Simulation Technology to Predict Impact Sounds Made during Paper Transport in a Multifunction Device

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.

a: Lead-edge impact soundb: Tail-edge impact soundc: Tail-edge snapping sound

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.

  1. Stage when paper hits an object and the impact is applied to paper (Red arrow in Fig. 2)... Force model (model to predict impact)
  2. Stage when paper vibrates and is excited, leading to acoustic emission (Green arches in Fig. 2)... Acoustic emission model (model to predict the volume of sound)

Fig. 2: Process of Generating Impact Sound (Force Model + Acoustic Emission Model)

We discovered the following by studying Stage 1 for each impact sound.

  • It is possible to predict the impact that causes impact sounds (a) and (c) by using a general model.Note1
  • It is possible to predict the impact that causes impact sound (b) by coupling a general model with Euler equations that enable the correct calculation of air resistance.

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

General models such as RecurDyn/MTT2D, which is a Multi Body Dynamics (MBD) analysis tool of FunctionBay, Inc. Paper transport can be analyzed by using this tool as it allows for making a model of paper by linking small two-dimensional rigid bodies.