Abstract: This invention aims to provide a communication device, installation structure for the communication device, a method of manufacturing the communication device, and a method of communication with the communication device in which the communication device is able to exceedingly restain a conductive material from attenuating magnetic flux and to expand communication distance even when the communication device is attached to a conductive member e.g., metal, in a closely contacting manner. This invention has a sheet-like amorphous magnetic material being arranged in a manner extending from a magnetic flux generating portion of a concentric disk-shaped antenna coil of an RFID tag serving as the communication device to an outer area of the antenna coil.

Abstract: A communication device having a long communication range by greatly suppressing the attenuation of the magnetic flux because of a conductive member even if the communication device is installed near the conductive member such as of metal. Its installation structure, manufacturing method, and communication method are also disclosed. An RFID tag (1a) serving as a communication device (12) is characterized in that an amorphous magnetic sheet (5) extends from a magnetic flux generation portion (A) of a concentric display antenna coil (2a) of the RFID tag (1a) toward the outside of the antenna coil (2a).

Abstract: The present invention is provided with a key hole insertion fitted to a manhole cover, a manhole cover locking apparatus equipped with the key hole insertion, a manhole cover locking system, a method for unlocking the manhole cover, and a control system for opening and a closing manhole cover, which is designed to prevent an external access to the key hole of the manhole cover, thus attaining a sound and severe locking management. The electrical locking assembly can be added to conventional manhole covers in a simple way. The structure of the invention is characterized in a key hole insertion A inserted in a key hole 3b of the inner manhole cover 3 or the key hole 5b of the manhole cover 5 enough to engage pins 11b with engaging openings 12b of the cap holding member 12 secured to the key hole 3b or the key hole 5b. This allows the key hole insertion A to be locked to the key hole 3b or the key hole 5b.