Patent ID: 8172063

Claim:
A substrate transporting apparatus comprising: a plurality of rotatable shafts arranged in a row; one or more transporting rollers fixedly coupled with each shaft of the plurality of shafts to rotate with the shaft, the transporting rollers comprising an outer circumferential surface having a first diameter; and a guide unit located proximate an end of a first shaft of the plurality of shafts, the guide unit configured to guide the linear movement of a substrate transported by the transporting rollers, the guide unit comprising: an outer ring having a first circumferential surface and a second circumferential surface each comprising a diameter that is equal to the first diameter of the outer circumferential surface of the transportation rollers, the outer ring further comprising a guide disposed between the first and second circumferential surfaces and protruding outwardly from the first and second circumferential surfaces for contacting a side of the substrate, the outer ring further comprising an axis that is perpendicular to each of the first and second circumferential surfaces such that at least a portion of the bottom surface of the substrate contacts one of the first or second circumferential surfaces and such that the guide is symmetrically disposed about the axis; and an inner ring fixedly coupled to the first shaft to rotate with the first shaft and the transporting rollers; wherein the guide unit is configured for installation in a first direction and a second direction, when installed in the first direction a portion of the bottom surface of the substrate contacts the first circumferential surface, and when installed in the second direction a portion of the bottom surface of the substrate contacts the second circumferential surface.