Focus detection unit, image capturing apparatus, and focus detection method
AssigneeCanon Kabushiki Kaisha
InventorsNaoki Maruyama, Seiya Ohta, Ryo Kawasaki
Life of this patent
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Abstract
An image capturing apparatus includes an image capturing unit configured to capture an image focused on a light receiving surface, a gain unit configured to multiply a gain to an image signal output from the image capturing unit and be able to electronically change brightness of an image that the image signal represents, and a focus signal generating unit configured to extract a signal in a frequency band from the image signal output from the gain unit and generate a focus signal from the extracted signal. The focus signal generating unit changes the frequency band for the signal to be used in generating the focus signal in accordance with the magnitude of the gain.
Claims5
An image capturing apparatus comprising:
- one or more processors;
- and
- at least one memory coupled to the one or more processors and storing instructions that, when executed by the one or more processors, cause the image capturing apparatus to function as:
- an image capturing unit configured to capture an image focused on a light receiving surface;
- a gain unit configured to multiply a gain to an image signal output from the image capturing unit and be able to electronically change brightness of an image that the image signal output represents;
- and
- a focus signal generating unit configured to extract a signal in a frequency band from the image signal output from the gain unit and generate a focus signal from the extracted signal,
- wherein the focus signal generating unit changes the frequency band for the signal to be used in generating the focus signal in accordance with magnitude of the gain,
- wherein the focus signal generating unit changes the frequency band for the signal to be used in generating the focus signal by extracting from output of the gain unit a signal in a first frequency band and a signal in a second frequency band, which is a higher frequency band than the first frequency band, generating the focus signal from a synthesis signal obtained by synthesizing the signal in the first frequency band with the signal in the second frequency band, and changing a ratio of the signal in the first frequency band and the signal in the second frequency band in the synthesis signal,
- wherein the focus signal generating unit sets a ratio of the signal in the first frequency band in the synthesis signal to be higher as the gain is higher.
Dependencies are inferred from the claim text.