Amount-of-shake sensing apparatus, imaging apparatus, and method for detecting the amount of shake
The apparatus of the invention is characterized by executing radius-of-rotation calculation operation for calculating a radius of rotation from a velocity change found by time integration of acceleration, and an angular velocity; velocity calculation operation in which during a given time from a start of exposure, velocity is calculated based on the angular velocity and the radius of rotation calculated before the start of exposure, and after a lapse of the given time, the acceleration is cumulatively added to the velocity detected during the given time to calculate the velocity, and amount-of-movement calculation operation for time-integrating the velocity calculated in the velocity calculation operation to calculate the amount of movement.
1. An amount-of-shake sensing apparatus, comprising:
an angular velocity sensor which detects an angular velocity concerning rotational motion of a casing,
an acceleration sensor which detects an acceleration applied to the casing,
a movement calculator which calculates an amount of movement of the casing based on the angular velocity and the acceleration, wherein:
the movement calculator executes:
a radius-of-rotation calculation operation for calculating a radius of rotation from a change of an amount of a velocity found by time integration of the acceleration, and the angular velocity,
a velocity calculation operation in which during a given time from a start of exposure, the velocity is calculated based on the angular velocity and the radius of rotation calculated before the start of exposure, and after a lapse of the given time, the acceleration is cumulatively added to the velocity detected during the given time to calculate the velocity, and
an amount-of-movement calculation operation for time-integrating the velocity calculated in the velocity calculation operation to calculate the amount of movement.
2. The amount-of-shake sensing apparatus according to claim 1 , wherein
the movement calculator executes:
the radius of rotation used for the velocity calculation operation has been calculated in the radius-of-rotation calculation operation before impacts are generated from a movable part operating in response to an image-taking operation start instruction.
3. The amount-of-shake sensing apparatus of claim 1 , wherein the movement calculator executes:
the velocity calculation operation calculates a velocity in a first axis direction based on the radius of rotation, an angular velocity around a second axis vertical to the first axis direction and being detected for an amount of movement, and an angular velocity around a third axis vertical to the first axis and the second axis.
4. The amount-of-shake sensing apparatus according to claim 1 , wherein the movement calculator executes:
the velocity calculation operation calculates a velocity in a second axis direction based on the radius of rotation, an angular velocity around a first axis vertical to a second axis direction and being detected for an amount of movement, and an angular velocity around a third axis vertical to the first axis and the second axis.
5. The amount-of-shake sensing apparatus according to claim 1 , wherein the movement calculator executes:
the given time is adjusted based on the acceleration detected in the acceleration sensor.
6. An imaging apparatus, comprising:
an amount-of-shake sensing apparatus according to claim 1 ,
an optical system which images light from an object as an object image,
an imaging device which transforms an object image formed by the optical system into image signals, and
a drive unit which drives at least one of the optical system and the imaging device in a direction of canceling out the amount of movement calculated by the amount-of-shake sensing apparatus.
7. A method for detecting an amount of shakes, comprising steps of:
A detecting an angular velocity concerning rotational motion of a casing,
a detecting an acceleration applied to the casing, and
an executing calculation operation for calculating an amount of movement of the casing based on the angular velocity and the acceleration, wherein:
the calculation operation includes:
a radius-of-rotation calculation operation for calculating a radius of rotation from a change of a velocity found by time integration of the acceleration, and the angular velocity,
a velocity calculation operation in which during a given time from a start of exposure, the velocity is calculated based on the angular velocity and the radius of rotation calculated before the start of exposure, and after a lapse of the given time, the acceleration is cumulatively added to the velocity detected during the given time to calculate the velocity, and
an amount-of-movement calculation operation for time-integrating the velocity calculated in the velocity calculation operation to calculate the amount of movement.