Patent ID: 6476978
Filing Date: 2002-11-05
Classification: G03B

Abstract:
A linear-motion helicoid mechanism for a CCTV camera, comprising:a lens frame for holding lenses, which comprises a cylindrical lens holder having a first multicrest helicoid and at least one keyway on an outer periphery of said cylindrical lens holder; a key member that comprises a cylindrical part having at least one key for engagement with said keyway at an inner periphery of said cylindrical part of said key member; a helicoid female member that comprises a cylindrical part having a second multicrest helicoid that screws together with said first multicrest helicoid, at an inner periphery of said cylindrical part of said helicoid female member; and a rotating frame that fixes a position of said helicoid female member to said key member in an optical axis direction of said lenses and rotatably supports said helicoid female member about the optical axis; wherein said helicoid female member and said rotating member are formed integrally.