Focus adjustment device and method

Claim 2

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; drive amount calculation means for calculating a drive amount based on the defocus amount detected by said focus detecting means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of defocus amounts stored by said storing means; and two-stage control means for controlling driving of the photographic lens, comprising: 1) a pre-shutter release stage where driving of the photographic lens is based on the drive amount calculated by said drive amount calculation means prior to a shutter release operation, said control means not driving the photographic lens until a magnitude of the defocus amount exceeds a predetermined value after an in-focus state has been determined based on the detected defocus amount prior to the shutter release operation; and 2) a post-shutter release stage for controlling driving the photographic lens based on the adjusted drive amount calculated by said adjusted drive amount calculation means when the shutter release operation occurs.

Claim 3

The focus adjustment device according to claim 1, further comprising statistical processing determining means for determining whether statistical processing of the plurality of defocus amounts by said adjusted drive amount calculation means is appropriate, and for causing said adjusted drive amount calculation means to perform statistical processing of the plurality of defocus amounts when determined to be appropriate by said statistical processing determining means.

Claim 4

The focus adjustment device according to claim 1, wherein said adjusted drive amount calculation means calculates the adjusted drive amount based on an average value of the plurality of defocus amounts stored by said storing means, the defocus amounts used for statistical processing being obtained after reaching the in-focus state.

Claim 5

The focus adjustment device according to claim 1, wherein said adjusted drive amount calculation means includes a means for removing inappropriate data such that statistical processing by said adjusted drive amount calculation means is performed after removal of said inappropriate data by said removal means.

Claim 6

The focus adjustment device according claim 1, further comprising means for limiting at least one of a storage time for defocus amounts and a number of defocus amounts stored, such that statistical processing by said adjusted drive amount calculation means is performed with a recent data set.

Claim 7

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; image plane position calculation means for calculating a plurality of image plane positions based on the plurality of defocus amounts stored by said storing means; drive amount calculation means for calculating a drive amount based on the image plane positions calculated by said image plane position calculation means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of image plane positions calculated by said image plane position calculation means; and two-stage control means for controlling driving of the photographic lens, comprising: 1) a pre-shutter release stage where driving of the photographic lens is based on the drive amount prior to a shutter release operation, and 2) a post-shutter release stage for controlling driving of the photographic lens based on the adjusted drive amount when a shutter release operation occurs.

Claim 8

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; image plane position calculation means for calculating a plurality of image plane positions based on the plurality of defocus amounts stored by said storing means; drive amount calculation means for calculating a drive amount based on the image plane positions calculated by said image plane position calculation means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of image plane positions calculated by said image plane position calculation means; and two-stage control means for controlling driving of the photographic lens, comprising: 1) a pre-shutter release stage where driving of the photographic lens is based on the drive amount prior to a shutter release operation, and 2) a post-shutter release stage for controlling driving of the photographic lens based on the adjusted drive amount when a shutter release operation occurs.

Claim 9

The focus adjustment device according to claim 6, further including statistical processing determining means for determining whether statistical processing of the plurality of image plane positions by the adjusted drive amount calculation means is appropriate, and for causing said adjusted drive amount calculation means to perform statistical processing of the plurality of image plane positions when determined to be appropriate by said statistical processing determining means.

Claim 10

The focus adjustment device according to claim 6, wherein said adjusted drive amount calculation means calculates the adjusted drive amount based on regression analysis of the plurality of image plane positions as a function of time.

Claim 11

The focus adjustment device according to claim 6, wherein said adjusted drive amount calculation means includes a means for removing inappropriate data such that statistical processing by said adjusted drive amount calculation means is performed after removal of said inappropriate data by said removal means.

Claim 12

The focus adjustment device according to claim 6, further comprising means for limiting at least one of a storage time for image plane positions and a number of image plane positions stored, such that statistical processing by said adjusted drive amount calculation means is performed with a recent data set.

Claim 13

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; image plane position calculation means for calculating a plurality of image plane positions based on the plurality of defocus amounts stored by said storing means; drive amount calculation means for calculating a drive amount based on the image plane positions calculated by said image plane position calculation means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of image plane positions calculated by said image plane position calculation means; statistical processing determination means for determining whether statistical processing of the plurality of image plane positions by said adjusted drive amount calculation means is appropriate; and control means for controlling driving of the photographic lens based on the adjusted drive amount calculated by said adjusted drive amount calculation means when statistical processing of the plurality of image plane positions is determined to be appropriate by said statistical processing determination means.

Claim 14

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; image plane position calculation means for calculating a plurality of image plane positions based on the plurality of defocus amounts stored by said storing means; drive amount calculation means for calculating a drive amount based on the image plane positions calculated by said image plane position calculation means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of image plane positions calculated by said image plane position calculation means; statistical processing determination means for determining whether statistical processing of the plurality of image plane positions by said adjusted drive amount calculation means is appropriate; and control means for controlling driving of the photographic lens based on the adjusted drive amount calculated by said adjusted drive amount calculation means when statistical processing of the plurality of image plane positions is determined to be appropriate by said statistical processing determination means.

Claim 15

The focus adjustment device according to claim 11, wherein said adjusted drive amount calculation means includes a means for removing inappropriate data such that statistical processing by said adjusted drive amount calculation means is performed after removal of said inappropriate data by said removal means.

Claim 16

The focus adjustment device according to claim 11, further comprising means for limiting at least one of a storage time for image plane positions and a number of image plane positions stored, such that statistical processing by said adjusted drive amount calculation means is performed with a recent data set.

Claim 17

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; drive amount calculation means for calculating a drive amount based on the defocus amount detected by said focus detecting means; image plane position calculation means for calculating a plurality of image plane positions based on the plurality of defocus amounts stored by said storing means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of image plane positions calculated by said image plane position calculation means; and two-stage control means for controlling driving of the photographic lens: 1) a pre-shutter release stage where driving of the photographic lens is based on the drive amount calculated by said drive amount calculation means prior to a shutter release operation, said control means not driving the photographic lens until a magnitude of the defocus amount exceeds a predetermined value after an in-focus state has been determined based on the detected defocus amount prior to the shutter release operation; and 2) a post-shutter release stage for controlling driving the photographic lens based on the adjusted drive amount calculated by said adjusted drive amount calculation means when the shutter release operation occurs.

Claim 18

A focus adjustment device for focusing a photographic lens in a camera, comprising: focus detecting means for repeatedly detecting a defocus amount; means for storing a plurality of defocus amounts detected by said focus detecting means; drive amount calculation means for calculating a drive amount based on the defocus amount detected by said focus detecting means; image plane position calculation means for calculating a plurality of image plane positions based on the plurality of defocus amounts stored by said storing means; adjusted drive amount calculation means for calculating an adjusted drive amount by statistically processing the plurality of image plane positions calculated by said image plane position calculation means; and two-stage control means for controlling driving of the photographic lens: 1) a pre-shutter release stage where driving of the photographic lens is based on the drive amount calculated by said drive amount calculation means prior to a shutter release operation, said control means not driving the photographic lens until a magnitude of the defocus amount exceeds a predetermined value after an in-focus state has been determined based on the detected defocus amount prior to the shutter release operation; and 2) a post-shutter release stage for controlling driving the photographic lens based on the adjusted drive amount calculated by said adjusted drive amount calculation means when the shutter release operation occurs.

Claim 19

The focus adjusted device according to claim 14, further comprising statistical processing determining means for determining whether statistical processing of the plurality of image plane positions by the adjusted drive amount calculation means is appropriate, and for causing said adjusted drive amount calculation means to perform statistical processing of the plurality of image plane positions when determined to be appropriate by said statistical processing determining means.

Claim 20

The focus adjustment device according to claim 14, wherein said adjusted drive amount calculation means calculates the adjusted drive amount based on regression analysis of the plurality of image plane positions as a function of time.

Claim 21

The focus adjustment device according to claim 14, wherein said adjusted drive amount calculation means includes a means for removing inappropriate data such that statistical processing by said adjusted drive amount calculation means is performed after removal of said inappropriate data by said removal means.

Claim 22

The focus adjustment device according to claim 14, further comprising means for limiting at least one of a storage time for defocus amounts and a number of defocus amounts stored, such that statistical processing by said adjusted drive amount calculation means is performed with a recent data set.

Claim 25

The method according to claim 19, further comprising: determining whether statistical processing of the plurality of defocus amounts to obtain said adjusted drive amount is appropriate; and causing statistical processing of the plurality of defocus amounts when determined to be appropriate.

Claim 26

The method according to claim 19, wherein said calculation of said adjusted drive amount includes calculating the adjusted drive amount based on an average value of the stored plurality of defocus amounts, the defocus amounts used for statistical processing being obtained after reaching the in-focus state.