| 摘要 |
PROBLEM TO BE SOLVED: To keep a bar code to be read for obtaining the information of position or the like by an orbital truck, in the state of exactly reading it for a long time. SOLUTION: At the center on the surface of grating 1 as a floor material, a guide groove 1c is formed for guiding wheels when traveling a carrier. On the surface of a scale plate 20 fixed on the base of the groove 1c, a bar code B and lines 21a-21c to be detected are printed. The bar code B is extended parallelly with the guide groove 1c so that its reading direction can be orthogonal with the guide groove 1c, namely, orthogonal with the advancing direction of the carrier. The lines 21a, 21b and 21c are provided for detecting the read starting position of the bar code B corresponding to the advancing direction of the carrier. The address code of a position for the carrier to detect the current position is set to the bar code B. |
