Portable terminal system, option apparatus for portable terminal unit, and method for connecting portable terminal unit and option apparatus for portable terminal unit

A portable terminal system comprising:

• a portable terminal unit;
• an option apparatus used with said portable terminal unit;
• and
• a cable connecting said portable terminal unit to said option apparatus,
• said option apparatus being comprised of:
• a first connection circuit coupled to said cable;
• a first key switch input unit;
• a first infrared receiving unit that receives a first infrared signal from said portable terminal unit and converts said first infrared signal into a first electric signal;
• a first infrared emitting unit that converts a second electric signal into a second infrared signal and transmits said second infrared signal to said portable terminal unit;
• a first control unit;
• a first radio transmitter/receiver unit that receives electromagnetic waves transmitted from a base station, derives a second information signal from said received electromagnetic waves, converts a first information signal supplied by said first control unit into electromagnetic waves and transmits said electromagnetic waves to the base station;
• said first control unit being operative to produce said second electric signal based on said second information signal, to supply said second electric signal to said first infrared emitting unit, to produce said first information signal based on said first electric signal, to supply said first information signal to said first radio transmitter/receiver unit and to selectively activate said first connection circuit or said first infrared receiving unit and said first infrared emitting unit in response to an instruction issued from said first key switch input unit;
• said portable terminal unit being comprised of:
• a second infrared receiving unit that receives said second infrared signal and converts said second infrared signal into a third electric signal;
• a second infrared emitting unit that converts a fourth electric signal into said first infrared signal and transmits said first infrared signal to said option apparatus;
• a second control unit that produces a third information signal based on said third electric signal, supplies said third information signal to said second radio transmitter/receiver unit, produces said fourth electric signal based on a fourth information signal, and provides said fourth electric signal to said second infrared emitting unit;
• a second radio transmitter/receiver unit that receives electromagnetic waves transmitted from the base station, derives said fourth information signal from said received electromagnetic waves, converts said third information signal into electromagnetic waves and transmits said converted electromagnetic waves to the base station;
• a second connection circuit coupled to said cable;
• and
• a second key switch input unit;
• said second control unit being further operative to selectively activate said second connection circuit or said second infrared receiving unit and said second infrared emitting unit in response to an instruction issued from said second key switch input unit.

A method for connecting a portable terminal unit to an option apparatus used with the portable terminal unit, comprising:

• as a first step, transmitting information from said option apparatus to said portable terminal unit;
• and
• as a second step, transmitting information from said portable terminal unit to said option apparatus,
• said first step comprising, in said option apparatus:
• receiving electromagnetic waves transmitted from a base station;
• deriving a first information signal from the received electromagnetic waves;
• converting the derived first information signal into a first infrared signal, and
• transmitting said first infrared signal to said portable terminal unit;
• and, in said portable terminal unit:
• receiving said first infrared signal;
• and
• deriving a second information signal from said first infrared signal;
• said second step comprising,
• in said portable terminal unit:
• converting a third information signal into a second infrared signal;
• and transmitting the second infrared signal to said option apparatus;
• and, in said option apparatus:
• receiving said second infrared signal;
• deriving a fourth information signal from the received infrared radiation;
• converting the fourth information signal into electromagnetic waves;
• and
• transmitting the converted electromagnetic waves to the base station;
• said first step further comprising, in said option apparatus:
• converting a fifth information signal into a third infrared signal;
• and
• transmitting the fifth infrared signal to said portable terminal unit;
• and in said portable terminal unit:
• receiving said third infrared signal;
• deriving a sixth information signal from said third infrared signal;
• converting the sixth information signal into electromagnetic waves, and transmitting said converted electromagnetic waves to the base station;
• said second step further comprising, in said portable terminal unit:
• receiving electromagnetic waves transmitted from the base station;
• deriving a seventh information signal from said received electromagnetic waves;
• converting said seventh information signal into a fourth infrared signal;
• and
• transmitting said fourth infrared signal to said option apparatus;
• and in said option apparatus:
• receiving said fourth infrared signal.