Imaging apparatus, a focusing method, a focus control method and a recording medium storing a program for executing such a method

Claim 2

The imaging apparatus as claimed in claim 1, further comprising: previous focus result storing means for storing a result of a previous focusing operation; and alarm displaying means for displaying an alarm when no focus is acquired according to the result of a previous focusing operation that has been stored in said previous focus result storing means when designation of the focal range is made by said focus range designation means.

Claim 3

The imaging apparatus as claimed in claim 1 or 2, further comprising focus range displaying means for displaying the focus range at present.

Claim 4

The imaging apparatus as claimed in claim 1, 2 or 3, further comprising focus range position changing means for changing a position of the limited focus range designated by said focus range designating means.

Claim 5

The imaging apparatus as claimed in claim 1, 2, 3 or 4 further comprising focus range designation means for canceling the setting of the limited focus range designated by said focus range designating means.

Claim 6

The imaging apparatus as claimed in any one of the preceding claims, further comprising macro mode switching means for switching between a macro mode and a normal mode, the macro mode for taking a picture of a photographing object at an extremely short distance, the normal mode for taking a picture of a photographing object at a normal distance larger than the extremely short distance, wherein said focus range designating means is permitted to designate the focus range only when the macro mode is set.

Claim 7

The imaging apparatus as claimed in any one of the preceding claims, further comprising: macro mode switching means for switching between a macro mode and a normal mode, the macro mode for taking a picture of a photographing object at an extremely short distance, the normal mode for taking a picture of a photographing object at a normal distance larger than the extremely short distance; and means for automatically canceling, when the focus range is designated by said focus range designating means, the designation of the focus range.

Claim 8

The imaging apparatus as claimed in any one of the preceding claims, further comprising: zooming means for changing a focal distance of an imaging lens; zoom magnification changing means for changing a zoom magnification achieved by said zooming means; and means for automatically canceling, when the focus range is designated by said focus range designating means, the designation of the focus range.

Claim 9

The imaging apparatus as claimed in any one of the preceding claims, further comprising: zooming means for changing a focal distance of an imaging lens; and zoom magnification changing means for changing a zoom magnification achieved by said zooming means; and means for changing the focus range in accordance with the zoom magnification set by said zoom magnification changing means.

Claim 10

The imaging apparatus as claimed in any one of the preceding claims, further comprising: expanded distance re-measurement selecting means for selecting whether to perform a distance measurement again by expanding a distance measurement range when a focusing operation is performed in a state where the limited range is designated by said focus range designating means; and means for performing the focusing operation again with a range larger than the focus range set by said focus range designating means when no focus is acquired with the limited range set by said focus range designating means and the expanded distance measurement with the expanded distance is permitted by said expanded distance re-measurement selecting means.

Claim 11

A focusing method of an imaging apparatus, characterized by comprising: a focal lens position detecting step of detecting a current position of a focal lens; a focus range designating step of designating as a focus range a limited range near the current position of the focal lens; and a focal point detecting step of detecting a focal point by moving the focal lens within a range corresponding to the focus range designated in said focus range designating step.

Claim 12

An imaging apparatus in which one of a macro mode and a normal mode is selectable, the macro mode for setting a photographing range to a distance range shorter than a predetermined range, the normal mode for setting the photographing range to a distance longer than the predetermined range, the imaging apparatus comprising: focus control means for sequentially detecting a focal point while moving a focal lens and stopping the focal lens at the focal point so as to perform an automatic focusing operation, characterized by : range control means for causing said focus control means to perform the automatic focusing operation by limiting a movable range of the focal lens to a range narrower than an entire focus range with an immediately preceding focal point when taking a picture in said macro mode and a predetermined condition is satisfied.

Claim 13

The imaging apparatus as claimed in claim 12, wherein said predetermined condition includes that said automatic focus operation was performed at least one time after said macro mode was set, and said range control means includes means for causing said focusing operation to be performed on said limited range when the predetermined condition is satisfied.

Claim 14

The imaging apparatus as claimed in claim 12 or 13, wherein said range control means includes: means for monitoring a focus state in said focus control means; and means for causing the focussing operation on said limited range when the predetermined condition is satisfied, the predetermined condition including that a focus state after an immediately preceding focusing operation is maintained base on said means for monitoring.

Claim 15

An imaging apparatus as claimed in claim 12, 13 or 14, further comprising distance measurement means for measuring a distance to a photographing object, wherein said range control means comprises: means for monitoring a change in the distance measured by said distance measurement means; and means for causing the focusing operation on said limited range when the predetermined condition is satisfied, the predetermined condition including that the change in the distance after an immediately preceding automatic focusing operation is equal to or less than a predetermined value base on the monitoring by said means for monitoring.

Claim 16

The imaging apparatus as claimed in claim 12, 13, 14 or 15, further comprising brightness distribution measuring mean for measuring a brightness distribution in a picture screen, wherein said range control means comprises: means for monitoring a change in the brightness distribution measured by said brightness distribution measuring means; and means for causing the focusing operation on said limited range when the predetermined condition is satisfied, the predetermined condition including that the change in the brightness distribution after an immediately preceding automatic focusing operation is equal to or less than a predetermined amount base on the monitoring by said means for monitoring.

Claim 17

The imaging apparatus as claimed in claim 12, 13, 14, 15 or 16, further comprising an imaging optical system using a zoom optical system that optically changes a zoom magnification, wherein said range control means comprises: means for monitoring a change in the zoom magnification in said imaging optical system; and means for causing the focusing operation to be performed on an entire focus range when the zoom magnification has changed based on the monitoring of said means for monitoring.

Claim 18

An imaging apparatus according to any one of claims 12 to 17 wherein said focus control means is for sequentially acquiring from an image signal an automatic focus evaluation value, which is acquired in correspondence with sharpness of an edge portion of a photographing object image, said focal point being set to a maximum point of the automatic focus evaluation value.

Claim 19

The imaging apparatus as claimed in claim 18, wherein said range control means comprises: means for monitoring the automatic focus evaluation value in said focus control means; and means for causing the focussing operation on said limited range when the predetermined condition is satisfied, the predetermined condition including that the change in the automatic focus evaluation value after an immediately preceding automatic focusing operation is equal to or less than a predetermined value base on the monitoring by said means for monitoring.

Claim 20

A focus control method of an imaging apparatus in which one of a macro mode and a normal mode is selectable, the macro mode for setting a photographing range to a distance range shorter than a predetermined range, the normal mode for setting the photographing range to a distance longer than the predetermined range, the focus control method comprising: performing an automatic focusing operation by sequentially detecting a focal point while moving a focal lens, which constitute at least a part of an imaging optical system of said imaging apparatus, and stopping the focal lens at the focal point, characterized by : causing said automatic focusing operation to be performed by limiting a movable range of the focal lens to a range narrower than an entire focus range with an immediately preceding focal point set as a reference when said macro mode is set and a predetermined condition is satisfied.

Claim 21

A focus control method according to claim 21 wherein the step of performing an automatic focussing operation comprises sequentially acquiring from an image signal an automatic focus evaluation value, which is acquired in correspondence to sharpness of an edge portion of a photographing object image while moving a focal lens, which constitute at least a part of an imaging optical system, and stopping said focal lens at a focal point being set as a maximum point of the automatic focus evaluation value.

Claim 22

A computer program comprising program code means that, when executed by an imaging apparatus, instruct the apparatus to execute the method of any one of claims 11, 20 and 21.