| 摘要 |
A gap scanning system for a variable sized gap bounded on a first side by a first member and on the other side to the first side by a second member movable relative to the first member wherein a plurality of emitters of a beams of electromagnetic radiation, such as of infra red, are directed from one side of the gap of variable size to the other side to the one side where a beam from one emitter in the plurality can be received by a complementary receiver in a plurality thereof; characterised in that the number of emitters in the plurality thereof differs substantially from the number of receivers in the plurality thereof and the plurality containing the greater number of emitters or receivers is located on the first side of the gap. The invention further includes a lift door system incorporating a gap scanning system as aforesaid. |
