| 摘要 |
1,144,527. Photographic flash-gun. PRONTOR-WERK ALFRED GAUTHIER G.m.b.H. March 14, 1967 [March 18, 1966], No. 11879/67. Heading G2A. Photographic flash-gun for use with expendable flash-bulbs has, in front of a bulb in the firing position, a screen which is electronically closed to prevent further illumination of the subject, when the latter has been sufficiently illuminated for a correct photographic exposure as determined by a photo-resistor R4. The screen may comprise a pair of flaps 7, 8, or a series of louvre-like pivotally mounted blades, which are closed when a spring-loaded cammed lever (13) or (32) is electromagnetically released for rotation. The flash-gun may take either an individual flashbulb 6 or a flash-cube (25). After firing, lever (13) or (32) is recocked and the screen re-opened on ejecting the used flash-bulb 6 by depressing a knob (22) or on manually rotating through 90 degrees a plate (27) in which a flash-cube (25) is mounted. Film sensitivity and aperture values set on the camera used in conjunction with the gun may be taken into account by partially masking photo-resistor R4 by a slit diaphragm 45 and a grey wedge 47 respectively. The electronic circuit may be provided with an over-ride which closes the screen after a predetermined time if it has not already been closed, and with a manual over-ride. |
