Digital camera utilizing illumination from a flash light for focus detection and control

Claim 2

A digital camera comprising: an image sensing element for generating image data of an object; a light emission device for emitting light to illuminate the object during photography; a first detector for detecting contrast of the image data; a focus evaluator for evaluating focus of a lens based on the detected contrast; a lens driver for driving the lens based on the contrast detected by the first detector in response to the focus evaluation; a second detector for detecting luminance of the image data; a light emission controller for executing the light emission of the light emission device to detect the contrast when the luminance detected by the second detector is less than a specific value; a power source for supplying an electrical power to the light emission device, the power source being chargeable, wherein a determination of whether the detected contrast is a maximum value is made in parallel with charging the power source; and a lens drive controller for inhibiting the driving of the lens by the lens driver during charging of the power source.

Claim 3

The digital camera according to claim 1 , further comprising a discriminator for discriminating whether or not the lens is focused based on the contrast obtained by the first detector during light emission of the light emission device, and the lens driving drives the lens repeatedly when the lens is not focused.

Claim 4

The digital camera according to claim 2 , wherein when the lens driving is again executed, the light emission controller for executing the light emission of the light emission device when the luminance detected by the second detector is less than a specific value.

Claim 5

The digital camera according to claim 1 , wherein the light emission controller controls an amount of light emission for detecting the contrast so as to be less than the light emission during photography.

Claim 6

A digital camera comprising: an image sensing element for generating image data of an object; a light emission device for emitting light to illuminate the object during photography; a first detector for detecting contrast of the image data; a focus evaluator for evaluating a focus condition based on the detected contrast; a lens driver for driving a lens based on the contrast detected by the first detector responsive to a focus evaluation; a second detector for detecting luminance of the image data; a setter for setting prohibition of the light emission by the light emission device; and a light emission controller for prohibiting the light emission during detection of the contrast when prohibition of flash emission has been set by the setter, and for executing the light emission of the light emission device to detect the contrast when the luminance detected by the second detector is less than a specific value and when the prohibition of flash emission has not been set, wherein a determination of whether the detected contrast is at a maximum value is performed while charging the light emission device.

Claim 7

A digital camera comprising: an image sensing element for generating image data of an object; a light emission device for emitting light to illuminate the object during photography; a first detector for detecting contrast of the image data; a focus evaluator for evaluating a focus condition based on the detected contrast; a lens driver for driving a lens based on the contrast detected by the first detector responsive to a focus evaluation; a second detector for detecting luminance of the image data; a setter for setting prohibition of the light emission by the light emission device; and a light emission controller for prohibiting the light emission during detection of the contrast when prohibition of flash emission has been set by the setter, and for executing the light emission of the light emission device to detect the contrast when the luminance detected by the second detector is less than a specific value and when the prohibition of flash emission has not been set, wherein a determination of whether the detected contrast is at a maximum value is performed while charging the light emission device.

Claim 8

The digital camera according to claim 5 , further comprising an indicator for alerting that the lens driving based on the detected contrast is impossible when the detected luminance is less than a specified value and the light emission is prohibited.

Claim 9

The digital camera according to claim 6 , wherein the lens driver moves the lens to a specific position when the lens driving based on the detected contrast is impossible.

Claim 10

A digital camera comprising: an image sensing element for generating image data of an object; a light emission device for emitting light to illuminate the object during photography; a first detector for detecting contrast of the image data; a lens driver for driving a lens based on the contrast detected by the first detector; a second detector for detecting luminance of the image data; a light emission controller for executing the light emission of the light emission device to detect the contrast when the luminance detected by the second detector is less than a specific value; a power source for supplying an electrical power to the light emission device and being chargeable; and a discriminator for discriminating whether or not the detected contrast is a maximum value based on the contrast obtained by the first detector in parallel with the charging of the power source.

Claim 11

A digital camera comprising: an image sensing element for generating image data of an object; a light emission device for emitting light to illuminate the object during photography; a first detector for detecting contrast of the image data; a lens driver for driving a lens based on the contrast detected by the first detector; a second detector for detecting luminance of the image data; a light emission controller for executing the light emission of the light emission device to detect the contrast when the luminance detected by the second detector is less than a specific value; a power source for supplying an electrical power to the light emission device and being chargeable; and a discriminator for discriminating whether or not the detected contrast is a maximum value based on the contrast obtained by the first detector in parallel with the charging of the power source.