摘要 |
A capacitive proximity sensor for use in object and position sensing and/or position control in respect of a swing arm of a medical imaging system. The sensor comprises, within a cover (18), an emitter electrode (10) and a sense electrode (9) both of which are formed by spraying or otherwise coating or painting a layer of conductive material on the inner surface of the cover (18). A carrier plate (30) is mounted within the cover (18), at a distance therefrom, on which are provided an active guard electrode (13) in respect of the sense electrode (9) and a grounded shield member (15) in respect of the emitter electrode (10). As there is virtually no gap between the sense electrode (9) and the cover (18), the sensor is less sensitive to the effects of material changes caused by environmental changes in temperature and/or humidity, for example. |