| 摘要 |
<p>[OBJECT] When a trapezoid control is carried out for plural diaphragm values, an opening-time control for each of the plural diaphragm values is performed. In addition, an error correction inherent to a shutter can be easily carried out. [CONSTRUCTION] An aperture area (h1) for a prescribed diaphragm value of a shutter, times (t1, t2) required for opening and closing operations, data on an opening time (t) and correction amount inherent to the shutter are beforehand stored in the EEPROM or the like, and an opening time (t') for a set diaphragm value is calculated on the basis of the above data and an aperture area (h2) for the set diaphragm value. [EFFECT] Storage of the opening-time data every diaphragm value is not required, and a small amount of data is sufficient to a shutter control operation, so that a data ROM having small capacity can be used. In addition, various errors such as an error of the opening time due to the dispersion of the diaphragm area, an error due to the deviation in linearity of the opening and closing operations, etc. can be easily corrected, and thus the shutter control operation can be accurately performed. <IMAGE></p> |
