A Moire modulation which is a sine function of the phase variation of a phase object to be investigated in an interference electron microscope is proposed. When the phase variation is larger than 2-pi, the conventional cosine-functioned Moire-fringe pattern is observed, and when the phase variation is very less than 2-pi, phase-contrast Moire modulation which can never be achieved by the conventional Moire method is observed. The analogue and digital formations of this sine-functioned Moire modulation in a photographic film and video camera, respectively, are presented. Real-time observation is realized by the digital method.
