Focus adjusting apparatus and focus adjusting method
AssigneeCanon Kabushiki Kaisha
InventorYoshihito Tamaki
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Abstract
High-accuracy focus adjustment is achieved even when vignetting is caused by a taking lens. A first pixel group receives a light beam that passes through a first pupil area of an optical system that forms an object image, and a second pixel group receives a light beam that passes through a second pupil area. A first signal based on an output signal from the first pixel group and a second signal based on an output signal from the second pixel group are corrected using correction information with a sampling pitch that is changed in accordance with an amount of defocus. A focal state of the optical system is adjusted based on an amount of relative displacement between the corrected first signal and the corrected second signal after the image-signal correction process.
Claims20
An apparatus comprising:
- image pickup unit that includes a first pixel group and a second pixel group, the first pixel group receiving a light beam that passes through a first pupil area of an optical system that forms an object image and the second pixel group receiving a light beam that passes through a second pupil area;
- correcting unit that corrects a first signal based on an output signal from the first pixel group and a second signal based on an output signal from the second pixel group using correction information with a sampling pitch corresponding to an amount of defocus determined by an amount of relative image displacement between the first signal and the second signal;
- and
- focus adjusting unit that adjusts a focal state of the optical system on the basis of an amount of defocus determined by an amount of relative displacement between a corrected first image signal and a corrected second image signal obtained as a result of the correction.
A method for an apparatus including image pickup unit that includes a first pixel group and a second pixel group, the first pixel group receiving a light beam that passes through a first pupil area of an optical system that forms an object image and the second pixel group receiving a light beam that passes through a second pupil area, the method comprising:
- correcting a first signal based on an output signal from the first pixel group and a second image signal based on an output signal from the second pixel group using correction information with a sampling pitch corresponding to an amount of defocus determined by an amount of relative image displacement between the first signal and the second signal;
- and
- performing a control for adjusting a focal state of the optical system based on an amount of defocus and a corrected second signal obtained as a result of the correction performed in the correcting the first signal.
Dependencies are inferred from the claim text.