| 摘要 |
<p>A method of controlling an aperture which is defined by a set of movable blades wherein the required movement of the blades from a starting position to a stopping position is determined as a number of unit pulses, characterised in that the unit pulse number is split so that the blades are operated in at least two modes in one of which sets of unit pulse numbers determine incremental blade movement and in another of which unit pulse numbers, or smaller sets of unit pulse numbers, determine incremental blade movement.</p> |
