Noise Reduction for a Dot-Matrix Impact Printer

Abstract

In this report, practical noise reduction has been attempted for a dot-matrix impact printer. An about -5dB(A) noise reduction has been accomplished for the internal machinery noise by taking countermeasures for the internal machinery parts. The printer noise source was classified into the follwing four systems: printing head system, platen system, carriage system (stepping motor) and fans, and their contributions were estimated. The printing head and the platen system noise have much larger contributions than the others. Contermeasures for these have been taken. The noise reduction efficiency of the cover was investigated. Noise level decreases with decreasing aperture size? In an enclosed condition, average noise reduction efficiency was about -13dB(A). The dominant moise components were lower frequency noise, whose frequencies coincide with the basic printing frequency or are close to it.