ACTIVE IMAGE-PROCESSING AS APPLIED TO HIGH-RESOLUTION ELECTRON-MICROSCOPY .2. REAL-TIME PHASE-PLATELESS ELECTRON PHASE MICROSCOPY BY ACCELERATING-VOLTAGE MODULATION

Real-time phase-plateless electron phase microscopy based on active im age processing has been developed by utilizing accelerating-voltage mo dulation. This new method is based on the real-time subtraction of two images observed under the defocusing conditions on both sides of the just-focus condition. This method is particularly useful in practical transmission electron microscopic observation of, for example, biologi cal samples with comparatively low resolution where C(s) is regarded a s nearly zero. In order to achieve such a rapid defocus modulation to accommodate the real-time image processing, the drive-voltage of a tri angular wave form was simply supplied through the ripple monitor plug of the high voltage power supply of a commercial type electron microsc ope, namely the JEM-200CX. The present phase microscopy experiment has been confirmed through the Thon diagram. A bright central curve in th is diagram has demonstrated that the phase microscopy is realized with considerable success.