| 摘要 |
PURPOSE:To attain preventing a focus detection time from extending to many hours, and also, to improve the focus detection accuracy by executing read-out of a signal from the respective accumulating means through a common signal line. CONSTITUTION:In the focus detecting device, an output is applied to a storage circuit 3 in an inversion input terminal of a differential amplifier 2. Also, only an offset of the storage circuit 3 is left. Moreover, in this case, since the storage circuit 3 can be designed by taking a sufficiently large area, an offset portion can be designed so that it can be disregarded against a signal portion. Furthermore, this device uses in common a read-out line of an accumulating signal, and also, is provided with a circuit for storing a signal at the time of non- projection so that an output of said storage circuit is subtracted from a signal at the time of projection, therefore, unbalance portions of each circuit can be cancelled simultaneously, and the focus detection accuracy can be improved. |
