| 摘要 |
PURPOSE:To improve noise muffling effect by permitting a noise wave propagating in a waveguide chamber to resonate with a fluid oscillation system in a resonance noise muffling chamber via a communicating part. CONSTITUTION:Hammering noise generated following the printing action of a printer is propagated to a waveguide chamber 20 partitioned between a sleeve member 11 and an inner cylindrical member 12 through a rubber roller and the sleeve member 11 of a platen, and further is propagated in the waveguide chamber 20. The frequency of a main component of this propagating sound wave coincides with an intrinsic frequency of the oscillation system of an air column in a resonance noise muffling chamber 30 which communicates with the waveguide chamber 20 via a slit 12a and is partitioned by the inner cylindrical member 12. Therefore, said noise wave enters the resonance noise muffling chamber 30, resonating with an air column oscillation system in said chamber. A sound wave energy is converted to a thermal energy subsequent to the resonance phenomenon, resulting in the loss of energy and reduction of the noise level of hammering noise.
|
