| 摘要 |
PROBLEM TO BE SOLVED: To provide a focal-plane shutter of an electromagnetic drive system, which enables photographing at a prescribed exposure time, when two vane groups operate in either up or down direction and is suitable for cost reduction, thus downsizing and electric power saving. SOLUTION: Drive sources for the two vane groups are motors 2 and 3, and their drive pins 2b and 3b operating integrally with rotors 2a and 3a activate arms 4 and 7 back and forth, thereby activating the respecting three vanes (only the slit forming vanes 6 and 9 are illustrated), so that photographing is executed both, when these vanes are activated upward and when the vanes are activated downward. The slit forming edges of the slit forming vanes 6 and 9 are constituted so that the position right before the position, where the vanes operate upward is nearer the position apart from an aperture 1a for exposure than the position right before the position where the vanes operator downward.
|
