| 摘要 |
PURPOSE:To obtain a device with high accuracy, which can execute a TTL system and can function enough to an object to be photographed of a low contrast, by photodetecting a prescribed pattern image projected to the body to be photographed, by a one-dimensional photoelectric converting element array, detecting an out-of-focus state, and obtaining focusing signal. CONSTITUTION:A titled device is constituted so that a lattice diaphragm 2 having a one-dimensional lattice opening is illuminated by a luminous flux from a light source 1, the luminous flux which has passed through said diaphragm is projected onto an object to be photographed P through a light split member 3 and an objective lens 4, and its lattice image is made to pass through the lens 4 and the light split member 3, and goes to a lattice image 2a on a linear photosensor array 5. The sensor array 5 is constituted of many photoelectric elements placed in parallel along the pitch direction of the lattice. An out-of-focus signal is obtained by integrating a difference signal to the adjacent photoelectric element. In such a state, when the lens 4 is moved in the direction as indicated with an arrow A, a difference integrating signal shows a peak at the coincidence point of a focus. Also, according to a constitution in which a film surface exists by providing separately the light split member, the lens 4 serves as a photographic lens, too, and goes to a focus detecting device of a TTL system. Accordingly, this device has a good focusing accuracy, and it is not influenced by a contrast of the object to be photographed. |
