PURPOSE: To detect the abnormality of an optical system with high sensitivity and to prevent many image defects from being generated by comparing the data, which is obtained by processing the signal from an acceleration sensor by Fourier transformation, with a reference acceleration level.
CONSTITUTION: The detection signal of the acceleration sensor 41e is A/D- converted by an A/D converter A, inputted to a microcomputer 8, and stored in a RAM 18, and the stored data is processed through the Fourier transformation of an arithmetic means 82 to calculate acceleration spectrum by vibration frequencies. Then a comparing means 83 decides the presence of an abnormal spectrum and when it is decided that the abnormal spectrum is present thereon, a driving stopping means 92 stops the driving of the whole copying machine while a display means 91 makes an abnormality display. Consequently, the abnormality of fine vibration can be detected more accurately and many image defects are prevented from being generated.
OKAZAKI AKITAKA
EKUROKI MAKOTO
