| 摘要 |
<p>PURPOSE:To improve the accuracy of reading, by discriminating the type of bar through the presence/absence of bar detected at the 2nd detector, when the 1st and the 3rd detector provided on a traveling object detect the presence/absence of the bar and one end of the bar in the broadwise direction. CONSTITUTION:A series of bar codes 3 are stuck on a floor 1 at an interval (b) to detect position information of a traveling object 2 in traversing, the 1st- 3rd detctors 8-10 provided for the traveling object 2 read the said bar 3 for the detection of the position. The 2nd and the 3rd detectors 9, 10 are provided at locations of distances (d), (e), (e<a1<d<a1+b, d<a2, e<b) from the detecting position of the 1st detector 8 in the broadwise direction of the bar. When the 1st detector 8 detects one end of the broadwise detection of the bar and the 3rd detector 10 detects the presence of the bar, the type of the bar is discriminated in response to the detection output of the presence/absence of the bar of the 2nd detector 9. Thus, the mark is read accurately, even if the traveling object 1 goes forward or backward.</p> |
