A column analog-to-digital converter having a voltage comparator and a counter is arranged for each a vertical signal line. Under one mode, a first RAC of the wireless may generate data based on a first IF signal downconverted from a first RF signal. The illustration can arouse interest of an infant definitely since the object of interest of an infant depends on hisher age in months. An electrode may include conductive material and insulative material. A replication pair in a pair status in the power control unit is confirmed, set as a target to be switched to the power saving mode if it is of a constant value or less, and a management server is notified if there is an operation for creating a volume.