Lens barrel and camera

1. A lens barrel, comprising:

a plurality of lens groups;

a plurality of lens-retaining frames that retain the plurality of lens groups, respectively;

a lens-retaining frame driving device that drives the plurality of lens-retaining frames and moves at least one of the plurality of lens groups between a collapsed state and a photographing state; and

a movable lens cylinder that retains therein the plurality of lens-retaining frames,

wherein the plurality of lens-retaining frames includes:

a first retractable lens-retaining frame that retains at least one of the plurality of lens groups and retracts to a position located outside an inner radius of the movable lens cylinder in the collapsed state;

a second retractable lens-retaining frame that retains at least one of the plurality of lens groups and retracts to a position located outside an inner radius of the movable lens cylinder in the collapsed state;

a first retractable lens-moving member that retains and moves the first retaining frame; and

a second retractable lens-moving member that retains and moves the second retractable lens-retaining frame,

wherein at least one of the first and second retractable lens-retaining frames are retained to be movable relative to the respective retractable lens-moving member along an axis parallel to an optical axis direction in the collapsed state, and

wherein at least one of the first and second retractable lens-retaining frames includes a contact portion which makes at least one of the first and second retractable lens-retaining frames move along the axis parallel to the optical axis direction when the lens-retaining frames contact each other in the collapsed state.

2. The lens barrel as claimed in claim 1 , wherein the contact portion is a protruding element formed on at least one of the first and second retractable lens-retaining frames.

3. The lens barrel as claimed in claim 1 , wherein one of the first and second retractable lens-retaining frames is connected with the respective retractable lens-moving member via a bias member.

4. The lens barrel as claimed in claim 3 , wherein the bias member is compressed and biases the one of the first and second retractable lens-retaining frames toward an object side in the collapsed state and the bias member is relaxed in the photographing state.

5. The lens barrel as claimed in claim 3 , wherein the bias member is a leaf spring.

6. The lens barrel as claimed in claim 3 , wherein the bias member is a compression spring.

7. The lens barrel as claimed in claim 3 , wherein the bias member is a tension spring.

8. The lens barrel as claimed in claim 1 , wherein the first and second retractable lens-retaining frames contact each other in moving from the photographing state to the collapsed state and are collapsed simultaneously by maintaining contact.

9. The lens barrel as claimed in claim 1 , wherein one of the first and second retractable lens-retaining frames is firstly retracted away from the optical axis, then an other of the first and second retractable lens-retaining frames is retracted from the optical axis and pushes the firstly retracted retractable lens-retaining frame to move along the axis parallel to the optical axis direction in the collapsed state.

10. The lens barrel as claimed in claim 1 , wherein the first and second retractable lens-moving members have respectively a position detection device to detect whether the first and second retractable lens-moving members have been collapsed to the collapsed state; and the plurality of lens groups other than the first and second retractable lens groups are collapsed when the first and second retractable lens-moving members are detected by the respective position detection device to have been collapsed to the collapsed state.

11. The lens barrel as claimed in claim 1 , wherein the first and second retractable lens-moving members are actuated simultaneously.

12. The lens barrel as claimed in claim 1 , wherein one of the first and second retractable lens-moving members is firstly actuated and an other of the first and second retractable lens-retaining frames is actuated after a determined number of pulses or time is detected.

13. A camera comprising the lens barrel as claimed in claim 1 .

14. The lens barrel as claimed in claim 1 , wherein the first retractable lens-retaining frame and the first retractable lens-moving member are integrally formed.

15. The lens barrel as claimed in claim 1 , wherein the second retractable lens-retaining frame and the second retractable lens-moving member are integrally formed.