| 摘要 |
PURPOSE:To exactly execute automatic diaphragm control and manual diaphragm adjustment, as to a transmittivity control type electrochromic element (ECD) diaphragm. CONSTITUTION:When light of an object to be photographed becomes bright and the photodetecting quantity of CdS1 for photodetecting the light which has transmitted an ECD increases, the potential of a point (d) rises, the potential of a point (a) drops, and the potential of a point (b) rises, therefore, electrification for color development is executed through the ECD from the point (b) to the point (a). When transmittivity of the ECD decreases, the potential of the point (d) drops and it becomes the same potential as a point (c), the electrification stops, and a proper diaphragm is obtained. When light of the objcet to be photographed has become weak, electrification for color discharge is executed in the opposite direction. When an SW2 is switched to manual MAN, manual diaphragm set voltage is applied to the point (c), transmittivity detecting voltage by an LED and a CdS2 is applied to the point (d), electrification for color development or color discharge is executed until it is balanced with the disphragm set voltage, and a set diaphragm is obtained. |
