Anti-shake apparatus
View Patent ↗An anti-shake apparatus for a photographic device includes an angular velocity detector, a position signal generator, a shake corrector, and an exposure time setter. The angular velocity detector detects the angular velocity of the photographic device. The position signal generator generates position signals representing a position of the photographic device by integrating the angular velocity. The shake corrector corrects a shake of the photographic device, based on the position signals. The exposure time setter sets an exposure time of the photographic device. The shake corrector corrects the shake based on the position signals that have frequencies higher than the predetermined cut-off frequency, which is determined in accordance with the exposure time.
1. An anti-shake apparatus for a photographic device, said anti-shake apparatus comprising:
an angular velocity detector that detects an angular velocity of said photographic device;
a position signal generator that generates position signals representing a position of said photographic device, by integrating said angular velocity;
a shake corrector that corrects a shake of said photographic device, based on said position signals; and
an exposure time setter that sets an exposure time of said photographic device;
wherein said shake corrector corrects said shake based on said position signals that have frequencies higher than a predetermined cut-off frequency that is determined in accordance with said exposure time; and
wherein a cut-off frequency selecting operation is always carried out while the photographic device is operating, and when the generation of a subject image is commanded, a cut-off frequency in accordance with the exposure time set at the time is set.
2. The anti-shake apparatus according to claim 1 , wherein the shorter the said exposure time, the higher the said cut-off frequency.
3. The anti-shake apparatus according to claim 1 , further comprising a high-pass filter that excludes low-frequency components of said position signals.
4. The anti-shake apparatus according to claim 1 , wherein said photographic device comprises an imaging device, said shake corrector further comprises an imaging device mover that moves said imaging device, and said imaging device mover moves said imaging device so that said shake is corrected.
5. The anti-shake apparatus according to claim 1 , further comprising a cut-off frequency setter that sets said cut-off frequency, from a plurality of candidate cut-off frequencies that can be set, in accordance with said exposure time.
6. The anti-shake apparatus according to claim 5 , wherein said photographic device comprises an image-generating commander that command generation of a subject image, and said shake corrector corrects a shake of said photographic device, based on said position signals whose frequencies are higher than said cut-off frequency that is set when generation of a subject image is commanded.
7. The anti-shake apparatus according to claim 1 , wherein said cut-off frequency in Hz has the same value as one-tenth of a reciprocal number of said exposure time in second.
8. A photographic device comprising:
an angular velocity detector that detects an angular velocity of said photographic device;
a shake corrector that corrects a shake of said photographic device, based on said angular velocity; and
an exposure time setter that sets an exposure time of said photographic device;
wherein a component of said shake that said shake corrector can correct is determined in accordance with said exposure time; and
wherein a cut-off frequency selecting operation is always carried out while the photographic device is operating, and when the generation of a subject image is commanded, a cut-off frequency in accordance with the exposure time set at the time is set.
9. The photographic device according to claim 8 , wherein the shorter the said exposure time, the higher the minimum frequency of said shake that said shake corrector can correct.