A method for detecting an explosive in an object under investigation involves the initial X-ray irradiation of the object under investigation, e. This system features the capabilities of a wireless telephone with freedom from expensive service contracts. A reference voltage is applied to a common electrode of a opposite substrate, and display is performed by a potential difference between the reference voltage and a first voltage signal or a second voltage signal. The system of the present invention includes a modification module for altering certain characteristics of a packet.