Linear guiding mechanism of a zoom lens barrel of a photographing optical system

A linear guiding mechanism of a zoom lens barrel of a photographing optical system, comprising:

• a stationary block connected to a camera body;
• a barrel slidable with respect to said stationary block and precluded from rotation with respect to said stationary block;
• a cam ring which is threadedly engaged with said barrel on an inside of said barrel;
• a linear guiding plate for linearly guiding the photographing optical system in an optical axis direction, wherein said linear guiding plate is movable together with said cam ring in said optical axis direction, and wherein said cam ring is rotatable with respect to said linear guiding plate;
• a linear guiding groove which is provided on said barrel, wherein a guided projection formed on said linear guiding plate is slidably engaged in said linear guiding groove of said barrel to guide said linear guiding plate in said optical axis direction;
• and
• a driving gear for rotating said cam ring, wherein said driving gear is positioned in said linear guiding groove with an axial direction of said driving gear being parallel to said linear guiding groove, and wherein said driving gear is engaged with a circumferential gear formed on an outer peripheral surface of said cam ring, said guided projection of said linear guiding plate being provided in the vicinity of said driving gear.

A linear guiding mechanism of a zoom lens barrel of a photographing optical system, comprising:

• a stationary block connected to a camera body;
• a barrel slidably connected to said stationary block and having a rotation restricting portion, said stationary block determining an opening to accommodate said barrel and comprising a linear groove to slidably engage said rotation restricting portion of said barrel;
• a cam ring threadedly engaged with said barrel on an inside of said barrel;
• a linear guiding plate for linearly guiding the photographing optical system in an optical axis direction, wherein said linear guiding plate is movable together with said cam ring in said optical axis direction, and wherein said cam ring is rotatable with respect to said linear guiding plate;
• and
• a linear guiding portion formed on said barrel for guiding said linear guiding plate in said optical axis direction, wherein a section of said linear guiding portion is formed as an elongated hole, and wherein a remaining section of said linear guiding portion is formed as a blind-end groove on an inner peripheral surface of said barrel.