| 摘要 |
1,213,617. Electronic flash apparatus. FRANKE & HEIDECKE G. m. b. H. Jan.28, 1969 [Feb.1, 1968; Feb.7, 1968], No. 4584/69. Heading G2A. [Also in Division H2] A photographic discharge flash tube arrangement comprises a plurality of flash units (four shown), each with its own ignition circuit, and a single ignition impulse generator for continuous successive ignition of the flash units in accordance with a periodically repeated impulse programme. The flash intervals are made so short that they are imperceptible as such, individual flashes appearing as a single flash, and a known integrating photoelectric device, receiving flash light reflected from the subject being photographed, is used to interrupt the ignition impulse sequence when a certain preselectable threshold value is reached. Figs. 1, 2 (not shown) relate to flash tube circuits, each having two flash tubes operating alternately. Figs. 4, 5 (not shown) relate to ignition circuits for the flash tubes of Figs. 1, 2. A storage capacitor (21À31) is charged up before the beginning of the flash exposure, and the capacity thereof is great enough to be sufficient for the total ignition impulse sequence. Fig. 6 (not shown) relates to a circuit having three flash tubes the ignition circuits of which are controlled by an impulse distributer (58) consisting of a known ring selector circuit. In Fig. 7 (not shown), a photo-electric limiting system is described. Figs. 8, 10 (not shown) also relate to three flash tube arrangements, the former having separate transformers for each flash tube and the latter three additional switching tubes. |
