Image pickup apparatus capable of interchanging lenses and lens mount therefor

1. A lens mount provided in an image pickup apparatus body and configured to detachably mount an interchangeable lens having bayonet pawls to the image pickup apparatus body, comprising:

a fixed portion configured to be fixed to the image pickup apparatus body;

a stationary mount portion configured to be fixed to said fixed portion, said stationary mount portion having a body-side mount face configured for abutment with a lens-side mount face of the interchangeable lens and having a first screw portion;

a movable mount portion having pawls configured for engagement with the bayonet pawls of the interchangeable lens and having a second screw portion configured for threaded engagement with the first screw portion; and

arm portions provided in an area between said fixed portion and said stationary mount portion to project from said movable mount portion,

wherein said movable mount portion rotates with movement of said arm portions,

said movable mount portion moves toward said fixed portion with progress of engagement between the first and second screw portions caused by the rotation of said movable mount portion, and

the pawls of said movable mount portion are brought in abutment with the bayonet pawls of the interchangeable lens with the movement of said movable mount portion.

2. The lens mount according to claim 1 , further including:

a ring portion disposed for rotation relative to said stationary mount portion; and

an operating portion fastened to at least one of said arm portions through said ring portion and used for rotary operation of said movable mount portion.

3. The lens mount according to claim 2 , further including:

a second fixed portion configured to be fixed to said stationary mount portion and having finger rest portions that are used when said operating portion is rotated.

4. The lens mount according to claim 1 , wherein said stationary mount portion and said arm portions are each provided with an abutment face, and the abutment face of said stationary mount portion and the abutment face of at least one of said arm portions are brought in contact with each other to restrict an amount of rotation of said movable mount portion.

5. The lens mount according to claim 1 , wherein said stationary mount portion has a side face formed with a notch,

said movable mount portion has an elastic member configured to urge a spherical metal ball toward the side face of said stationary mount portion,

the spherical metal ball is fitted into the notch in a state where the bayonet pawls of the interchangeable lens and the pawls of said movable mount portion do not overlap with one another as viewed in an optical axis direction, and

the spherical metal ball rides on the side face of said stationary mount portion in a state that the bayonet pawls and the pawls overlap with one another as viewed in the optical axis direction.

6. The lens mount according to claim 1 , further comprising:

a body-side contact terminal portion configured to be urged toward a lens-side contact terminal portion of the interchangeable lens for contact with the lens-side contact terminal portion in a state where the interchangeable lens is mounted to the image pickup apparatus body,

wherein said stationary mount portion is formed with an opening into which the lens-side mount portion of the interchangeable lens is fitted, and

the lens-side contact terminal portion and the body-side contact terminal portion rub against each other in a direction substantially perpendicular to the optical axis when the lens-side mount portion is being fitted into the opening of said stationary mount portion.

7. The lens mount according to claim 6 , wherein said stationary mount portion has a guide portion configured to guide the lens-side mount portion when the lens-side mount portion is fitted into the opening of said stationary mount portion.

8. The lens mount according to claim 1 , wherein said arm portions are rotated to rotate said movable mount portion about an optical axis.

9. The lens mount according to claim 1 , wherein with rotation of said movable mount portion, a shift is made from a state where the bayonet pawls of the interchangeable lens and the pawls of said movable mount portion do not overlap with one another as viewed in an optical axis direction to a state where they overlap with one another as viewed in the optical axis direction.

10. An image pickup apparatus comprising:

an image pickup apparatus body having a lens mount configured to detachably mount an interchangeable lens having bayonet pawls to the image pickup apparatus body, comprising:

a fixed portion configured to be fixed to the image pickup apparatus body;

a stationary mount portion configured to be fixed to said fixed portion, said stationary mount portion having a body-side mount face configured for abutment with a lens-side mount face of the interchangeable lens and having a first screw portion;

a movable mount portion having pawls configured for engagement with the bayonet pawls of the interchangeable lens and having a second screw portion configured for threaded engagement with the first screw portion; and

arm portions provided in an area between said fixed portion and said stationary mount portion to proiect toward from said movable mount portion,

wherein said movable mount portion rotates with movement of said arm portions,

said movable mount portion moves toward said fixed portion with progress of engagement between the first and second screw portions caused by the rotation of said movable mount portion, and

the pawls of said movable mount portion are brought in abutment with the bayonet pawls of the interchangeable lens with the movement of said movable mount portion.