There have been growing demands for quiet multifunction devices and printers. Sounds made during paper transport account for almost 50 % of the noise generated when operating a multifunction device. As the following three types of impact sounds (a, b and c in Fig. 1) are most frequently heard and especially unpleasant, the sounds must be reduced. Fuji Xerox developed a simulation technology that can precisely predict the volume of these sounds.
Fig. 1: Target Impact Sounds (a, b, c)
Fig. 2 shows the. process of generating unpleasant impact sounds. We divided the process into the two stages (1 and 2) below and created a model for each stage.
Fig. 2: Process of Generating Impact Sound (Force Model + Acoustic Emission Model)
We discovered the following by studying Stage 1 for each impact sound.
Considering the study results above, we developed a model to calculate the three impact forces generated during paper transport.
For Stage 2, we investigated the relation between each impact sound and the impact that causes the sound by employing a regressive approach, including experiments. As a result, as shown in Fig. 3, we discovered that there is a proportional relation between each impact sound (sound pressure) and impact while the coefficient varies among the impact sounds.
This is how we calculate and predict the volume of impact sounds that are frequently made during paper transport in a multifunction device.
Fig. 3: Relation between Calculated Impact and Measured Sound Pressure