Focal plane shuttering apparatus and image capture device

1. A focal plane shuttering apparatus comprising:

a shutter base plate with an aperture;

a front curtain which is movable between a position where the front curtain covers the aperture and a position where the front curtain is retracted from the aperture;

a first elastic member which generates biasing force to make the front curtain run in such a direction as to get the front curtain retracted from the aperture;

a rear curtain which is movable between a position where the rear curtain covers the aperture and a position where the rear curtain is retracted from the aperture;

a second elastic member which generates biasing force to make the rear curtain run in such a direction as to have the rear curtain cover the aperture;

a charging member which applies biasing force to the first and second elastic members;

a front curtain locking mechanism which keeps the front curtain retracted from the aperture when the charging member applies biasing force to the first elastic member;

a rear curtain locking mechanism which keeps the aperture covered with the rear curtain when the charging member applies biasing force to the second elastic member; and

an unlocking member which is interlocked with the charging member that unlocks the front and rear curtain locking mechanisms.

2. The focal plane shuttering apparatus of claim 1 , wherein the charging member includes an unlocking portion to unlock the rear curtain locking mechanism in addition to the unlocking member.

3. The focal plane shuttering apparatus of claim 1 , further comprising a third elastic member which applies biasing force to urge the front curtain to cover the aperture,

wherein the front curtain locking mechanism maintains a state in which the front curtain is retracted from the aperture with biasing force applied to the first elastic member, but is ready to exit from the state, and

once the front curtain locking mechanism exits from the state, the aperture is able to be kept covered with the front curtain by the third elastic member.

4. The focal plane shuttering apparatus of claim 1 , further comprising a fourth elastic member which applies biasing force to get the rear curtain retracted from the aperture,

wherein the rear curtain locking mechanism maintains a state in which the aperture is covered with the rear curtain with biasing force applied to the second elastic member, but is ready to exit from the state, and

once the rear curtain locking mechanism exits from the state, the rear curtain is able to be kept retracted from the aperture by the fourth elastic member.

5. The focal plane shuttering apparatus of claim 1 , wherein when driving force is transferred from the charging member to the unlocking member, the unlocking member starts to be driven later than the charging member.

6. The focal plane shuttering apparatus of claim 1 , comprising:

a front curtain driving member which is coupled to the front curtain;

a front curtain setting member which receives force to generate the biasing force applied from the charging member to the first elastic member;

a third elastic member which applies weaker biasing force than the first elastic member does so that the front curtain driving member contacts with the front curtain setting member; and

a front curtain locking portion which makes the front curtain locking mechanism prevent the front curtain driving member from following the front curtain setting member under the biasing force applied from the third elastic member when the charging member applies biasing force to the first elastic member,

wherein the front curtain driving member and the front curtain setting member are able to run together under the biasing force applied from the first elastic member, and

when the charging member applies biasing force to the first elastic member, the front curtain setting member is driven separately from the front curtain driving member.

7. The focal plane shuttering apparatus of claim 1 , comprising:

a rear curtain driving member which is coupled to the rear curtain;

a rear curtain setting member which receives force to generate the biasing force applied from the charging member to the second elastic member;

a fourth elastic member which applies weaker biasing force than the second elastic member does so that the rear curtain driving member contacts with the rear curtain setting member; and

a rear curtain locking portion which makes the rear curtain locking mechanism prevent the rear curtain driving member from following the rear curtain setting member under the biasing force applied from the fourth elastic member when the charging member applies biasing force to the second elastic member,

wherein the rear curtain driving member and the rear curtain setting member are able to run together under the biasing force applied from the second elastic member, and

when the charging member applies biasing force to the second elastic member, the rear curtain setting member is driven separately from the rear curtain driving member.

8. The focal plane shuttering apparatus of claim 1 , wherein when driving force is transferred from the unlocking member to the charging member, the charging member and the unlocking member start to be driven substantially simultaneously.

9. The focal plane shuttering apparatus of claim 5 , comprising:

a motor; and

a gear train which transfers the driving force of the motor to the charging member,

wherein the charging member is driven by the gear train, and

the gear train and the charging member engage with each other at their missing teeth.

10. The focal plane shuttering apparatus of claim 8 , comprising:

a motor; and

a gear train which transfers the driving force of the motor to the unlocking member,

wherein the unlocking member is driven by the gear train, and

the gear train and the unlocking member engage with each other at their missing teeth.

11. The focal plane shuttering apparatus of claim 9 , wherein targets to which the driving force of the motor is transferred are changed from the gear train that drives the charging member into the gear train that drives the unlocking member, or vice versa, by changing the rotating direction of the motor.

12. The focal plane shuttering apparatus of claim 11 , wherein the targets are changed by changing the rotating direction of the motor using a planetary gear mechanism.

13. The focal plane shuttering apparatus of claim 2 , wherein when the rear curtain locking mechanism unlocks the rear curtain driving member, the unlocking portions of the charging member and the unlocking portions of the unlocking member are arranged at mutually different positions.

14. The focal plane shuttering apparatus of claim 8 , wherein the charging member includes:

a fifth elastic member which returns to an initial position where the fifth elastic member is engageable with the missing teeth;

a front curtain electromagnet which is able to hold the front curtain setting member at a position where the biasing force has been applied to the first elastic member; and

a rear curtain electromagnet which is able to hold the rear curtain setting member at a position where the biasing force has been applied to the second elastic member,

wherein if the charging member gets disengaged from the missing teeth when the front curtain and rear curtain electromagnets are powered, the charging member returns to the initial position under the biasing force applied from the fifth elastic member, the front curtain driving member is released by the front curtain locking mechanism, the front curtain gets held at the position where the aperture is covered with the front curtain, the rear curtain driving member is released by the rear curtain locking mechanism, and the rear curtain gets held at the position where the rear curtain is retracted from the aperture.

15. An image capture device comprising:

the focal plane shuttering apparatus of claim 1 ; and

an imager configured to capture a subject image that has come through the aperture and to output image data.

16. A shuttering apparatus comprising:

a shutter base plate with an aperture;

a front curtain which is movable between a position where the front curtain covers the aperture and a position where the front curtain is retracted from the aperture;

a first elastic member which generates biasing force to make the front curtain run in such a direction as to get the front curtain retracted from the aperture;

a rear curtain which is movable between a position where the rear curtain covers the aperture and a position where the rear curtain is retracted from the aperture;

a second elastic member which generates biasing force to make the rear curtain run in such a direction as to have the rear curtain cover the aperture;

a motor;

a charging member which applies biasing force to the first and second elastic members by using the driving force of the motor;

a front curtain locking mechanism which keeps the front curtain retracted from the aperture when the charging member applies biasing force to the first elastic member;

a rear curtain locking mechanism which keeps the aperture covered with the rear curtain when the charging member applies biasing force to the second elastic member; and

an unlocking member which unlocks the front and rear curtain locking mechanisms by using the driving force of the motor;

wherein a first difference between a timing at which the charging member applies biasing force to the first and second elastic members and a timing at which the unlocking member unlocks the front and rear curtain locking mechanisms when the motor rotates in one rotating direction is different from a second difference between a timing at which the charging member applies biasing force to the first and second elastic members and a timing at which the unlocking member unlocks the front and rear curtain locking mechanisms when the motor rotates in the other rotating direction.