| 摘要 |
An electro-optical sensor is used to scan a region and detect any changes or movement in this region. If any change or movement is detected, a receiver and/or transmitter next to the sensor is designed to look for a response signal from an identification card or marker which has to be carried by all people in this region. If a card or marker is found, the information stored on it is read and compared with the information required for authorized access and any deviation results in a signal, alarm or marking being generated. |
