WO2005053355A2

WO2005053355A2 - Carry case

Info

Publication number: WO2005053355A2
Application number: PCT/GB2004/004453
Authority: WO
Inventors: Martin Colloms; Paul Burton; Julian Fordham; Graham Christopher Ryan; Neil Firth
Original assignee: New Transducers Limited
Priority date: 2003-10-30
Filing date: 2004-10-21
Publication date: 2005-06-09
Also published as: WO2005053355A3; TW200526143A

Abstract

A carry case or bag comprising an outer structure (28, 30) made from flexible sheet material and a panel-form bending wave loudspeaker having a panel-form acoustic diaphragm (14, 16) formed by the flexible sheet material of the outer structure and a bending wave exciter (10, 12) coupled to the acoustic diaphragm (14, 16) to cause the diaphragm to resonate to produce an acoustic output. The carry bag may comprise an externally accessible control section for the loudspeaker.

Description

TITLE: CARRY CASE

DESCRIPTION

TECHNICAL FIELD The invention relates to carry cases and the like carry bags and back-packs . BACKGROUND ART Distributed mode panel form loudspeakers as exemplified in International Patent Application No. O97/09842 may be used in a wide variety of applications. The durability of such bending wave panels lends itself to carry bag applications where the speaker may simply be inserted in a sub compartment or slot formed in the bag. Bags are generally made of relatively soft textiles or plastics sheet materials, e.g. woven canvas, or textiles fabric and the inserted bending wave panel can operate relatively unimpeded, while the textiles fabric compartment acts sufficiently like a speaker grille cloth to allow the sound to pass through and be radiated to a listener. Traditional portable radios are large and heavy and contain air volumes to load conventional piston speakers. The casings are rigid and it is good practice that nothing is allowed to be loose or unattached since the vibration levels acting on such structures would result in unacceptable distortion and rattling. It is an object of the invention to provide an improved carry case and the like carry bag or back pack. DISCLOSURE OF INVENTION According to the invention, there is provided a carry case or bag comprising an outer structure made from flexible sheet material and a panel-form bending wave loudspeaker having a panel-form acoustic diaphragm formed by the flexible sheet material of the outer structure and a bending wave exciter coupled to the acoustic diaphragm to cause the diaphragm to resonate to produce an acoustic output. The bag may be of many kinds such as a sports equipment bag or in another example a compact disc (CD) carry case . The combination of bag constructions and bending wave speaker, where the speaker panel is formed from the material of the bag itself, provides designers of consumer electronics with new opportunities to create a new class of product which has the soft and resilient properties of a bag, the storage and carry potential of a bag and the additional functionality of a radio and/or sound reproducing apparatus, for example a CD player. The lower energy content of bending wave speakers combined with the intended resilience and self damping of the bag construction avoids or at least mitigates rattle or drumming-related vibration problems with the product in use. Bags are made from a variety of suitable materials such as textiles material as well as semi rigid polymers including foamed plastics such as foamed EVA [ethylene vinyl acetate] , foamed polyethylene, plasticised and similarly modified/augmented card and paper products. Fibre reinforced rubber materials are also used as are the more rigid, tougher canvas materials which may also be treated with a doping polymer to beneficially modify the acoustic properties in the panel region chosen to act as a diaphragm. Several of these bag materials have acoustic properties suited to propagating bending waves over a useful frequency range and are thus candidates for bending wave panel form speaker operation effective for general use. Regions of the panel elements of the bag may be used for different parts of the frequency range or for different signals or sound channels, e.g. two-channel stereo use or multi channel . The panels of the bag can be made to vibrate in response to audio and/or information signal by means of an electrodynamic exciter, e.g. a piezo or moving coil exciter, which may be used in combination for improved results . The bending wave panels may be parameterised e.g. by choice of bending stiffness, damping, area mass density, thickness, size and shape, alone or in conjunction with the aesthetic design aspects of the bag to provide desired a particular distribution or resonant modes in frequency and/or over area. For example, foamed EVA (Ethylene Vinyl Acetate) may be used and the parameters may be selected so that the density μ is in the range 0.5kg/m² to 1.75kg/m² and the bending stiffness B after compression is in the range 0.15Nm to 0.67Nm. The foamed EVA may be sandwiched between two skins and the compression may be in the range 15% to 25% whereby a good bonding with the outer skins may be achieved. Alternatively, the flexible sheet material may be polypropylene. The exciter location may be chosen to achieve desired coupling to the available modes. For example, the exciter location may be chosen to drive as many modes as possible, or may be chosen to drive only particular modes of interest, e.g. by mounting the exciter close to the antinodes or points of maximum motion for these modes. The exciter location may also be chosen so that particular modes are not driven, e.g. by mounting the exciter at the nodes or deadspots for these modes. The exciter may be a lightweight inertial dynamic type and may be wholly and exclusively mounted to the panel . Normally the exciter [s] would be located on the inside face [s] of the panel and may be protected by an internal division or compartment wall . The space local to the exciter may be used to accommodate an amplifier and other electronics and a power source e.g. dry-cell batteries . The bag may comprise an externally or internally accessible control section for the loudspeaker. The control section may be impact proof e.g. using fabric switch technology. Thus the control section can be soft structurally to match the feel and structure of the bag. Soft controls have the additional advantage of resilience and durability, which is a valuable feature for this type of application. The useful aspect of soft controls, e.g. of a flexible nature and implemented in polymers or fabric material, may be exploited by conveniently incorporating them in the surface structure of a first shell of a carry bag which also has operative bending wave panel speaker action. The soft controls are resistant to audio vibration and may form part of the sound radiating assembly and are compatible with the aim of the invention, that is to use the bag structure as a panel-form loudspeaker. Functional controls provided on the bag may include amplifier on/off, volume, tone controls, spatial processing and switching. Other functions may include handset remote control, control of an inserted/carried source of signal e.g. a CD player or MP3. Data processing/control circuits may be provided in the interface between the control panel and the device being controlled, and may scale and interpret the user contact with the control panel, suppressing unwanted actions and correctly filtering intended commands for unambiguous operation. To provide versatility for different devices to be controlled, the controls may have a sub structure including an infra red or radio receiver for remote control, or Bluetooth or similar two way remote data and audio signal interface and derive power from the bag batteries or the signal device, CD player or mobile phone; in particular these may provide radio signals and or received or recorded music stored in internal memory. A low frequency loudspeaker may be incorporated in or be integral with the carry case or bag. Low frequency sound has little directionality since the radiated sound wavelengths are long and thus the location of the loudspeaker within the carry case or bag is not critical. The loudspeaker may be placed in the floor or a base compartment of the bag whereby it is rendered effectively invisible . The low frequency loudspeaker may comprise a driver mounted within a pipe or duct. The pipe may be sealed at one or both ends or may be open. The driver may be mounted in an aperture in the wall of the pipe or duct to form an enclosure where the ends of the pipe or duct are closed. An aperture or duct may be introduced into a wall or an end of the enclosure whereby the loudspeaker is of bass reflex form. The driver may be mounted at a selected location along the length of the pipe or duct e.g. at the quarter wave location for a pipe closed at one end. The driver may also be located at one or the other end. The duct may be designed as a transmission line for a driver mounted at an end. Suitable fibrous or open cellular damping material may be introduced into the duct to adjust the low frequency behaviour . The pipe may have a rectangular or circular cross- section. The pipe may take the form of a shallow duct having a cross-section with a high aspect ratio. The pipe may be made of semi rigid impact resistant material, e.g. semi rigid EVA structural foamed plastic. The low frequency pressure losses along the pipe may be held sufficiently low for effective operation by appropriate selection of the material, thickness and cross section of the pipe. The low frequency loudspeaker may be monaural, i.e. with one channel, may use summed low frequency channel input, or may have two drivers, one for each channel. Two low frequency loudspeakers may be used, e.g. placed side by side concealed in the floor of the bag. The result is a flexible, durable carry bag which is safe, lightweight, crush and shock resistant, which makes use of the functionality of a personal media source CD player and the like which may carry the player and discs, and/or a mobile telephone which may provide a transparent interface for the user via the external control panel, and can reproduce audio in the manner of a larger radiating sound source, even with multichannnel or stereo operation. The bag may have storage and connection interfaces for mobile phones, CD players PDAs, and space for software, such as CDs and other items. The batteries in the bag for the local electronics and amplifiers may also provide power recharge service for the other electronic devices carried including, for example, a mobile phone. With a phone in the bag, the system may be organised for hands free operation making use of an additional microphone, and/or noise cancelling, and interface so that the user may be physically remote from the bag, e.g. a few metres and still respond to phone calls. The bag may comprise an external visual display, using for example, LEP polymers displays, LCD, EP, electronic paper, particularly the potentially flexible and resilient display technologies, EP and LEP, to provide status information about equipment, e.g. mobile communication equipment, in the bag. The display may be controlled from outside of the bag, i.e. for use without opening the bag . BRIEF DESCRIPTION OF THE DRAWINGS The invention is diagrammatically illustrated, by way of example, in the accompanying drawings, in which: - Figure 1 is perspective view of a carry case according to a first embodiment of the present invention; Figure 2 is a perspective view of the carry case shown in Figure 1 opened for access to the interior; Figure 3 is a perspective view of the carry case of Figure 1 in use on a surface; Figure 4 is a perspective view of the carry case shown in Figure 3 with a media player in a storage pocket; Figure 5 is perspective view of a carry case according to a second embodiment of the present invention; Figure 6 is perspective view of a carry case according to a third embodiment of the present invention, and Figure 7a is a cross-sectional view of a bag according to another embodiment of the invention; Figures 7b and 7c are cross-sectional and end views, respectively of the duct used in the bag of Figure 7a, and Figures 7d and 7e are cross-sectional and end views, respectively of an alternative duct which may be used in the bag of Figure 7a.

DETAILED DESCRIPTION Figures 1 and 2 show a carry case which may also accommodate a sound source such as a CD or MP3 player and/or a radio player in an inner pocket 46. The carry case comprises an outer structure of opposed first and second shells 28, 30 which are linked by a hinge 32 and are closed by a zip fastener 22 running around the perimeter of each shell. A carry strap 20 is attached to the top of the carry case, conveniently near the top of the hinge 32 so as not to impede the action of the zip fastener. The first and second shells 28, 30 are formed of semi rigid but still flexible canvas material of polymer type. The canvas material is shaped to form a largely self- supporting open box-like structure with an essentially panel form outer face. The panel form outer face forms an acoustic diaphragm which supports bending wave vibration. The canvas material may be thermo formed and/or suitably impregnated or doped with a reinforcing polymer or similar. Such treatment may be across the whole shell or in the region of the acoustic diaphragm. Other semi rigid but flexible materials may be used for the shell, e.g. foamed plastics which may also offer good handling and impact resistance, combined with satisfactory bending wave action for sound reproduction. First and second exciters 10,12 are mounted to first and second sound radiating regions 14,16 on the inside face of the acoustic diaphragm formed by the first shell 28. The exciters 10,12 energise the diaphragm and cause it to resonate to become a useful source of reproduced sound thereby providing a panel form bending wave loudspeaker as an integral component of the carry case. The exciters may drive the radiating regions separately to provide two channels or stereo sound. Alternatively, the two exciters may be driven together or only one exciter may be mounted to the diaphragm to provide a single channel version. The exciters 10, 12 are connected to a media player (not shown) by a cable terminating in a signal connector 42 and also to an amplifier 26 with operating controls also mounted to the inside face. The cable allows audio and other electrical signals to be routed between the signal source and the exciters . The exciters 10, 12 and amplifier are mounted in an inner compartment of the carry case concealed by an internal cover 38 which prevents damage or contact with the items be carried. A battery compartment cover 36 within the internal cover 38 provides access to the batteries in a battery compartment 24. As shown in Figure 2, restraining straps 40 are provided to hold the first and second shells 28, 30 in an open position. Inside the body of the carry case, the hinge 32 is covered with a hinge cover 34. A series of media storage leaves 50 having translucent or transparent media storage pockets 52 to store CDs and other media discs are attached adjacent the hinge cover 34. A media player storage pocket 46 with an elasticated upper edge 48 is attached to the inside surface of the second shell 22 to store the CD or other media player. In Figure 3, the carry case 60 is placed horizontally on a surface 64 e.g. a work-top or table with the open portion of the carry case facing the surface. The carry case 60 is held partly open by the restraining straps 40, which may be made of Velcro ™. The panel form acoustic diaphragm 62 faces the listener and the left and right sound radiating regions driven by the first and second exciters 10, 12 are appropriately orientated for stereo use. The carry case may acoustically engage with the surface to provide optimised stereo performance. In Figure 4, a media player 70 is mounted in the interior media storage pocket 46. The media player 70 is connected to the first and second exciters 10,12 by a signal wire 75 which terminates in a signal connector 76 which is plugged into a socket on the media player 70. The media player 70 may be controlled by player controls 72 on a front surface of the media player 70. These controls are partially obstructed by the pocket 46 and thus a user will probably remove the media player 70 from the pocket to operate the controls 72. Alternatively, the media player 70 may be controlled by controls on a small control hand-set 78. The hand-set 78 is connected to the media player 70 by a cable 80 which extends from the hand-set and terminates in a control connector 74 which is plugged into a socket on the media player 70. The cable and handset need to be zipped away when not being used since otherwise it will dangle and tangle etc. A known alternative (not illustrated) is a separate remote hand-set, but this may be lost. Figure 5 shows an embodiment of the present invention which addresses the problems of controlling of the media player described in relation to Figure 4. The carry bag is generally similar to that shown in Figures 1 to 4 except that a soft control panel 84 is integrally mounted to an external surface of the carry case . The soft control panel 84 is attached to a conductive fabric layer 86 which is bonded to the outer surface of the first shell 28. The soft control panel 84 includes controls for standard media player functions together with basic controls for the amplifier 26, i.e. On/Off (press play button) and a volume slider. Figure 6 shows a carry bag similar to that of Figure 5 in which the control section is also externally accessible. In this embodiment, a conventional control panel 88 having a slider control 92 and discrete buttons 94 is mounted in a recess 90 on the outer surface of the first shell 28. The control panel is hard and is a sub- assembly in the form of an integrated non-flexible surface. The embodiments of Figures 5 and 6 provide a sound producing carry bag or carry case, including externally accessible controls and related logic circuits, complementing the feel and structure of the bag and providing a new class of multi-functional objects. The controls are for the media player and amplifier and hence for the loudspeaker integrally incorporated in the carry case. Figure 7a shows a bag 100 which has many characteristics in common with the previous embodiments. The bag 100 is made of semi rigid but still flexible canvas material . The canvas material is shaped to form a largely self-supporting open box-like structure with two essentially panel form sides 102, two end panels (not shown) and a base (not shown) . A carry handle 104 is attached to the upper sides of the panel form sides 102. One panel form side 102 forms an acoustic diaphragm which supports bending wave vibration. First and second exciters 10,12 are mounted to first and second sound radiating regions on the inside face of the acoustic diaphragm. A low frequency loudspeaker is incorporated in a base compartment of the bag 100. The low frequency loudspeaker comprises a direct radiator speaker driver 106 mounted in a pipe 108. The pipe 108 increases the air-load on the driver and provides a resistance for the driver to push against whereby the lowest fundamental resonant frequency of the driver may be lowered. The pipe is open at both ends; both ends acting as sound sources which are out-of- phase with each other. As shown in Figure 7b and 7c, the pipe 108 has a generally rectangular cross-section. Such a shape may be used to accommodate a driver which has a generally rectangular cross-section or two cone shaped drivers mounted in a rectangular shaped support . In Figures 7d and 7e, an alternative pipe 108 has a generally circular cross-section. In both embodiments, the pipe is made of semi rigid impact resistant material which is compatible with the bag manufacture, e.g. semi rigid EVA structural foamed plastic. The low frequency pressure losses along the pipe are held sufficiently low by selecting the material, thickness of the pipe walls and cross section of the pipe .

Claims

1. A carry case or bag comprising an outer structure made from flexible sheet material and a panel-form bending wave loudspeaker having a panel-form acoustic diaphragm formed by the flexible sheet material of the outer structure and a bending wave exciter coupled to the acoustic diaphragm to cause the diaphragm to resonate to produce an acoustic output .

2. A carry case or bag according to claim 1, wherein the outer structure comprises an opposed pair of shells and means hinging the shells together.

3. A carry case or bag according to claim 1 or claim 2, wherein the flexible material of the outer structure is treated in the region of the acoustic diaphragm to modify the acoustic properties thereof.

4. A carry case or bag according to claim 3 , wherein the flexible material is treated by doping.

5. A carry case or bag according to any preceding claim, wherein the acoustic diaphragm comprises first and second regions associated with first and second acoustic channels.

6. A carry case or bag according to any preceding claim, wherein the acoustic diaphragm is designed using parameters selected from the group consisting of bending stiffness, damping, areal mass density, size and shape, to provide a desired frequency distribution of resonant modes.

7. A carry case or bag according to any preceding claim, wherein the bending wave exciter is coupled to the acoustic diaphragm at a position or location chosen to achieve desired coupling to available modes.

8. A carry case or bag according to any preceding claim, wherein the exciter is a lightweight inertial dynamic transducer . 5

9. A carry case or bag according to any preceding claim, wherein the exciter is wholly and exclusively mounted to the diaphragm. 10. A carry case or bag according to any preceding claim, comprising an externally accessible control section for

10 the loudspeaker.

11. A carry case or bag according to claim 10, wherein the control section is adapted to control a signal source, e.g. a CD player.

12. A carry case or bag according to claim 10 or claim 15 11, wherein the control section is impact-proof.

13. A carry case or bag according to any one of claims 10 to 12, wherein the control section is flexible and implemented in polymer or fabric material incorporated in the outer structure.

20 14. A carry case or bag according to any one of claims 10 to 13, wherein the control section forms part of the acoustic diaphragm.

15. A carry case or bag according to any one of the preceding claims, comprising a low frequency loudspeaker. 25

16. A carry case or bag according to claim 15, wherein the low frequency loudspeaker is concealed within a compartment of the carry case or bag.

17. A carry case or bag according to claim 15 or claim 16, wherein the low frequency loudspeaker comprises a driver mounted within a pipe.

18. A carry case or bag according to claim 17, wherein the pipe is open at both ends whereby both ends act as mutually out-of-phase sound sources.