| 摘要 |
PURPOSE:To prevent the theft and the surreptitious use of a portable computer including the software of the computer main body by providing a control mechanism that normally in a designated area only with use of a radio wave of a specific frequency and then disabling the system operation in the area except the designated one. CONSTITUTION:A receiver 42 receives the radio wave of a specific frequency radiated over a fixed area. A processor 2 contains a power control means which can apply an internal power supply of a device when its available state is decided from the reception contents of the receiver 42. |
