An injection mold including a connecting structure for separating confronting faces of a slide member and a mold base, respectively, during a movement of the slide member. An inclination of the mirror forming area with respect to a normal line of the screen close to the projector becomes larger than the inclination of the mirror forming area far from the projector within a cross section perpendicular to the mirror forming areas inside the screen. In such a system, the center apparatus provides print information corresponding to view conditions of a distributed content to the terminal apparatus in response to the request therefrom, and the terminal apparatus makes the print information appropriately printable by means of a printer. The second port communicates with the display and is coupled to the rotating assembly in order to permit the display to rotate. The grille system is used as a security grille or in the manufacture of garden furniture or plant supports.