Press button structure of ultrasonic diagnostic apparatus

A press button structure of an ultrasonic diagnostic apparatus, the press button structure comprising:

• a substrate including a fixed contact;
• a movable contact member disposed over the substrate, the movable contact member comprising:
• a base;
• a protrusion having a convex shape protruding upward, the protrusion having a movable contact on a lower face of the protrusion, the movable contact to be in contact with the fixed contact;
• and
• an elastic member connecting the base and the protrusion, the elastic member, in a natural state, urging the protrusion upward to hold the protrusion in a manner that the movable contact and the fixed contact are separated, the elastic member having an upward reaction force that changes in accordance with a pressing amount of the protrusion that is pressed downward,
• a cylindrical guide member disposed to surround a side of the protrusion;
• and
• a cap member mounted on the protrusion, the cap member comprising a top plate covering a top face of the protrusion and a side wall covering a side face of the protrusion, the side wall of the cap member being disposed adjacent and opposite an inner side face of the guide member in a manner that the side wall is slidable upward and downward along the inner side face.