| 摘要 |
PURPOSE:To suppress variation of a drum caused by an electrostatic force generated at the time of charging and thereby to reduce the noise by providing a damper base joined to the centeral part of drum inside and a beam-shape member fitted into the damper base. CONSTITUTION:The damper base 5 is fitted into inside the drum 1 and dynamic dampers 6, 7 of casntilever shape are joined to both end faces of the damper base. A charged brush 2 fixed to and supported by a brush holder 3 is in contact with the drum 1 and thereby the brush holder 3 rotates with the rotation of the drum 1 and slides on the drum 1 surface rubbing each other. Oscillating voltage is applied to the charged brush 2 from a power source 4 connected to the brush holder 3 to electrify the drum 1. Waveform of the oscillating voltage is composed of an AC component in addition to a DC component. Then, shape of the damper is determined and the vibration of the drum 1 is suppressed according to what is called a dynamic damper theory. |
