GB2386281A

GB2386281A - Aural interface for portable communications terminals

Info

Publication number: GB2386281A
Application number: GB0205358A
Authority: GB
Inventors: Kevin Krause
Original assignee: Matsushita Communication Industrial UK Ltd; Matsushita Electric Industrial Co Ltd
Current assignee: Matsushita Communication Industrial UK Ltd; Panasonic Holdings Corp
Priority date: 2002-03-07
Filing date: 2002-03-07
Publication date: 2003-09-10
Anticipated expiration: 2022-03-07
Also published as: GB2386281B; GB0205358D0; CN1444372A

Abstract

An aural interface comprises a transparent acoustic chamber (8) superimposed on the display (7) of a portable, communications terminal and receiving sound transmitted via a sound pipe (10) from a remote loudspeaker (9). The acoustic chamber has a flexible plastic upper surface (14) separated from a rigid planar lower surface (19) by adhesive strips (18). The adhesive strips form the side walls of the chamber. The arrangement provides an increase in the area of the display. Acoustic connection between loudspeaker and acoustic chamber may be via channels formed in the moulding of the housing.

Description

Aural interface for portable communications terminals.

This invention relates to portable communication terminals and in particular it relates to aural interface arrangements for such terminals.

Previously users of mobile phones and other small portable terminals were content with relatively small display units sufficient for the display of the limited amounts of text required. With the implementation of additional services, however, larger displays are needed for presentation of larger amounts of text and graphics. Customer demand for larger displays is accompanied by an expectation of smaller, lighter and cheaper portable electronic devices.

The elements of the user interface comprising microphone 2, keypad 3, display 4 and loudspeaker 5 are usually sited on one side of the device as shown in figure 1. The microphone 2 may be referred to as the vocal interface, keypad 3 the tactile interface, display 4 the visual interface and loudspeaker 5 the aural interface.

As the size and volume of a portable terminal is reduced, these user interface elements compete for space. Further reductions in the size of the keypad are very difficult to achieve because of the finger-width separation needed between individual keys. Any decrease in size and volume of the loudspeaker is a threat to audio performance and is likely to be unacceptable. In addition the location of the antenna usually is now inside the main housing of the terminal in the region of the loudspeaker.

Effective sealing of the sound apertures of the loudspeaker against ingress of moisture and electrostatic discharge (ESD) is also a design consideration.

Various means have been proposed for using the display area of portable terminals as part of a loudspeaker. A transparent piezoelectric speaker incorporated in a mobile telephone display is disclosed in GB 2 343 811.

An electromechanical transducer is connected to a flexible display element whose vibrations provide the loudspeaker output in GB 2 360 901.

The resonant panel-form loudspeakers of WO 00/02417 are proposed for use as transparent diaphragms superimposed on the display of a mobile phone or like device. These distributed mode loudspeakers have rigid plastic or glass panels to generate the acoustic output.

All of the above arrangements require a vibration exciting means to be connected directly to an acoustic radiator and demand the use of relatively expensive or specialised components. An acoustic pipe is used in W098/59483 to connect a vocal audio input at the end of a flip with a microphone in the main body of the phone.

It is an object of the present invention to provide a simple and economical aural interface whose components may be disposed conveniently to ease conflicting location requirements in design of portable communication devices.

According to the present invention there is provided apparatus as set out in the attached claims.

An example of the invention will now be described with reference to the accompanying drawings in which like parts are designated like reference numerals and in which; Figure 1 provides a general view of a mobile phone showing the user interface elements as configured in the prior art, Figure 2 provides a general view of a mobile phone with an enlarged display area, Figure 3 is a cross sectional view of a mobile phone having an aural interface constructed according to the present invention The perspective view of figure 1 shows a mobile phone and the arrangement of user interface elements as configured in the prior art.

An outer housing 1 moulded from a plastic material such as PC/ABS may be formed, conveniently, as a"clam shell"construction with a top part la and a bottom part lb. The user interface elements of the phone are indicated in figure 1 as microphone 2, keypad 3, display 4 and loudspeaker 5.

The further perspective view of figure 2 illustrates the user interface elements of a phone embodying the present invention. The display area 4 of the phone in figure 2 is much greater than the display area of the phone in figure 1. The increase in the display area has been achieved at the expense of loudspeaker 5 as can be seen by comparison of the two figures.

An increase in the range of the aural interface has also been achieved by implementation of the invention. The position of the terminal relative to the ear of the user is less critical in the terminal of figure 2 and the sound emanating from the terminal can be received more easily. Microphone 2 and keypad 3 and their locations remain essentially the same in both arrangements.

With reference to figure 3 a simplified cross sectional view of part of a mobile phone is shown to illustrate the components associated with an aural interface constructed according to the present invention. A printed circuit board (PCB) 6 carries and interconnects most of the electronic components of the terminal. A liquid crystal display 7 of standard type e. g. model number SED15EO available from Seiko-Epson is located on PCB 6. An acoustic chamber 8 is superimposed on LCD 7. A loudspeaker 9 of standard type e. g OOH-1531 C is located on the inside of the bottom part of the case lb. A pipe 10 connects loudspeaker 9 with acoustic chamber 8.

The components 11 and 12, RF module and antenna respectively, do not form part of the aural interface. The siting of these components 11 and 12 serves to illustrate, however, the problems associated with the positioning of the loudspeaker. A transparent rigid plastic window panel 13 covers the whole surface of LCD 7 and extends beyond it in this embodiment to provide convenient access for sound pipe 10 to acoustic chamber 8. A thin transparent plastic sheet 14 extends over the whole of the window panel and is secured to the window panel by adhesive strips 18 around its

perimeter. The adhesive strips 18 form the side walls of the acoustic chamber and set the distance between sheet 14 and window panel 13.

The criterion of transparency required for the invention relates to the line of sight from the user to the main part of the display and remains materially unaffected by colouring of the adhesive strips 18 or by peripheral printing on the surfaces of sheet 14. Transparent sheet 14 is a flexible plastic and transmits to the ear of the user the sound delivered to acoustic chamber 8 via sound pipe 10.

Preferably characteristics of the plastic from which sheet 14 is formed will include good scratch resistance, and good resistance to deterioration through the effects of temperature and incident radiation. One suitable material for plastic sheet 14 has been found to be polyethylene napthalate (PEN) which is readily available in a variety of forms. Printing of characters or icons may be applied to either side of the PEN plastic sheet 14.

Sound in sound pipe 10 is admitted to acoustic chamber 8 through a port 15 in window panel 13. Where sound pipe 10 exits loudspeaker 9 and where it enters acoustic chamber 8, the interfaces may be profiled to provide improved acoustic impedance. Sound pipe 10 traverses PCB 6 through a drilled hole 16.

In this embodiment a single sound pipe 10 connects acoustic chamber 8 with loudspeaker 9. Owing to space constraints in the region of the display,

the cross-sectional area of the sound pipe 10 will be reduced as far as possible whilst retaining sufficient performance in acoustic transfer. As will be evident to those skilled in the art, many routes for and types of acoustic channel may be available to connect acoustic chamber 8 with loudspeaker 9. A rigid material would normally be preferred for sound pipe 10 in terms of acoustics but a semi-rigid plastic serves better to accommodate mechanical shock and practical routing problems.

The loudspeaker 9 is located, preferably, adjacent the cover of the terminal but may be located elsewhere within the terminal, for example on the PCB 6. The location of loudspeaker 9 is, in any event remote from the acoustic chamber 8 and interfaces with the acoustic chamber 8 only through the acoustic channel (sound pipe 10). In this embodiment a normal dual sound output is provided. In alternative embodiments the acoustic chamber 8 may be the primary, secondary or singular sound output channel.

The sound output from the larger, higher powered, part of loudspeaker 9, indicated as 9b in figure 3 is through perforations 17 in the bottom part of the case lb. The higher power output from 9b is more suitable for the hands-free mode of operation when the user is at some distance from the terminal. When the terminal is held against the ear of the user, the smaller lower powered part 9a of the loudspeaker 9 may be used and the sound conducted through sound pipe 10.

The medium of sound transmission in sound pipe 10 and acoustic chamber 8 is air, permeating the complete space from loudspeaker through sound

pipe 10 and acoustic chamber 8. Some advantages in sound transmission may be obtained by use of a non-compressible fluid medium such as water.

With sufficient attention to sealing, a transparent fluid may be in communication throughout the sound pipe and acoustic chamber. Non transparent fluids, if used for the sound pipe, would require a transducer to connect with the acoustic chamber. Each of the spaces, loudspeaker/sound pipe/acoustic chamber, may be sealed to contain separate fluids.

The acoustic channel from remote loudspeaker to acoustic chamber may be formed as an integral part of the moulding for the housing of the terminal.

An integration of this sort would be relatively difficult with the clam shell construction of the embodiment described herein. The discontinuity at the abutments of the two parts of the housing could cause some degradation in performance of the acoustic channel. For other configurations, however, improved acoustic channels may be formed in the moulding, generally to follow the contour around the inside of the housing.

Various combinations and numbers of loudspeakers, acoustic channels and acoustic chambers may be implemented to accommodate differing requirements. More than one acoustic channel may connect a single loudspeaker output with a single acoustic chamber through more than one port to the acoustic chamber. Separate loudspeakers may connect with a single acoustic chamber through one or more ports to the acoustic chamber.

Separate loudspeakers may connect with two or more acoustic chambers superimposed on a single display or superimposed separately on two or more displays.

Many constructions have been presented in which more than one display is incorporated in a communications terminal, for example in GB 2 358 985.

A separate acoustic channel may be provided for each display with both acoustic channels connecting with a single loudspeaker. Sound output from the loudspeaker may be directed through one or other of the two acoustic channels by switching. The switch from one acoustic channel to another may be implemented or activated by the movement associated with a change of configuration of the terminal.

In a flip phone or PDA (personal digital assistant) for example a closing action can block the acoustic channel to an internal display and simultaneously open an acoustic channel to an external display. A simple switch can comprise a mechanical shutter inserted or removed from the acoustic channel or caused to compress or release a flexible wall in part of a sound pipe.

In order for the acoustic chamber 8 to operate most effectively, the upper surface 19 of window 13 should be maintained in a spaced parallel relationship with plastic sheet 14. Any variation in the thickness of window 13 to produce amplification of the images on display 7 should be obtained by profiling of the lower surface 20 of window 13 or by other techniques. Where profiling of the upper surface 19 does take place two or more acoustic chambers may be used to reduce the variation between plastic sheet (s) 14 and the upper surface 19 of window 13.

Claims

Claims 1. A portable communications terminal having an aural interface comprising a transparent acoustic chamber superimposed on a display and a loudspeaker, remote from said acoustic chamber and connected with said acoustic chamber through an acoustic channel.
2. A portable communications terminal as in claim 1 in which the transparent acoustic chamber comprises a flexible sheet maintained in parallel spaced relationship from a rigid planar surface by side walls.
3. A portable communications terminal as in claim 2 in which the side walls are adhesive strips.
4. A portable communications terminal as in claims 1 to 3 in which the flexible sheet is PEN
5. A portable communications terminal as in claims 1 to 4 in which the acoustic channel is a sound pipe
6. A portable communications terminal as in claims 1 to 4 in which the acoustic channel is formed as an integral part of a housing of said terminal.
7. A portable communications terminal as in claim 6 in which the acoustic channel formed as an integral part of the housing follows generally the profile of the interior of the housing.

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8. A portable communications terminal as in any preceding claim in which the sound transfer medium from loudspeaker to acoustic chamber is air.
9. A portable communications terminal as in any preceding claim in which a non compressible transparent fluid is the sound transfer medium.
10. A portable communications terminal as in claim 9 in which the non compressible sound transfer medium is water.
11. A portable communications terminal substantially as hereinbefore described with relation to or as illustrated in the accompanying figures.