Camera device and gravity compensation method
A camera device includes an image sensor which images a subject, a lens unit that includes a lens for forming an image of the subject on a light receiving surface of the image sensor, a shaking corrector that includes a movable portion that includes the image sensor and moves the movable portion in a direction perpendicular to an optical axis of the lens unit according to shaking of the camera device to correct shaking, and a gravity support that supports the movable portion in a direction opposite to a direction of a component force of the gravity with a force equal to a component force of gravity applied to the movable portion along a direction perpendicular to the optical axis of the lens unit.
1. A camera device comprising:
an image sensor that images a subject;
a lens for forming an image of the subject on a light receiving surface of the image sensor;
a shaking correction frame that includes a movable portion which holds the image sensor and that moves the movable portion in a direction perpendicular to an optical axis of the lens according to the shaking of the camera device to correct shaking; and
a gravity support that supports the movable portion in a direction opposite to a direction of a component force of the gravity with a force equal to a component force of gravity applied to the movable portion along a direction perpendicular to the optical axis of the lens, the gravity support comprising:
an elastic member connected to the movable portion,
a gear that adjusts a length of the elastic member,
a motor that supplies a driving force to the gear, and
a motor driver that controls the driving force of the motor.
2. The camera device of claim 1 , further comprising:
a position sensor that acquires information on a position of the image sensor in a direction perpendicular to the optical axis of the lens with respect to the lens,
wherein the motor driver controls the driving force of the motor so that the image sensor is disposed at a reference position based on information on the position of the image sensor detected by the position sensor.
3. The camera device of claim 2 ,
wherein the position sensor transmits information on the detected position of the image sensor to the gravity support and the shaking correction frame.
4. The camera device of claim 2 ,
wherein the reference position is positioned on the optical axis of the lens.
5. The camera device of claim 2 ,
wherein the reference position is a position where an optical axis deviation of the lens is adjusted.
6. The camera device of claim 1 , further comprising:
an inclination sensor that detects an inclination angle of the lens; and
a derivation unit that derives a component force of gravity applied to the movable portion along a direction perpendicular to the optical axis of the lens based on the inclination angle of the lens,
wherein the motor driver controls the driving force of the motor based on the derived component force of gravity.
7. The camera device of claim 6 ,
wherein the motor driver makes the driving force of the motor invariable during a period in which the shaking correction is performed by the shaking correction frame.
8. The camera device of claim 6 , further comprising:
an inclination acquiring unit that acquires information on the inclination angle of the lens,
wherein, in a case where an inclination angle of the lens acquired by the inclination acquiring unit is changed, the motor driver changes the driving force of the motor.
9. The camera device of claim 1 ,
wherein the motor driver makes the driving force of the motor invariable during a period in which the shaking correction is performed by the shaking correction frame.
10. The camera device of claim 1 , further comprising:
an inclination acquiring unit that acquires information on the inclination angle of the lens,
wherein, in a case where the inclination angle of the lens acquired by the inclination acquiring unit is changed, the motor driver changes the driving force of the motor.
11. A gravity compensation method in the camera device that includes a shaking corrector which has a movable portion that holds the image sensor and moves the movable portion in a direction perpendicular to an optical axis of the lens unit that forms an image of a subject on a light receiving surface of the image sensor according to shaking of the camera device to correct shaking, the method comprising:
supporting the movable portion, via a gravity support having an elastic member connected to the movable portion, having a gear that adjusts a length of the elastic member, having a motor that supplies a driving force to the gear, and having a motor driver that controls the driving force of the motor, in a direction opposite to the direction of a component force of gravity by a force having the same magnitude as the component force of the gravity applied to the movable portion along a direction perpendicular to the optical axis of the lens unit.