Autofocus apparatus

Claim 2

An autofocus apparatus comprising: an image pickup device configured to convert a subject light via a lens system into an electric signal, and to output the electric signal as an image data; an A/D conversion unit configured to A/D-convert the image data into a digital image signal; an AF evaluation unit configured to output an AF evaluation value based on a high frequency component of a luminance signal of the digital image data; a sampling unit configured to sample the AF evaluation value obtained by said AF evaluation unit while shifting a focus lens position; a focus driving unit configured to detect an in-focus position based on the AF evaluation value sampling result obtained by said sampling unit; a first mode of shifting the focus lens at a fine step interval so as to sample an AF evaluation value, and to detect an in-focus position based on a sampling AF evaluation value; and a second mode of shifting the focus lens at a coarse step interval so as to sample an AF evaluation value, and to detect a rough in-focus position based on the sampling AF evaluation value, and subsequently, shifting the focus lens at a fine step interval so as to sample an AF evaluation value in the vicinity of the rough in-focus position, and to detect an in-focus position based on the sampling AF evaluation value, wherein the autofocus apparatus selects the first mode in areas other than a macro area and selects the second mode in the macro area.

Claim 3

The autofocus apparatus according to claim 1 , wherein said autofocus apparatus automatically selects the first mode and the second mode.

Claim 4

The autofocus apparatus according to claim 1 , wherein said autofocus apparatus automatically selects the first mode and the second mode in accordance with a focal length.

Claim 5

The autofocus apparatus according to claim 1 , wherein said autofocus apparatus automatically selects the first mode and the second mode in accordance with a recording pixel aspect ratio.

Claim 6

The autofocus apparatus according to claim 1 , wherein said autofocus apparatus automatically selects the first mode and the second mode in accordance with an F-number.

Claim 7

An autofocus apparatus comprising: an image pickup device configured to convert a subject light via a lens system into an electric signal, and to output the electric signal as an image data; an A/D conversion unit configured to A/D-convert the image data into a digital image signal; an AF evaluation unit configured to output an AF evaluation value based on a high frequency component of a luminance signal of the digital image data; a sampling unit configured to sample the AF evaluation value obtained by said AF evaluation unit while shifting a focus lens position; a focus driving unit configured to detect an in-focus position based on the AF evaluation value sampling result obtained by said sampling unit; a setting unit configured to set a plurality of focus lens shifting ranges for sampling the AF evaluation value, and to set a sequence of detecting an in-focus position in each set shifting range; a first mode of shifting the focus lens at a fine step interval so as to sample an AF evaluation value, and to detect an in-focus position on the basis of a sampling AF evaluation value; and a second mode of shifting the focus lens at a coarse step interval so as to sample an AF evaluation value, and to detect a rough in-focus position based on the sampling AF evaluation value, and subsequently, shifting the focus lens at a fine step interval so as to sample an AF evaluation value in the vicinity of the rough in-focus position, and to detect an in-focus position based on the sampling AF evaluation value, wherein the autofocus apparatus selects the first mode in areas other than a macro area and selects the second mode in the macro area for each shifting range set by said setting unit, and detects an in-focus position in each shifting range according to the sequence set by said setting.

Claim 8

An autofocus apparatus comprising: an image pickup device configured to convert a subject light via a lens system into an electric signal, and to output the electric signal as an image data; an A/D conversion unit configured to A/D-convert the image data into a digital image signal; an AF evaluation unit configured to output an AF evaluation value based on a high frequency component of a luminance signal of the digital image data; a sampling unit configured to sample the AF evaluation value obtained by said AF evaluation unit while shifting a focus lens position; a focus driving unit configured to detect an in-focus position based on the AF evaluation value sampling result obtained by said sampling unit; a setting unit configured to set a plurality of focus lens shifting ranges for sampling the AF evaluation value, and to set a sequence of detecting an in-focus position in each set shifting range; a first mode of shifting the focus lens at a fine step interval so as to sample an AF evaluation value, and to detect an in-focus position on the basis of a sampling AF evaluation value; and a second mode of shifting the focus lens at a coarse step interval so as to sample an AF evaluation value, and to detect a rough in-focus position based on the sampling AF evaluation value, and subsequently, shifting the focus lens at a fine step interval so as to sample an AF evaluation value in the vicinity of the rough in-focus position, and to detect an in-focus position based on the sampling AF evaluation value, wherein the autofocus apparatus selects the first mode in areas other than a macro area and selects the second mode in the macro area for each shifting range set by said setting unit, and detects an in-focus position in each shifting range according to the sequence set by said setting.

Claim 9

The autofocus apparatus according to claim 6 , wherein said autofocus apparatus automatically selects the first mode and the second mode.

Claim 10

The autofocus apparatus according to claim 6 , wherein said autofocus apparatus automatically selects the first mode and the second mode in accordance with a focal length.

Claim 11

The autofocus apparatus according to claim 6 , wherein said autofocus apparatus automatically selects the first mode and the second mode in accordance with a recording pixel aspect ratio.

Claim 12

The autofocus apparatus according to claim 6 , wherein said autofocus apparatus automatically selects the first mode and the second mode in accordance with an F-number.