| 摘要 |
PURPOSE:To predict and discover fault from the level and frequency of noises generated from the device. CONSTITUTION:A local oscillator 306 is controlled by sweep frequency regulation signal outputted from CPU 200. The noises generated from various elements constituting a copying machine is caught by a loop antenna 301 provided inside the copying machine and the generated noise frequency and the noise level are detected through an amplifier 302, a mixer 303, a wave detector 304 and a low-pass filter 305. Whether the various elements are at a normal level, a level predicting a possibility of the generation of fault or a fault level is judged based on the detected frequency of noise and the noise level and a warning is displayed. |
