| 摘要 |
Disclosed is an embodiment (50) of an optical sensor device adapted to detect presence of an object by reflected radiation such as visible or invisible light within viewing field (8) of an optical sensor (4) over a broader distance ("X")range without having to make physical position adjustments of a single radiation source heretofore required. Device (50) is provided with a pair of spaced-apart radiation sources (14, 16) that are positioned such that their respective radiation beams (18, 20) angularly intersect optical axis ("O") of viewing field (8) at respective angles ( theta 1, theta 2) to provide three respective zones comprising a first zone (1), second zone (2) and an intermediate third zone (3) therebetween containing at least a portion of the first and second zones (1, 2) within viewing field (8) from any one or more of which reflected radiation from an object is able to be detected by sensor (4). Device (50) is particularly useful as a counter and has the further advantage of optimization in that the intensity of radiation beams (18, 20) is adjustably controllable.
|
