| 摘要 |
PURPOSE:To detect surface defect within a short time by a method wherein a condensing means is installed traversing above an object for inspection to be fed rectilinear to the traversing direction for optical scanning in the traverse direction. CONSTITUTION:A table 12 is slidden on a fixed table 11 by a pulse motor 14 moving a mask 1 in X direction with respect to a condenser 15 to emit laser light 19 and scanning the mask 1 through a Kalvar's mirror 20 to project parallel scanning luminous flux 23 in Y direction on the surface of the mask 1. When the projected light irradiates a defect 5 on the mask 5, turbulent reflected light is projected into the condenser 15 through a slit 16 to be detected 17 through optical fiber. A detected signal is processed 25 and making use of feed amount 27 in X direction, scanned amount 28 of laser light in Y direction to compute 26 a defective position. The patterns on the glass mask 1 are preliminarily memorized by the operator 26 and the defect detecting signals from the condenser 15 corresponding to the patterns are erased and obtain the defect and address as required. Through said constitution, the detecting precision may be improved since the table 12 may be simplified while accelerating scanning speed and increasing the density of detecting points. |
