| 摘要 |
PROBLEM TO BE SOLVED: To obtain a defect inspection apparatus in which an inspection processing operation is executed in parallel and in which a processing speed can be doubled by a method wherein a plurality of beam splitters are arranged in tandem on the optical axis of a laser beam and beams of reflected light by the respective beam splitters are received by CCD arrays whose number is identical to that of the beam splitters. SOLUTION: Beam splitters B0 to Bn which are arranged in tandem as n+1 pieces of optical reflection means are fixed in the upper part of a magnetic recording disk 1 in a state such that their reflection faces are tilted by 45 deg. to the same direction. By using the beam splitter B0 which is the closest to the disk 1, a laser beam which is irradiated from a laser light source 3 arranged horizontally so as to face the beam splitter is deflected downward, and the laser beam irradiates the disk face of the disk 1 vertically. When there is defect, the laser beam is reflected diffusely by the part of the defect on the surface of the disk 1, and it is received by CCD arrays C1 to Cn in such a way that a shade part is generated by a pixel. A light received result is output to A/D convertes A1 to An, it is converted into a digital signal so as to be given to an image processing part 4, and luminance data on the CCD arrays C1 to Cn is compared with a luminance threshold for every pixel.
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