Zoom actuating apparatus for cameras

A zoom actuating apparatus for a camera, the apparatus comprising:

• i) a lens barrel provided with a fixed cylinder, a movable cylinder supported in the fixed cylinder such that the movable cylinder is capable of moving along an optical axis direction, and a helicoid mechanism for moving the movable cylinder along the optical axis direction through engagement of an internal helicoid, which is formed on an inner circumferential surface of the fixed cylinder, and an external helicoid, which is formed on an outer circumferential surface of the movable cylinder,
• ii) zoom actuating means for actuating the movable cylinder for rotation, and
• iii) a lens barrier interlocked with the rotation of the movable cylinder such that the lens barrier operates to open or close an opening section formed in a front cover, through which opening section the movable cylinder moves forwardly and backwardly, in accordance with the rotation of the movable cylinder,
• wherein the helicoid mechanism is provided with an unengaged region, in which the internal helicoid and the external helicoid are in an unengaged state, within a rotation region between a collapsed state of the movable cylinder and a wide end of the movable cylinder, and
• the opening or closing operation of the lens barrier is performed by the rotation of the movable cylinder in the unengaged region of the helicoid mechanism.