抄録
This paper introduces a method of upstream product design for low-noise MFP (Multifunctional Peripherals). At first, noise level of similar MFP is measured and the acoustic power level of each noise source is calculated. If motors of new MFP differ, single noise source data is acquired separately. Non-stationary noise such as paper collision noise and clutch, are extracted by subtracting stationary noise (ex. motor) from copying noise applying spectral subtraction. Acoustic power levels are predicted according to specifications such as noise level and copying speed and the contributing rate of noise sources are calculated. Next, the level of noise sources are assigned according to the size of the contributing rate and the difficulty level of noise control so that a new MFP noise level will fit in the specifications. The rank order of noise sources with high contributing rate was properly extracted.