Patent ID: 6243214
Filing Date: 2001-06-05
Classification: G02B

Abstract:
A lens barrel comprising a resin cylindrical cam provided with spiral cam slot for moving a photographing lens system forwardly and backwardly in the direction along the optical axis, said lens barrel being characterized in:that the spiral cam slot is composed of a plural number of areas divided around the axis of the cylindrical cam;that in each of said cam areas, the spiral cam slot has a cam surface and a surface opposite to the cam surface, said cam surface being formed at one side of a section of the spiral cam slot taken along a plane containing a normal line to the axis of the cylindrical cam and orthogonal to the locus along the cam slot and said opposite surface being formed at the other side of said section and inclined to said cam surface providing that these opposite surfaces in adjacent areas be inclined in opposite directions to each other; andthat every adjoining part between cam areas includes a first border portion in which said inclined surface is formed by a surface approximately parallel to said cam surface, or a second border portion in which said inclined surface is formed by two oppositely inclined adjacent surfaces, said first and second border portions being disposed alternately in said plural number of cam areas.