Kabushiki Kaisha Toshiba

Masakuni Hyodo

Osamu Kurokawa

Ken Nakamura

Akira Ishikura

Yoshihiro Nomura

Takuya Kanazumi

Masatomo Kanbara

Yoshimasa Takahashi

Naoki Kaji

Mobile radio communication apparatus having a plurality of MINs

This invention provides a dual-mode radio communication apparatus which can make normal communications even when an external apparatus is connected to a radio communication apparatus, the communication scheme of which is set in a digital mode. When the radio communication apparatus is not connected to a vehicle-mount kit via a connector in an analog mode, a switch control means of a controller switches a switching circuit to communicate a signal with a base station using a built-in antenna. When the apparatus is connected to the vehicle-mount kit, the switch control means switches the switching circuit to communicate a signal with the base station using an external antenna via the vehicle-mount kit and a booster unit. In the digital mode, the switch control means switches the switching circuit to communicate a signal with the base station using the built-in antenna independently of the connection with the vehicle-mount kit.

Dual-mode radio connected to an apparatus for communicating through in analog mode

According to the present invention, an analog-mode discharge characteristic storage area ( ) and a digital-mode discharge characteristic storage area ( ) store threshold data of remaining battery display in an incoming-call standby status in an analog mode and that in a digital mode, respectively. A remaining battery determination means ( ) determines a remaining battery level corresponding to a selected communication mode based on both a voltage of detected by a voltage detection circuit ( ) and data stored in the analog-mode discharge characteristic storage area ( ) or the digital-mode discharge characteristic storage area ( ). A remaining battery display control means ( ) causes the remaining battery to be displayed on an LCD display of a control unit ( ) in accordance with a determination result of the remaining battery determination means ( ).

Dual-mode radio communication device having function for selectively using analog or digital mode

The present invention provides a cheap handsfree unit which can prevent the howling phenomenon and reduce the input sound from the loud-speaker into the microphone in both the analog and digital modes. A reception side comprises a signal level adjusting circuit constituted by a switch circuit and attenuators, and a transmission side comprises a signal level adjusting circuit constituted by a switch circuit and attenuators, to introduce the attenuation of 15 dB or 30 dB in response to the analog or digital mode. A voice switch is constituted so that the analog reception signal and the analog transmission signal are rectified respectively by rectifiers, the levels of both signals are compared by a comparator, and either switch or switch having a higher input signal level becomes conductive as a result of the comparison. The attenuation is introduced on the basis of the communication mode, only to either the analog reception signal or analog transmission signal having a smaller signal intensity.

Handsfree unit

Growing community of inventors

Tokyo, Japan

Masakuni Hyodo