WO1996007243A1

WO1996007243A1 - Auxiliary equipment for mobile telephones

Info

Publication number: WO1996007243A1
Application number: PCT/FI1995/000462
Authority: WO
Inventors: Veijo Haapanen
Original assignee: Co-Pat Oy
Priority date: 1994-08-30
Filing date: 1995-08-30
Publication date: 1996-03-07
Also published as: AU3260095A; FIU940435U0; FI1638U1

Abstract

Auxiliary equipment for a mobile telephone (14) to facilitate the simultaneous use of the mobile telephone (14) and an automobile radio (12) includes a detection unit (16) to measure radio wave field intensity in the vicinity of the mobile telephone (14). The detection unit (16) is connected to an antenna (17) and a control unit (20). The control unit (20) controls automobile radio (12) by at least one actuator in response to the radio wave field intensity measured by the detection unit (16).

Description

AUXILIARY EQUIPMENT FOR MOBILE TELEPHONES

Field of invention

This invention relates to auxiliary equipment for mobile telephones that automatically controls an automobile radio to reduce audio and RF interference between a mobile te¬ lephone and the automobile radio.

Background of the invention

Mobile telephones, such as handheld cellular telephones, are increasingly used as businesses and consumers recognize their benefits. One benefit of these telephones is their portability, which promotes their use in automobiles. Howe¬ ver, mobile telephones, especially digital telephones, emit radio waves or frequencies, that can interfere with automo¬ bile radios. This interference is sometimes manifested by a "buzzing" sound from an automobile radio when the transmit- ter of the mobile telephone is transmitting. Another type of interference arises when the sound from the radio is loud enough to impair a conversation using the mobile telephone.

These types of interference can be eliminated by turning the radio off, or by attenuating or muting the sound from the automobile radio. Yet eliminating the interference by such techniques is physically complicated and can cause unneces¬ sary danger to the safe operation of the automobile since the operator must operate both the mobile telephone and the automobile radio while steering the automobile.

Yet another type of interference occurs when the sound from the radio is so loud that an incoming telephone call to the mobile telephone cannot be audibly detected. The magnituse of the deleterious affect of this interference is commensu¬ rate with the importance of the undetected incoming telepho- ne call .

Summary of the invention

The present invention eliminates the disadvantages mentioned above by providing a system that renders mobile telephone use in an automobile safer and easier than before. The pre¬ sent invention provides a detector unit that, with the aid of an antenna, measures the field intensity of radio wave or frequency emissions in the vicinity of the mobile telephone.

A control unit is connected to the detector unit that, based on the field intensity measured by the detector unit, cont¬ rols at least one actuator to preferably mute sound genera- ted by an automobile radio.

The present invention automatically switches the automobile radio off or automatically mutes the sound from the automo¬ bile radio by activating the actuator when the mobile te- lephone is used, or when an incoming call from a digital telephone (e.g. in a GSM system) is detected. In digital telephones namely the transmitter is activated immediately after incoming calls. The muting will last as long as the call is active. This provides increased safety of the auto- mobile operation since the operator does not have to physi¬ cally interact with the automobile radio while using the mobile telephone and steering the automobile. In addition, the present invention can reduce the sound level of audible interference from the automobile radio so that safe simula- taneous use of the mobile telephone and the automobile radio is facilitated.

Numerous other advantages and features of the present inven¬ tion will become readily apparent from the following detai- led description of the invention and the embodiments there¬ of, from the claims and from the accompanying drawings in which details of the invention are fully and completely disclosed as a part of this specification.

Brief description of the Drawings

In the drawings:

Fig. 1 is a block diagram illustrating an embodiment of the present invention;

Fig. 2 is a perspective view of an automobile utilizing the figure 1 embodiment in a first configuration;

Fig. 3 is a perspective view of the figure 1 embodiment in a second configuration; and

Fig. 4 is a block diagram of a second embodiment of the present invention.

Detailed description

As shown in figure 1, mobile telephone axiliary equipment system or device 10 includes an antenna 12 connected by a lead 14 to a detection unit 16. Antenna 12 and detection unit 16 preferably have wide band capabilities that pick up high frequencies, such as 900 Mhz.

Detection unit 16 is connected by a lead 18 to a control unit 20. control unit 20 provides a signal on a lead 22 to actuators 24 and 26. Actuators 24 and 26 provide signals on respective leads 28 and 30. Actuator 26 may be discrete from or integral with control unit 20. A power supply 32 is con- nected to actuator 26 via lead 34. The power supply 32 can be the power system of the automobile.

To illustrate the operation of device 10 shown in figure 1, antenna 12 first receives high frequency signals, such as 900 Mhz signals. These signals can represent an incoming or outgoing call from a mobile telephone. The signals are con¬ ducted by a lead 14 to detection unit 16. Detection unit 16 detects changes in the field intensity of those signals that are caused by either incoming or outgoing telephone calls, detection unit 16 sends a signal on lead 18 to control unit 20 if changes are detected.

Control unit 20 then sends an activation signal to actuators 24 and 26 on lead 22. Actuator 24 preferably is a muting coupling or circuit that is integral with an automobile radio. Hence, the signal provided on lead 28 from actuator 24 need not have high power. The signal provided on lead 28 will cause the automobile radio to mute the sound signal it is generating while there is a high frequency signal of predetermined magnitude that is present in the vicinity of the mobile telephone.

If actuator 24 is not provided in the automobile radio, or it is desirable not to use lead 28, then actuator 26 can be used to mute the generated sound signal. This is accom¬ plished by connecting lead 30 to the power supply terminals of the automobile radio. When actuator 26 is activated, it cuts off current on lead 30. Since lead 30 provides power to the automobile radio, it should provide a high power signal. Thus, power supply 32 is connected to actuator 26 to provide the high power for the signal. The capability of system 10 to use either actuator allows the system to be used with many different automobile radios. A further signal can be provided by control unit 20 that enables only one actuator at a time so that both are not providing power. In this manner, power is conserved through avoiding undesirable power dissipation from the unused actu- ator.

It is preferred that the enumerated components of device 10 are housed in a single package as shown in figure 3. Howe¬ ver, the components can be housed in separate packages as depicted in figure 2.

Turning to figure 2, an automobile 50 is fitted with an automobile radio 52 that is connected to an automobile radio antenna 54. A mobile telphone 56, such as a GSM mobile te- lephone, -is placed in automobile 50. A mobile telephone antenna58 is connected to mobile telephone 56 and positioned on the roof of automobile 50 as illustrated in figure 2. Alternatively, mobile telephone antenna 58 can be positioned closer within the vicinity of or attached to mobile telepho- ne 56.

Detection unit 60, contained in a discrete package, is con¬ nected to a wide band antenna 62 and both are placed inside automobile 50. Wide band detection unit 60 measures the radio wave or frequency field intensity inside automobile 50. Wide band detection unit 60 is connected to a control unit 64, also in a discrete package, which can be positioned in a motor compartment 66 of automobile 50. Control unit 64 outputs at least one control signal that controls an actu- ator in response to a signal from wide band detection unit 60 that corresponds to the measured radio wave fiels inten¬ sity inside automobile 50. The actuator may be integral with the automobile radio 52, external to both radio 52 and de¬ tection unit 60, or packaged with detection unit 60. The control unit 64 can include a plurality of output sig¬ nals to allow the control unit 64 to be used universally in automobiles. One output signal can control automobile radio 52 as discussed above using either the internal muting coup¬ ling or circuitry in the automobile radio, or by using an actuator that controls the power to automobile radio 52 that is preferably internal to the device 10.

Alternatively, an output signal can control other types of actuators tha, for example, control the signal tone. Furt¬ her, control unit 64 can have a delay in the control of the actuator so that the sound signals from the automobile radio 52 are not affected for a short period of time when the mobile telephone 56 transmitter begins to transmit. This delay can be for a short duration while, for example, mobile telephone 56 sends certain protocol signals to a base stati¬ on.

Referreing to figure 3, the present invention is represented as having the detector unit, control unit, antenna and at least one actuator integrated into a package 70 that con¬ tains device 10. Package 70 is especially suited for easy and hidden installation behind the instrument panel of an automobile. To this end, the preferred dimensions of package 70 are 3 3/4" length, 2 1/8" width and 1 1/4" height.

Package 70 includes terminals 72 - 82. Preferably, leads providing a voltage potentila and a ground potentila from the automobile power supply are respectively connected to terminals 72 and 82. Lead 34 (shown in figure 1) provides the power from the terminals 72 and 82 to actuator 26. Ter¬ minals 74 and 80 are connected to the muting circuit or actuator 24 provided in the automobile radio, if provided. Lead 30 (shown in figure 1) is internally connected to leads 74 and 80.

If the automobile radio does not provide the muting coupling or actuator 24, or it is desired not to use such coupling or actuator, then the power supply terminals of the automobile radio can be connected to terminals 76 and 78. Lead 28

(shown in figure 1) is internally connected to terminals 76 and 78. With this connection configuration, the automobile radio can be turned on or off when an incoming or outgoing telephone call is detected by controlling the power supplied to the automobile radio. Actuator 26 is included in package

70 to control the power supplied to the automobile radio.

Also illustrated in figure 3 is antenna 12 that receives high frequency signals which transmit an incoming or out¬ going telephone call.

In an example of the preferred operation of the present invention, mobile telephone 56 is called and it responds by transmitting radio waves or frequencies. Wide band detection unit 60 subsequently detects the intensity changes of the high frequency radio field inside automobile 50 that is caused by the transmission. In order to prevent the high frequency radio field from interfering with the sound sig¬ nals produced by automobile radio 52, control unit 64 cont¬ rols, for example, a mute coupling in the automobile radio 52 to ultimately quiet sound from the automobile radio while mobile telphone 56 is used. Or actuator 26 (figure 1) can cut off the current fed to automobile radio 52.

Figure 4 shows a second embodiment of the present invention. Device 100 includes a receiver 102 and detection unit 104. The receiver 102 includes an IC 106. A capacitor 108 is connected to the inputs of IC 106 via conductors 110 and 112. The length of the conductors 110 and 112 are optimally dimensioned for tuning to the frequency band of a desired radio frequency used by the mobile telephone, typically 300 Mhz - 2 Ghz. The length of the conductors 110 and 112 are typically from a few millimeters to a few centimeters. A voltage is induced between the conductors 110 and 112 when a radio frequency field at the tuned frequency band is pre¬ sent. These conductors 110 and 112 form an alternative structure to antenna 62 in figure 2.

The voltage induced by the radio frequency field between both conductors 110 and 112 charges capacitor 108. capacitor 108 controls IC 106, from which a control signal is fed to the detector 104 via lead 114. IC 106 is a low frequency, e.g. 300 - 400 Hz, oscillator that is triggered by the above-mentioned high frequencies and thus operates as an receiver.

The detector 104 has a delay circuit 116 connected to lead 114 to receive the control signal and connected to a control unit 118 via lead 120. The control signal si first fed to the delay circuit 116, which causes a delay to the signal, typically 3 s. This ensures that the control signal is not triggered by a radio frequency field that merely represents a checking signal of the transmitter of the mobile telephone or some other corresponding signal. The time delay can also be set so that the device operates in digital networks, like GSM, where the transmitter is pulsating. Also, the end of the mobile telephone transmission is analogously delayed.

After the delay circuit 116, the delayed control signal is connected to a comparator (not shown) in the control circuit 118, which provides at least one output signal that controls a mute coupling circuit (not shown) in a car radio 122. Both positive and negative voltages are provided via respective leads 124 and 126 to radio 122 in order to control the in¬ ternal mute coupling circuit. Alternatively, the control circuit 118 can provide both voltages, but the radio 122 will have only one terminal, depending on whether it opera¬ tes on a positive or negative voltage.

An alternative to using the mute coupling circuit in radio 122 would be to electrically connect a switch between the power supply terminal of radio 122 and the power supply (not shown) . Switch 128 would receive an output control signal from control circuit 118 via a lead 130 (broken line) . When the output control signal is active, power provided over lead 132 -(broken line) would be cut off from radio 122. The switch can be a power transistor or other switching device.

Device 100 can be offered in discrete components, or as one package. If offered as one package, leads 124, 126 and 130 are provided, as well as leads (not shown) that are connec¬ ted to the positive and negative sides of the power supply, as wires that extend from the package. The wires provided in this manner facilitate installation.

Also, using the antenna configuration shown in figure 4 will allow the entire device 100 to be packaged, instead of the antenna 112 being visible as shown in figure 3.

The present inventin does not require electrical or mechanical connection to the mobile telephone or to special car kits. It can work with any mobile telphone, such as a handportable or handheld cellular telephone, that operates in the 900 Mhz band, including most common analog and digi¬ tal systems, like the worldwide digital GSM system. With the additional feature of muting the automobile radio by either cutting off power or activating on internal muting circuit, the present invention is well suitd for use with almost any type of automobile radio. Package 70 additionally provides for easy installation.

Numerous variations and modifications of the ambodiments described above may be effected without departing from the spirit and scope of the novel features of the invention. It is to be understood that no limitations with respect to the specific device illustared herein are intended or should be inferred. It is, of course, intended to cover by the appen¬ ded claims all such modifications as fall within the scope of the claims.

Claims

1. An auxiliary equipment for a mobile telephone comprising:

a detection unit (16) ;

an antenna (17) connected to the detection unit (16) that measures radio wave field intensity in a vicinity of the mobile telephone (14);

at least one actuator, and

a control unit (20) connected to the detection unit (16) and at least one actuator, which in response to the radio wave field intensity measured by the dtection unit (16) can cont¬ rol the at least one actuator.

2. The equipment of claim 1 wherein the at least one actu¬ ator is integrated in an automobile radio (12) to mute sound generated by the automobile radio (12) .

3. The equipment of claim 1 wherein the control unit (20) provides a plurality of control outputs.

4. The equipment of claim 1 wherein the detection unit (16) and the antenna (17) have wide band characteristics.

5.The equipment of claim 1 wherein the at least one actuator controls current to an automobile radio (12) .

6. The equipment of claim 1 wherein the control unit (20) can delay the control of at least one actuator.

7. A system for reducing interference between a mobile te- lephone and an automobile radio comprising:

a detection unit (16) ;

an antenna (17) connected to the detection unit (16) in the vicinity of the mobile telephone (14) to measure radio wave field intensity caused by the mobile telephone (14);

at least one actuator connected to control the automobile radio (12); and

a control unit (20) connected to the detection unit (16) and at least one actuator, which in response to the radio wave field intensity measured by the detection unit (16) activa- tes the at least one actuator to control the automobile radio 812) .

8. A packaged device for eliminating interference between a mobile telephone and an automobile radio comprising:

a wide band antenna (12) ;

a detection unit (16) connected to the antenna (12) to de¬ tect high frequency field intensity changes associated with the mobile telephone (56) and to output a first signal in response to the detected high frequency field intensity; and

a control unit (20) connected to the detection unit (16) to receive the signal and provide a second signal in response to the first signal, and

an actuator (26) coupled to receive the second signal to cut off the power supply to the automobile radio (52) .

9. The packaged device of claim 8 wherein the automobile radio includes an actuator (24) that is activated by the second signal to mute a sound signal generated by the auto¬ mobile radio (52) .

10. The packaged device of claim 8 further comprising a plurality of first, second and third paired terminals, the first paired terminals (72,82) coupled to th epower supply

(32), the second paired terminals (74,80) coupled to an external actuator (24) and the third paired terminals (72,82) coupled to another actuator (26).