| 摘要 |
PURPOSE:To decide whether a light quantity adjusting function operates normally or not automatically in advance by detecting the quantities of light at respective aperture values of a stop means which has plural aperture vales for adjusting the quantity of light and storing the detected quantites of light together with the aperture values. CONSTITUTION:The quantity of light is controlld on the basis of the rotation driving angle of a stop blade 16, and the relation between the aperture value of the stop blade 16 and the actual quantity of light is checked. The stop is set to a maximum aperture firstly and a counter 54 counts the quantity of photodetection of a photodetecting element 32 at this time as the number n1 of output pulses of a V/F converter 50 within a specific period. Then, the aperture value and the quantity n1 of photodetection of the photodetecting element 23 are stored in corresponding relation as an aperture table, and this storing operation is carried out up to closed aperture as minimum aperture. The aperture table contains data obtained by interpolation except actually measured values and stored in a RAM34 in the form of a characteristic curve between the driving angle of the stop blade and the quantity of light. Then, the driving angle of the stop blade at which a desired quantity of light is obtained is calculated reversely from the characteristic curve.
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