A character input method is implemented in a device with a plurality of keys. A recessed tip wall portion of the tip wall is recessed inboard from a pressure side of an airfoil outer wall of an airfoil of the blade forming a tip shelf therebetween. The high-frequency circuit section and the antenna section are arranged respectively on first and second faces of a secondary printed board. A layer of passivation material is then disposed over the layer of conductive material. The configuration of the projector allows blockage of light incident on the lens barrel and hence prevention of distortion of the lens barrel. An installation for carrying out this procedure is also described.