초록 ▼

A camera with an automatic focusing device has an objective lens mounted on a camera. An image formed by the objective lens is divided into a plurality of zones. In each zone, a brightness distribution is obtained so as to detect a rough focusing condition in each zone, thereby producing a plurality

A camera with an automatic focusing device has an objective lens mounted on a camera. An image formed by the objective lens is divided into a plurality of zones. In each zone, a brightness distribution is obtained so as to detect a rough focusing condition in each zone, thereby producing a plurality of rough focusing condition data. Based on the result of the rough focusing condition data, one zone is selected. Furthermore, a precise focusing condition is detected in the selected zone based on the light contained in the selected zone, so as produce a precise focusing condition data. Based on the precise focusing condition data obtained from the selected zone, the objective lens is driven to an infocus condition.

대표청구항 ▼

An automatic focus detection system for detecting a focusing condition of an objective lens, comprising: an optical means; an image sensor means for receiving light from an object to be photographed by the objective lens through the optical means to output analog signals; an A/D converting means for

An automatic focus detection system for detecting a focusing condition of an objective lens, comprising: an optical means; an image sensor means for receiving light from an object to be photographed by the objective lens through the optical means to output analog signals; an A/D converting means for converting the analog signals to digital signals; a first calculating means for performing a first calculation with the digital signals of a first number of at least one bit to obtain a first defocus amount of the objective lens; a second calculating means for performing a second calculation with the digital signals of a second number of bits to obtain a second defocus amount of the objective lens, the second number being larger than the first number, and a selecting means for selecting either of the first defocus amount and the second defocus amount on the basis of a predetermined condition.