Patent attributes
Provided is a waterproof/drainage structure for a lower casing (11) having a plurality of pushbuttons (16) on a surface thereof. The waterproof/drainage structure has a cover member (14) forming the surface and provided with a plurality of button holes (14a) the plurality of pushbuttons (16), and a sheet portion (17) retaining the plurality of pushbuttons (16) at predetermined positions. The waterproof/drainage structure includes a button unit (15), in which the sheet portion (17) is arranged along a back surface (14b) of the cover member (14) and in which an outer peripheral portion of the sheet portion (17) is held in close contact with the cover member (14), with the pushbuttons (16) being inserted in button holes (14c) of the cover member (14). The sheet portion (17) is provided with a groove-like drainage channel (22) having a channel portion that is opposed to each of the pushbuttons (16) and is larger than a surface area within a maximum outer periphery of the pushbuttons (16).