| 摘要 |
PURPOSE:To adjust a focus at a high speed and with high accuracy by executing a focus detection of a camera by discriminating a distance of an object, by a trigonometrical distance measuring type focus detecting system first, and thereafter, executing the focusing by an image phase difference type focus detecting system. CONSTITUTION:A trigonometrical distance measuring type focus detecting system allows a light beam from an LED 17 to pass through a projection lens 16, allows a light beam reflected by an object to be photographed to pass through a photodetecting lens 18, photodetects it by a photodetector 19, and discriminates a distance of the object from the intensity of the light beam. Also, an image phase difference type focus detecting system allows a luminous flux from an image pickup lens 7, to pass through a beam splitter part 8, allows it to be reflected by mirrors 10, 15, allows an image sensor 14 to generate two images by image re-formation lenses 12, 13 and discriminates a distance of an object to be photographed. In this state, at the time of detecting a focus of a single-lens reflex camera, etc., first of all, by detecting a distance of the object to be photographed, by a trigonometrical distance measuring type, the image pickup lens 7 is driven in the focusing direction. After its driving has been started, by executing a distance measurement by an image phase difference type, a focus is adjusted with high accuracy. Accordingly, a movement of a lens becomes smooth, and focusing can be executed at a high speed. |
