Curved-surface button structure

A curved-surface button structure, comprising:

• a housing, comprising a first case and a second case assembled with each other, the first case comprising a through hole, a curved surface and an internal surface, the curved surface and the internal surface arranged at two sides of the first case opposite to each other, the through hole communicating between the curved surface and the internal surface;
• a button, arranged in the housing, comprising a base and a driven part, the driven part pressably connected with the base to face the internal surface;
• a button assembly, comprising a pressing plate, an installation seat and an extending column, the installation seat arranged on the internal surface, the pressing plate connected with the installation seat corresponding to the through hole, the extending column extended from the pressing plate toward the button;
• and
• a positioning sleeve, adapted to sheathe an end of the extending column, and an inner diameter of the positioning sleeve being greater than an outer diameter of the driven part;
• wherein when the button assembly is not pressed by an external force, the pressing plate is accommodated in the through hole, and a gap is defined between the extending column and the driven part;
• wherein when the button assembly is pressed by an external force, the pressing plate is moved further into the through hole, the extending column presses the driven part, and the positioning sleeve surrounds the driven part;
• wherein an installation distance is defined between an end surface of the positioning sleeve away from the first case and an end surface of the extending column away from the first case, and the installation distance is greater than or equal to 0.5 mm and less than or equal to 3 mm.