RADIO FREQUENCY TELEPHONE HANDS FREE KIT

Abstract: A mobile phone hands free kit comprising an earphone (1), a microphone (3), and a two-way communication optical fibre link (12) for connecting the microphone (3) and the ear phone (1) to a radio frequency telephone (220). First and second transducer means 10, 14 and 25, 28 respectively) are provided, each of which comprises a first transducer (10, 25) located at one end of the optical fibre link (12) and a second transducer (14, 28) located at the other end of the optical fibre link (12). The first transducer means (10, 14) is operable, in use, to receive electrical signals from the microphone (3), convert the electrical signals into light signals for transmission by the optical fibre link (12(a)), receive the light signals from the optical fibre link (12(a) and convert them to electrical signals to be used by the telephone (22). The second transducer means (25, 28) is operable, in use, to receive electrical signals from the telephone (22), convert the electrical signals into light signals for transmission by the optical fibre link (12(b)), receive the light signals from the optical fibre link (12(b)), receive the light signals from the optical fibre link (12(b)) and convert them to electrical signals to be used by the ear phone (1).

Description: RADIO FREQUENCY TELEPHONE HANDS FREE KIT This invention relates to a radio frequency telephone hands free kit of the type comprising an earphone, microphone and micro-jack all interconnected by pairs of conductive wires clad in plastic, enabling a user to engage in a telephone conversation whilst simultaneously being able utilise both hands for other activities. One of the advantages of hands free kits was thought to be that they would eliminate or reduce harmful electromagnetic radiation of the transmitted or received signals in and around the brain of the telephone user. It is now generally accepted that such hands free kits act as an antenna that, rather than reduce the radiation in and around the brain of the user, actually inadvertently concentrates the radiation in and around the brain of the user. An object of this invention is to provide radio frequency telephone hands free kit, which, when utilised will significantly reduce the users exposure to radio frequency radiation, especially to the brain of the user. According to one aspect of the present invention as claimed in the attached claims hands free kit that utilises an optical fibre in addition to a conventional wire conductor is provided that, in use, will reduce exposure of the user to radio frequency radiation. The present invention will now be described, by way of examples, with reference to the accompanying drawings, in which Figures 1 to 8 show, schematically, different designs of hands free kits constructed in accordance with the present invention. Referring to Figure 1 there is shown a hands free kit comprising a prior known design of an earphone 1 , and microphone 3 that are connected to a three terminal micro-jack 5 by three plastic covered conductors of cables 2, and 4. As is well known in such an arrangement, the earphonel and microphone 3 share a common earth connection. The micro-jack 5 is inserted into the input socket of a transducer means 6 having a common earth connection connected to an earthed connection of a power supply 8 that is provided within the transducer means 6. The transducer means 6 comprises a plastic case that accommodates a pair of transducers 10, 28 that are connected to the power supply 8 by way of twin core cables 9, and 29 that supply positive and negative potentials. The transducers 10, 28 are connected to an optical fibre link 12 that comprises two discrete optical fibres 12(a) and 12(b). Preferably the two fibres 12(a), 12(b) are contained within a single outer covering to form a unitary optical cable link 12. The transducer 10 is connected to the optical fibre 12(a) and converts the electrical signal from the microphone 3 into a light signal that is transmitted through the optical fibre 12(a). A second pair of transducers 14, 25 is located in a transducer means 18 that also houses a power supply 16 that powers the transducers 14, 25. The transducers 14,25 are connected to the other end of the optical fibre link 12. The transducer 14 receives the light signals generated by the transducer 10 and converts the light signal received from the optical fibre 12(a) to an electrical signal that is supplied to the input socket of the mobile telephone 22. Data transmitted by the telephone 22 as an electrical signal, is received by the transducer 25 that operates to convert the electrical signal derived from the telephone into light signals that are transmitted to the transducer 28 located in the transducer means 6, by the optical fibre 12(b). The transducer 28 converts the light signal from optical fibre 12(b) into an electrical signal that is fed to the earphone 1 by one conductor of the cable 2. In greater detail, the hands free kit shown in Figure 1 works as follows. To send data such as speech to be transmitted in a telephone conversation, the user speaks into the microphone 3. The data is sent as an electrical signal along one of the non-earthed conductors of the cable 4 through the micro-jack 5 to the input socket of the transducer means 6. The electrical signal is fed by a wire 7 in the transducer means 6 and is converted to an optical light signal by the transducer 10. The optical signal is then sent to the transducer 14 of the transducer means 18 via an optical fibre 11 (part of the transducer means 6), the optical fibre 12(a), and an optical fibre 13 located in a second transducer means 18. The transducer 14 converts the light signal into an electrical signal, drawing current from a power source 16, and the electrical signal is sent along a wire 17 enclosed in the transducer means 18 and a conductor of an external cable 19. The signal is supplied to the micro jack 20 where it enters into the mobile phone 22 via adapter 21 , and is processed by the telephone 22. By altering the bottom coupler connection of the adapter to suit each model of telephone 22, the adapter 21 can be used for any brand of radio frequency phone. To receive data during a conversation, the radio frequency phone 22 receives the data transmitted as a radio frequency signal, converts it into an electrical signal and then sends the electrical signal via the adapter 21 through the mini jack 20 and through a second conductor of the cable 19 to a transducer 25 of the transducer means 18. The transducer 25 converts the signal from an electrical signal to an optical light signal that is then sent to a transducer 28 housed inside the transducer means 6, along the optical fibre 26 (enclosed in transducer means 18), optical fibre 12(b), and optical fibre 27. The transducer 28 converts the light signal back into an electrical signal and sends it along wires 30, and the non-earthed conductor of cables 4 and 2 to the earphone 1. The earphone converts the electrical signal into sound waves. The transducers 10, 14,25, 28 are powered by a compatible power source such as a battery or cell connected to the appropriate transducers by the twin conductor cables 9, 15,24 and 29. The phone is placed a distance away from the users head and body whilst 'wearing' the earphones 1 and the microphone 3. The case of the transducer means 6 has a clip (not shown) to attach it to the user's clothing. The hands free kit shown in Figure 2 is very similar to that shown in Figure 1. Accordingly like components are numbered with the- same reference numbers as used in Figure 1. Referring to Figure 2, the transducer means 18 is effectively combined with the adapter of 21 of Figure 1. The transducer means 18 includes the transducers 14 and 25, optical fibre 13, and wires 17. The wires 17 are connected via the interface port on the base of the telephone 22 to the terminals connected to the battery of the telephone. The electrical signal from the transducer 14 is supplied directly to the data input socket of the phone 22. The telephone 22 processes the data and transmits it to a recipient's telephone. Similarly the data from the telephone 22 is transmitted to the earphone 1 through the wires, transducers 25 and 28 and the optical fibre 12(b) as described in connection with Figure 1. The transducers 14 and 25 are powered from a battery 16 through twin core cables 23, 24. The hands free kit shown in Figure 3 is very similar to that shown in Figure 2. Accordingly like components are numbered with the same reference numbers as used in Figure 2. Referring to Figure 3 an internal module 18 within the telephone 22 effectively replaces the combined adapter and transducer means 18 shown in Figure 2. The internal module 18 constitutes a transducer means, and includes basically the transducers 14 and 25, and wires 17. The wires 17 are connected to the terminals of the battery of the telephone 22, and the optical fibres 12(a). 12(b) of the optical fibre link 12 are connected directly to the appropriate transducers 14, 25 within the module 18. The hands free kit shown in Figure 4 is very similar to that shown in Figure 1. Accordingly like components are numbered with the same reference numbers as used in Figure 1. Referring to Figure 4 the transducer means 18 is provided with additional components to those shown in Figure 1. The additional components comprise a radio requency transmitter 33 and radio frequency receiver 43. The electrical signals produced by the transducer 14 are fed by wires 17 in the transducer means 18 directly to the transmitter 33 and the signals are transmitted by the transmitter as a radio frequency signal. The telephone 22 is provided with a radio receiver / transmitter 35 that comprises a receiver 36 that receives the radio signal transmitted by the transmitter 33, and a transmitter 41 that receives an output electrical signal from the telephone 22. The transmitter 41 transmits the radio signal from the telephone 22 to the receiver 43. The receiver/transmitter 35 is connected via cable 19 to the adapter 21 , which, in turn is connected to the telephone 22. The transmitters 33, 41 and the receivers 36, 43 are powered from the respective power supplies 16, 47 by means of twin core cables supplying positive and negative ptentials. The hands free kit shown in Figure 5 is very similar to that shown in Figure 4. Accordingly like components are numbered with the same reference numbers as used in Figure 4. Referring to Figure 5, the transmitter/receiver 35 is made as part of the adapter and the cable 19 is dispensed with. In this case, the transmitter 36 and receiver 41 are powered from the battery of the telephone22 through twin core cables 37 and 40 respectively, and the electrical signal from the transducer 36 is supplied via wires 38 connected to the input terminal of the telephone 22. Similarly the electrical output signal from the telephone 22 is supplied via wires 39 to the transmitter 41. The hands free kit shown in Figure 6 is very similar to that shown in Figure 4. Accordingly like components are numbered with the same reference numbers as used in Figure 4. Referring to Figure 6, an internal module 48 within the telephone effectively replaces the transmitter/receiver 35 shown in Figure 4. The internal module 48 includes basically the transmitter 36 and receiver 43 and they are powered from the internal battery of the phone. The hands free kit shown in Figure 7 is very similar to that shown in Figure 1. Accordingly like components are numbered with the saiηe reference numbers as used in Figure 1. Referring to Figure 7, two transducer means 6 and 18 are accommodated within the same casing 50. The transducers 10 and 14 are linked together by an optical fibre link 12(a) and the transducers 25 and 28 are linked together by an optical fibre link 12(b). In other respects the kit operates in the same way as that of Figure! In the above-described embodiments, the microphone is described as a conventional electromagnetic microphone connected by a pair ' of wires in cable 4 to the transducer 10. It is to be understood that the microphone could be a piezo electric microphone, or a micro- machined Near Field silicon microphone that generates an electrical signal that is supplied directly to the transducer 10. Indeed it would be advantageous to mount such a microphone directly to the transducer means 6 to reduce or eliminate the conductors in cable 4 that are connected to the microphone. It may be advantageous to reduce the length of the wires in cables 2 and 4 connected to the earphone 1 or eliminate them altogether. One way of doing this would be to extend the optical fibre link 12(a) so that it terminates in the earphone (1). The transducer 10 would then be located in the earphone 1 and a separate power supply (battery) would be provided in the earphone 1 to power the transducer 10 and earphone 1. In this arrangement the first transducer means (6) effectively embraces the transducer 10 in the earphone 1 as well as transducer 28. In the above-described embodiments, the transducers 10,14,25,and 28, the transmitters 33, 41 , and receivers 35, 43 are powered by a compatible power source such as a battery or cell. If desired, the optical fibre link 12 could be provided with a third optical fibre 12(c) as shown in Figure 8 that is dedicated to providing power to the transducers 10, 28. Transducers 54 55 provided at each end of the. third optical fibre 12(c) respectively generate and receive light signals that are transmitted by the fibre 12 (c). The electrical signal generated by transducer 55 is used by an intelligent power supply management chip incorporated in the power supply 8 and converted into electrical current to power the transducers 10, 28, or is used to charge a rechargeable battery. The third fibre 12 (c) could also be used to power the other transducers 25 28 and /or the transmitter 33 and / or the receiver 43. The third fibre 12 (c) could be extended to the earphone to power the earphone 1 and transducer 10, in which case the transducer 55 would be provided in the earphone 1. If desired, the power supply 8 could be provided by a solar panel that generates sufficient power either to drive the transducers, transmitters and receivers, or to re-charge chargeable batteries. There is an emerging technology developed by a company called Bookham Technologies Inc. that incorporates an optical fibre in a microchip for applications related to optical links to computers. It may be possible to incorporate such technology into the embodiments of the present invention. For telephones that download MPEG files for playing music over the phone, the earphone 1 could be replaced by stereo earphones providing the suitable modifications are made in order to make the earphones work properly.

Claims: CLAIMS 1. A mobile phone hands free kit comprising an earphone (1), a microphone (3), a two way communication optical fibre link (12, 12 (a), 12(b)) for connecting the microphone (3) and the ear phone (1) to a radio frequency telephone (22), there being a first transducer means (6) located at one end of the optical fibre link (12) for converting electrical signals from the microphone (3) into light signals to be transmitted through the optical fibre link (12), and for receiving light signals transmitted by the optical fibre link (12, 12(b)) and converting the light signals into electrical signals to be used by the earphone (1), and a second transducer means (18) located at the other end of the optical fibre link (12), for converting light signals transmitted by the optical fibre link (12, 12(a) into electrical signals to be used by the telephone (22), and for converting electrical signals from the telephone (22) into light signals to be transmitted through the optical fibre link.(12, 12(b)). 2. A hands free kit according to claim 1 wherein the optical fibre link (12) comprises two discrete optical fibres (12(a), 12(b)). 3. A hands free kit according to claim 1 or claim 2 wherein each transducer means (6,18) comprises two transducers (10, 28, or 14, 25); one (10, 25) for converting electrical signals into light signals and one (14, 28) for converting light signals into electrical signals. 4. A hands free kit according to claim 3 wherein a first transducer (10) of the first transducer means (6) is operable, in use, to receive electrical signals from the microphone (3), a second transducer (28) of the first transducer means (6) is operable, in use, to receive light signals from the optical fibre link (12(b)) and convert them to electrical signals to be used by the earphone (1), a first transducer (14) of the second transducer means (18) is operable, in use, to receive the light signals from the optical fibre link (12(a)) and convert them to electrical signals to be used by the telephone (22), and a second transducer (25) of the second transducer means(18) is operable, in use, to receive electrical signals from the telephone 22, and convert them into light signals for transmission by the optical fibre link 12(b). 5. A hands free kit according to any one of the preceding claims wherein the second transducer means (18) accommodates a transmitter (33) adapted to receive an electrical signal generated by a transducer (14) from light signals transmitted through the optical fibre link 12(a), and transmit said electrical signal as a radio signal to the telephone (22), and a receiver (43) adapted to receive radio signals transmitted by the telephone (22) and produce therefrom an electrical signal that is supplied to a transducer (25), the telephone (22) being further provided with a radio receiver (36) for receiving the radio signal transmitted by the transmitter (33) of the second transducer means (18) and a radio transmitter (41) for transmitting an output signal to the receiver (43) of said second transducer means (18), said receiver (43) of the second Transducer means being operable, in use, to convert the radio signal received from the telephone (22) into electrical signals that are converted to light signals that are transmitted to the earphone (1) via the optical fibre link (12(b) and transducers (25, 28). 6. A hands free kit according to claim 2 wherein one of the optical fibres (12(a)) is dedicated to receiving and handling signals derived from the microphone (3) and the other optical fibre (12(b) is dedicated to receiving and handling signals derived from the telephone (22). 7. A hands free kit according to any one of claims 2 , 5 or 6 wherein a third optical fibre (12(c)) is provided for supplying power to be used by the transducers (10, 28) of the first transducer means (6). 8. A hands free kit according to any one of claims 2 , 5, 6 or 7) wherein a third optical fibre (12(c)) is provided for supplying power to be used by the transducers (14, 25) of the second transducer means (18). 9. A hands free kit according to any one of claims 2, 5, 6, 7, or 8 wherein a third optical fibre (12(c)) provides power to the transmitter (33) and the receiver (43) of the second transducer means (18). 10. A hands free kit according to any one of the preceding claims wherein an analogue-to- digital converter is provided to convert analogue electrical signals from the microphone (3) to the first transducer means (6), and analogue signals from the telephone (22) to the second transducer means (18) into digital signals, and a digital-to-analogue converter is provided for converting digital electrical signals from the transducers (14, 28) into analogue signals for supply to the earphone (1) or the telephone (22) as the case may be. 11. A hands free kit according to any one of the preceding claims wherein the first and second transducer means (66, 18) are accommodated in a common casing, and optical fibres (51 , 52) are provided within the casing to connect the transducers of the first transducer means (6) to the transducers of the second transducer means (18). 12. A hands free kit according to anyone of the preceding claims wherein the microphone is mounted on a casing in which the first transducer means is provided. 13. A hands free kit according to any one of the preceding claims wherein the microphone (3) is a piezo electric microphone. 14. A hands free kit according to any one of the preceding claims wherein the microphone (3) is a near field effect silicon microphone. 15. A hands free kit according to any one of the preceding claims wherein a transducer (10) of the first transducer means (6)-is located in the earphone (1).

Inventors: HALL JAMES, HALL, JAMES
Applicants: HALL JAMES, HALL, JAMES
Application year: 2001
Main classification: H04M1
IPC codes: H04B1, H04M1