| 摘要 |
PROBLEM TO BE SOLVED: To simplify a configuration of a light emitting device drive system and to reduce a drive current value of a light emitting device when adjusting a width of a monitoring area by one spot light unit with an electrical method.SOLUTION: A sensor for an automatic door sets a pitch W1 between elements of the light emitting device and a lens inter-center distance W2 of a two-divisional lens to a relationship of W1>W2 so that emission spots from one light emitting device become adjacent to each other. The sensor for an automatic door is configured to arrange three light emitting devices (1 to 3) and (4 to 6) for two two-divisional lenses 110 each in a light emitting part 10B. A light emitting part 20B is applied with a combination of four elements a to d and a three-divisional lens 210 with the light emitting devices connected in series as a combination of (1, 2), (3, 4) and (5, 6), and is alternately driven and turned on so as to take a round of each combination in a predetermined order for each combination unit, and when its turn to turn on the detection spot to be eliminated comes, a light receiving signal from a light receiving device corresponding to the detection spot to be eliminated is set as non-selection. |
