Dust indicator for a vacuum cleaner

摘要

This invention relates to a dust indicator in a vacuum cleaner, which dust indicator (200) is arranged in a wall (102) at least partly defining a space of the vacuum cleaner that is set under negative pressure with respect to the outside of the wall during operation of the vacuum cleaner. The dust indicator comprises an air channel (211) having an air inlet (212) arranged at an outer side of the wall, and an air outlet (213) arranged at an inner side of the wall, such that an airflow is directed into the space during operation of the vacuum cleaner due to the negative pressure. The dust indicator further comprises a sensor (220) arranged for detecting dust by means of sending and/or receiving an electromagnetic signal which is transmitted through the space. The air channel is arranged such that the airflow prevents dust from sticking in an area of the path of the electromagnetic signal of the sensor. The sensor is arranged behind a transparent window (232) such that it is shielded from dust and debris within said space.

主权项

1. A vacuum cleaner comprising:
a dustbin having a dustbin wall, the dustbin being configured to be placed under negative pressure with respect to a surrounding atmosphere during operation of the vacuum cleaner; a transparent window forming at least a portion of the dustbin wall; a sensor outside the dustbin and adjacent the transparent window, the sensor comprising an electromagnetic emitter and/or detector configured to emit and/or receive an electromagnetic signal along an optical path that passes through the dustbin and through the transparent window; an air channel passing through the dustbin wall and configured such that an airflow passes through the air channel during operation of the vacuum cleaner, the air channel being adjacent the transparent window at a location offset from the optical path, and comprising:
an air inlet at an outer side of the dustbin wall and in fluid communication with the surrounding atmosphere,a protrusion into the dustbin from an inner side of the dustbin wall, andan air outlet passing through the protrusion, the air outlet being oriented to direct the airflow towards the transparent window and across the optical path during operation of the vacuum cleaner.