An optical element, such as a lens, is described that provides good transmission of radiation in the infrared portion of the electromagnetic spectrum, that can be molded using an injection molding technique. An on- or off-line multi-roll calender formed of separate sets of rolls is used for calendering, and the fibrous web is subjected to intermediate moistening between the sets of rolls. Each of the of amplifiers includes a plurality of cards as respective functional sections and a transmission and reception-integrated section that collects transmission and reception signals input to and output from each of the plurality of cards and terminates communication with the modulation and demodulation equipment. The calendar data object includes scheduling information indicating, explicitly andor implicitly, future time when the first user is available. One end of each of the data lines is connected between the first diode group and the other end thereof is connected between the second diode group via the transmission gate.