STRUCTURE OF ZOOM LENS BARREL EMPLOYING DOUBLE HELICOD RING AND CAM GUIDE

摘要

PURPOSE: A structure of zoom lens barrel employing double helicoid ring is provided to smooth the zooming operating and streamline the structure while maintaining high magnifying power. CONSTITUTION: In a structure of zoom lens barrel, a double helicoid ring(30) includes a barrel(10) fixed to the camera body and two helicoids(39,36). The helicoid ring(30) is set up and rotates inside the fixed barrel(10). A front-end lens supporter(60) and a back-end lens supporter(50) are connected to the two helicoids(39,36) respectively through screws. The structure also includes two guides(20,40) guiding the front-end lens supporter(60) and the back-end lens supporter(50) respectively. Here, the guides have a cam forming on the path of the second helicoid(36) of the back-end lens supporter(50).