| 摘要 |
Orientation indicating apparatus including a liquid charged chamber (1, 47, 103, 164) having a bubble (2, 111) movable within the chamber as the orientation of the chamber is changed. Two radiation emitting means (3, 4, 108, 109, 169, 170) are arranged to emit radiation into the chamber along two paths to impinge on the end edges, and two radiation detecting means (7, 8, 51, 52, 110, 165, 166) are arranged to detect radiation reflected laterally from the two end edges when the chamber is in a predetermined orientation and to generate respective intensity signals indicative of the reflected radiation intensity detected from the two end edges. Signal comparing means receives the two intensity signals and compares those signals so as to determine whether the chamber is in the predetermined orientation. |
