| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic flash device constituted so that light is reliably emitted from a discharge tube irrespective of a change in the frequency characteristics of a piezoelectric transducer. SOLUTION: As for the electronic flash device including a charging circuit and a trigger circuit, the piezoelectric transducer for generating high voltage based on an oscillation signal outputted from an oscillation circuit is arranged in the trigger circuit in order to generate a high voltage signal for prompting the discharge of the discharge tube, and in the case of prompting the emission of light from the discharge tube, the frequency of the oscillation signal outputted from the oscillation circuit is swept from a high frequency side to a low frequency side. In this case, it is preferable to design the piezoelectric transducer to be put in use so that at least one of the peaks of the output characteristics of the piezoelectric transducer (for example, samples A, B and C) is included in the oscillation frequency sweeping range while taking account of the dimensional change of the piezoelectric transducer and the general difference of frequency characteristics due to temperature changes. |
