摘要 |
A mobile device including a source for emitting electromagnetic radiation, an enclosure having a side wall, and a detector for detecting electromagnetic radiation emitted by the source is described. At least a portion of the sidewall is adapted to transmit electromagnetic radiation from the source. The source and detector are positioned inside the enclosure. The detector is spaced from the source, and is arranged to detect electromagnetic radiation from the source that is reflected from an object outside the enclosure and passes through the portion of the side wall. |