Abstract: An electron beam pattern is formed on an object while correcting the deflection distortion of electron beam upon controlling the deflection of electron beam. Prior to pattern formation, reference marks provided on the object are scanned by electron beam to measure their positions, and a processing unit determines correction data for correcting the deflection distortion through interpolation on the basis of results by interpolation. Upon actual pattern formation, data necessary for forming a pattern is corrected by the correction data to be thus produced as a deflection signal for deflecting the electron beam. As a result, the deflection distortion can precisely be corrected for even though the physical performance of the deflector system is slightly poor.

Abstract: An analyzing apparatus is controlled by a microcomputer which reads out programmed information from a magnetic card. The magnetic card does not always travel at a constant speed, and therefore, it is difficult for the microcomputer to entirely resort to the software for carrying out the signal processing required for the control of the analyzing apparatus. In order to obviate this difficulty, a hard logic circuit is provided to read out inverted bit information from the magnetic card, and the information thus read out is supplied to the microcomputer so that the microcomputer can reliably carry out the processing steps including bit counting and data reception. The hard logic circuit includes a flip-flop storing an FM signal recorded on the magnetic card and an exclusive-OR gate comparing the flip-flop output with the FM signal. A simple logic circuit is also provided for writing the FM signal on the magnetic card.