Abstract: 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).

Abstract: 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.