WO2001082648A2

WO2001082648A2 - Portable communications equipment

Info

Publication number: WO2001082648A2
Application number: PCT/GB2001/001740
Authority: WO
Inventors: Henry Azima; David Gamble; Neil Simon Owen
Original assignee: New Transducers Limited
Priority date: 2000-04-20
Filing date: 2001-04-18
Publication date: 2001-11-01
Also published as: AU5049601A; WO2001082648A3; GB0009704D0

Abstract

The combination of a personal portable communications device having an audio output intended for use when proximate to a user's ear, and a physically separable accessory to amplify the audio output of the communications device for remote reception, the accessory comprising a bending wave panel-form acoustic radiator, and the communications device comprising vibration transducer means for coupling to the radiator to drive bending wave energy into the radiator to produce an acoustic output therefrom.

Description

TITLE: PORTABLE COMMUNICATIONS EQUIPMENT

DESCRIPTION

TECHNICAL FIELD

The invention relates to portable communications equipment, e.g. personal communications equipment, e.g. mobile telephones or data organisers.

BACKGROUND ART It is a problem for small portable personal communications devices such as mobile telephones, hereinafter "mobile phones" and the like to achieve a sufficient sound output to be effective otherwise than when directly adjacent to the user's ear, for example, at a distance for use simultaneously by more than one person, e.g. as in a conference call, or in a noisy environment. It is an object of the invention to provide means whereby portable personal communications equipment can achieve higher sound levels.

DISCLOSURE OF INVENTION According to the invention, there is provided the combination of a personal portable communications device having an audio output intended for use when proximate to a user's ear, and a physically separable accessory to amplify the audio output of the communication device for remote reception, the accessory comprising a bending wave panel- form acoustic radiator, and the communications device comprising vibration transducer means capable of being detachably coupled to the radiator to drive bending wave energy into the radiator to produce an acoustic output therefrom. The radiator may operate as a resonant panel loudspeaker e.g. a distributed mode loudspeaker (DML) as set out in WO97/09842. The separate accessory may be as simple as a single piece of flat or shaped material e.g. a panel or a complex docking station containing many features such as power supply, additional displays etc.

BRIEF DESCRIPTION OF DRAWINGS The invention is diagrammatically illustrated, by way of example, in the accompanying drawings in which: -

Figure 1 is a side view of a first embodiment of the invention;

Figure 2 is a front view of the embodiment of Figure 1;

Figure 3 is a side view of a second embodiment of the invention;

Figure 4 is a front view of the embodiment of Figure 3;

Figures 5 and 6 are side views of respective third and fourth embodiments of the invention, and Figure 7 a frequency response graph.

BEST MODES FOR CARRYING OUT THE INVENTION In Figures 1 and 2 of the drawings, there is shown an accessory object or device (3) for amplifying the sound output of an electronic personal portable communications device (4), e.g. a mobile phone, the accessory device comprising a generally rectangular rigid lightweight bending wave acoustic radiator panel (3) having downwardly facing compliant ground engaging projections (6) in its corners and adapted to lay flat above a suitable surface (not shown) , e.g. a desk top, and so as to be raised from the surface by the projections (6) which thus form feet. The panel is adapted to carry the mobile phone or other device (4) on upstanding compliant projections (5) extending from the upper surface of the panel so that the device (4) is raised from the surface of the panel. The panel is formed with a domed portion (2) adapted to couple to a vibration exciter or transducer (1) in the device (4) so that the exciter (1) can drive bending wave vibration into the panel (3) to produce an acoustic output, e.g. as taught in WO97/09842. In this way the acoustic output from the device (4) can be amplified at low cost.

The device (3) of Figures 3 and 4 is generally similar to that described above, but in this case the panel (3) is supported generally upright by feet in the form of brackets (8) engaging the panel (3) near to its corners. For this reason, the device (4) is supported on a spring bracket (9,10) on the panel, so that its vibration exciter is coupled to the panel.

The electronic equipment, e.g. mobile phone, (4) may already contain a bending wave panel or other loudspeaker (7) from which the excitation for the accessory panel (3) can be obtained. The additional panel (3) can then amplify the acoustic output to provide a more clearly audible signal of greater loudness, bandwidth or both. A reduction in distortion might also be possible from certain configurations. A mechanical coupler (2) may be provided on the device (4) as the route by which the vibration force is imparted to the accessory panel (3) . The properties of the coupler may be tailored to achieve the required result but in general a longitudinally stiff connection would be appropriate . The coupler may be operated in compression such that the variations in force due to vibration component do not cause disconnection of the coupler. In Figs 1,2 & 6 this is achieved using the force of gravity, i.e. using the weight of the equipment (4) bearing on the coupler. Alternatively a locking coupling as shown in Fig. 5 may be employed. Here a mechanism is used which is able to carry the force due to vibration without separating the excitation device (1) from the panel (3) . For removal, the electronic device is separated from the panel by using a force in a perpendicular direction or a force greater than that due to vibration in the same axis as the coupled vibration. Magnetic coupling may also be used. 5 Figs 3 & 4 show a force imparted on the coupler by a spring clip (9,10) . The spring itself (9) may be dispensed-with if the gravitational force is sufficient for operation. The stand (8) or feet (6) may be coupled to the bending wave panel at points of low vibrational activity as

10 determined by DML design rules as set out in WO97/09842 so that it does not unduly affect the performance of the panel. Similarly the position at which the device (4) is coupled to the panel may also be determined by DML design rules to effect the required performance.

15 Figure 7 shows the results of a test mobile phone when used in conventional fashion and as depicted in Figures 3 and 6. The test mobile phone is fitted with a bending wave panel and exciter loudspeaker system that produces the result shown in the thickest line. The measurement is

20 taken at 1 metre with the test mobile phone resting on a large flat surface to represent a desk or similar object. The bending wave panel speaker of the test mobile phone is facing upwards and the measurement microphone is directly above it. The test mobile phone measures 50mm by 100mm by

25 12mm thick and has a mass of 45 grams. The bending wave panel of the test mobile phone measures 38mm by 47mm and is made of 1mm polycarbonate. All measurements are carried out with the same drive level from the amplifier. The accessory device (3) which forms the bending wave radiator measures 230mm by 320mm by 2mm thick and is made from "Acoustic 66" material. A convex coupler dome (2) and four feet (6) were fitted in accordance with DML design rules as set out in WO97/09842 so as not to unduly affect the performance of the panel .

The thin curve shows the result of the accessory radiator when lying flat on a large surface as depicted in Figure 6. The object is spaced from the surface by its four feet to a height of βmm. The test mobile phone is placed on the accessory device such that the coupler dome rests at the excitation position of the test mobile phone bending wave panel. The coupling force is obtained from the weight of the test mobile phone only and no additional fixings were used. Two small feet were fitted to the test mobile phone to give a tripod support when used collectively with the dome coupler. These space the test mobile phone at a distance of 3mm from the accessory panel.

The response is measured as previously described. ^"It is clear that the bandwidth has been substantially improved, with useful output down to 700Hz as opposed to 2.5kHz obtained with the test mobile phone on its own. There^' are no substantial changes to the high frequency performance. The average sensitivity can be seen to have also increased over the usable range with particular emphasis to -the speech intelligibility range of 1 to 3kHz.

The medium thickness curve shows the performance with the accessory panel now supported as depicted in Figure 3. The angle of the^' panel was set to 75 degrees to the horizontal as this still allows coupling by gravity alone, and no clip (9) was required. The measurement was carried out at 1 metre, parallel to the horizontal and aligned with the centre of the accessory panel . This curve shows that the usable bandwidth has now increased further and there is useful output down to 320Hz. The sensitivity over the usable range is no higher than the test mobile phone but the sensitivity-bandwidth product has increased substantially. In this configuration the sound quality is exceptional when compared with the test mobile phone alone.

The increased bandwidth allows for speech or music reproduction with clarity and sufficient volume to fill a small room. It will be appreciated that mobile phones are known having sound outputs which can be adjusted between a personal use position, in which the phone is held proximate to the user's ear and a second position in which the sound level from the phone is higher for remote use. The present invention is nevertheless effective to amplify still further the sound output from such devices .

Claims

1. The combination of a personal portable communications device having an audio output intended for use when proximate to a user' s ear, and a physically separable accessory to amplify the audio output of the communication device for remote reception, the accessory comprising a bending wave panel-form acoustic radiator, and the communications device comprising vibration transducer means capable of being detachably coupled to the radiator to drive bending wave energy into the radiator to produce an acoustic output therefrom.

2. The combination of claim 1, wherein the radiator is formed with ground engaging feet adapted to raise the radiator from a ground surface.

3. The combination of claim 2, wherein the ground engaging feet support the radiator at an acute angle with respect to the ground surface.

4. The combination of any one of claims 1 to 3 , wherein the communications device is adapted to be supported on the radiator, whereby coupling of the vibration transducer means to the radiator is at least partially by gravity.

5. The combination of any preceding claim, wherein the radiator is formed with a raised coupler portion.

6. The combination of claim 5, wherein the radiator is formed with means to support the communications device above the radiator.