| 摘要 |
<p>PURPOSE:To perform highly accurate and high-speed controlling by using pulse motors having two modes in which the rotating angles per pulse are 1 aperture unit and n aperture unit, and separating and counting the aperture unit number up to an aperture set value with these two modes. CONSTITUTION:With respect to input information such as film sensitivity (ASA), photometric value (e), shutter speed (s) or manual aperture set value (m), an optimum aperture value is operated in a CPU1, and the aperture unit number N from the initial position up to an optimum position is calculated. On the other hand, with pulse motors 3A, 3B, the rotating angles per pulse are alpha deg., nalpha deg., and alpha deg. is assumed to correspond to one aperture unit. The CPU further calculates the pulse numbers (a), (b) to be supplied to the pulse motors 3A, 3B as b=[N/n], a=N-bXn, and these pulses are inputted to driving parts 2A, 2B respectively, and are applied to the pulse motors 3A, 3B after having been amplified.</p> |
