| 摘要 |
PURPOSE:To improve the detecting accuracy with the use of a simple construction by arranging a focal point detector in front of a pentagonal prism so that a semitransparent detecting reflective element is mounted in a foldable manner on the front side of a movable mirror. CONSTITUTION:Major half of the light having passed through a taking lens 1 transmits through a detecting reflective element 11 and is reflected on a movable mirror 2. The light reflected is focused upon a focusing screen 3 so that it reaches an eyepiece 6 through a pentagnal prism 4. On the other hand, the light reflected on the element 11 reaches a detector 7 through a condensing lens 8 so that the detector 7 generates its output which is to be fed to a signal processing circuit. When this output reaches a preset value in the signal processing circuit, the display of the focused condition is made. When a shutter button is depressed, the movable mirror 2 goes out of the photographic optical path so that the reflective element 11 is folded below the focusing lens 3. Thus, with the use of such simple construction, it is possible to make the detected results high accurate and to reduce the size of the camera as a whole. |
