IMAGE BLUR CORRECTION APPARATUS AND IMAGING APPARATUS

• US 20160127649A1
• Filed: 01/12/2016
• Published: 05/05/2016
• Est. Priority Date: 07/22/2013
• Status: Active Grant

• Current Assignee: OM Digital Solutions Corporation
• Original Assignee: Olympus Corporation
• Inventors: TSUCHIYA, Hitoshi
• Granted Patent: US 9,591,223 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G03B 2205/0038 by displacing the image plane with respect to the optical axis in case of an electronic image sensor H04N23/68
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

An image blur correction apparatus includes: a blur correction actuator that corrects image blur by moving a lens or by moving an image sensor; a shake detection unit that detects a postural change amount of the imaging apparatus; a storing unit that stores three or more postural change amounts detected at different times; an estimating unit that calculates an estimate of a postural change amount after a predetermined time period on the basis of the three or more postural change amounts and on the basis of an approximation based on a temporal change in the postural change amounts; a blur amount calculating unit that calculates an image blur amount on the basis of the estimate; and a driving control unit that calculates a movement amount of a lens or image sensor to be moved by the blur correction actuator on the basis of the image blur amount.

Claims

1. An image blur correction apparatus that corrects image blur that is based on a postural change in an imaging apparatus, the image blur correction apparatus comprising:

an optical system that forms a subject image;

an image sensor that captures the subject image formed by the optical system;

a blur correction actuator that corrects image blur by moving a lens included in the optical system vertically to an optical axis or by moving the image sensor onto an image plane;

a shake detection unit that detects a postural change amount of the imaging apparatus on a cycle of a predetermined detection time;

a storing unit that stores a first postural change amount detected at a first time by the shake detection unit, and a second postural change amount and third postural change amount detected at second and third times by the shake detection unit, the first time being a present time, the second and third times being different from the first time;

an estimating unit that calculates a fourth postural change amount on the basis of the first, second, and third postural change amounts stored by the storing unit and on the basis of an approximation that includes a plurality of coefficients that are preset constants based on a temporal change in the postural change amounts, the fourth postural change amount being an estimate of the postural change amount achieved at a fourth time that is a predetermined time period after the first time;

a blur amount calculating unit that calculates an image blur amount on the basis of the fourth postural change amount calculated by the estimating unit, the image blur amount being a movement amount of the subject image; and

a driving control unit that calculates a movement amount of the lens or image sensor to be moved by the blur correction actuator on the basis of the image blur amount calculated by the blur amount calculating unit, wherein

the plurality of coefficients each depend on a time interval between the first and second times and a time interval between the first and third times.

3. The image blur correction apparatus according to claim 1, wherein

the estimate calculated at the fourth time by the estimating unit corresponds to a value after a period of processing time extending from the first time at which the shake detection unit or the image-plane-movement-amount detecting unit performs the detecting to a time at which the blur correction actuator performs the correcting.

5. The image blur correction apparatus according to claim 1, wherein

a time interval between the second time and the first time and a time interval between the first time and the third time are each a power of 2 relative to the cycle of the predetermined detection time, and

the first, second , and third times are times at which the shake detection unit or the image-plane-movement-amount detection unit detects the three postural change amounts or three image plane movement amounts to be used by the estimating unit to calculate the approximation.

7. The image blur correction apparatus according to claim 1, wherein

the shake detection unit includes

an angular velocity sensor that detects, on the cycle of the predetermined detection time, an angular velocity associated with a postural change in a rotation made by the imaging apparatus in a pitch direction or yaw direction with a rotational axis-vertical to a direction of an optical axis of the optical system,

an acceleration sensor that detects, on the cycle of the predetermined detection time, an acceleration associated with a postural change in a parallel movement of the imaging apparatus in a vertical direction or horizontal direction with respect to the direction of the optical axis of the optical system, and

an integration unit that calculates, on the cycle of the predetermined detection time, a moving velocity associated with the postural change in the parallel movement of the imaging apparatus by performing an integration operation of the acceleration detected by the acceleration sensor, wherein

the postural change amount is a state amount consisting of the angular velocity and the moving amount,

the storing unit

stores a first angular velocity detected at a first time by the angular velocity sensor, and a second angular velocity and third angular velocity detected at second and third times by the angular velocity sensor, the first time being a present time, the second and third times being different from the first time, and stores a first moving velocity, a second moving velocity, and a third moving velocity respectively calculated at the first, second, and third times by the integration unit,

the estimating unit includes

an angular velocity estimating unit that calculates a fourth angular velocity on the basis of the first, second, and third angular velocities stored by the storing unit and on the basis of an approximation that includes preset coefficients based on a temporal change in the angular velocity, the fourth angular velocity being an estimate of the angular velocity achieved at a fourth time that is a predetermined time period after the first time, and

a velocity estimating unit that calculates a fourth moving velocity on the basis of the first, second, and third moving velocities stored by the storing unit and on the basis of an approximation that includes preset coefficients based on a temporal change in the moving velocities, the fourth traveling velocity being an estimate of the traveling velocity achieved at a fourth time that is a predetermined time period after the first time, wherein

the blur amount calculating unit calculates an image blur amount on the basis of an estimate consisting of the fourth angular velocity calculated by the angular velocity estimating unit and the fourth moving velocity calculated by the velocity estimating unit.

8. An imaging apparatus comprising:

the image blur correction apparatus according to claim 1.

2. An image blur correction apparatus that corrects image blur that is based on a postural change in an imaging apparatus, the image blur correction apparatus comprising:

an optical system that forms a subject image;

an image sensor that captures the subject image formed by the optical system;

a blur correction actuator that corrects image blur by moving a lens included in the optical system vertically to an optical axis or by moving the image sensor onto an image plane;

a shake detection unit that detects a postural change amount of the image sensor on a cycle of a predetermined detection time;

an image-plane-movement-amount detecting unit that detects an image plane movement amount that is a movement amount of the subject image that is based on the postural change amount detected by the shake detection unit;

a storing unit that stores a first image plane movement amount detected at a first time by the image-plane-movement-amount detecting unit, and a second image plane movement amount and third image plane movement amount detected at second and third times by the image-plane-movement-amount detecting unit, the first time being a present time, the second and third times being different from the first time;

an estimating unit that calculates a fourth image plane movement amount on the basis of the first, second, and third image plane movement amounts stored by the storing unit and on the basis of an approximation that includes a plurality of coefficients that are preset constants based on a temporal change in the image plane movement amounts, the fourth image plane movement amount being an estimate of the image plane movement amount achieved at a fourth time that is a predetermined time period after the first time; and

a driving control unit that calculates a movement amount of the lens or image sensor to be moved by the blur correction actuator on the basis of the fourth image plane movement amount calculated by the estimating unit, wherein

the plurality of coefficients each depend on a time interval between the first and second times and a time interval between the first and third times.

4. The image blur correction apparatus according to claim 2, wherein

the estimate calculated at the fourth time by the estimating unit corresponds to a value after a period of processing time extending from the first time at which the shake detection unit or the image-plane-movement-amount detecting unit performs the detecting to a time at which the blur correction actuator performs the correcting.

6. The image blur correction apparatus according to claim 2, wherein

a time interval between the second time and the first time and a time interval between the first time and the third time are each a power of 2 relative to the cycle of the predetermined detection time, and

the first, second , and third times are times at which the shaking detection unit or the image-plane-movement-amount detection unit detects the three postural change amounts or three image plane movement amounts to be used by the estimating unit to calculate the approximation.

9. An imaging apparatus comprising:

the image blur correction apparatus according to claim 2.