| 摘要 |
PURPOSE:To clarify the astimatism correction procedure and determine correction conditions in a short time by associating correction quantities fed to two pairs of astimatism correctors. CONSTITUTION:With theta set to 0 deg. by an angle control unit 19, a correction amplitude I is gradually increased from 0 by an amplitude control unit 18. The information of a probe diameter is stored in the memory of a maximum-value detection unit 23 as the output of a signal processing circuit. The maximum- value detection unit compares the memory contents in sequence as the correction value I is increased and detects the maximum value, i.e., correction quantity I0. The amplitude control unit 18 sets the output of an amplitude generating circuit 11 to I0. Under this condition, the angle control unit 19 gradually increases the correction angle theta from 0 deg.. The maximum-value detection unit 23 detects the astimatism direction theta=alpha. Next, the correction angle theta of the angle control unit 19 is set to alpha, the amplitude control unit 18 changes the correction amplitude I within a range of [I0, 2<1/2>I0], thus the probe diameter is made minimum. |
