| 摘要 |
PURPOSE:To accurately detect a pallet even when the illumination of disturbance light is large, by using this device by changing over signals for detecting the pallet in response to the illumination of disturbance light. CONSTITUTION:When the illumination of disturbance light is not very large, modulation light components are extracted from the detecting signals of a light receiving element 3b, and a pallet 4 is detected on the basis of the dimension of the modulation light components; When the illumination of disturbance light is as large as the light receiving element 3b is saturated, the detecting signals are used as they are because modulation light components cannot be extracted, and the pallet 4 is detected on the basis of the dimension of the signals. This device is utilized by changing over signals for detecting the pallet 4 in response to the illumination of disturbance light as mentioned above, thus accurately detecting the pallet 4 even when the illumination of disturbance light is large. |
