| 摘要 |
PURPOSE:To provide a high accurate focus detector which is not influenced by environmental change caused by temperature change. CONSTITUTION:This focus detector is constituted of a member using a material which is not influenced by the environmental change, and it is provided with a condenser lens 3 disposed near the scheduled image forming surface 2 of a photographing lens 1, a brightness diaphragm 4 having a pair of aperture parts juxtaposed at a distance at which focusing accuracy is secured, a pair of image reforming lens 5 disposed corresponding to the respective aperture parts, and a photoelectric conversion means consisting of a photoelectric conversion element train 6; and two luminous fluxes passing through the different areas of the lens 1 are received by the element train 6 and a phase difference between two luminous fluxes is detected based on the light intensity distribution of the light receiving surface of the element train 6, thereby discriminating the focusing state of the lens 1 on a subject. |
