| 摘要 |
<p>PURPOSE:To make constitution simple and inexpensive by providing a photo detector below a turning mirror, setting F-number at coarse accuracy of several stages by the reflected light of an auxiliary mirror and adjusting shutter speed at fine accuracy by the reflected light from film plane, etc. CONSTITUTION:A turning mirror 11 is provided with its optical axis being aligned to that of a lens group 8 within the box body 4 of the camera and a rectangular opening 11b is provided in the central part thereof. An auxiliary mirror 5 is turnably provided behind said opening. A photo detector 16 is faced to the film plane and is fixed in the lower part within the box body 4. At the time of aperture setting, the photo detctor 16 receives the light entered through the lens 8 and enters the auxiliary mirror 5 through the opening 11b of the mirror 11 and the aperture quantity, i.e., F- number, is set at coarse accuracy of several stages by an aperture control mechanism. At the shutter releasing, the mirror 11 turns upward and at the same time, the auxiliary mirror also turns and becomes parallel to the mirror 11, thus the reflected light from the film plane or shutter curtain is recieved and the shutter speed is finely adjusted, whereby photographing is accomplished.</p> |
