GB2362287A

GB2362287A - Hands free adapter for mobile telephones comprising a non-metallic two way communication link.

Info

Publication number: GB2362287A
Application number: GB0011270A
Authority: GB
Inventors: Peter Lockhart; Bradley Richard Firth
Original assignee: Roke Manor Research Ltd
Current assignee: Roke Manor Research Ltd
Priority date: 2000-05-11
Filing date: 2000-05-11
Publication date: 2001-11-14
Anticipated expiration: 2020-05-11
Also published as: GB0011270D0; GB2362287B

Abstract

A hands free mobile phone of a mobile phone hands free adapter comprising a non-metallic two way audio communication link between the user and the mobile phone apparatus proper. The mobile phone hands free adapter may comprise an adapter body, an ear piece coupled acoustically to the adapter body via an acoustic waveguide, an optical transducer microphone positioned and arranged to receive in use, acoustic signals corresponding to a user's voice, and to produce corresponding optical signals, and a fibre optic link via which the optical signals are transmitted to the adapter body, and a connector integral with the adapter body for coupling the adapter body to a complementary connector portion of a mobile phone so that audio signals from the phone are conveyed in one direction via the acoustic waveguide from the mobile phone to the ear piece and signals corresponding to a user's voice are conveyed in the opposite direction via the fibre optic link to the mobile phone.

Description

2362287 Improvements in or relating to mobile phones.

This invention relates to mobile phones and more particularly but not exclusively it relates to mobile phone hands free adapters.

Hands free adapters and adapter kits for mobile phones, which enable a phone to be used in a vehicle without the need for hand support, are very well known. Such adapters were introduced for safety reasons to facilitate hands free use of the phone by a driver so that vehicle control is not adversely affected by phone use. However, it is now recognised that such adapters may act as antennas which serve to concentrate, (albeit inadvertently) radio signals radiated from the phone during normal transn-fissions, in a region which includes a user's head. The effects of this concentration of radiation in and around the brain, although not fully understood, are generally accepted to be undesirable at the frequencies used, and consequently should be avoided if at all possible.

It is an important object of the present invention to provide a mobile phone hands free adapter wherein the aforesaid disadvantage of radiation concentration in or around a user's head is obviated or very significantly reduced.

According to the present invention as broadly conceived, a mobile phone or a mobile phone hands free adapter comprises a non-metallic two way audio conununication link between the user and the mobile phone apparatus proper.

According to one aspect of the present invention, the mobile phone hands free adapter may comprise an adapter body, an ear piece coupled acoustically to the adapter body via an acoustic waveguide, an optical transducer microphone positioned and arranged to receive in use, acoustic signals corresponding to a user's voice, and to produce corresponding -2optical signals, and a fibre optic link via which the optical signals are transmitted to the adapter body, and a connector integral with the adapter body for coupling the adapter body to a complementary connector portion of a mobile phone so that audio signals from the phone are conveyed in one direction via the acoustic waveguide ftom the mobile phone to the ear piece and signals corresponding to a user's voice are conveyed in the opposite direction via the fibre optic link to the mobile phone.

By using an acoustic waveguide and a fibre optic link which are both nonmetallic, it is apparent that the adapter can not inadvertently act as an antenna, which would serve to concentrate radio signals produced by the mobile phone in or around a user's head.

Although a hands free adapter may be provided in accordance with one aspect of the invention, it is also contemplated that a purpose built hands free mobile phone may be provided in accordance with an alternative aspect of the invention, which comprises a mobile phone housing, an ear piece coupled acoustically to the housing via an acoustic waveguide, an optical transducer microphone positioned and arranged to receive in use, acoustic signals corresponding to a user's voice, and to produce corresponding optical signals, and a fibre optic link via which the optical signals are transmitted to the housing, so that in use, audio signals from a speaker in the housing are conveyed in one direction via the acoustic waveguide ftorn the housing to the ear piece and so that signals corresponding to a user's voice are conveyed in the opposite direction via the fibre optic link to optical detector apparatus in the housing.

The optical transducer microphone may comprise any suitable optical displacement transducer based either on the interferometric principle using a coherent light source such as a semiconductor laser, or -3alternatively on the use of an incoherent light source, both of which are well known and which accordingly will not be described herein in great detail.

In the case of the use of an incoherent light source, this may comprise an LED (light emitting diode) for example, which is used to transmit light via the optical fibre to a near field silicon microphone which in use serves to modulate LED light with received audio signals to provide corresponding light modulation which is reflected back down the optical fibre to be received by a photo detector.

The photo detector may comprise a photo diode coupled to the optical fibre.

In the case of an adapter, an interface between the adapter and the mobile phone may comprise electrical connections only, conversion as appropriate of optical and acoustic signals to electrical signals being effected in the adapter.

Alternatively, an interface which facilitates the transfer of audio and optical signals from the adapter to the mobile phone may be provided.

A still further alternative would be an interface which is designed to provide for a combination of electrical and acoustic and/or audio signals.

One embodiment of the invention will now be described with reference to the accompanying drawings in which; Figure 1, is a somewhat schematic view of a hands free mobile phone assembly and; Figure 2, is a block schematic diagram of a sensor system which forms a part of the hands free mobile phone assembly as shown in Figure I.

Referring now to Figure 1, the assembly comprises an ear-piece 1, which is arranged to convey sound from a mobile phone 2, to the ear 3, of a user 4, via an adapter 5, and an acoustic waveguide 6, which waveguide 6, serves to acoustically couple the adapter 5, to the ear-piece 1. The assembly additionally comprises an optical transducer microphone 7, which serves to convert signals corresponding to the voice of the user 4, to corresponding optical signals which are carried via a flexible plastics multi-mode optical fibre 8, to the adapter 5. The mobile phone 2, and the adapter 5, are arranged to embody complementary interface connector parts 2a, and 5a respectively which co-operate to complete a non-metallic link for the transmission of signals between the user 4, and the mobile phone 2, which since it is non-metallic, can not serve as an antenna for the inadvertent radiation of microwave signals around the head of the user 4.

As shown in Figure 2, wherein parts corresponding to those shown in Figure 1, bear as appropriate the same numerical designations, the earpiece 1, comprises a micro-machined near field silicon microphone 9, which is positioned and arranged to be acoustically stimulated by the voice of the user 4, so that radiation received from an LED 10, in the adapter 5, which is transmitted along the optical fibre 8, to the n- ficrophone 9, is modulated at audio frequency. Light from the LED thus modulated, is reflected back along the optical fibre 8, to the adapter 5, wherein it is received at a coupler 11, and used thereafter to stimulate a photo-diode 12. Corresponding electrical signals from the photo-diode 12, are then amplified in an amplifier 13, and fed to the mobile phone via the interface connector parts 5a, 2a, which mutually couple the mobile phone to the adapter 5.

Various modifications may be made to the arrangements as just -5before described without departing from the scope of the invention. For example the coupler 11, may alternatively comprise a beam splitter and instead of the silicon microphone a reflective diaphragm may be used, the essential feature being to provide for communication without the use of an electrical conductor which might serve unintentionally to produce unwanted radiation.

Additionally it will be readily apparent that the functions performed by the adapter as hereinbefore described could be included within the mobile phone itself, thereby to provide a purpose built mobile phone which affords the important advantage of hands free operation without the possible attendant risks which are thought to be associated with relatively high levels of micro-wave radiation around the head of a user.

Claims

CLAIMS.

1. A hands free mobile phone or a mobile phone hands free adapter comprising a non-metallic two way audio communication link between the user and the mobile phone apparatus proper.

2. A hands free mobile phone as claimed in Claim 1, comprising a mobile phone housing, an ear piece coupled acoustically to the housing via an acoustic waveguide, an optical transducer microphone positioned and arranged to receive in use, acoustic signals corresponding to a user's voice, and to produce corresponding optical signals, and a fibre optic link via which the optical signals are transmitted to the housing, so that in use, audio signals from a speaker in the housing are conveyed in one direction via the acoustic waveguide from the housing to the ear piece and so that signals corresponding to a user's voice are conveyed in the opposite direction via the fibre optic link to optical detector apparatus in the housing.

3. A mobile phone hands free adapter as claimed in Claim 1, comprising an adapter body, an ear piece coupled acoustically to the adapter body via an acoustic waveguide, an optical transducer microphone positioned and arranged to receive in use, acoustic signals corresponding to a user's voice, and to produce corresponding optical signals, and a fibre optic link via which the optical signals are transmitted to the adapter body, and a connector integral with the adapter body for coupling the adapter body to a complementary connector portion of a mobile phone so that audio signals from the phone are conveyed in one direction via the acoustic waveguide from the mobile phone to the ear piece and signals corresponding to a user's voice are conveyed in the opposite direction via the fibre optic link to the mobile phone.

4. A hands free mobile phone adapter as claimed in Claim 1, or Claim 3, in operative association with a mobile phone.

5. A hands free mobile phone or a mobile phone hands free adapter as claimed in any preceding claim wherein the optical transducer 5 microphone comprises an optical displacement transducer.

6. A hands free mobile phone or a mobile phone hands free adapter as claimed in Claim 5, wherein the optical displacement transducer comprises an LED or a semiconductor laser which is used to transmit light via the optical fibre to a near field silicon microphone which in use serves to modulate this light with received audio signals to provide corresponding light modulation which is reflected back down the optical fibre to be received by a photo detector.

7. A hands free mobile phone or a mobile phone hands free adapter as claimed in Claim 6, wherein the photo detector comprises a photo diode coupled to the optical fibre.

8. A mobile phone hands free adapter as claimed in Claim 1, or any of claims 3, to 7, wherein an interface between the adapter and the mobile phone comprises electrical connections only, conversion as appropriate of optical and acoustic signals to electrical signals being effected in the adapter.

9. A hands free mobile phone substantially as hereinbefore described with reference to the accompanying drawings.

10. A hands free mobile phone adapter substantially as hereinbefore described with reference to the accompanying drawings.