DEVICE FOR MEASURING SLOPE ANGLE AND SHIFT LENGTH OF ROBOT BLADE

摘要

PURPOSE: A device for measuring slope angle and shift length of a robot blade is provided to prevent a wafer from scratch or breakage by compensating measured slope angle and length by making a blade measure slope angle and length accurately. CONSTITUTION: A pair of light emitting parts(1) is horizontally placed on the upper and the lower of a robot blade(B) carrying wafers. An optical sensor(2) is placed on a certain wall(W) placed in the direction of which the robot blade moves forward to sense the light emitted from the light emitting parts. An operation part(3) is prepared to output slope angle and length of the blade according to the data sensed in the optical sensor. The operation part outputs slope angle, theta and shift length, delta y of the blade by applying the variables, delta which is the distance of a pair of lights projected to the wall after being emitted from the light emitting part while the blade is shifted delta y upward or downward while being inclined angular degrees theta, y which is perpendicular length between the protected positions by the condition and a normal condition, b which is the thickness of the blade, and x which is horizontal length between the blade and the wall to formulas theta is cos-1(delta/b) and delta y is y-xtan(theta).