JP2643111B2 - Optional equipment for mobile phones - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optional device for a portable telephone, and more particularly to an optional device for a portable telephone which can be used for portable telephones having different circuit voltages.

[0002]

2. Description of the Related Art New functions are added to mobile phones,
Various accessory devices can be connected to improve the usability (hereinafter, such accessory devices are referred to as "optional devices", and by connecting these optional devices, a mobile phone is newly added. Functions that improve or improve usability are called “optional functions”). The optional device is sold or leased as an option of the mobile phone, and examples include a hands-free adapter and a data adapter.

A hands-free adapter is mounted on, for example, a steering wheel (so-called steering wheel) of an automobile or a console between a driver's seat and a passenger's seat, and when a portable telephone is connected to the hands-free adapter to switch to a hands-free mode, The functions of the speaker and the microphone provided in the mobile phone are switched to the speaker and the microphone provided in the hands-free adapter, so that the mobile phone can communicate while driving without having to hold the mobile phone by hand. .

When data communication is performed between a portable telephone and a personal computer or a portable facsimile or the like, the data adapter connects the portable telephone and the personal computer to each other and modulates and demodulates a data signal transmitted and received between the portable telephone and the personal computer. Things. That is, by connecting this data adapter to a mobile phone, data communication with other devices is enabled.

[0005] Since these optional devices are sold or leased as an option of the mobile phone, they operate with an interface and circuit voltage suitable for the mobile phone body.

[0006]

In recent years, portable telephones have tended to reduce the circuit voltage (for example, from 5 V to 3 V). However, when a portable telephone with a low circuit voltage is purchased, a high circuit voltage before that is obtained. However, an optional device that is compatible with the conventional mobile phone cannot be used, and a new optional device with a low circuit voltage is required. Conversely, there is a problem that an optional device suitable for a mobile phone having a low circuit voltage cannot be used for a conventional mobile phone having a high circuit voltage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an optional device for a portable telephone which can be shared by portable telephones having different circuit voltages.

[0008]

In order to achieve the above object, according to the present invention, an optional device for executing an optional function and a voltage adjusting unit are provided in an optional device for a mobile phone connected to the mobile phone, The voltage adjustment unit adjusts the voltage so that the output voltage from the option circuit matches the circuit voltage of the mobile phone.

Further, the voltage adjustment unit determines a circuit voltage of the mobile phone through a connection of the mobile phone with the optional device for the mobile phone, and determines whether or not the circuit voltage of the optional circuit is high .
La output voltage is to voltage regulation.

Further, as another aspect, a voltage adjusting unit for interconnecting a portable telephone and a portable telephone optional unit is provided with a voltage adjusting unit, and the voltage adjusting unit is provided with the voltage adjusting option of the portable telephone. The circuit voltage of the mobile phone is determined via a connection with the device, and the output voltage from the mobile phone optional device is adjusted.

[0011]

[Function] Even if the circuit voltage of the mobile phone is different from the circuit voltage of the optional circuit of the optional device, since the voltage output to the mobile phone is adjusted by the voltage adjusting unit of the optional device, the mobile phone of a different circuit voltage can be shared. It is.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a state where an optional device 3 for a portable telephone according to the present invention is connected to a portable telephone 1.

The portable telephone 1 and the optional device 3 are connected by connecting a composite connector (see FIG. 2) of a cable with a composite connector to the connector connection portion 8 of the optional device 3. Optional circuit 7 is optional device 3
In this embodiment, the circuit voltage of the mobile phone 1 is set to 3V, and the circuit voltage of the option circuit 7 of the option device 3 is set to 5V.

The option device 3 is provided with a connector connection section 8 and a voltage adjustment section 4 in addition to the option circuit 7. The connector connection section 8 and the voltage adjustment section 4 determine the circuit voltage of the mobile phone 1. Then, if necessary, adjust the voltage. The voltage adjustment unit 4 includes a voltage adjustment switching circuit 5 and a voltage adjustment circuit 6.

Here, an example of the determination of the circuit voltage of the mobile phone 1 by the option device 3 will be described with reference to FIGS.

FIG. 2A shows a cable 19 with a composite connector connected to the mobile phone 1 and a connector connection portion 8 of the optional device 3. In the case of a mobile phone having a circuit voltage of 3 V, the composite connector 20 of the cable 19 is provided with a connection terminal 22 and a projection 21, and the connection terminal 2
The connection with the optional device 3 is completed by inserting each of the protrusion 2 and the projection 21 into the connection terminal port 23 and the hole 24 provided in the connector connection portion 8 of the optional device 3. Note that the projection 21 is not provided on the composite connector of the cable for a cellular phone having a circuit voltage of 5V.

FIG. 2B shows a projection 21 of the composite connector 20.
FIG. 2C shows a state in which the connector 24 is not connected to the hole 24 of the connector connection section 8 of the optional device 3, and FIG. A spring 25 is mounted inside the hole 24, and the spring 25 is interlocked with the changeover switch 5a of the voltage adjustment changeover circuit 5 shown in FIG. A force is always applied downward to the spring 25, and the changeover switch 5a shown in FIG. 1 is connected to the contact a unless the projection 21 is inserted into the hole 24.

Now, as shown in FIG. 2B, when the projection 21 is not inserted into the hole 24 or when the circuit voltage is 5 V
When the composite connector 20 of the mobile phone having no projection as in the case of the mobile phone is connected to the connector connection portion 8 of the optional device 3, no action is exerted on the spring 25, so that it is shown in FIG. The switch 5a remains connected to the contact a. Therefore, in the case of a composite connector having no protrusion, such as a mobile phone having a circuit voltage of 5 V, signals are exchanged between the circuit in the mobile phone 1 and the optional circuit 7 without performing voltage adjustment. This is a matter of course because the optional device 3 is prepared as an option for a mobile phone having a circuit voltage of 5V.

On the other hand, when the composite connector 20 has a projection 21 like a portable telephone having a circuit voltage of 3 V and the projection is inserted into the hole 24 as shown in FIG. 2C, the spring 25 is pushed up. The changeover switch 5a shown in FIG. 1 is switched to connect to the contact b. Therefore, when the circuit voltage is 5
The voltage output from the option circuit 7 of V is adjusted by the voltage adjustment circuit 6 so as to match the circuit of the mobile phone 1 whose circuit voltage is 3 V, and is output to the mobile phone 1.

In this embodiment, the portable telephone and the optional device are connected by a cable with a composite connector.
The composite connector provided on the mobile phone body may be directly connected to the optional device. Further, in the present embodiment, the determination of the circuit voltage of the mobile phone is performed based on the presence or absence of the protrusion provided on the composite connector. However, another determination unit, for example, a terminal that outputs the circuit voltage of the mobile phone is provided. Various means are conceivable, such as detecting the circuit voltage of the mobile phone by connecting its terminal to the voltage adjustment unit of the optional device.

Next, the circuit configuration and operation of the voltage adjusting circuit 6 will be described with reference to FIG. The voltage adjustment circuit 6 is M
It comprises an OS type FET (N-channel type) 6a (hereinafter referred to as a transistor 6a) and an inverter 6b, and the source of the transistor 6a is a mobile phone circuit 1a.
The drain is connected to the option circuit 7.

When the switch 5a of the voltage adjustment switching circuit 5 shown in FIG. 1 is connected to the contact b, a signal is sent to the inverter 6b and the power supply line is turned on.
A voltage is supplied to the gate of a, and the transistor 6a is turned on.
I do.

Power supply voltage 5 V input to voltage adjustment circuit 6
Is dropped to 4.2 V by the protection diode 3a, and the point D
The voltage at the point A is 4.2 V because the voltage is supplied to the gate of the transistor 6a via the inverter 6b.

At the point B, that is, if the voltage applied to the drain of the transistor 6a is 3 V or less, a current flows through the channel from the drain to the source of the transistor 6a with a small resistance of 2 to 3Ω. When the voltage applied to the point B becomes 3 V or more, the resistance gradually increases. When the voltage applied to the point B reaches 4 V, pinch-off of the channel occurs, and the current does not increase any more.

Therefore, if the voltage at the point B is 3 V or less, the voltages at the points B and C become the same because the connection is made with an equivalent resistance of 5 Ω or less. Determined by the lower one.

On the other hand, even when the voltage is equal to or greater than 4V at point B, the output of the point C without following the input voltage at point B, remains in V _CC -V _T (V _cc power supply voltage or gate voltage, V _T Is a threshold voltage of the N-channel transistor 6a, usually 1V). That is, 4.2V-1V = 3.2
V, and the output voltage from the voltage adjustment circuit 6 to the mobile phone circuit 1a is 3.2 V at the maximum.

As described above, the output voltage from the 5 V system optional circuit 7 is suppressed to 3.2 V or less by the voltage adjusting circuit 6 and output to the portable telephone circuit 1a.

The inverter 6b of the voltage adjusting circuit 6
May be a switch that is turned on and off in accordance with the switching of the switch 5a of the voltage adjustment switching circuit 5 shown in FIG.

Finally, in the above-described embodiment, the voltage adjusting section is provided in the optional device. However, as in the second embodiment shown in FIG. It may be. That is, if the mobile phone 1 and the hands-free adapter 10 having different circuit voltages are connected via the optional device 9 for voltage adjustment,
It is not necessary to provide a voltage adjustment unit in all optional devices.

[0031]

As described above, the portable telephone optional device according to the present invention determines the circuit voltage of the portable telephone, and if the circuit voltage is different from the optional device circuit voltage , outputs the output voltage from the optional device to the portable telephone circuit. Since the voltage is adjusted so as to match the voltage, it is possible to handle even one mobile phone having a different circuit voltage with one optional device, and it is not necessary to purchase or lease an optional device for each mobile phone having a different circuit voltage.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a state in which an optional device for a mobile phone according to the present invention is connected to a mobile phone.

2A is a perspective view showing a cable with a composite connector and a connector connection portion of an optional device, FIG.
(C) is a diagram showing a state where the composite connector and the connector connection part of the optional device are not joined and a state where they are joined, respectively.

FIG. 3 is a diagram showing a circuit configuration of a voltage adjustment circuit.

FIG. 4 is a second embodiment of the optional device for a mobile phone according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cellular phone 3 Optional device 4 Voltage adjustment part 5 Voltage adjustment switching circuit 6 Voltage adjustment circuit 7 Option circuit 8 Connector connection part

Claims (5)

(57) [Claims] 1. An option device for a mobile phone connected to a mobile phone, comprising an option circuit for executing an optional function and a voltage adjustment unit, wherein the voltage adjustment unit outputs an output voltage from the option circuit to the mobile phone. An optional device for a mobile phone, wherein a voltage is adjusted so as to match a circuit voltage of the phone. 2. A decision circuit voltage of the mobile telephone via a connection between the mobile phone for optional device of the voltage regulator is the mobile phone, from the option circuit
2. The optional device for a mobile phone according to claim 1, wherein the output voltage of the mobile phone is adjusted. 3. A voltage adjustment option device for interconnecting a mobile phone and a mobile phone option device, comprising a voltage adjustment unit, wherein the voltage adjustment unit is connected to the voltage adjustment option device of the mobile phone. A circuit voltage of the mobile phone is determined through a unit, and an output voltage from the mobile phone optional device is adjusted. 4. The mobile phone according to claim 1, wherein the voltage adjustment unit includes a voltage adjustment switching circuit that switches a power supply line depending on whether or not to perform voltage adjustment, and a voltage adjustment circuit that performs voltage adjustment. Optional equipment. 5. The voltage adjustment unit according to claim 3, wherein the voltage adjustment unit includes a voltage adjustment switching circuit that switches a power supply line depending on whether or not to perform the voltage adjustment, and a voltage adjustment circuit that performs the voltage adjustment. Optional equipment.