DE29801085U1 - Auto audio system for cellular phone - Google Patents

Description

CAR AUDIO SYSTEM FOR CELLULAR PHONE

DESCRIPTION

The present invention relates to a car audio system and, more particularly, to a car audio system for a cellular phone for improving the convenience of the cellular phone and simplifying the structure thereof.

A conventional portable wireless cellular telephone (hereinafter referred to as a cellular telephone) is widely used to allow people to conveniently perform office work in a car or on the road away from the office where they normally work.

However, with the increasing popularity of cellular phone, many problems have arisen as side effects. For example, a driver makes a call and talks on the cellular phone with one hand while driving a car with the other hand, which reduces the driver's concentration while driving and increases the risk of traffic accidents.

In addition, the user of a cellular phone usually holds the cellular phone close to the ear while talking on the cellular phone that generates harmful electromagnetic waves, so that the user is exposed to the harmful electromagnetic waves, which adversely affects the brain waves of the user while talking on the cellular phone. Therefore, there is a problem with the conventional cellular phone in that the harmful heat energy of the electromagnetic waves generated by the cellular phone may cause health problems for the user.

In order to solve the above-mentioned problems, a cellular telephone which can be used hands-free has been developed (hereinafter referred to as a cellular telephone). A speakerphone device of the cellular telephone as shown in Figure 1 includes a speakerphone unit (2) fixed to one side of a car body (3) for attaching or detaching the cellular telephone (1), an external microphone (4) and a loudspeaker arranged on another side of the car body (3), while the microphone (4) and the loudspeaker are electrically connected to the speakerphone unit (2).

This speakerphone unit (2) is used to supply the power generated by a car battery to the cellular phone (1), to output speech from the cellular phone (1) to the loudspeaker (5) and to input speech sent to the cellular phone (1) via the external microphone (4). The driver therefore hears speech with the loudspeaker (5) and speaks via the external microphone (4) while driving and therefore uses the cellular phone (1) without holding it in one hand.

However, the conventional speakerphone of the cellular phone has problems in that the speakerphone unit is fixed in a hole made in the car body, which causes difficulty in installation, damage to the car body, poor appearance of the car body due to the installation of the speakerphone unit on the car body, and trouble and inconvenience for the driver and passengers.

In addition, there are additional problems with the conventional speakerphone of the cellular phone in that an external microphone and a loudspeaker are used, which complicates the structure of the cellular phone system and changes the appearance of the car.

bodywork can be deteriorated by the electrical wiring and cause problems for the driver and passengers.

The present invention is intended to solve the above-mentioned problems, and it is an object of the present invention to provide a car audio system for a cellular phone which prevents damage to a car body or deterioration of the appearance of a car due to installation of a separate speakerphone.

Another object of the present invention is to use a speaker already built into the car audio system for both a cellular phone and a radio or a cassette tape and a display element of the cellular phone for displaying a current usability state of the cellular phone or the car audio system and thereby simplify its structure.

In order to achieve the objects of the present invention, there is provided a car audio system for a cellular phone having a low frequency amplifier for amplifying and outputting a low frequency of voice signals tuned and demodulated from the electric waves induced by an antenna and a low frequency of voice signals regenerated on the cassette tape, and a speaker for outputting the voice signals changed from the low frequency of the voice signals into mechanical vibrations after being amplified at the low frequency amplifier, the system comprising:

an automatic signal selector for selecting and outputting voice signals transmitted from the cellular telephone to the low frequency amplifier when the cellular telephone is in use, or for outputting voice signals transmitted from a demodulator to the low frequency amplifier

frequency amplifiers when the cellular phone is not in use;

a power supply unit for supplying power from the car battery to the car audio system;

a recharge circuit for supplying power from the power supply unit to the cellular phone;

an amplifier for amplifying the voice signals input from the external microphone for transmission to the cellular telephone;

a cellular phone receiving unit disposed at a front of the car audio system; and

a connector unit formed on one side of the cellular phone receiving unit for electrically connecting the cellular phone and the car audio system.

For a more complete understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings. In the drawings:

Figure 1 is a simple diagram of a speakerphone of a cellular telephone according to an embodiment of the prior art;

Figure 2 is a simple view of a car audio system for a cellular phone according to a first embodiment of the present invention;

Figure 3 is a block diagram of a car audio system for a cellular phone according to a first embodiment of the present invention;

Figure 4 is a simple view of a car audio system for a cellular phone according to a second embodiment of the present invention;

Figure 5 is a block diagram of a car audio system for a cellular phone according to a second embodiment of the present invention;

Figure 6 is a schematic view of a car audio system for a cellular phone according to a third embodiment of the present invention;

Figure 7 is a block diagram of a car audio system for a cellular phone according to a third embodiment of the present invention;

Figure 8 is a perspective view showing a car audio system for a cellular phone according to a fourth embodiment of the present invention;

Figure 9 is a separated perspective view showing a car audio system for a cellular phone according to a fourth embodiment of the present invention;

Figure 10 is a perspective view of a cellular telephone shown in Figure 9;

Figure 11 is a block diagram of a car audio system for a cellular phone according to a fourth embodiment of the present invention; and

Figure 12 is a block diagram of a cellular telephone shown in Figure 11.

The present invention will be described in detail with reference to the accompanying drawings. Figure 2 is a schematic view of a car audio system for a cellular phone according to a first embodiment of the present invention. Figure 3 is a block diagram of a car audio system for a cellular phone according to a first embodiment of the present invention.

In the car audio system for a cellular phone (30) according to a first embodiment of the present invention, a first connector (11) formed on a rear side of a car audio system (10) and a second connector (31) connected to a cellular phone (30) are electrically connected to the cellular phone and the external microphones (41 and 42).

A first external microphone (41) is arranged on a side of a sun visor mounted on an upper part of the front of the car and a second external microphone (42) is mounted on a front of the car audio system (10).

The car audio system (10) includes an antenna (12), a tuner (13), an intermediate frequency amplifier (14), a demodulator (15), an automatic signal selector (16), a low frequency amplifier (17), a loudspeaker (18), a power supply unit (19), a recharger circuit (21), a microphone selector (22) and an amplifier (23).

The tuner (13) selects a specific frequency from electrical waves input to the antenna (12) and converts it into the intermediate frequency to be sent to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and transmits them to the demodulator (15). The demodulator (15) demodulates only the low frequency speech signals to be sent to the automatic signal selector (16) from the intermediate frequency signals input by the amplifier (14).

The automatic signal selector (16) selects the voice signals output from the cellular phone (30) according to the control signal transmitted from the cellular phone (30) via the second connector (31) and the first connector (11) to thereby input them into the low frequency amplifier (17) or selects the low frequency voice signals output from the demodulator (15) to thereby input them into the low frequency amplifier (17).

The automatic signal selector (16) selects the voice signals output by the cellular telephone (30) when the cellular telephone (30) is in use in order to convert them into the low-frequency

frequency amplifier (17), and selects the low frequency speech signals output from the demodulator (15) when the cellular phone (30) is not in use to input them to the low frequency amplifier (17).

The low frequency amplifier (17) amplifies the signals input from the automatic signal selector (16) to output them to the loudspeaker (18), which converts the signals sent from the low frequency amplifier (17) into mechanical vibrations to thereby output voices.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharge circuit (21) which supplies power from the power supply unit (19) via the first connector (11) and the second connector (31) to the cellular phone (30).

The microphone selector (22) inputs the voice signals input from the first and second external microphones (41 and 42) selectively according to the operation of a microphone selector knob (25) mounted on a front side of the car audio system (10). The amplifier (23) amplifies the voice signals input through the microphone selector (22) for transmission to the cellular phone (30) via the first and second connectors (11 and 31).

Figure 4 is a schematic view of a car audio system for a cellular phone according to a second embodiment of the present invention. Figure 5 is a block diagram of a car audio system for a cellular phone according to a second embodiment of the present invention. In Figures 4 and 5, the same or equivalent parts or portions in Figures 2 and 3 are designated by the same numerals for the sake of simplicity of illustration.

Position and explanation use the same reference numbers and symbols and superfluous references are omitted.

In the car audio system for a cellular phone according to a second embodiment of the present invention, a first connector (11) formed on the front of a car audio system (10) and a second connector (31) connected to a cellular phone (30) are electrically connected to each other.

The car audio system (10) includes an antenna (12), a tuner (13), an intermediate frequency amplifier (14), a demodulator (15), an automatic signal selector (16), a low frequency amplifier (17), a loudspeaker (18), a power supply unit (19), a recharge circuit (21), an amplifier (23) and a signal selection knob (26).

The tuner (13) selects a specific frequency from electrical waves input to the antenna (12) and converts it into the intermediate frequency to be input to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and transmits them to the demodulator (15). The demodulator (15) demodulates only the low frequency speech signals to be sent to the automatic signal selector (16) from the intermediate frequency signals input by the amplifier (14).

The automatic signal selector (16) selects the voice signals output from the cellular telephone (30) according to the operation of the signal selector knob (26) for input to the low frequency amplifier (17), selects the low frequency voice signals output from the demodulator (15) for input to the low frequency amplifier (17), or simultaneously outputs the caller's voice signal and a signal input from the cellular telephone (30) and the demodulator (15).

Low frequency speech signal into the low frequency amplifier (17).

The automatic signal selector (16) selects the voice signals output from the cellular phone (30) by manipulating the signal selection knob (26) when the cellular phone (30) is in use to input them to the low frequency amplifier (17), and selects the low frequency voice signals output from the demodulator (15) by manipulating the signal selection knob (26) when the cellular phone (30) is not in use to input them to the low frequency amplifier (17). When the user manipulates the signal selection knob (26) to simultaneously select the caller's voice signal and the low frequency voice signal from the cellular phone (30) and the demodulator (15), the caller's voice signal and the low frequency voice signal are simultaneously input to the low frequency amplifier (17).

The low frequency amplifier (17) amplifies signals input from the automatic signal selector (16) for output to the loudspeaker (18), which converts the signals sent from the low frequency amplifier (17) into mechanical vibrations to output voices.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharger circuit (21) which supplies power from the power supply unit (19) via the first connector (11) and the second connector (31) to the cellular phone (30).

The amplifier (23) amplifies the voice signals input from the external microphone (42) installed on the front of the car audio system (10) for input via the

first and second connectors (11 and 31) to the cellular telephone (30).

Figure 6 is a schematic view of a car audio system for a cellular phone according to a third embodiment of the present invention. Figure 7 is a block diagram of a car audio system for a cellular phone according to a third embodiment of the present invention. In Figures 6 and 7, like reference numerals and symbols are used to designate like or equivalent parts or portions in Figures 2 and 3 for simplicity of illustration and explanation, and redundant references are omitted.

In the car audio system for a cellular phone according to a third embodiment of the present invention, there are a car audio system (10), a speakerphone unit (20) arranged on an outside of the car audio system (10) in electrical connection therewith, and a cellular phone (30), and an external microphone (41) electrically connected to the speakerphone unit (20). The external microphone (41) is mounted on a side of the sun visor arranged on an upper part of the front of the car to input the voice signals of the caller into the speakerphone unit (20).

The speakerphone unit (20) transmits the voice signals and control signals output from the cellular phone (30) to the car audio system (10). The first and second connectors (27 and 28) are assembled to supply power from the car audio system (10) to the cellular phone (30) by connecting the recharger circuit (21), the amplifier (23) and the speakerphone unit (20) to the car audio system (10) and cellular phone (30).

The first connector (27) is arranged for electrically connecting the loudspeaker unit (20) to the external microphone (41) and the car audio system (10), while the second connector (28) is arranged for electrically connecting the loudspeaker unit (20) to the cellular phone (30).

The recharge circuit (21) is intended to supply the voice signal from the car audio system (10) via the first and second connectors (27 and 28) to the cellular telephone (30). The amplifier (23) amplifies the voice signals input from the external microphone (41) via the first connector (27) for transmission to the cellular telephone (30) via the second connector (28).

The first and second connectors (27 and 28) are electrically connected for inputting voice signals and control signals sent from the cellular phone (30) to the car audio system (10).

The car audio system (10) includes an antenna (12), a tuner (13), an intermediate frequency amplifier (14), a demodulator (15), an automatic signal selector (16), a low frequency amplifier (17), a loudspeaker (18) and a power supply unit (19).

The tuner (13) selects a specific frequency from electrical waves input to the antenna (12) and converts it into the intermediate frequency to be input to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and transmits them to the demodulator (15). The demodulator (15) demodulates only the low frequency speech signals to be sent to the automatic signal selector (16) from the intermediate frequency signals input by the amplifier (14).

The automatic signal selector (16) selects the voice signals input from the cellular phone (30) according to the control signals input from the cellular phone (30) via the second and first connectors (28 and 27) for input to the low frequency amplifier (17) or selects the low frequency voice signals input from the demodulator (15) for input to the low frequency amplifier (17).

The automatic signal selector (16) selects the voice signals output from the cellular telephone (30) when the cellular telephone is in use for input to the low frequency amplifier (17), and selects the low frequency voice signals output from the demodulator (15) when the cellular telephone is not in use for input to the low frequency amplifier (17).

The low frequency amplifier (17) amplifies signals input from the automatic signal selector (16) for output to the loudspeaker (18), which converts the signals sent from the low frequency amplifier (17) into mechanical vibrations to thereby output voices.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and via the first connector (27) to the recharging circuit (21) of the loudspeaker unit (20).

Figure 8 is a perspective view showing a car audio system for a cellular phone according to a fourth embodiment of the present invention. Figure 9 is a separated perspective view showing a car audio system for a cellular phone according to a fourth embodiment of the present invention. Figure 10 is a perspective view of a cellular phone shown in Figure 9.

In the car audio system for a cellular phone according to a fourth embodiment of the present invention, a car audio system (10) includes a cellular phone receiving unit (62) arranged at the front of the car audio system (10) for placing the cellular phone (30) and a connection unit (70) arranged at a side of the cellular phone receiving unit (62) for electrically connecting the car audio system (10) and the cellular phone (30) when the cellular phone (30) is placed on the cellular phone receiving unit (62).

The antenna (33) of the cellular telephone (30) is pivotally mounted and an antenna receiving unit is provided in a section on the back of the cellular telephone (30).

(35) to connect the antenna (33) of the cellular phone

(30) during its rotation.

Figure 11 is a block diagram of a car audio system for a cellular phone according to a fourth embodiment of the present invention, and Figure 12 is a block diagram of a cellular phone shown in Figure 11. In Figures 11 and 12, like reference numerals and symbols are used to designate like or equivalent parts or portions in Figures 2 and 3 for the sake of simplicity of illustration and explanation, and redundant references are omitted.

The car audio system (10) includes an antenna (12), a tuner (13), an intermediate frequency amplifier (14), a demodulator (15), an automatic signal selector (16), a low frequency amplifier (17), a loudspeaker (18), a power supply unit (19), a recharging circuit (21), an amplifier (23) and a microcomputer (60).

The tuner (13) selects a specific frequency from electrical waves input to the antenna (12) and

converts them into the intermediate frequency to be input to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and transmits them to the demodulator (15). The demodulator (15) demodulates from the intermediate frequency signals input by the amplifier (14) only the low frequency speech signals to be sent to the automatic signal selector (16).

The microcomputer (60) controls the general functions of the car audio system (10) and the automatic signal selector (16) according to the control signals input via the connection unit (70) from the cellular telephone (30) placed on the receiving unit (62) formed on the front part of the car audio system (10).

When the cellular telephone is in use, the cellular telephone (30) inputs a control signal for selecting the caller's voice signals output from the cellular telephone (30) to the microcomputer (60) via the connection unit (70). When the cellular telephone (30) is not in use, the cellular telephone (30) inputs a control signal for selecting the low frequency voice signals output from the demodulator (15) to the microcomputer (60) via the connection unit (70).

The automatic signal selector (16) selects the voice signals input from the cellular phone (30) when the cellular phone is in use for input to the low frequency amplifier (17) according to the control of the microcomputer (60), or selects the low frequency voice signals input from the demodulator (15) when the cellular phone is not in use for input to the low frequency amplifier (17). ''.

The low frequency amplifier (17) amplifies a signal input from the automatic signal selector (16) to

Output to the loudspeaker (18), which converts the signals sent by the low frequency amplifier (17) into mechanical vibrations in order to output voices.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharger circuit (21), which supplies power from the power supply unit (19) via the connection unit (70) to the cellular phone (30).

The amplifier (23) amplifies the voice signals input from the external microphone (41) mounted on the front of the sun visor for input to the cellular phone (30) via the connection unit (70).

The cellular phone (30) includes a microcomputer (36), a display element (37), and a display element control unit (38). The microcomputer (36) electrically connects the cellular phone (30) and the car audio system (10) via the connection unit (70) when the cellular phone (30) is placed in the cellular phone receiving unit (62).

The microcomputer (36) detects the time when the cellular phone (30) is placed in the cellular phone receiving unit (62) to transmit a control signal for displaying the cellular phone display data to the display element driving unit (38) and cellular phone display data for displaying the current state of the cellular phone (30). The microcomputer (36) outputs a control signal for displaying car audio system display data to the display element driving unit (38) when the cellular phone (30) is removed from the car audio system (10).

The display element driver unit (38) sends a cellular telephone display data input from the microcomputer (36)

to the display element (37) when the corresponding control signal is input, and car audio system display data from the microcomputer (36) to the display element (37) when the corresponding control signal is input.

The display element (37) consists of a liquid crystal display (LCD) element for displaying the cellular phone display data or car audio system display data output from the display element drive unit (38).

Next, the operating methods and operating effects of the car audio system for a cellular phone will be described in detail. As described in a first embodiment of the present invention, the tuner (13) selects a targeted frequency from the electric waves inputted to the antenna (12) and converts it into the intermediate frequency for inputting to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and inputs them to the demodulator (15). The demodulator (15) demodulates only the low frequency voice signals from the intermediate frequency signals inputted from the amplifier (14) to send them to the automatic signal selector (16).

The automatic signal selector (16) selects the voice signals input from the cellular phone (30) according to the control signal transmitted from the cellular phone (30) via the second connector (31) and the first connector (11) for input to the low frequency amplifier (17) or selects the low frequency voice signals input from the demodulator (15) for input to the low frequency amplifier (17).

When the cellular telephone (30) is in use, the control signal for selecting the caller’s voice signals output by the cellular telephone (30) is transmitted via the second

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and first connector (31 and 11) into the automatic signal selector (16). Thereafter, the automatic signal selector (16) inputs the caller's voice signals output from the cellular phone (30) into the low frequency amplifier (17) in accordance with the control signal sent from the cellular phone (30).

When the cellular phone (30) is not in use, the control signal for selecting the low frequency voice signals output from the demodulator (15) is input to the automatic signal selector (16) via the second and first connectors (31 and 11). Thereafter, the automatic signal selector (16) inputs the low frequency voice signals output from the cellular phone (30) to the low frequency amplifier (17) in accordance with the control signal sent from the cellular phone (30).

Furthermore, the low frequency amplifier amplifies

(17) the voice signals input from the automatic signal selector (16) for output to the loudspeaker (18), which converts the voice signals sent from the low frequency amplifier (17) into mechanical vibrations to thereby output voices.

Accordingly, the caller’s voice signals emitted by the cellular phone (30) are transmitted to the loudspeaker

(18) when the cellular phone is in use. On the other hand, the low frequency speech signals output from the demodulator (15) for listening to a radio or a cassette tape are regenerated at the speaker (18) when the cellular phone (30) is not in use.

When a caller selects a first external microphone (41) located on the sun visor by operating the microphone selector knob (25) located on the front of the car audio system (10), the microphone selector (22)

the voice signals sent from the first external microphone (41) into the amplifier (23). When a caller selects a second external microphone (42) located on the front of the car audio system (10) by operating the microphone selector knob (25), the microphone selector (22) inputs the voice signals sent from the second external microphone (42) into the amplifier (23).

The amplifier (23) amplifies the voice signals input via the microphone selector (22) for transmission via the first and second connectors (11 and 31) to the cellular phone (30), which transmits the voice signals input via the amplifier (23) of the car audio system (10) to a telephone base station, whereby calls can be made.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharger circuit (21) which supplies power from the power supply unit (19) via the first connector (11) and the second connector (31) to the cellular phone (30).

As described in the second embodiment of the present invention, the tuner (13) selects a targeted frequency from the electric waves input to the antenna (12) and converts it into the intermediate frequency for input to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and inputs them to the demodulator (15). The demodulator (15) demodulates only the low frequency speech signals from the intermediate frequency signals input from the amplifier (14) for transmission to the automatic signal selector (16).

The automatic signal selector (16) selects the voice signals entered by the cellular telephone (30)

according to the operation of the signal selection knob (26) for input to the low frequency amplifier (17), selects the low frequency voice signals input from the demodulator (15) for input to the low frequency amplifier (17) or simultaneously selects the caller's voice signal and the low frequency voice signals from the cellular telephone (30) and the demodulator (15) for input to the low frequency amplifier (17).

In other words, when the caller manipulates the signal selection knob (26) to input the control signal for selecting the caller's voice signals output from the cellular phone (30) into the automatic signal selector (16), the automatic signal selector (16) selects the voice signals output from the cellular phone (30) via the second and first connectors (31 and 11) for input to the low frequency amplifier (17).

When the caller manipulates the signal selection knob (26) to input a control signal for simultaneously selecting the caller's voice signal and the voice signals output from the cellular phone (30) and the demodulator (15) into the automatic signal selector (16), the automatic signal selector (16) selects the caller's voice signal and the low frequency voice signals output from the cellular phone (30) and the demodulator (15) for input into the low frequency amplifier (17).

The low frequency amplifier (17) amplifies a signal input from the automatic signal selector (16) for output to the loudspeaker (18), which converts the signals sent from the low frequency amplifier (17) into mechanical vibrations to thereby output voices.

The caller’s voice signals emitted by the cellular phone (30) are regenerated at the loudspeaker (18).

rized when the cellular phone is in use. On the other hand, the loudspeaker (18) regenerates the low frequency speech signals output by the demodulator (15) for listening to a radio or a cassette tape when the cellular phone (30) is not in use.

The caller's voice is then input to the amplifier (23) via the external microphone (42) located on the front of the car audio system (10). The amplifier (23) amplifies the voice signals input via the signal selector (22) for transmission via the first and second connectors (11 and 31) to the cellular phone (30), which sends the input voice signals to a telephone base station via the amplifier (23) of the car audio system (10), whereby calls can be made.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharger circuit (21) which supplies power from the power supply unit (19) via the first connector (11) and the second connector (31) to the cellular phone (30).

As described in the third embodiment of the present invention, the tuner (13) selects a targeted frequency from the electric waves input to the antenna (12) and converts it into the intermediate frequency for input to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and inputs them to the demodulator (15). The demodulator (15) demodulates only the low frequency speech signals from the intermediate frequency signals input from the amplifier (14) for transmission to the automatic signal selector (16).

The automatic signal selector (16) selects the voice signals of the caller entered by the cellular telephone (30).

fers according to the control signals input from the cellular phone (30) via the second and first connectors (28 and 27) for input to the low frequency amplifier (17) or selects the low frequency voice signals input from the demodulator (15) for input to the low frequency amplifier (17).

When the cellular telephone is in use, the control signal for selecting the caller's voice signals output from the cellular telephone (30) is input via the second and first connectors (28 and 27) to the automatic signal selector (16), which selects the caller's voice signals according to the control signal input from the cellular telephone (30) for input to the low frequency amplifier (17).

When the cellular phone is not in use, the control signal for selecting the voice signals output from the demodulator (15) is input via the second and first connectors (28 and 27) to the automatic signal selector (16) which selects the low frequency voice signals output from the demodulator (15) for input to the low frequency amplifier (17).

The low frequency amplifier (17) amplifies a signal input from the automatic signal selector (16) for output to the loudspeaker (18), which converts the signals sent from the low frequency amplifier (17) into mechanical vibrations to output voices.

The caller's voice signals output from the cellular phone (30) are regenerated at the loudspeaker (18) when the cellular phone is in use. On the other hand, the low frequency voice signals output from the demodulator (15) are regenerated at the loudspeaker (18) for listening to a radio signal.

dios or cassette tape when the cellular phone (30) is not in use.

The caller's voice is then input to the amplifier (23) of the loudspeaker unit (20) via the external microphone (41). The amplifier (23) amplifies the voice signals input from the external microphone (41) for transmission via the second connector (28) to the cellular telephone (30), which sends the voice signals input via the amplifier (23) of the loudspeaker unit (20) to a telephone base station, whereby calls can be made.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharge circuit (21) of the speakerphone unit (20) via the first connector (27). The recharge circuit (21) of the speakerphone unit (20) sends the power supplied by the power supply unit (19) via the first connector (27) to the cellular phone (30) via the second connector (28).

As described in the fourth embodiment of the present invention, the tuner (13) selects a targeted frequency from the electric waves inputted to the antenna (12) and converts it into the intermediate frequency for inputting to the intermediate frequency amplifier (14), which then amplifies the intermediate frequency signals and inputs them to the demodulator (15). The demodulator (15) demodulates only the low frequency speech signals from the intermediate frequency signals inputted from the amplifier (14) for transmission to the automatic signal selector (16).

When the cellular phone (30) is not in use, the cellular phone (30) emits a control signal to

Selection of the low frequency voice signals output from the demodulator (15) via the connection unit (70) to the microcomputer (60), which controls the automatic signal selector (16) according to the control signal input from the cellular phone (30) to select and output the low frequency voice signals output from the demodulator (15).

When the cellular telephone (30) is in use, the cellular telephone (30) inputs a control signal for selecting the caller's voice signals output from the cellular telephone (30) to the microcomputer (60) of the car audio system via the connection unit (70), which controls the automatic signal selector (16) in accordance with the control signal input from the cellular telephone (30) for selecting and outputting the voice signals output from the cellular telephone (30).

The automatic signal selector (16) selects the caller's voice signals input from the cellular phone (30) according to the control signal of the microcomputer (60) for input to the low frequency amplifier (17) or selects the low frequency voice signals input from the demodulator (15) for input to the low frequency amplifier (17).

The low frequency amplifier (17) amplifies a signal input from the automatic signal selector (16) for output to the loudspeaker (18), which converts the signals sent from the low frequency amplifier (17) into mechanical vibrations to thereby output voices.

The caller's voice signals output from the cellular phone (30) are regenerated at the loudspeaker (18) when the cellular phone is in use. On the other hand, the low frequency voice signals output from the demodulator (15) are regenerated at the loudspeaker (18) for listening to a radio

dios or a cassette tape when the cellular telephone (30) is not in use.

The caller's voice input via the external microphone (41) is then amplified for transmission via the connection unit (70) to the cellular telephone (30), which sends the input voice signals via the amplifier (23) of the car audio system (10) to a telephone base station, thereby enabling calls to be made.

The power supply unit (19) supplies the power from the car battery (50) to power the car audio system (10) and to recharge the recharger circuit (21), which supplies power from the power supply unit (19) via the connection unit (70) to the cellular phone (30).

On the other hand, the microcomputer (36) of the cellular phone (30) detects the time when the cellular phone (30) is taken out from the cellular phone receiving unit (62) with the cellular phone (30) and the car audio system (10) being electrically disconnected by the connection unit (70), and sends a control signal for displaying the cellular phone display data and cellular phone display data for displaying the current state of the cellular phone (30) to the display element driving unit (38).

When the cellular phone (30) is placed on the cellular phone receiving unit (62) of the car audio system (10) so that the cellular phone (30) and the car audio system (10) can be electrically connected through the connection unit (70), the microcomputer (36) outputs a control signal for displaying car audio system display data to the display element driving unit (38).

The display element drive unit (38) sends a cellular phone display data input from the microcomputer (36)

lit · ·

to the display element (37) when the corresponding control signal is input, and car audio system display data from the microcomputer (36) to the display element (37) when the corresponding control signal is input.

The antenna (33) of the cellular phone (30) is pivotally mounted and an antenna receiving unit (35) for storing the antenna (33) of the cellular phone (30) when it rotates is included on a portion of the back of the cellular phone (30). It is therefore possible to rotate and extend the antenna (33) when necessary or to place the antenna (33) on the receiving unit (35).

From the above-mentioned description, it is apparent that in the car audio system for the cellular phone, there are advantages in that a speakerphone is not separately installed, thereby preventing damage to a car body or deterioration of the appearance of a car.

In addition, further advantages in the car audio system for the cellular phone are that a speaker already installed on the car audio system is used in dual operation for a radio or a cassette tape and a cellular phone, and the display element of the cellular phone is used in common, thereby simplifying the structure of the cellular phone system.

Claims (8)

26 PaffiSH CLAIMS 1. A car audio system for a cellular telephone having a low frequency amplifier for amplifying and outputting low frequency voice signals tuned and demodulated from the electrical waves induced by an antenna and low frequency voice signals regenerated on the cassette tape, and a loudspeaker for outputting the voice signals changed from the low frequency of the voice signals into mechanical vibrations after amplification at the low frequency amplifier, the system comprising: an automatic signal selector for selecting and outputting voice signals transmitted from the cellular telephone to the low frequency amplifier when the cellular telephone is in use, or for outputting voice signals transmitted from a demodulator to the low frequency amplifier when the cellular telephone is not in use; a power supply unit for supplying power from the car battery to the car audio system; a recharge circuit for supplying power from the power supply unit to the cellular phone; and an amplifier to amplify the voice signals input from the external microphone for transmission to the cellular phone. 2. The system of claim 1, wherein the external microphone comprises: a first microphone arranged on one side of a sun visor; a second microphone mounted on a front panel of a car audio system; a microphone selector knob mounted on a front panel of a car audio system; and a microphone selector that selectively transmits the voice signals input from the first or second external microphone to the amplifier according to the operation of the microphone selector knob. 3. The system of claim 1, wherein the automatic signal selector selects voice signals of the caller or low frequency voice signals output from the cellular phone to send them to the low frequency amplifier upon manipulation of a signal selector knob mounted on a front panel of the car audio system, or selects the voice signals of the caller and low frequency voice signals to simultaneously transmit to the low frequency amplifier. 4. The system of claim 1, wherein the cellular phone is electrically connected to the car audio system through a connector disposed on a front of the car audio system. 5. The system of claim 1, wherein the amplifier and the recharge circuit are embedded on an exterior portion of the car audio system at the speakerphone unit, and the speakerphone unit electrically connects the cellular phone and the car audio system. 6. The system of claim 1, wherein a cellular phone receiving unit is disposed on a front side of the car audio system, and a connector unit is formed on a side of the cellular phone receiving unit for electrically connecting the cellular phone and the car audio system when the cellular phone is placed on the cellular phone receiving unit. 7. The system of claim 6, wherein a cellular telephone antenna is rotated and an antenna receiving means hext is where the antenna is turned and placed. 8. The system of claim 6 or 7, wherein the cellular telephone comprises: a microcomputer for controlling general functions of the cellular phone and for outputting cellular phone display data for displaying a current state of the cellular phone and for sending a control signal upon detecting whether the cellular phone and the car audio system are electrically connected to each other when the cellular phone is placed on the cellular phone receiving unit; a display element for displaying cellular phone display data or car audio system display data input from the car audio system; and a display element driving unit for driving the display element to display the car audio system display data when the control signal for displaying the electrical connection between the cellular phone and the car audio system is input from the microcomputer or to display the cellular phone display data when the control signal for displaying the electrical disconnection between the cellular phone and the car audio system is input from the microcomputer.