Lens accessory, lens apparatus, and image pickup apparatus

1. A lens accessory detachably attached to a lens barrel, the lens accessory comprising:

a first holder and a second holder configured to hold the lens barrel;

an operation member configured to move at least one holder of the first holder and the second holder between a first position and a second position; and

a biasing mechanism configured to apply a biasing force to the at least one holder so as to hold the lens barrel,

wherein the biasing mechanism includes a first biasing member and a moving member that moves the at least one holder from the first position to the second position according to an operation of the operation member via the first biasing member, and

wherein when the at least one holder contacts the lens barrel, the first biasing member is displaced by the moving member.

2. The lens accessory according to claim 1 , wherein the moving member is biased by the first biasing member so as to be movable relatively to the at least one holder according to a movement of the at least one holder from the first position to the second position.

3. The lens accessory according to claim 1 , wherein the operation member moves the at least one holder between the first position and the second position according to a rotational operation of the operation member.

4. The lens accessory according to claim 1 ,

wherein the first position is a position where at least one of the first holder and the second holder is retractable from the lens barrel, and

wherein the second position is a position where the lens barrel is capable of being held by using the first holder and the second holder.

5. The lens accessory according to claim 1 ,

wherein the first holder is fixed, and

wherein the second holder moves between the first position and the second position according to the operation of the operation member.

6. The lens accessory according to claim 5 , wherein the biasing mechanism further includes a second biasing member that biases the second holder in a second direction opposite to a first direction.

7. The lens accessory according to claim 6 ,

wherein the first biasing member is biased in the first direction by the moving member, and

wherein the second biasing member is biased in the second direction by the moving member.

8. The lens accessory according to claim 7 , wherein the first biasing member is provided between a receiving surface of the second holder and the moving member.

9. The lens accessory according to claim 7 , wherein the biasing mechanism includes a transmission member that transmits a biasing force of the second biasing member to the moving member.

10. The lens accessory according to claim 7 , wherein the operation member changes a biasing force in the first direction that is applied to the second holder by the first biasing member according to a rotational operation of the operation member.

11. The lens accessory according to claim 10 ,

wherein the operation member is provided with an inclined surface to change the biasing force, and

wherein the moving member is biased to the inclined surface of the operation member by the second biasing member.

12. The lens accessory according to claim 11 , wherein the moving member moves while maintaining a state of contacting the inclined surface of the operation member to move the second holder between the first position and the second position according to the rotational operation of the operation member.

13. The lens accessory according to claim 10 ,

wherein the moving member is inserted into an elongate hole formed on the second holder,

wherein the elongate hole of the moving member includes a first end portion that restricts a movement of the moving member in the first direction and a second end portion that restricts a movement of the moving member in the second direction, and

wherein the moving member is biased toward the second end portion according to a reaction force of the biasing force by the first biasing member.

14. The lens accessory according to claim 1 , wherein the lens accessory is a lens drive adapter for driving an operation ring of the lens barrel.

15. A lens apparatus comprising:

a lens barrel; and

a lens accessory detachably attached to the lens barrel,

wherein the lens accessory comprises:

a first holder and a second holder configured to hold the lens barrel;

an operation member configured to move at least one of the first holder and the second holder between a first position and a second position; and

a biasing mechanism configured to apply a biasing force to at least one of the first holder and the second holder so as to hold the lens barrel, and

wherein the operation member moves at least one of the first holder and the second holder between the first position and the second position according to a rotational operation of the operation member.

16. An image pickup apparatus comprising:

a lens barrel;

an image sensor configured to photoelectrically convert an optical image formed via the lens barrel to output image data; and

a lens accessory detachably attached to the lens barrel,

wherein the lens accessory comprises:

a first holder and a second holder configured to hold the lens barrel;

an operation member configured to move at least one of the first holder and the second holder between a first position and a second position; and

a biasing mechanism configured to apply a biasing force to at least one of the first holder and the second holder so as to hold the lens barrel, and

wherein the operation member moves at least one of the first holder and the second holder between the first position and the second position according to a rotational operation of the operation member.