Anti-shake apparatus
An anti-shake apparatus for image stabilizing comprises an angular velocity sensor and a controller. The angular velocity sensor detects an angular velocity. The controller controls the angular velocity sensor and performs an anti-shake operation on the basis of an output signal from the angular velocity sensor. The controller performs a modification of an offset output in the value of the output signal during a predetermined period of the anti-shake operation, and does not perform the modification except for during the predetermined period.
1. An anti-shake apparatus for image stabilizing, comprising: an angular velocity sensor that detects an angular velocity; and a controller that controls said angular velocity sensor and performs an anti-shake operation on the basis of an output signal from said angular velocity sensor, said controller beginning performing a modification of an offset output in the value of said output signal at a beginning of a predetermined period of said anti-shake operation, wherein said predetermined period begins when a release switch of a photographing apparatus including said anti-shake apparatus is set to an ON state and ends after a first time elapses.
2. The anti-shake apparatus according to claim 1 , wherein a length of said first time is double a time constant of a circuit that performs a high-pass filter processing operation on said output signal from said angular velocity sensor.
3. The anti-shake apparatus according to claim 1 , wherein said modification is performed as said offset output decreases linearly from a commencement of said predetermined period to a finish of said predetermined period.
4. The anti-shake apparatus according to claim 1 , wherein said controller does not perform said modification except for during said predetermined period.
5. A photographing apparatus, comprising: an angular velocity sensor that detects an angular velocity; and a controller that controls said angular velocity sensor and performs an anti-shake operation for image stabilizing on the basis of an output signal from said angular velocity sensor, said controller beginning performing a modification of an offset output in the value of said output signal at a beginning of a predetermined period of said anti-shake operation of a photographing operation, wherein said predetermined period begins when a release switch of a photographing apparatus including said anti-shake apparatus is set to an ON state and ends after a first time elapses.
6. The anti-shake apparatus according to claim 1 , wherein the controller performs the modification of the offset output by subtracting the offset output from the output signal of the angular velocity sensor.
7. The anti-shake apparatus according to claim 1 , wherein the controller further performs A/D conversion of the output signal from the angular velocity sensor before performing the modification of the offset output.
8. The anti-shake apparatus according to claim 1 , further comprising a high-pass filter circuit, wherein the high-pass filter circuit reduces a low frequency signal component from an analog signal of the output signal from the angular velocity sensor before performing the modification of the offset output, and the controller further reduces a low frequency signal component from a digital signal of the output signal from the angular velocity sensor after performing the modification of the offset output.
9. The anti-shake apparatus according to claim 1 , further comprising a driver that moves an imaging unit to correct a hand-shake effect,
wherein the controller performs the anti-shake operation by producing a driving signal of the driver based on the output signal from the angular velocity sensor, from which the offset output has been reduced.
10. The photographing apparatus according to claim 5 , wherein a length of said first time is double a time constant of a circuit that performs a high-pass filter processing operation on said output signal from said angular velocity sensor.
11. The photographing apparatus according to claim 5 , wherein said modification is performed as said offset output decreases linearly from a commencement of said predetermined period to a finish of said predetermined period.
12. The photographing apparatus according to claim 5 , wherein said controller does not perform said modification except for during said predetermined period.
13. The photographing apparatus according to claim 5 , wherein the controller performs the modification of the offset output by subtracting the offset output from the output signal of the angular velocity sensor.
14. The photographing apparatus according to claim 5 , wherein the controller further performs A/D conversion of the output signal from the angular velocity sensor before performing the modification of the offset output.
15. The photographing apparatus according to claim 5 , further comprising a high-pass filter circuit, wherein the high-pass filter circuit reduces a low frequency signal component from an analog signal of the output signal from the angular velocity sensor before performing the modification of the offset output, and the controller further reduces a low frequency signal component from a digital signal of the output signal from the angular velocity sensor after performing the modification of the offset output.
16. The photographing apparatus according to claim 5 , further comprising a driver that moves an imaging unit to correct a hand-shake effect,
wherein the controller performs the anti-shake operation by producing a driving signal of the driver based on the output signal from the angular velocity sensor, from which the offset output has been reduced.