the sun visor
10
. The covering layer
34
need not be secured to the panel
12
of the sun visor
10
along all four edges, and, if secured along only two or three edges, then a pocket can be formed between the panel
26
of the loudspeaker attachment
24
and the panel
12
of the sun visor
10
, into which other articles can be inserted. It has been found that the frequency response usually improves if the covering layer
34
is stretched tight.
Referring now to
FIG. 6
, the loudspeaker attachment
24
of the fourth embodiment comprises a pair of the panels
26
A,
26
B, which are hinged to each other along an edge of each of the panels
26
A,
26
B, and a spring
38
urges the panels
26
A,
26
B together in the direction denoted by the arrows
40
. Between the two panels
26
A,
26
B, a respective one of the piezo-electric elements
28
is secured to each of the panels
26
A,
26
B, and the piezo-electric elements
28
are connected together by wires (not shown) in a similar fashion to that described above with reference to
FIGS. 2
to
4
. Accordingly, as shown in
FIG. 7
, the loudspeaker attachment
24
forms a clip by which it can hold itself to a conventional sun visor
10
, with the panel
12
of the sun visor
10
gripped between the spring-loaded panels
26
A,
26
B of the loudspeaker attachment
24
.
In the embodiments described above with reference to
FIGS. 2
to
6
, a thin electrical protection film layer may be applied to the rear face of the loudspeaker attachment
24
, and this may have the dual function of providing added protection against electrical shock as well as modifying and potentially smoothing the frequency response of the panel.
Referring now to
FIGS. 8 and 9
, an embodiment is shown in which the loudspeaker function is provided integrally in the sun visor
10
and which differs from the embodiments described above in the following respects. The sun visor
10
comprises a rectangular frame
42
having, as seen in
FIG. 9
, a top limb
42
T, a bottom limb
42
B, and left and right limbs
42
L,
42
R, which may be integrally formed or assembled from components. Two of the rectangular panels
26
A,
26
B are positioned within the frame
42
, with a gap
44
between the peripheries of the panels
26
A,
26
B and the inside edge of the frame
42
. The frame
42
and the panels
26
A,
26
B are enveloped with a layer
34
, which may or may not be of the acoustic absorbing material mentioned above, and which is adhered to the frame
42
and the outwardly-facing faces of the panels
26
A,
26
B. The panels
26
A,
26
B are held generally parallel and spaced apart.
The top limb
42
T of the frame has a bore
46
extending at least part way along its length
20
from one end, and the crank
16
is tubular and its arm
14
is a sliding friction fit in the bore
46
so that the sun visor
10
can be pivoted up and down. Two of the piezo-electric elements
28
are secured to the inwardly-facing faces of each panel
26
A,
26
B, and the four piezo-electric elements
28
are connected together in series and/or parallel by wires
30
which pass through an aperture
48
in the top limb
42
T and through the tubular crank
16
so as to exit therefrom at the end connected to the mounting plate
20
. A pair of notches
50
are formed halfway along the lower edges of the panels
26
A,
26
B to accommodate a microphone
52
which is secured to the bottom limb
42
B of the frame. Wires
54
for the microphone also pass through the aperture
48
in the top limb
42
T of the frame and along the tubular crank
16
.
Referring now to
FIG. 10
, a hands-free in-car telephone system comprises a handset
56
which is releasably connected to a cradle
58
. Audio signals are input to the handset
56
from a microphone
52
(see also
FIG. 7
) via wires
54
, a junction box
64
and the cradle
58
. Audio signals are output from the handset
56
via the cradle
58
and the junction box
64
. In a conventional such system, the audio signals from the junction box
64
would be output to a conventional loudspeaker, such as a moving-coil loudspeaker. However, rather than this, the output signals supplied to the piezo-electric element(s)
28
of the flat panel loudspeakers described above with reference to
FIGS. 2
to
9
, via a step-up transformer
66
. The transformer
66
increases the voltage of the signals output from the junction box
64
to a voltage suitable for driving the piezo-electric element(s)
28
of the flat panel loudspeakers. The transformer
66
might typically have a
10
:
1
step-up ratio. As an addition or an alternative to the transformer
66
, a high-voltage amplifier may be used, the transformer
66
merely being an example of a technique to match the electrical requirement of a typical piezo-electric element with the electrical output of a typical hands-free telephone system. Alternatively, the junction box
64
could be re-engineered. In the case where the sun visor
10
of
FIGS. 8 and 9
is employed in the system of FIG.
10
,the microphone
52
provided in the sun visor
10
of
FIGS. 8 and 9
may constitute the microphone
52
shown in FIG.
10
. Accordingly, a hands-free in-car telephone system is provided in which not only is the microphone positioned conveniently for the driver and so as to provide a high signal-to-noise ratio, but also the loudspeaker is positioned unobtrusively close to the driver so that the driver can more naturally use the system.
It should be noted that the embodiments of the invention have been described above purely by way of example, and that many modifications and developments may be made to them.
For example, the sun visor attachments
24
of
FIGS. 2
to
6
may also be provided with microphones
52
.
Also, the number of piezo-electric elements
28
provided on each panel
26
;
26
A,
26
B may be other than two, for example one, three or four. The piezo-electric elements
28
on each panel
26
;
26
A,
26
B may have different characteristics or be coupled to the panel differently, so that each produces a different frequency response characteristic so that the overall frequency response characteristic of the panel is more uniform.
Furthermore, the sun visor attachments
24
described with reference to
FIGS. 2
to
4
may be provided in pairs, for attachment to either side of the panel
12
of the sun visor
10
. In this case, or in the case of the embodiments described with reference to
FIGS. 6
to
9
, the panels of each pair may have different frequency response characteristics so that the overall frequency response characteristic of the pair of panels is more uniform. Moreover, in the case of the embodiments of
FIGS. 6
to
9
, the piezoelectric element(s) may be provided on only one of the panels
26
A,
26
B.
Further, in the embodiment described with reference to
FIGS. 8 and 9
, the piezo-electric elements
28
may bridge the space between the panels
26
A,
26
B, so that each piezo-electric element
28
is directly coupled to both of the panels
26
A,
26
B.
Also, the flat panel loudspeakers described above need not necessarily be used as part of a telephone system. Additionally or alternatively, they may be used in in-car entertainment systems o replace, or as an addition to, the conventional front loudspeakers. In this case, the driver's and front seat passenger's sun visors or attachments to them may be fed with left and right channels of a stereo signal. Even in the case of a telephone system, both the driver's and front seat passenger's sun visors may be provided with loudspeakers to facilitate the passenger listening to a telephone conversation.
Many other modifications and developments may also be made to the invention.
Claims
- 1. A loudspeaker unit for a vehicle, comprising:a piezo-electric loudspeaker comprising: a panel with first and second faces facing in opposite directions; and a piezo-electric actuator coupled to a first face of the panel and operable to vibrate the panel in response to a driving signal so as to radiate sound from the first face of the panel and thus act as a loudspeaker; and means for attaching the piezo-electric loudspeaker to the vehicle, wherein the means for attaching is arranged to releasably attach the panel to a sun visor of the vehicle with the second face of the panel facing a face of the sun visor.
- 2. The loudspeaker unit of claim 1, further comprising a microphone.
- 3. The loudspeaker unit of claim 1, wherein the attaching means is arranged to second face of the panel.
- 4. The loudspeaker unit of claim 1,wherein the attaching means comprises:a second panel hinged to the first-mentioned panel; and means for biasing the first-mentioned panel and the second panel toward each other so as to be operable to grip the sun visor therebetween.
- 5. The loudspeaker unit of claim 4, wherein the second panel has first and second faces facing in opposite directions and the second panel is hinged to the first panel and the biasing means is arranged as to be operable to grip the sun visor between the second faces of the first and second panels, and further comprising:a second piezo-electric actuator coupled to the first face of the second panel and operable to vibrate the second panel in response to the, or a further, driving signal so as to act as a second loudspeaker by radiating sound from the first face of the second panel and.
- 6. The loudspeaker unit of claim 5, wherein the first-mentioned loudspeaker and the second loudspeaker have substantially different frequency response characteristics.
- 7. A loudspeaker unit for a vehicle, comprising:a panel having first and second faces facing in opposite directions and vibratable to generate sound from one of first and second faces of the panel; and means for attaching the panel to the vehicle adjacent an upper edge of a windscreen of the vehicle to form a sun visor of the vehicle; and a piezo-electric actuator coupled to the first face of the panel and operable to vibrate the panel in response to a driving signal so as to act as a loudspeaker bv radiating sound from the first face of the panel.
- 8. The loudspeaker unit of claim 7, further comprising a second panel generally parallel to the first-mentioned panel and having first and second faces facing in opposite directions, with the second faces of the first and second panels facing towards each other; a second piezo-electric actuator coupled to a first face of the second panel and operable to vibrate the second panel in response to the, or a further, driving signal so as to radiate sound from the first face of the second panel and act as a second loudspeaker.
- 9. The loudspeaker unit of claim 8, wherein the first-mentioned loudspeaker and the second loudspeaker have substantially different frequency response characteristics.10.The loudspeaker unit of claim 7, further comprising a microphone.
- 11. A vehicle hands-free telephone system, comprising:a loudspeaker unit for a vehicle, comprising: a panel having first and second faces facing in opposite directions and vibratable to generate sound from one of the first and second faces; and means for attaching the panel to the vehicle adjacent an upper edge of a windscreen of the vehicle to form a sun visor of the vehicle; a piezo-electric actuator coupled to the first face of the panel and operable to vibrate the panel in response to a driving signal so as to act as a loudspeaker by vibrating sound from the first face of the panel; and a microphone operably coupled to the loudspeaker unit and the piezo-electric actuator.
- 12. The system of claim 11,wherein the microphone of the telephone system is a microphone of the loudspeaker unit.
- 13. A vehicle hands-free telephone system, comprising:a piezo-electric loudspeaker comprising: a panel with first and second faces facing in opposite directions; and a piezo-electric actuator coupled to the first face of the panel and operable to vibrate the panel in response to a driving signal so as to radiate sound from the first face of the panel and thus act as a loudspeaker; and means for attaching the piezo-electric loudspeaker to the vehicle, wherein the means for attaching is arranged to releasably attach the panel to a sun visor of the vehicle with the second face of the panel facing a face of the sun visor; and a microphone operably coupled to the loudspeaker unit and the piezo-electric actuator.
- 14. The system of claim 13, wherein the microphone of the telephone system is a microphone of the piezo-electric loudspeaker.
- 15. A vehicle having a loudspeaker unit, comprising:a panel having first and second faces facing in opposite directions and vibratable to generate sound from one of the first and second faces; and means for attaching the panel to the vehicle adjacent an upper edge of a windscreen of the vehicle to form a sun visor of the vehicle; and a piezo-electric actuator coupled to the first face of the panel and operable to vibrate the panel in response to a driving signal so as to act as a loudspeaker by radiating sound from the first face of the panel.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9621523 |
Oct 1996 |
GB |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/GB97/02728 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO98/16409 |
4/23/1998 |
WO |
A |
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
4300433 |
Jul 1994 |
DE |