Disclosed is a reflecting wavelength plate that deflects and reflects a light path and adds a phase difference with respect to plural incident light having different wavelengths. Each memory cell includes at least a first capacitor, a second capacitor, and a transistor which functions as a switching element for controlling supply, storage, and release of charge in the first capacitor and the second capacitor. In one illustrative system, the program originator is a broadcast station that includes a conventional encoder and a broadcast station computer. The trip edge blade is also sufficiently high to prevent damage to the upper snow plow blade due to impacts with curbs or other high obstacles. According to this construction, the mechanical strength of the central portion of the pressed mask becomes large, whereby it is possible to restrain the occurrence of undesired deformation of the pressed mask 1 due to the increase of the radius of curvature of the central portion and it is possible to uniformize brightness over the entire screen. Flow of material may be controlled by providing a vacuum in the crucible.