Aperture stop-down confirmation device for camera

摘要

The present invention relates to an aperture stop-down confirmation device for a camera. So far, in order to carry out the aperture stop-down operation for confirming the depth of focus before photographing in the case of a camera having a mechanical diaphragm device, it is necessary to drive the diaphragm member against the strength of the charge spring of the diaphragm device so that considerable strength is needed for carrying out the diaphragm closing, which is inconvenient. In accordance with the present invention, a diaphragm device whose aperture is controlled by means of an electrical signal such as a diaphragm device making use of a property of matter is so designed that the light admitting part and the light shading part are constituted by varying the light transmittance. The aperture is constituted with the light admitting part or an electromagnetic diaphragm device is used while an aperture stop-down confirmation switch is provided in such a manner that an electrical signal is applied to the diaphragm device by means of the switch so as to carry out the diaphragm closing in order to eliminate the above-mentioned shortcomings.