| 摘要 |
<p>PROBLEM TO BE SOLVED: To minimize errors of measurement even when the accuracy is increased for the detection of the distance to an detection object and to accurately control the floodlight quantity of a floodlight means. SOLUTION: The photoelectric sensor 11 is composed of a floodlight part 13 for irradiating the detection object 12 with light, a drive circuit 14 for driving the floodlight part 13, a monitoring light-receiving element 15 which receives part of the light emitted by the floodlight part 13, a control circuit 16 for controlling the floodlight quantity of the floodlight part 13 based on the light- reception quantity of the element 15, a light-receiving part 17 for receiving reflected light from the object 12, and a detection circuit 18 connected to the light-receiving part 17 for detecting a change in the distance of the object 12 based on a light-reception signal outputted by the light-receiving part 17. The floodlight part 13 is composed of an LED and a floodlight lens, and the light- receiving part 17 is composed of a PSD and a light-receiving lens. In this case, the PSD and the LED are disposed in such a manner that the displacement direction of the light-receiving position of the PSD is approximately orthogonal to an extending direction of a wire for bonding from an LED chip.</p> |
