| 摘要 |
<p>502,908. Photo - electric exposure meters. JUNGHANS AKT.-GES., GEB. Sept. 28, 1937, No. 26239. Convention date, Oct. 31, 1936. [Class 98 (i)] In a photographic shutter combined with a photo electric exposure meter, the parts of the exposure meter other than the photocell, are built into one or more drum-shaped housings coxially mounted on the rear collar of the shutter housing. The main housing 8 and the front lens support 9 enclose an annular space 10 in which are located the' photo-cell 1 and the mechanical part of the shutter. A drumshaped housing 11 is mounted on the lens support 8a and contains an indicating instrument 13, a permanent magnet 14 and a variable resistance 17. The pointer 15 of the instrument may be observed through the window 16, and a pointer 18 on the ring 18a controls the resistance. Two diaphragms 6, 7 provided with half crescent shaped vanes are arranged in front of the photo-cell 1, and are respectively connected to the speed-adjusting and diaphragm-adjusting members of the shutter. The pointer of the instrument is brought to a fixed mark by adjustment of the speed and diaphragm members. In a modification, the rear housing is divided into two or more housings which may contain some of the parts of the shutter mechanism in addition to the parts of the exposure meter. A window obliquely mounted in the rear wall of the rear housing for observation of the pointer, is also described. The Specification as open to inspection under Sect. 91 also comprises several different means of mounting the sensitive cell. In one example, the cell is mounted, in its own casing coaxially with the lens support, and may be of annular or semi-annular form. The casing may be in front, on, or behind the shutter casing. The cell may also be accommodated in a casing which is hinged to, and may cover, the lens aperture. When folded back from the lens, the casing presents the photo cell to the light. This subject-matter does not appear in the Specification as accepted.</p> |
