Abstract: Binoculars include first and second lens barrels. A bridge interconnects the lens barrels. First and second optical systems are accommodated in respectively the lens barrels. First and second focus lenses are included in respectively the first and second optical systems, for focus adjustment by moving in an optical axis direction. An operation barrel is secured to the bridge, and externally rotatable and movable in the optical axis direction between a focus adjusting position and a diopter adjusting position. A focus adjuster with gear teeth and screw threads moves the first and second focus lenses simultaneously in the optical axis direction when the operation barrel is rotated in the focus adjusting position. A diopter adjuster, including gear teeth, an intermediate rod and screw threads, moves the second focus lens in the optical axis direction when the operation barrel is rotated in the diopter adjusting position.

Abstract: Binoculars include first and second lens barrels. A bridge interconnects the lens barrels. First and second optical systems are accommodated in respectively the lens barrels. First and second focus lenses are included in respectively the first and second optical systems, for focus adjustment by moving in an optical axis direction. An operation barrel is secured to the bridge, and externally rotatable and movable in the optical axis direction between a focus adjusting position and a diopter adjusting position. A focus adjuster with gear teeth and screw threads moves the first and second focus lenses simultaneously in the optical axis direction when the operation barrel is rotated in the focus adjusting position. A diopter adjuster, including gear teeth, an intermediate rod and screw threads, moves the second focus lens in the optical axis direction when the operation barrel is rotated in the diopter adjusting position.