| 摘要 |
PURPOSE:To permit the expansion of object to be observed by a procedure in which excitation intensity of object lens is varied by a fixed amount in combination with an operation by which a sample is moved toward on or outside of the light axle of electron beam by means of a sample device. CONSTITUTION:In case a large-scale sample 7 is observed, a sample device 21 is operated to move the top portion 22 toward the outside of the light axle of electron beam. The control signal of a controller 29 controls a correcting circuit 28 to set up the intensity of a object lens at an adequate value. In case a small-size sample is observed with a high resolving power, the sample device 21 is operated to move the top portion 22 toward on the light axle of electron beam. Thus, the controlling circuit 29 controls the correcting circuit 28 and strong exciting current is supplied to the object lens coil 4. |
