Focus adjustment apparatus, method for controlling focus adjustment apparatus, and storage medium

A focus adjustment apparatus comprising:

• an image sensor configured to capture an image formed by a photographing optical system including a focus lens;
• a processor;
• and
• a memory containing instructions that, when executed by the processor, cause the processor to perform operations comprising:
• setting focus detection areas corresponding to respective areas of the image sensor,
• detecting, as a first detecting, a focus state which includes a defocus amount and a focusing direction of each of the focus detection areas by detecting a phase difference between a pair of image signals output from the image sensor,
• detecting, as a second detecting, contrast information of the focus detection areas based on signals output from the image sensor, and
• controlling driving of the focus lens based on a detection result of at least one of first detecting and the second detecting,
• wherein, in a case where the detection result of the first detecting satisfies a first condition, controlling includes controlling driving of the focus lens by using the detection result of the first detecting,
• wherein, in a case where a number of detection areas where a detection result of the first detecting indicates a reliability that is higher than a reliability indicated by a first level is greater than or equal to a first threshold, the first condition is satisfied, and
• wherein the first threshold is set lower in case of a first degree of in-focus than in case of a second degree of in-focus, wherein the degree of in-focus is determined based on the contrast information and the second degree of in-focus is higher than the first degree of in-focus.

A focus adjustment apparatus comprising:

• an image sensor configured to capture an image formed by a photographing optical system including a focus lens;
• a processor;
• and
• a memory containing instructions that, when executed by the processor, cause the processor to perform operations comprising:
• setting focus detection areas corresponding to respective areas of the image sensor,
• detecting, as a first detecting, a focus state which includes a defocus amount and a focusing direction of each of the focus detection areas by detecting a phase difference between a pair of image signals output from the image sensor,
• detecting, as a second detecting, contrast information of the focus detection areas based on signals output from the image sensor, and
• controlling driving of the focus lens based on a detection result of at least one of the first detecting and the second detecting,
• wherein, in a case where a number of detection areas where a detection result of the first detecting indicates a reliability that is higher than a reliability indicated by a first level is greater than or equal to a first threshold, the first condition is satisfied,
• wherein the photographing optical system is configured to further include a zoom lens, and
• wherein, in a case where the zoom lens is being driven, controlling includes setting the first threshold to be higher than when the zoom lens is stopped.

A method for controlling a focus adjustment apparatus having an image sensor configured to capture an image formed by a photographing optical system including a focus lens, the method comprising:

• setting focus detection areas corresponding to respective areas of the image sensor;
• detecting, as a first detecting, a focus state which includes a defocus amount and a focusing direction of each of the focus detection areas by detecting a phase difference between a pair of image signals output from the image sensor;
• detecting, as a second detecting, contrast information of the focus detection areas based on signals output from the image sensor;
• and
• controlling driving of the focus lens based on a detection result of at least one of the first detecting and the second detecting,
• wherein, in a case where a reliability of a detection result of the first detecting is lower than a second level, controlling includes determining whether a number of detection areas where the detection result of the first detecting indicates a reliability that is higher than a reliability indicated by a first level is greater than or equal to a first threshold,
• wherein, determining a number of detection areas where a detection result of the first detecting indicates a reliability that is higher than a reliability indicated by a first level is greater than or equal to the first threshold, controlling the driving of the focus lens by using the detection result of the first detecting,
• wherein the second level is set to a value such that the defocus amount and the focusing direction each have a reliability that is higher than a predetermined value, and the first level is set to a value such that the focusing direction has a reliability that is higher than a predetermined value.

A method for controlling a focus adjustment apparatus having an image sensor configured to capture an image formed by a photographing optical system including a focus lens, the method comprising:

• setting focus detection areas corresponding to respective areas of the image sensor;
• detecting, as a first detecting, a focus state which includes a defocus amount and a focusing direction of each of the focus detection areas by detecting a phase difference between a pair of image signals output from the image sensor;
• detecting, as a second detecting, contrast information of the focus detection areas based on signals output from the image sensor;
• and
• controlling driving of the focus lens based on a detection result of at least one of first detecting and the second detecting,
• wherein, in a case where the detection result of the first detecting satisfies a first condition, controlling includes controlling driving of the focus lens by using the detection result of the first detecting,
• wherein, in a case where a number of detection areas where a detection result of the first detecting indicates a reliability that is higher than a reliability indicated by a first level is greater than or equal to a first threshold, the first condition is satisfied, and
• wherein the first threshold is set lower in case of a first degree of in-focus than in case of a second degree of in-focus, wherein the degree of in-focus is determined based on the contrast information and the second degree of in-focus is higher than the first degree of in-focus.

A method for controlling a focus adjustment apparatus having an image sensor configured to capture an image formed by a photographing optical system including a focus lens, the method comprising:

• setting focus detection areas corresponding to respective areas of the image sensor;
• detecting, as a first detecting, a focus state which includes a defocus amount and a focusing direction of each of the focus detection areas by detecting a phase difference between a pair of image signals output from the image sensor;
• detecting, as a second detecting, contrast information of the focus detection areas based on signals output from the image sensor;
• and
• controlling driving of the focus lens based on a detection result of at least one of the first detecting and the second detecting,
• wherein, in a case where a number of detection areas where a detection result of the first detecting indicates a reliability that is higher than a reliability indicated by a first level is greater than or equal to a first threshold, the first condition is satisfied,
• wherein the photographing optical system is configured to further include a zoom lens, and
• wherein, in a case where the zoom lens is being driven, controlling includes setting the first threshold to be higher than when the zoom lens is stopped.