Abstract: A communication system capable of preventing a lost transmitter from being used by an unauthorized user for a bad purpose, and also capable of easily enabling the lost transmitter to be used again when it is found.

Abstract: The invention provides a communication system capable of preventing a lost transmitter from being used by an unauthorized user for a bad purpose, and also capable of easily enabling the lost transmitter to be used again when it is found somewhere.

Abstract: A communication apparatus for preventing an unauthorized use of a lost transmitter, and for making a use of that transmitter possible by a simple operation when the lost transmitter is subsequently found, including a receiver having a storage unit for storing an ID code, a signal processing unit for comparing a received ID code transmitted from a transmitter with the stored ID code, and for transmitting a control signal corresponding to a function code received from the transmitter to a controlled unit when the received ID code matches the stored ID code, and a mode control unit for either setting the operation mode of the signal processing unit to a ID code write mode in which a the received ID code is written into the storage unit, for setting to a control signal output stop mode which stops an output of the control signal from the signal processing unit to prevent unauthorized use of a lost transmitter, or resetting from the control signal output stop mode to a normal mode to allow re-use of the lost trans

Abstract: A transmission and reception system including a transmitter for transmitting a signal including identification (security) information and function information, and a receiver for receiving and decoding the signal and for executing the operation defined by the function information upon verification of the identification information. The transmitter divides one or more of the identification information and the function information into two or more bit groups, and transmits these bit groups such that identification information bit groups are separated by function information and function information bit groups are separated by identification information.