Patent Issued for Apparatus for Automatically Correcting a Positional Deviation of a Load

摘要

News editors obtained the following quote from the background information supplied by the inventors: "When thin sheet-like substrates, such as glass plates or wafers, are conveyed to each processing stage, a cassette containing these substrates, which are stacked in layers, is used. This cassette is lowered by a transfer apparatus onto a supporting board disposed at a substrate-taking-out position of each processing stage. The substrates contained in the cassette are then taken out by a substrate-taking-out robot provided beside the supporting board, and are supplied to a processing position. The substrate-taking-out robot is automatically controlled, and hence, in order to allow the robot to reliably and smoothly take the substrates out of the cassette without exerting an excessive force on the substrates, the accuracy of the posture or position of the cassette transferred onto the supporting board disposed at the substrate-taking-out position must be made sufficiently high. Therefore, a cassette-deviation automatic correction apparatus used to automatically correct positional deviations in horizontal two-dimensional directions of the cassette vertically lowered by the transfer apparatus is provided on the supporting board at the substrate-taking-out position to which the cassette is transferred. Examples of conventional load-positioning apparatuses that can be used for such a cassette-deviation automatic correction apparatus include an apparatus that needs a driving source and that is of a type that pushes a load, which has been lowered on the supporting board while being kept in a positionally deviated state, toward a fixed position by use of a pusher driven by a driving means and an apparatus that does not need a driving source and that is of a type that drives a pusher (roller) that pushes a load toward a fixed position by use of the weight of the load vertically lowered by a transfer apparatus as disclosed by Japanese Published Unexamined Utility Model Application No. H5-37755.