초록 ▼

A photographing lens is driven on the basis of an operation result representing a focus condition of the photographing lens, which has been calculated on the basis of the output signal from an image sensor, when such operation result has been judged reliable. A so-called scanning operation is made,

A photographing lens is driven on the basis of an operation result representing a focus condition of the photographing lens, which has been calculated on the basis of the output signal from an image sensor, when such operation result has been judged reliable. A so-called scanning operation is made, in which the photographing lens is driven in a specified direction to find out a location offering a reliable operation result, when said operation result has been judged not reliable. First and second setup modes are provided. In the first setup mode, the accumulation time of the image sensor is set on the basis of the previously set accumulation time and the output signal of the image sensor obtained during said previously set accumulation time. In the second setup mode, the accumulation time of the image sensor is set according to the output of the monitor sensor arranged in the vicinity of a plurality of photoelectric elements and detecting the intensity of the light incidental to the image sensor. When the second setup mode is selected and the output signal of the image sensor does not satisfy the predetermined condition, no scanning operation is made even if the operation result is judged not reliable.

대표청구항 ▼

Autofocus camera comprising: an image sensor including a plurality of photoelectric elements to accumulate an electric charge generated during a set accumulation time and to output a signal corresponding to said accumulated electric charge; an optical system which directs the light having passed thr

Autofocus camera comprising: an image sensor including a plurality of photoelectric elements to accumulate an electric charge generated during a set accumulation time and to output a signal corresponding to said accumulated electric charge; an optical system which directs the light having passed through a photographing lens to said image sensor; an operation means for calculating an operation result representing a focus condition of said photographing lens on the basis of said output signal of said image sensor and judging whether or not said operation result is reliable; a lens drive control means for driving said photographing lens on the basis of said operation result when said operation result has been judged to be reliable and performing scanning operation in which the photographing lens is driven in a specified direction to find out a location where a reliable operation result can be obtained when said result has been judged not reliable; and an accumulation control means, in a first setup mode, setting the accumulation time of said image sensor on the basis of the previously set accumulation time and the output signal of said image sensor obtained during said previously set accumulation time and, in the second setup mode, setting the accumulation time of said image sensor according to the output of the monitor sensor arranged in the vicinity of said plurality of photoelectric elements and detecting the intensity of the light incidental to said image sensor; wherein said lens drive control means does not perform said scanning operation in the condition where said accumulation control means selects said second setup mode and the output signal of said image sensor does not satisfy predetermined conditions, even if said operation result has been judged not reliable.