| 摘要 |
The electromagnetic shutter consists of a plurality of shutter sectors made of plastic material, printed electric coils operatively coupled with the shutter sectors, and permanent magnets fixed to the shutter at positions where the permanent magnets cooperate electromagnetically with the printed electric coils, respectively, so that, when electric current is supplied for a predetermined time period to the printed electric coils, electromagnetic force is generated by the printed electric coils so as to open the shutter sectors for the predetermined time period and thereafter closed to complete a required exposure. The printed electric coils are formed on the shutter sectors or on a sector ring coupled with the shutter sectors by vacuum evaporation of metal or by sticking a foil of metal. In order to improve wear-resisting property of the shutter sectors and the sector ring, a wear-resisting layer of the same material as that of the printed electric coils is formed on both surfaces each of the shutter sectors or the sector ring simultaneously with the formation of the printed electric coil(s) by the same forming process. In case the shutter includes a pair of shutter sectors adapted to be moved symmetrically oppositely with respect to the aperture and each having a light receiving window formed therein for allowing the scene light to pass through the aperture when at least a portion of the window is brought in alignment with the aperture, the shutter sector may be formed further with a light intercepting layer of the same material as that of the printed electric coils simultaneously with the formation thereof by one and the same forming process, and, further, a thin light receiving aperture defining layer of the same material as that of the printed electric coils may be formed around the peripheral portion of the aperture which projects slightly inwardly beyond the periphery of the aperture.
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