| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect deformation in each hold part of a hand, surely hold a wafer, also prevent interference with a cassette or the like in the hold part, and prevent damage and dust generation in the wafer, hold part, etc., relating to a robot provided in parallel a plurality of the hold parts respectively simultaneously holding a plurality of the wafers mutually with a space apart in the hand. SOLUTION: Corresponding to a reference position in a moving range of a hand 1, an optical sensor 40 is previously fixedly arranged, and in a condition that the hand 1 is in the reference position, a hold part 4 in the lowermost end provided in a position just beside an optical sensor 40 is detected. Hereinafter, the hand 1 is displaced to a down side successively by a distanceΔZ equal to a space of a plurality of the hold parts 4, 4,... from the reference position, and by the optical sensor 40, whether the other hold part 4, 4,... is provided or not is detected. The deformed hold part 4 is provided not accurately in a position just beside the optical sensor 40, and by generating output abnormality of the optical sensor 40, this abnormality is detected as the deformation of the hold part 4.</p> |
