| 摘要 |
<p>A back cover has a through hole in a vicinity of a lower end portion of the first circumferential wall portion. An outer surface of a connector member is provided with a flow path groove which circumferentially and vertically extends. In addition an inner surface of the back cover includes a flow path surface which continues from a portion that opposes the flow path groove on a lower side of the flow path groove to the through hole. Liquid droplets adhering to the connector member flow down the flow path groove and the flow path surface and are discharged from the through hole to an outside of the back cover. Therefore the liquid droplets may be suppressed from adhering to the brush without the need for an O ring or a gasket as an essential component.</p> |
