Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
1998-03-23
2001-07-03
Tsang, Fan (Department: 2746)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S571000, C455S557000, C455S343200, C455S575100
Reexamination Certificate
active
06256520
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mobile communication device, and particularly to a power supply for a mobile communication device carrying out wireless data communication.
2. Description of the Related Art
Conventionally, in a mobile communication device such as a portable telephone and a car telephone, during communication to a base station, when a battery voltage becomes lower than a voltage necessary for the communication, the communication is cut off. Thus, after exchanging a battery, a user of the communication device must make operations again for connection of a communication line, such as a calling operation. Besides, since various kinds of information required for communication operations or for signal processing are stored in a RAM, they are lost at the exchange of the battery.
With regard to such a problem, for example, Japanese patent application Laid-open No. Hei. 5-22188 discloses a technique in which when a battery voltage is lowered, data stored in a RAM is stored in an EEPROM to protect the data.
FIG. 1
is a structural block diagram schematically showing a mobile communication device disclosed in the publication.
In
FIG. 1
, at the reception of a signal from a not-shown base station, the signal received through an antenna
51
is subjected to processing such as amplification and demodulation by a wireless section
52
. Thereafter, the output of the wireless section is subjected to predetermined signal processing by a signal processing section
53
and is outputted as a voice from a speaker
54
.
On the other hand, when a signal is transmitted to the base station, a line is connected by the operation of a key pad
60
. Thereafter, a voice from a microphone
55
is subjected to predetermined signal processing by the signal processing section
53
, and then, is subjected to processing of demodulation and amplification and is transmitted from the antenna
51
.
A micro-computer (hereinafter referred to as a microcomputer)
56
is a circuit for controlling and processing these transmitting/receiving operations, and the information regarding the controlling or processing is stored in a RAM
57
.
A battery
62
supplies power to the respective sections of the communication device, and the output voltage thereof is monitored by a voltage monitoring circuit
61
. On the basis of the output of the voltage monitoring circuit
61
, when the battery voltage becomes lower than a predetermined value, the microcomputer
56
stores the information stored in the RAM
57
into an EEPROM
58
. In this way, the information is protected.
Thereafter, after an exchange of batteries is ended, the information stored in the EEPROM
58
is restored in the RAM
57
, and on the basis of the information from the RAM
57
, the microcomputer
56
makes setting of a transmission/reception channel, transmission/reception output level, and the like. That is, the state before the power was cut off is recovered. Then the operation of the device shifts to a communication operation.
On the other hand, in recent years, wireless communication of data from an information terminal such as a personal computer is carried out by using a mobile communication device. It is also possible to use the above described mobile communication device in this wireless data communication.
However, in the above described conventional mobile communication device, when a drop in battery voltage is detected, the information must be transmitted from the RAM to the EEPROM, and the information must be recovered from the EEPROM to the RAM after the exchange of batteries is ended.
On the other hand, even if the above described conventional mobile communication device is applied to the wireless data communication, data from the information terminal is lost by the voltage drop of the mobile communication device. Otherwise, it is necessary to interrupt the data communication by a communication application which has operated until now at the side of the information terminal. Thus, if the application at the side of the information terminal does not retransmit all the data lost during the interruption, data communication after resumption can not be realized. That is, the data communication which has been carried out by the communication application at the side of the information terminal comes to nothing, and the same data communication must be carried out again, so that finite radio frequencies are wasted, and also time is wasted.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above described problems and to provide an improved mobile communication device.
Another object of the present invention is to provide a power supply device for a mobile communication device and a power supply method by which a battery can be exchanged without cutting off the connection of wireless communication.
Still another object of the present invention is to provide a power supply device for a mobile communication device and a power supply method by which data communication can be continued without interrupting or terminating an application at the side of a data terminal so that it is not necessary to carry out wasteful wireless data communication following reconnection.
Still another object of the present invention is to provide an improved data terminal connection modem card which will be clarified later.
In order to achieve the above described objects, a mobile communication device according to the present invention which carries out wireless data communication to an external device, comprises a transmitting section for transmitting data to the external device, a battery for supplying power to the mobile communication device, an interface for receiving power from a data terminal having the data through a modem card connected to the mobile communication device, and a control section for making power supply from one of the battery and the interface.
The mobile communication device further comprises a detecting section for detecting a voltage of the battery, and a comparing section for comparing a detected voltage with a predetermined voltage value. It is preferable that the control section stops data transmission from the transmitting section when the detected voltage becomes lower than the predetermined voltage value.
It is preferable that the control section selects power supply from the interface when the detected voltage becomes lower than the predetermined voltage value.
The control section may resume data transmission from the transmitting section when the detected voltage becomes equal to or higher than the predetermined voltage value after the detected voltage became lower than the predetermined voltage value.
Also, in the present invention, in a modem card for connecting a mobile communication device carrying out wireless data communication to an external device, to a data terminal for transmitting data to the mobile communication device, the data is transmitted from the data terminal to the mobile communication device, and a power supply current supplied from the data terminal is fed to the mobile communication device.
Further, it is preferable that the modem card includes a memory for storing the data from the data terminal.
It is preferable that the modem card stores the data into the memory in response to a first control signal from the mobile communication device, and outputs the stored data to the mobile communication device in response to a second control signal from the mobile communication device.
Further, according to the present invention, a power supply device of a mobile communication device for carrying out wireless data communication to an external device, comprises a data terminal for transmitting data to the mobile communication device, and a modem card for connecting the data terminal to the mobile communication device so as to supply the data to the mobile communication device, and the mobile communication device receives power from the data terminal having the data through the modem card.
Further, it is preferable that the mobile communica
McGinn & Gibb PLLC
NEC Corporation
Sobutka Philip J.
Tsang Fan
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